Ethnomedical knowledge of plants used in alternative medicine to treat hemorrhoidal diseases in Lubumbashi, Haut-Katanga province, Southern Democratic Republic of Congo

Abstract

Background

A variety of medicinal plants are used in traditional medicine in Lubumbashi for the management of hemorrhoidal diseases. However, no investigation has been conducted to gather the knowledge required for this type of management in the region. The present study was conducted to inventory the plants used in Lubumbashi to treat hemorrhoidal diseases and to relate their ethnomedical characteristics.

Methods

This study was conducted between March 2022 and February 2023 by interviews using semi-structured questionnaire with households (n = 1520), herbalists (n = 25), and traditional healers: THs (n = 59).

Results

The 1,604 respondents (sex ratio M/F = 0.9; mean age: 56 ± 3 years; experience: 12 ± 3 years) provided information on 100 taxa, 84 of which are used against internal hemorrhoids, Phyllanthus amarus being the most cited (Citation Index, CI: 0.76). Most of them are trees (38%) or shrubs (32%), belonging to 90 genera and 45 families dominated by the Fabaceae (10%) and Asteraceae (9%). They are indicated in 76 other pathologies, dominated by gastrointestinal disorders (GID), wounds and sexually transmitted infections (CI > 0.57). From these 100 taxa, 117 anti-hemorrhoidal formulations were derived, 11 of which combined more than one plant. In all these recipes, the leaf is the most commonly used part (> 60%) and the liniment (> 45%) is the most popular form of application. For the first time, this study reports 14 taxa as plants used in the treatment of hemorrhoids. Among these taxa, Ficus stuhlmannii, Ficus laurifolia, and Ocimum centraliafricanum are listed as medicinal plants for the first time. Khaya nyasica, and Syzygium cordatum, each with 11 uses, have the highest traditional medicinal value.

Conclusion

The findings of this study indicate that a significant number of medicinal plants are used in traditional medicine in Lubumbashi for the treatment of hemorrhoidal diseases. Some of these plants are endemic to the biodiversity area, while others are shared with other cultures and regions. A series of pharmacological studies is currently underway with the objective of validating the anti-hemorrhoidal properties of these plants and in order to identify phytochemical compounds responsible of this activity.

Graphical Abstract

Background

Hemorrhoids are a network of arterial and venous vessels that are present in the normal state at the level of the anal canal. They contribute to the maintenance of continence [1]. Hemorrhoids may be located either under the skin of the anal orifice (external hemorrhoids) or higher up under the mucosa of the anal canal (internal hemorrhoids) [2]. Normally, hemorrhoids may exhibit a slight degree of swelling during the act of defecation. However, when they remain permanently dilated, they constitute pathological hemorrhoids or Hemorrhoidal diseases [3, 4].

Hemorrhoidal diseases are defined by the presence of symptoms such as irritation, extreme pain, and itching around the anus, a painful or itchy lump or swelling near the anus, fecal leakage, painful stools, and the presence of blood on the tissue after defecation [5,6,7]. A number of studies have identified a number of risk factors for the development of hemorrhoidal diseases, including chronic constipation [8, 9], diarrhea, insufficient dietary fiber, exertion and prolonged sitting, particularly during defecation [10], abdominal obesity, depression, pregnancy [11], hypertension, smoking [12], as well as advanced age and a sedentary lifestyle [13]. The severity of hemorrhoidal disease is typically evaluated according to the Goligher classification system, which is based on the degree of prolapse through the anus. The Goligher classification system defines four grades of hemorrhoidal disease. Grade 1 is defined as a hemorrhoid that bleeds but does not prolapse. Grade 2 is defined by the capacity of the hemorrhoid to prolapse upon exertion, which may or may not be accompanied by spontaneous reduction or return to the anal canal. Grade 3 is defined by the ability of the hemorrhoid to prolapse on exertion, which can be manually pushed back into the anal canal. Grade 4 is defined by the permanent prolapse of the hemorrhoid, which cannot be manually reduced [13,14,15].

Hemorrhoidal disease is one of the most frequently encountered anorectal conditions in general practice [16]. However, its true prevalence in the general population is not well known, in part because many patients do not seek treatment in hospital facilities [17]. A multicenter study conducted in Europe and Brazil reported a prevalence of 11% [16]. Partial prevalences have been reported in various countries around the world, but these studies are not truly representative of their countries. In the literature, we find that 16.6% of cases occur in Korea [12]; 48.1% in Eastern India [18]; 16% in Saudi Arabia [19]; and 38.9% in Australia [20]. In Africa, the reported incidence ranges from 7% to 13.1% in Ethiopia [9, 21], 56.2% in Bamako [22], 2.3% in Brazzaville [23], 14.6% in Ouagadougou [24], and 54% in Nigeria [25]. To date, no studies have been conducted on the prevalence of hemorrhoids in the Democratic Republic of the Congo, particularly in Lubumbashi.

The treatment of hemorrhoids is aimed at correcting the underlying cause, which may be a variety of factors. In cases where the condition is relatively straightforward, it is advisable to adopt a diet high in fiber, drink plenty of water, and apply local anesthetic creams to relieve itching and pain. In symptomatic cases, treatments containing analgesics, non-steroidal anti-inflammatories, or anesthetics are employed to address hemorrhoidal attacks. Another potential treatment option is the application of a ligature to the hemorrhoidal artery. In the event of disease progression, surgical intervention is the definitive treatment for severe and thrombosed external hemorrhoids [26,27,28].

