Table 2 Evidence of biological activity of the compounds found in the plant materials
Plant species and manufacturer therapeutic claim | Bioactive compound | Evidence of Biological activity of bioactive compound related to traditional use of the plant | Mechanism of action |
|---|---|---|---|
Eucalyptus globulus pain relief, URT disorders, mouth wash, GIT disorders | Aromadendrine (dihydrokaempferol) | Anti-inflammatory Ani-oxidant | Scavenging of reactive oxygen species, chelation of metal ions [16] |
Antibacterial; against Staphylococcus aureus, Streptococcus mutans | Inhibits biofilm formation [17] | ||
1,8-cineol | Antibacterial-against K. pneumoniae, S. aureus, P. aeruginosa | Disruption of bacterial cell membrane & loss of intracellular materials [18] | |
Antiasthma, anti-bronchitis, anti COPD, Anti-influenza | Downregulation of inflammation cytokines such as interleukin- 1b (IL-1b) and tumor necrosis factor-a resulting in bronchial muscle relaxant and reduction in mucus secretion [19] | ||
Anti-inflammatory Ani-oxidant | Regulates nuclear factor-kappa B (NF- κB) and nuclear factor erythroid-2-related factor 2 (Nrf2) pathways [20, 21] | ||
Analgesic/sedative | Suppression on the CNS by modulating glutamatergic & dopaminergic systems, activates transient receptor potential melastatin 8 [22, 23] | ||
Antispasmodic and antisecretory, gastroprotective, antidiarrheal | Promotes regeneration of the gastric cells, increases gastric mucus, antioxidant anti-inflammatory effects [20] | ||
globulol | Antibacterial-against K. pneumoniae, S. aureus, P. aeruginosa [24, 25] | ||
α-terpineol | Anti-inflammatory & antioxidant mainly analgesic | Suppresses superoxide production by monocytes; inhibits release of inflammatory mediators including serotonin, histamine, bradykinin, & prostaglandins [26, 27] | |
Antibacterial-against K. pneumoniae, S. aureus, P. aeruginosa | As 1,8-cineole | ||
Anti-gastric ulcer | As 1,8-cineole | ||
Aloe barbadensis cracked lips, mouth wash, URT disorders, GIT disorders | Aloin A and B Aloe emodin | Laxative | Inhibition of Na+/K + pump & Cl-channels increase gastric motility; stimulate secretion of mucus and chloride ions [28, 29] |
immuno-modulatory effects | Inhibition of histamine release from mast cells -reduced production of Tumor Necrosis Factor (TNF)-α [30] | ||
anti-inflammatory- antioxidant | Cyclooxygenase pathways and reducing prostaglandin E2 production [31, 32] | ||
antibacterial activity-H pylori | Activation of phagocytic leukocytes; inhibition of the N-acetyltransferase activity of H. pylori [33, 34] | ||
Acemannan | Wound healing anti-inflammatory | Activates macrophages to release fibrogenic cytokines; inhibits thromboxane A2 [35, 36] Cyclooxygenase pathways and reducing prostaglandin E2 production [30] | |
Mannose 6 phosphate | Wound healing | ||
Lupeol | Anti-inflammatory- antioxidant Wound healing effect | Lupeol reduces TNF-α, IL-1, and IL-6 cytokine production. This lowers the infiltration macrophage to damaged tissues, hence reducing inflammation. [39]. It also chelates toxins such as heavy metal ions [40] Stimulates the production, and migration of keratinocytes and fibroblasts to injured tissues, by activating the PI3K-PKB/Akt and p38/ERK/MAPK pathways [41]. | |
Albizia coriaria URT disorders, | Lupeol and lupenone | Anti-inflammatory Analgesic | |
Immunomodulating; anti allergen, anti-asthmatic, | Reduces the production eosinophils, thus interleukins-reduced fluid production in the bronchoalveolar pathway [44] | ||
Antibacterial-against S. aureus, K. pneumoniae, P. aeruginosa [45, 46] | |||
Anti-viral-herpes simplex [47] | Inhibits virus plaque formation [48] | ||
Betulinic acid/betulin | Anti-inflammatory Analgesic | Inhibits production of nitric oxide & PG2 (cyclooxygenase-2 activity); also decreases production of pro-inflammatory cytokines including IL-1β, IL-6, IL-8, IL-12, & TNF [49, 50] | |
Antibacterial-P. aeruginosa, S. aureus, Mycobacterium tuberculosis [51] | Enhance the rate of electron transport chain activity, which results in excess production of ROS, which damage DNA, and cause bacterial death [52]. | ||
Anti-viral-against herpes simplex [53] | Inhibits viral plaque formation [48] | ||
(+/-) Catechin | Anti-inflammatory | Radical scavenging; activates production of erythroid-derived factor 2 which regulates antioxidant enzymes [54] | |
Immunomodulatory; anti-allergenic | Reduces production & infiltration of lung tissue by inflammatory cytokines such as TNF-α, IL-1β [55] | ||
Inhibits viral receptor binding [58] | |||
Mangifera indica URT disorders, | Mangiferin | Antioxidant, anti‑inflammatory, antipyretic, analgesic, | Scavenging of ROS, chelation of toxic metal ions; downregulates phosphorylation of NF- κB pathways-reduces production of proinflammatory cells [59, 60] |
