Table 3 Preclinical (in vivo) Pharmacologic Activities of Africa Potato in different formulations

Male rats

Acute testing: 0.45; 0.90 and 1.8 mg/ kg infusion

Urine volume and total urinary outputs of creatinine, sodium, and potassium.

Increased plasma creatinine concentration, renal fluid, and electrolyte retention and reduced GFR compared with controls, APE may impair renal function.

[29]

Chronic: APE 30 mg/ kg infusion

Healthy mice

Corm aqueous extract (100–800 mg/kg i.p.)

Effect against pentylenetetrazole-, picrotoxin- and bicuculline-induced seizures.

APE has anticonvulsant activity possibly by enhancing GABAergic neurotransmission and/or action in the brain.

[30]

Doses of ≥400 mg/kg resulted in dose-related sedation and drowsiness.

Phenobarbitone and diazepam used as the reference.

Rats and guinea-pigs

Corm aqueous extract 25–400 mg/ml orally

Uterine horns isolated from rats and guinea-pigs.

Extract showed uterolytic activity

[31]

Inhibited the amplitude and sometimes, the frequency of the spontaneous, rhythmic contractions.

Relaxed pregnant uterine muscles.

Mechanism is unknown, probably mediated through a non-specific spasmolytic mechanism.

Extracts to 2.5 g/kg did not produce any toxic manifestations or mortalities.

Newborn suckling rats

African Potato ethanol or aqueous extract (50 mg/kg and a high dose of 200 mg/kg) via a stomach tube

Viscera removed for gross and microscopic morphometric measurements.

At a low dose, the mean weight gain was significantly increased.

[32]

The high dose of aqueous extract increased the weight of the caeca.

The low dose of alcohol extract reduced the pancreas weight.

No adverse effects, no signs of pathology.

Healthy rats and mice

Corm aqueous extract (APE, 50–400 mg/kg, orally)

Effect against castor oil-induced diarrhea, entero-pooling, intestinal transit, and intestinal fluid.

APE delayed the onset of copious diarrhea, reduced number, and weight of wet stools, inhibited the severity of diarrhea, inhibited intestinal transit and delayed gastric emptying.

[33]

Atropine and loperamide used as positive controls.

Speculated mechanism that the sterols, stanols and sterolins, especially rooperol and β-sitosterol are responsible for antimotility, spasmolytic and anticholinergic effects.

Healthy mice

AP methanolic extract (15 mg of extract orally)

After Brachyspira hyodysenteriae –induced typhlocolitis; weight loss, gross and histological lesions, MPO activity, and intestinal epithelial proliferation were evaluated.

AP extract reduced weight loss, the severity of typhlocolitis, inflammation and intestinal epithelial proliferation.

[34]

Albino rats

Aqueous corm decoction (10 ml/kg) and 20 ml/kg orally

Parameters assayed were TBARS, SGOT, SGPT, GSH, ascorbic acid, tocopherol, superoxide dismutase and glutathione peroxidase in RBC and in the liver.

Protection from oxidative stress generated by chloroquine, strengthen the antioxidant system under normal conditions.

[35]

STZ – Induced diabetic male Wistar rats

Aqueous solution (200 mg/kg or 800 mg/kg) administered orally

Oxidative stress biomarkers, hepatic injury, and selected biomarkers in the liver and kidney.

Both dosages showed significant antihyperglycemic effects, both showed antioxidant effects in the liver tissue.

[36]

At higher concentration, the activity of liver enzymes was increased and a negative effect on the kidneys was observed.

Lower concentrations ameliorated liver injury.