In Lubumbashi, as in most developing countries, the use of traditional medicine is a primary approach to addressing health concerns such as hemorrhoidal diseases [29, 30]. A recent study indicated that 79.4% of the Lubumbashi population sought traditional medicine for various pathologies and social issues. This form of medicine is largely based on the use of medicinal plants. The study additionally revealed that hemorrhoidal diseases represent the primary reason for consulting traditional medicine in Lubumbashi [31]. However, neither national nor local studies have been conducted on the plants used to treat hemorrhoidal diseases.

Several ethnomedicinal studies have been conducted in Africa on the use of medicinal plants to treat hemorrhoidal diseases. For illustrative purposes, ethnobotanical studies have been conducted in Nigeria [32, 33], Cameroon [34], Tanzania [35], and Kenya [36].

In Lubumbashi, the majority of ethnobotanical studies have focused on the targeted pathologies. Some of these studies, although oriented towards other pathologies, have yielded insights into the treatment of hemorrhoidal diseases by medicinal plants that have been inventoried on this occasion. This is exemplified by Vernonia shirensis [synonym of Baccharoides adoensis var. mossambiquensis (Steetz) Isawumi, El-Ghazaly & B Nord, Asteraceae], whose macerated leaves are used locally against hemorrhoids [37]. Another example is the macerated leaves or stem bark of Aframomum angustifolium (Sonn.) K.Schum (Zingiberaceae)[38]. Furthermore, the decoction of the roots of Bridelia atroviridis Müll Arg, Phyllanthaceae [39]; the leaves of Asparagus africanus Lam, Asparagaceae [40]; the leaves of Pericopsis angolensis (Baker) Meeuwen, Fabaceae [41], and the roots of Piliostigma thonningii Schumach Milne-Redh, Fabaceae [42] are employed as an anti-hemorrhoidal agent in local non-conventional medicine. Nevertheless, no study has yet focused on the plants utilized in traditional medicine in Lubumbashi to treat hemorrhoidal diseases. In light of the above, the objective of this study was to conduct an ethnobotanical survey with the aim of documenting plants used in traditional medicine in Lubumbashi to treat hemorrhoidal diseases. The list was to be compiled from both the general population and among traditional medicine professionals in the region. The objective was to identify the most commonly utilized plants in the region for the management of hemorrhoidal diseases and to highlight the region’s characteristic taxa.

Material and methods

Experimental framework

The study was conducted in the seven communes of the city of Lubumbashi: Annexe, Kampemba, Katuba, Kamalondo, Kenya, Lubumbashi, and Rwashi, in the province of Haut-Katanga in the Democratic Republic of Congo (Fig. 1).

Fig.1

Lubumbashi’s city in Haut-Katanga province, Democratic Republic of Congo

Lubumbashi is situated between 11°26’ and 11°55’ north latitude and 27°15’ and 27°40’ east longitude at an altitude of 1,230 m. The climate is tropical, with an average annual temperature of 22.4 °C and an average annual rainfall of 512.7 mm.³. The study area experiences two distinct seasons, with a relatively shorter rainy season spanning from November to April. The Miombo clear forest is the most prevalent vegetation type [42]

Ethnomedical data collection

This is a descriptive, cross-sectional study. The research was conducted by interviews using semi-structured questionnaire (supplementary data S1). Ethnomedical data were collected from a variety of sources, including households, herbalists, and traditional healers (THs), in Lubumbashi between March 2022 and February 2023. The interviews were conducted in Swahili. The sample size of household respondents was determined using two-stage sampling, comprising a stratified sample and a cluster sample. For each commune, considered as a stratum, the corresponding commune office provided the population size (Table 1). The size of the representative sample at this level was determined by the following formula according to [43, 44]:

$$n = \frac{\text{p x }\left(1-\text{p}\right)\text{ x N x}{\text{ t}}_{\text{p}}^{2}}{{\text{t}}_{\text{p}}^{2}\text{ x p }\left(1-\text{p}\right)+\left(\text{N}-1\right)\text{x}{\text{ y}}^{2}}$$

(1)

Table 1 Household sample size

Where, n = sample size, N = actual population size, p = expected proportion of respondents (estimated p at 0.5), tp = sampling confidence interval (tp = 1.96 given that we set a 95% confidence interval) and y = margin of sampling error: we set this at 0.05. This yields a household population of 2,690 (Table 1).

Of the 2,690 people contacted during the household surveys, 264 did not agree to participate in the study, 407 said they had never suffered from hemorrhoidal diseases, and 499 said they had never used traditional medicine to treat hemorrhoidal diseases. Therefore, the results of this study, based on data collected from households, concern only 1,520 households.

The study population was divided into clusters, with each cluster representing a specific avenue. This was achieved by counting every three households. In each household, we included any adult (≥ 18 years old) who had ever used plants to treat hemorrhoids, provided they were sufficiently unfamiliar with the interviewers.

Due to the lack of reliable data on the size of the herbalist population in Lubumbashi, the objective was to interview as many herbalists as possible, accessible through markets and other public spaces. This stage enabled us to meet 25 herbalists, all of whom consented to participate in the study.