Antiallergic, anti-asthmatic, immunomodulatory | Reduces tracheal contraction by inhibiting the nitric oxide‑cyclic GMP pathway [61]; Inhibits production of nitric oxide and PG2 (cyclooxygenase-2 activity); also decreases production of pro-inflammatory cytokines including [62] | ||
Antibacterial-activity against S. aureus [63] | Increased antibody titers; increases cell mediated immunity. Stimulates lysozyme activity, [64] | ||
Antiviral-against Herpes simplex [65] | Inhibits viral replication [66] | ||
(+/-) Catechin, epicatechin | Anti-viral, anti-inflammatory and anti-allergenic | Activity against influenza A and B; catechins inhibit receptor binding and sialidase activities [58]. Catechins regulate the production of proinflammatory agents such as TNF-α, NF-κB, COX-2 in lung tissue. They also scavenge noxious metal ions and ROS [67, 68]. | |
Gallic acid | Antioxidant, anti-inflammatory | Scavenging of ROS, chelation of toxic metal ions; downregulates phosphorylation of NF- κB pathways-reduces production of proinflammatory cells [50,51,52] | |
Antimicrobial- P. aeruginosa, S. aureus | Interferes with colonization by inhibiting motility & adherence; disrupts cell membrane leading to leakage of cell nutrients; inhibits dihydrofolate reductase, topoisomerase IV [69, 70] | ||
Antiviral - Haemophilus influenza A & B | Disruption of the viral particles [71] | ||
Quercetin | Antioxidant, anti-inflammatory, | Scavenging of ROS, chelation of toxic metal ions; downregulates phosphorylation of NF- κB pathways-reduces production of proinflammatory cells, inhibits cyclooxygenase & lipoxygenase enzymes [67, 72,73,74] | |
Immune-modulatory; anti-allergic | Inhibits IL 8 & 6, TNF-α [75] | ||
Antibacterial; P. aeruginosa, S. aureus, B. subtilis, M. tuberculosis, K. pneumoniae | Inhibits nucleic acid synthesis, disrupts plasma membrane, inhibits glutamine synthetase, inhibits biofilm formation [76, 77] | ||
Antiviral - Influenza-A virus [78] | Interacts with Hemagglutinin (HA) glycoprotein to prevent entry into the host cell, thereby inhibiting viral replication. It also inhibits the M2 protein and neuraminidase (NA) glycoprotein interfering with packaging of genome segments into influenza virus particles [79]. | ||
Azadirachta indica URT disorders, cracked lips | Tetranortriterpenes- Azadirachtin | Anti-inflammatory, antipyretic, antioxidant Wound healing, Anti-gastric ulcer | Inhibits cyclooxygenase (COX), & lipoxygenase (LOX) enzymes. Modulates transcription factors NF-κB, radical scavenging |
Immunostimulant | Inhibits TNF-induced biological responses [80] | ||
Antibacterial- against S. aureus & MRSA | Inhibits biofilm formation [81] | ||
Nimbidin, Nimbin, | Suppresses production of inflammatory cytokines from neutrophils & macrophages [84] | ||
Anti-gastric ulcer | Reduces secretion of gastric acid by inhibiting histamine (H2) receptors and muscarinic receptors [85] | ||
Immunomodulatory; anti-allergic | Inhibits macrophage migration [86] | ||
Nimbolide | Antibacterial [87] | ||
Mahmoodin | Anti-inflammatory, Antibacterial [88] | ||
Diterpens-Margolone, margolonone, margolonone | Antibacterial-against Klebsiella, Staphylococcus & Serratia Species [88] | ||
Zingiber officinalis URT disorders, GIT disorders | Gingerols 8- gingerol 10-gingerol 12-gingerol 6-gingerol Shogaols 6-shogaol | Antioxidant activity, Anti-inflammatory, analgesic: 6-gnigerol and 6-shogaol most studied | Scavenging of ROS, chelation of metal ions; oxygenation arachidonic acid, a substrate for cyclooxygenase enzymes, thus inhibiting production of prostaglandins; reduced activation of macrophages; inhibit nitrite oxide (NO) production [89, 90] |
Anti-asthmatic, anti-allergen | Reduced contraction of smooth respiratory muscles by reduction in Ca2 + influx & β2 receptor activation; reduced production of proinflammatory cytokines [91] | ||
Antibacterial- S. aureus, Mycobacteria, Streptococcus pyogenes, Streptococcus pneumoniae, Haemophilus influenzae | Inhibition of biofilm formation, inhibition of hydroxymethyl-7, 8- dihydro pterin pyrophosphokinase, 6-gingero > 8- gingerol > 10-gingerol > 12-gingerol [92, 93] | ||
Anti-gastric-ulcer activities -anti- H. pylori, 10-gingero > 8- gingerol > 6-gingerol > 6-shogaol [94] -anti-emetic- | Inhibit 5-hydroxytryptamine to increase gastric motility and emptying [95, 96] | ||
Zingerone (major pungent compound in ginger) | Anti-inflammatory antioxidant activity | Reducing ROS production; chelation of metal ions [97] | |
Antibacterial activity | Dihydro pterin pyrophosphokinase inhibition | ||
Warburgia ugandensis URT disorders, | Drimane sesquiterpenes Muzigadial, Muzigadiolide Warburganal, warburgadione, warburgadial, warburgin Ugandensidial, Ugandensolide polygodial | Anti-inflammatory and anti-allergic – polygodial | inhibition of phospholipase A2 and neuropeptide release [98] |
Antimicrobial-antimycobacterial (muzigadial & muzigadiolide) [99] | |||
Antibacterial (against K. pneumoniae, P. aeruginosa, S. aureus (warburganal, ugandensidial, and polygodial) [100] |