The respondents in the Traditional Healer (TH) category were identified from a list of 50 Traditional Practitioners compiled during a recent survey conducted in the study area [42]. This step facilitated contact with 35 HTs, all of whom consented to participate in the study. Subsequently, we proceeded with a snowball sampling approach to augment the sample size, which enabled us to engage with an additional 30 HTs, 24 of whom consented to participate in the study. Among these 24, four THs who were on the initial list of 50 THs and had not yet interacted with us through this list were also included. The survey of the THs was thus conducted on 59 respondents.

The study encompassed a total of 1,604 individuals, representing 1,520 households, 25 herbalist practitioners, and 59 Traditional Herbalists (THs).

Data processing and analysis

The names of the inventoried plant species were collected in the local languages during the surveys in the company of interviewers. At the same time, the voucher specimen were prepared and deposited in the Kipopo Herbarium, where the scientific names were assigned by the herbarium’s botanical experts. The plant names were updated by comparison with the online botanical platforms: Plants of the World Online (https://powo.science.kew.org/) (The World Flora Online (http://www.worldfloraonline) or the African Plant Database https://africanplantdatabase.ch/).

In light of the current controversy surrounding ethnobotanical indexes [45], and in order to provide quantitative support for this study, we have employed only headcounts and three ratios.: citation index (CI), medicinal use index (MUI) and medicinal capability index (MCI). The plant citation index (CI) was calculated using the formula:

$$\text{CI} = \frac{Number\,of \,informants \,citing \,the \,plant} {Total \,number \,of \,informants \,who \,participated \,in \,the \,study}$$

(2)

The medicinal use index (MUI) was calculated by the formula:

$$\text{MUI} = \frac{Number\; of \;uses \;reported \;for \;a \;taxon}{Total \;number \;of \;uses \;reported \;for \;the \;entire \;study}$$

(3)

The medicinal capability index (MCI) was calculated by the formula:

$$\text{MCI} = \frac{NNumber\; of \;taxa \;cited \;to \;manage \;a \;given \;pathology}{Total \;number \;of \;taxa \;inventoried \;during \;the \;survey}$$

(4)

In this study, the CI allows us to determine the number of times a plant has been cited in the management of hemorrhoids in the region, and consequently to identify the level of consensus within the population on the curative use of a given species in the management of hemorrhoids. The MUI highlights the level of medicinal use of a plant among the population studied. Finally, the MCI enables us to measure the potential of a given community to manage a well-defined pathology.

Ethics approval and consent to participate

The project proposal and ethical rules were reviewed and approved by the Department of Pharmacology, Faculty of Pharmaceutical Sciences, University of Lubumbashi, Democratic Republic of Congo (FSPUNILU-DP-BD-022022). Prior to data collection, voluntary verbal consent was obtained from all 59 traditional healers, 25 herbalists, and 1,520 households in accordance with the ethical standards of the University of Lubumbashi. All participants agreed to participate in the study and were informed that the data collected would be used for academic purposes only. Participants were assured of confidentiality and informed that the aim of the study was scientific and not commercial..

Results

General knowledge of hemorrhoidal diseases among the interviewees

The informants interviewed for this study (herbalists: n = 25, traditional practitioners: n = 59, and households: n = 2690) demonstrated a clear distinction between internal and external hemorrhoidal diseases. However, only 1,520 individuals, representing 56.5% of the initial population, were responsible for the ethnobotanical knowledge of this category of the survey population.

In fact, of the 2690 individuals interviewed, 264 had not provided informed consent, 407 had never suffered from hemorrhoidal diseases, and 499 had never utilized plants during a hemorrhoidal crisis. Consequently, the proportion of the population who had ever suffered from hemorrhoids was 2019 out of 2426, or 83.2%, and the proportion who had ever used plants during a hemorrhoidal crisis was 1520, or 62.6%.

The survey population diagnosed hemorrhoidal diseases, locally known as “Kilonda ntumbu,” based on nine symptoms: itching, pain in the anal region, fever, irritation, bleeding during or after bowel movements, internal burning sensations, and protuberances protruding from the anus. These symptoms were reported by over 50% of the subjects consulted, regardless of their category (Table 2).

Table 2 Healers’ knowledge of hemorrhoidal disease

The 12 factors identified as responsible for hemorrhoidal diseases include frequent constipation, pregnancy, habitual spicy food, carrying heavy loads on a daily basis, and long and frequent sitting positions. These factors were reported by over 60% of interviewees in all categories (Table 2).

These informants are aware that hemorrhoidal diseases can have a number of consequences, including pain and discomfort, as well as the frequent desire to have a bowel movement with no result. These consequences were reported by over 80% of them. The experience of the traditional medical practitioners consulted (herbalists and traditional practitioners) indicates that the majority of individuals who consult them for hemorrhoids are between 30 and 50 years of age (Table 2).

General Characteristics of Inventoried Plants

Ethnobotanical surveys have revealed that 100 plant species belonging to 90 genera and 45 botanical families are used to treat hemorrhoidal diseases in Lubumbashi (Table 3). The majority of these medicinal taxa are trees (38%), followed by shrubs (32%) (Fig. 2). These taxa are native to seven geographical regions, with the TA (Tropical Africa) and TA-SA (South Africa) regions accounting for over 60% of the taxa inventoried (Fig. 3). The taxa are named in 16 local ethnic languages, with Swahili, Luba-Kat, and Bemba accounting for over 50% of the names of the taxa collected (Fig. 4).

Table 3 General characteristics on plants inventoried during the survey

Fig. 2

Morphological types (n = 100)

Fig. 3

Geographical type. Legend: TA(Tropical Africa); NEA(North-East Africa); CA (Central Africa); SA(Southern Africa); MA(Madagascar); EA(East Africa); NA(North Africa); WE(West Africa)

Fig. 4

Plant naming languages. Seventeen families have more than two taxa each. The Fabaceae (10 species), Asteraceae (9 plant species), Lamiaceae (7 species), Phyllanthaceae (6 species), Anacardiaceae (5 species), Euphorbiaceae (4 species), Malvaceae (4 species) and Sapindaceae (4 species) families are the eight most important, collectively accounting for 49% of all plants cited (Fig. 5)

Fig. 5

Family with taxa n ≥ 2. The most frequently cited taxa are Phyllanthus amarus Schumach. & Thonn. (Phyllanthaceae), Terminalia mollis MA Lawson (Combretaceae), and Mesosphaerum suaveolens (L.) Kuntze (Lamiaceae). These taxa were claimed by over 1123 resource persons (CI ≥ 0.728) in total, with each species being cited individually (Table 2)

Medicinal plants used to treat hemorrhoidal diseases

A total of 100 taxa are utilized in 117 anti-hemorrhoidal recipes within the study area. Of these, 101 employ a single plant, while 17 utilize mixtures of two or three plants. Three of the single-plant recipes are employed for mixed hemorrhoidal diseases, 14 for external hemorrhoids, and the remaining 84 for internal hemorrhoids. In contrast, all the mixed-plant recipes are utilized for mixed hemorrhoids. The leaves of the plant are the most commonly used part in the preparation of herbal remedies, representing 69% of the cases, followed by root barks, which represent 36% of the cases (Fig. 6).

Fig. 6

Parts of plants used to treat hemorrhoids. The most prevalent method of preparing herbal remedies is decoction (51%) in mono-herbal recipes and pounding (44%) in polyherbal recipes (Fig. 7). Topical administration of herbal remedies is employed in five forms, with liniment (CI: 0.49–0.38) and sitz bath (CI: 0.30–0.25) representing over 50% of anti-hemorrhoidal recipes (Fig. 8)

Fig. 7

Mode of anti-hemorrhoidal recipe’s preparation

Fig. 8

Form of uses of recipe

The respondents indicated that they utilize a variety of utensils, including teaspoons, tablespoons, cups, and bottles, to adjust the doses according to the patient’s age (child or adult) and/or physiological state (e.g., pregnancy). In order to contextualize the results of this ethnobotanical survey, we sought to estimate the quantities of solutions (volumes) and solids (mass or powdered plant parts) as reported by respondents. This was done in reference to a previous study [137], which had attempted to do the same. The informants indicated that the treatment of hemorrhoidal diseases typically lasts between two and five days.

The information provided by the resource persons interviewed indicates that liniments are prepared by mixing three parts of palm oil with one part of solution (exudates, expression, decoction, macerated, or infused) or vegetable matter reduced to paste or powder, as the case may be. Ointments are prepared by mixing two parts of beeswax that have been melted in a water bath with one part of hot palm oil. Subsequently, plant extracts (30–40%) or dry matter are added to the aforementioned mixture.

With regard to the 16 recipes resulting from mixtures of two (12 recipes) or three taxa (3 recipes), these involve 27 taxa. It is notable that Euphorbia hirta (4 recipes) plays a significant role in several recipes, accounting for 25% of the total. The next most prevalent taxa are Ageratum conyzoides, Albizia adianthifolia, Bridelia micrantha, Khaya nyasica, Monodora myristica, and Parinari curatellifolia, which are each involved in two recipes. The remaining nine taxa are reported in only one polyherbal recipe. The most frequently cited polyherbal recipes are those based on the mixture of P. angolensis (leaves) and P. thonningii (root bark) (121 citations) and the mixture of A. cordifolia (root bark) and A. hybridus (roots) (107 citations) (Table 4).

Table 4 Characteristics of herbal healing recipes used in blends

Medicinal uses of plants surveyed

The taxa reported in this study are known and utilized by householders, herbalists, and traditional healers for the treatment of hemorrhoids (Fig. 9). The taxa are employed to treat internal hemorrhoids (83 taxa), external hemorrhoids (14 taxa), or both types concomitantly (3 taxa). Nevertheless, these taxa are also involved in the management of 75 other pathologies, signs, or symptoms, where gastrointestinal disorders are particularly prevalent. The most frequently cited indications were gastrointestinal disorders (CI: 0.622) and wounds (CI: 0.68) (Table 4).

Table 5 Other pathologies treated by plants inventoried during surveys

Fig. 9

Distribution of plants inventoried across the 3 categories of people surveyed. The five pathologies for which the resource persons in this study have the most taxa, in addition to hemorrhoids, are GID (31 taxa), diabetes (15 taxa), sexually transmitted infections (STI; 14 taxa), malaria (13 taxa), and wounds (11 taxa) (Table 5)

According to the informants consulted, the taxa with the greatest number of medicinal uses in the study area are Khaya nyasica Stapf ex Baker f.b (Meliaceae), with 11 uses; Syzygium cordatum Subsp.a (Myrtaceae), with 11 uses; and Ficus sur Forssk f (Moraceae), with 9 uses. The next most frequently cited taxa are Albizia adianthifolia (Schum.) W. Wight (Fabaceae) (8 uses) and Crossopteryx febrifuga (Afzel. ex G. Don) Benth. (Rubiaceae) (8 uses). Collectively, they are implicated in over 60% of the pathologies mentioned in this study (Table 2).

Socio-demographic profile of persons consulted

The individuals consulted in this study were either household contacts (94.8%), herbalists (1.6%), or practitioners of traditional medicine (3.8%), with the majority being women (57.9%). The age range of the individuals consulted was 50 to 60 years old, with the youngest being 21 and the oldest 73 years old. The most respondents had received no formal education (37.6%) or had completed only primary school (36.7%). The informants were distributed across the 44 districts that comprise the seven communes of the city of Lubumbashi in similar proportions, ranging from 12.9% to 22.4%. However, in the Kamalondo and Kampemba communes, the proportion was slightly lower, at 7.9% and 9.9%, respectively. The respondents were engaged in six occupational categories, with housework (40.8%) and liberal (21.2%) representing the most prevalent types. In the majority of cases, the informants have accumulated over 11 years of experience in the use of medicinal plants (Table 6).

Table 6 Socio-demographic characteristics of people consulted

Discussion

Plants used to treat hemorrhoidal diseases.

Until now, traditional medicine has been the primary means of treating hemorrhoidal diseases in Katanga, and various plants are used for this purpose. This study reports for the first time 24 taxa of the 100 plants reported in our surveys as plants used in the management of hemorrhoidal diseases, in view of the available literature (Table 3). These are Acmella caulirihza Delile (Asteraceae), Aidia micrantha (K.Schum.) Bullock ex F.White (Rubiaceae), Amaranthus hybridus L. (Amaranthaceae), Anonidium mannii (Oliv). Engl. & Diels (Annonaceae), Antirrhinum majus L. (Plantaginaceae), Baccharoides adoensis (Sch.Bip. ex Walp.) H.Robc (Asteraceae), Chromolaena odorata (L.) R.M. King & H. Rob. (Asteraceae), Crossopteryx febrifuga (Afzel. ex G.Don) Benthc (Rubiaceae), Diplorhyncus condylocarpon (Mull. Arg.) (Apocynaceae), Droogmansia munamensis De Wild (Fabaceae), Erigeron bonariensis L. (Asteraceae), Ficus laurifolia Lam.f (Moraceae), Ficus stuhlmannii Warb (Moraceae), Ficus sur Forssk (Moraceae), Garcinia punctata Oliv. (Clusiaceae), Indigofera capitata Kotschyb (Fabaceae), Mesosphaerum suaveolens (L.) Kuntze (Lamiaceae), Ocimum centraliafricanum R.E.Fr. (Lamiaceae), Passiflora foetida L. (Passifloraceae), Pericopsis angolensis (Baker) (Fabaceae), Symphytum officinale L. (Boraginaceae), Uapaca guineensis Müll.Arg.c (Phyllanthaceae), Zanha africana (Radlk.) Exellb (Sapindaceae) and Zanthoxylum chalybeum Engl. (Rutaceae) (Table 2). The most cited by more than 60% of interviewees are: Mesosphaerum suaveolens (CI: 0.704), Ficus laurifolia (CI: 0.635), Ficus stuhlmannii (CI: 0.635) and Erigeron bonariensis (CI: 0.623).

Of the 24 taxa, 14 have not previously been studied for their anti- inflammatory activity. In order of importance of citation, the taxa are as follows: Crossopteryx febrifuga, Ficus stuhlmannii, Ficus laurifolia, Indigofera capitata, Diplorhynchus condylocarpon, Droogmansia munamensis, Baccharoides adoensis. Aidia micrantha, Erigeron bonariensis, Garcinia punctata, Acmella caulirhiza, Amaranthus hypochondriacus, Anonidium mannii, and Ocimum centralafricanum. According to Plants of the World Online (https://powo.science.kew.org), all of these taxa are native to the DRC, with the exception of Erigeron bonariensis and Amaranthus hypochondriacus, which are introduced taxa.

Of the 14 taxa initially reported by this study as plants with anti-hemorrhoidal uses in Katanga, a literature search revealed that only eight taxa, namely Acmella caulirhiza [138], Aidia micrantha [81], Amaranthus hypochondriacus [139], Anonidium mannii [140], Crossopteryx febrifuga [40, 41], Diplorhynchus condylocarpon [37, 42, 141], Droogmansia munamensis [40], Garcinia punctata [142, 143] have previously been documented as medicinal plants in Congolese traditions.

Although not reported as medicinal plants in the Democratic Republic of the Congo (DRC), three of the fourteen taxa; Indigofera capitata, Baccharoides adoensis, and Erigeron bonariensis, are reported as medicinal plants in other African regions. In Nigeria [144] and, in Uganda [145], powder from Indigofera capitata is employed as a remedy for snakebites, while in the Republic of Congo, the dried infrutescences of this plant are utilized for their hallucinogenic properties [146]. In Zimbabwe, Baccharoides adoensis is traditionally employed for the treatment of fever, upper respiratory tract infections, and currently for tuberculosis [147]. In Kenya, the root decoction is utilized for the treatment of sexually transmitted diseases, heart and kidney problems, while the leaves are employed in the treatment of malaria and tuberculosis [148]. In South Africa, the decoction of Erigeron bonariensis [synonym: Conyza bonariensis (L.)] is a folk remedy that is widely used for the treatment of tuberculosis. The leaves of this plant are employed as folk medicine for the treatment of a number of ailments, including rheumatism, gout, cystitis, nephritis, dysmenorrhea, toothache, and headaches [149].

To the best of our knowledge, although Ficus stuhlmannii, Ficus laurifolia, and Ocimum centraliafricanum are considered native plants to the country, according to POWO, no medicinal use has yet been reported for any of them. This study, therefore, presents the first account of their related ethnomedicinal knowledge. The fact that Ocimum centraliafricanum was reported only by the household population indicates that ethnomedicinal knowledge in our study area is not the exclusive domain of traditional healers. This is further corroborated by the fact that ethnomedicinal knowledge in our area is a family legacy, as evidenced by the findings of previous studies [37, 40, 42, 150]. Although these plants are not reported as having anti-hemorrhoidal uses, some taxa of the same genus are used in traditional medicine to treat hemorrhoidal ailments. This is exemplified by Ocimum gratissimum, whose leaves are utilized in Benin as a decoction against typhoid fever [151]. The same is true of the species Ocimum basilicum L described in the Persian pharmacopoeia, which has been demonstrated to possess anti-inflammatory and myorelaxant properties in vivo, thus confirming its indication in the management of hemorrhoids [152]. In the Ficus genus, several taxa have been reported to be used in traditional medicine to treat hemorrhoids, including Ficus vallischoudae delile [153], Ficus exasperata Vahl [154], Ficus carica L [152], Ficus umbellata (Vahl) [155], Ficus benghalensis [156], Ficus sycomorus L, Ficus palmata Forssk, and Ficus vasta Forssk [30]. The two taxa of the Ficus genus reported in our study contribute to the growing list of numerous species of this genus used in various cultures for the management of hemorrhoidal diseases.

The majority of the medicinal plants mentioned by the respondents belong to the Fabaceae family, with 10 taxa identified (Fig. 3a). The prevalence of Fabaceae in this study can be attributed to the fact that it is the most dominant family of medicinal plants in the region. Ethnobotanical studies conducted in the Miombo region (Democratic Republic of the Congo, Tanzania, Angola, Zambia, Malawi, Zimbabwe, and Mozambique) have demonstrated that Fabaceae is the most prevalent family of medicinal plants. A case in point is the study carried out in the Sikonge district of Tanzania [35], in the province of Bié in Angola [157], in the provinces of Western, Copperbelt, Central and Northern Zambia [158], in Zomba, Malawi [159] and in Gokwe, Zimbabwe [160], where Fabaceae were the most cited. A bibliographical review of medicinal plants in Mozambique also highlighted the preponderance of Fabaceae, with 95 out of 731 taxa [161]. In the Democratic Republic of the Congo (DRC), the Miombo forest covers the provinces of Lualaba, Tanganyika, and Haut-Katanga. In Haut-Katanga province, where the city of Lubumbashi is located, no study has inventoried and characterized all the medicinal plants in the region. However, several ethnomedicinal studies targeting a specific pathology have been carried out, and in most cases, Fabaceae have taken the lead. These include the study of plants used to treat gastrointestinal disorders in Kamina and Kanyama (n = 10 taxa, Fabaceae = 2 taxa) [162], the study of anti-cariogenic plants in Lubumbashi (n = 14 taxa, Fabaceae = 3 taxa) [163], and the study of anti-malarial plants in the Lubumbashi area and its surroundings (n = 19, Fabaceae: 11 taxa [164], n = 96, Fabaceae = 22 taxa [41]). The study on anti-diabetic plants from Lubumbashi and its surroundings yielded 45 taxa, with Fabaceae accounting for 11 taxa [40]. The study on plants used against urogenital schistosomiasis yielded 61 taxa, with Fabaceae accounting for 17 taxa [37]. The study on plants used in the management of sexual dysfunctions in the Kampemba commune (Lubumbashi) yielded 21 taxa, with Fabaceae accounting for 7 taxa [165] is followed by the study on plants used in Lubumbashi and surrounding areas to treat gastritis (n = 14, Fabaceae = 3 taxa [166]. Finally, the study on plants used in Lubumbashi to treat typhoid fever (n = 54, Fabaceae = 20 taxa) [42] is presented.

Each of the plants reported in this study is named in one of the DRC’s local languages, with Swahili, Luba, and Bemba being the most prevalent (Fig. 3b). This result is consistent with previous ethnobotanical studies conducted in the region [37, 40, 165, 167], which have reported the predominance of Bemba and Luba in the practice of traditional medicine in Katanga. It is noteworthy that the names of ethnic groups not endemic to Katanga, such as Lingala and Kikongo, which are languages spoken in the west of the country, also appear in the list. This may be indicative of a certain degree of cultural cross-fertilization that traditional Katangese medicine has undergone [42].

A citation index: CI of 0.7 or greater was observed in three taxa, which were the most frequently cited in the overall study. The most frequently cited taxa were Phyllanthus amarus Schumach & Thonn f. (Phyllanthaceae), Terminalia mollis MA Lawson f. (Combretaceae) and Mesosphaerum suaveolens (L) Kuntze (Lamiaceae). These taxa were reported by both traditional healers and the general population. According to Plants of the World Online (https://powo.science.kew.org/), only Terminalia mollis is native to the DRC, while the two other taxa are introduced plants. To the best of our knowledge, only the first two taxa are reported as medicinal plants in the DRC.

In southern Katanga, the infusion of Phyllanthus amarus leaves is employed to treat asthma, diabetes, typhoid fever, hepatitis, bronchial infections, and peptic ulcer [42], while decoction of the whole plant is utilized to treat dysentery [39]. In Central-Kongo, infusion of the plant’s leaves is employed to promote diuresis, while maceration of the roots is utilized to treat amoebiasis and snail fever [140]. Its potential use in the treatment of haemorrhoidal pathologies may be based not only on its anti-inflammatory properties, as demonstrated in vitro [118], but also on the numerous flavonoids reported in its leaves [168], which have been associated with strengthening blood vessel walls, increasing venous tone and lymphatic drainage, and normalizing capillary permeability at the anal level [169, 170].

The root bark of Terminalia mollis is employed in Katanga as a decoction for a variety of ailments, including dysentery, intestinal worms, cancer, lice, diarrhea, abdominal pain [141, 171], typhoid fever [42], sexual dysfunction [165], diabetes, and syphilis [40]. In powder form, they are employed as a treatment for jaundice. The anti-inflammatory activity observed in vitro and the presence of tannins in its root barks may be the basis for its use against hemorrhoids.

To the best of our knowledge, Mesosphaerum suaveolens has never been reported as a medicinal plant in the Democratic Republic of the Congo (DRC). However, the plant is a species that has been traditionally used for the treatment of a wide range of ailments, including stomach pain, cough, verminosis, ulcer, liver disease, fever, influenza, nasal congestion, and inflammation in various countries, such as Brazil, Benin, India, Nigeria, and Togo [172]. The use of the plant against hemorrhoids is linked to the presence of numerous phenolic compounds isolated from its leaves and to its anti-inflammatory activity in vitro [103].

The majority of the taxa identified in this study are either trees or shrubs (Fig. 5), which is consistent with previous ethnobotanical studies conducted in the region [39, 42, 164, 173]. Previous ethnomedicinal studies targeting anti-hemorrhoidal plants have yielded varying results regarding the predominant morphology of the taxa used, depending on the study. In a study conducted in southwestern Nigeria, the majority of taxa inventoried were trees [73]. This is also the case for the study carried out in southeast Cameroon [34] or in Tabora, Tanzania [35]. The results were similar to those reported in our study. In contrast, in studies conducted in Madurai district in India [174] or in north-central Nigeria [32], grass was in the majority. The morphological aspect of taxa is therefore not a specific characteristic of plants with a reputation for anti-hemorrhoidal action. However, the preferential use of tree or shrub morphological types offers the advantage of year-round availability of plant material, providing the possibility of uninterrupted pathology management throughout the year. However, this practice increases the risk of extinction of a species in great demand, especially in the current context of global warming [175,176,177]. It would be beneficial for traditional healers to receive training in plant species conservation techniques, particularly in situ and ex vivo methods and biotechnological approaches. Additionally, it is crucial for the country to regulate harvesting practices and the use of plant resources for the intensive management and conservation of medicinal plants, with the objective of perpetuating the practice of traditional medicine while eradicating the risk of extinction of interesting taxa.

Anti-hemorrhoidal Recipes

Of the 117 anti-hemorrhoidal recipes, over 60% are based on leaves, which have been prepared in 7 different ways, with decoction being the most common method (Fig. 8). The preponderance of leaves and decoction as the part used and mode of extraction of the active ingredient are reported in various ethnobotanical studies carried out in Katanga [37, 41, 163, 164]. However, it should be noted that these modes of extraction are not universally consistent. In other ethnobotanical studies conducted in the same region, the root was found to be the main organ used [40, 178]. This diversity in the organ preferentially used is also observed in ethnobotanical studies focusing on plants with anti-hemorrhoidal uses. In some cases, the leaf is the most commonly used organ [30, 32, 179], while in others, the root [35, 180,181,182], stem bark [34], or aerial parts [183] are the preferred choice. The lack of consensus on the most important organ for the use of plants in the management of hemorrhoidal diseases can be justified by the diversity of compounds likely to contribute to the management of hemorrhoidal disorders. The utilization of leaves as a source of raw material offers a number of advantages. (i) Leaves are generally more accessible and abundant than other plant parts such as roots or bark, which may require damaging the plant to harvest [184]; (ii) they can contain a high concentration of bioactive compounds because they are the site of photosynthesis and other metabolic processes, which can lead to the accumulation of beneficial phytochemicals [185]. (iii) They are more readily dried and ground than other plant parts, which renders them more convenient for preparing extracts and medicines [185]. (iv) They are more sustainable as they can be harvested without killing the plant, allowing for continuous use and conservation of plant species [184].

In traditional medicine, the preparation of a medicinal recipe through the use of a decoction offers several advantages. Firstly, it is an optimal method for extracting active compounds that are stable at high temperatures. Secondly, the process does not necessitate the use of complex or expensive equipment, thereby facilitating its widespread applicability. Thirdly, the process is relatively straightforward and does not necessitate the involvement of a trained operator, which is advantageous in traditional settings. Fourthly, it is a cost-effective method that can be readily implemented in a domestic setting. Nevertheless, decoctions are unsuitable for the extraction of heat-sensitive constituents, as the boiling process may result in their degradation [186, 187]. Nevertheless, it is necessary to await the results of biological experiments before a proper assessment of the choice of organ and method of preparation used for each recipe can be made.

In contrast to previous ethnobotanical studies conducted in the region, which predominantly reported oral administration [40,41,42], our study primarily focused on topical applications. This is consistent with previous studies on plants purported to have anti-hemorrhoidal properties [30, 32, 34]. This is particularly evident when considering the localized nature of hemorrhoidal diseases.

The majority (n = 101) of the recipes documented in this study utilize a single plant, a finding consistent with several ethnobotanical studies conducted in Katanga [37, 38, 40]. However, there are also recipes resulting from mixtures of two or three taxa (n = 16), a pattern observed in other ethnobotanical studies conducted in the region [42, 165]. While the combination of plants may be based on the search for a certain synergy, there is a risk of increasing the risk of drug interactions and collateral effects. Nevertheless, it is of the utmost importance to remain vigilant during biological experiments in order to ensure that each recipe is duly evaluated.

Knowledge of Hemorrhoidal Diseases

In this survey, respondents referred to hemorrhoidal pathologies hemorrhoidal diseases in Swahili as “Kilonda ntumbu,” which translates to “the wound of the belly.” This term is linked to the perception among the local population that hemorrhoidal diseases originate from a specific type of diet, which is reflected in the allusion to the stomach.

The fact that more than 65% of subjects mentioned symptoms typically associated with hemorrhoidal diseases (Table 6) suggests that the people interviewed were familiar with the pathology for which they mentioned healing plants. This finding is consistent with previous studies that have demonstrated the prevalence of hemorrhoids in Lubumbashi [31].

Other pathologies treated by inventoried plants

In the Democratic Republic of the Congo (DRC), the 10 most deadly pathologies are in order of importance, as follows: malaria, tuberculosis, lower respiratory infections, neonatal disorders, diarrheal diseases, stroke, ischemic heart disease, road injuries, hypertensive heart disease, and cirrhosis and other chronic liver diseases [176]. Among the most deadly pathologies, the plants inventoried in this study were cited in the treatment of diarrhea (31 taxa), malaria (10 taxa), lower respiratory infections (7 taxa), and tuberculosis (2 taxa) (Table 4). It can be reasonably concluded that the resource persons consulted during this study have plant resources capable of coping with at least four of the ten most deadly pathologies in the Democratic Republic of the Congo. This provides indirect evidence of the capacity of traditional medicine in Lubumbashi to address the major health challenges facing the DRC.

In addition to hemorrhoidal diseases, the resource persons have identified at least ten taxa for each of the following five pathologies: In descending order of importance, these are gastrointestinal disorders, diabetes, sexually transmitted infections, malaria, and wounds (Table 4). The availability of multiple taxa to treat a given pathology indicates the community’s capacity to address the condition in question. Given that traditional medicine is culturally specific, this can provide insight into the particular management approaches of a given community in the context of specific pathologies.

The socio-demographic characteristics of the interviewees

In contrast to previous ethnobotanical studies conducted in Lubumbashi, this study interviewed a greater proportion of women than men [40,41,42, 165]. This discrepancy can be attributed to the fact that, unlike the present study, the aforementioned studies were conducted among practitioners of traditional medicine, predominantly men. In contrast, the present study’s account was conducted with the general population, which, like the national population in the 40–60 age range, is predominantly female according to Index Mundi in 2023 (https://www.indexmundi.com). Furthermore, the fact that the majority of informants were met in households may also explain the preponderance of women. Indeed, in households, the probability of encountering women during surveys is higher than that of encountering men, particularly given that in our society, household tasks are typically performed by women. Almost two-thirds of those surveyed had experience with the use of medicinal plants to treat their ailments, which suggests that traditional medicine plays a role in the study area. These data are consistent with a study conducted in the region on the practice of traditional medicine, which found that 79.4% of respondents had utilized traditional medicine to address their health or social concerns [31]. Moreover, several of the plants referenced in this study have been identified as anti-hemorrhoidal agents in other regions, and some have been demonstrated to possess indirect anti-hemorrhoidal properties (Table 2). These findings should enhance the credibility of the information presented in the present study.

It is essential to consider the constraints of this study when interpreting its findings. Firstly, there is a paucity of data concerning the precise manner in which the plants in question were utilized for the treatment of a range of pathologies, with the exception of hemorrhoidal diseases. Secondly, there is a dearth of knowledge regarding the practices that could potentially safeguard biodiversity despite the use of the aforementioned plants. Finally, there is an absence of evidence concerning alternative natural resources utilized by the Lubumbashi population for the treatment of hemorrhoidal diseases.

Conclusion

The findings of this study indicate that the population of Lubumbashi (DRC) employs a diverse range of taxa to treat hemorrhoidal diseases, particularly internal hemorrhoids. However, these plants offer considerable potential for managing a wide range of other pathologies, including gastrointestinal disorders, wounds, sexually transmitted infections, and diabetes. Among the taxa employed, some are endemic to the study area and specific to the region. Currently, studies are being conducted to assess the efficacy of these plants in the management of hemorrhoidal diseases. Nevertheless, further ethnopharmacological studies are required to validate the other properties of these plants. Such studies could result in the development of improved traditional medicines or the identification of new drug candidate molecules. These findings provide compelling evidence to motivate self-sufficient communities to explore sustainable methods of conserving these plants for the collective benefit of biodiversity conservation in the Miombo.

Funding 

No funding was received for this research.