Nutritional evaluation of Kedrostis africana (L.) Cogn:An edible wild plant of South Africa

Objective:To evaluate the nutritional composition and elemental constituents of Kedrostis africana and their safety aspect.Methods:Proximate parameters(moisture,ash,crude fibre,crude fat,proteins,and carbohydrate and energy) were evaluated using ALASA methods,and elemental analysis by ICP-OES technique.Results:The results from nutritional analysis showed that the tuber used for this study had a low content of crude fat and high content of ash,crude protein,crude fibre,carbohydrate and energy having the recommended dietary allowances.The tuber was rich in major minerals Na,K,Ca and Mg,there was sufficient amount of trace elements Fe,Cu,and Zn while the anti-nutrients oxalate,phytate,alkaloids,and saponins were detected in amounts that are not harmful according to Food and Agriculture Organization/World Health Organization.Conclusions:The outcome of this study suggests that this wild plant has very good nutritional potentials to meet the recommended dietary allowance and it could be a cheap source of essential nutrients that may ameliorate most nutritional challenges and can contribute remarkably to the amount of nutrient intake in human and animal diet.

Phytochemical screening and in vitro evaluation of antioxidant and antimicrobial activities of Kedrostis africana(L.)Cogn

Objective: To investigate phytochemical, antioxidant and antimicrobial activities of Kedrostis africana(K. africana).Methods: Dried tubers of K. africana were extracted in acetone, water and ethanol. The total phenol, flavonoid, proanthocyanidin and tannin contents were determined spectrometrically. The antioxidant activity was examined using 2,2-diphenyl-1-picrylhydrazyl,2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt, nitric oxide and hydrogen peroxide assays. The antimicrobial activity was determined by agar dilution method using minimum inhibitory concentration against 3 g positive and three gram negative strains while four fungal strains were also investigated.Results: Total phenol, flavonoids, proanthocyanidin and tannin contents ranged from(5.32 ± 0.01) to(10.51 ± 0.01) mg GAE/g;(42.58 ± 0.02) to(529.23 ± 0.01) mg QE/g;(15.05 ± 0.00) to(585.64 ± 0.00) mg CE/g and(0.301 ± 0.010) to(0.937 ± 0.000) mg TAE/g, respectively. The IC_(50) values of the ethanol extract for 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and hydrogen peroxide were 0.054 and 0.057 mg/mL,respectively, aqueous extract had an IC_(50) value of 0.135 7 mg/mL for nitric oxide while the acetone extract had an IC_(50) value of 0.300 mg/mL for 2,2-diphenyl-1-picrylhydrazyl.The ethanol extract demonstrated effective antimicrobial activity against the tested pathogenic species with minimum inhibitory concentrations values ranging from 2.5–5.0 mg/mL for bacteria and(0.312 5–5.000 0) mg/mL for fungi, respectively.Conclusions: The tuber of K. africana showed potent free radical scavenging property and antimicrobial activity.

Evaluation of acute and subacute toxicity of whole-plant aqueous extract of Vernonia mespilifolia Less. in Wistar rats

Objective： This study investigated the acute and subacute toxicity of whole-plant aqueous extract of Vernonia mespilifolia Less. （AEVM） in rats for evaluating its safety profile. Methods： AEVM for the acute （2000 and 5000 mg/kg） and subacute （200, 400 and 600 mg/kg） toxicity studies was administered orally to rats according the guidelines 425 and 407 of Organization for Economic Cooperation and Development, respectively. Food and water intake as well as body and organ weight of animals were recorded. Signs of toxicity were assessed, and hematological, biochemical and histopathological analyses were performed. Results： In the acute toxicity study, a single dose of the aqueous extract at 2000 or 5000 mg/kg caused no mortality in the animals, suggesting that the median lethal dose is greater than 5000 mg/kg. In the subacute toxicity study, administration of the extract for 28 d, at all doses, caused no significant changes in the body weights or organ weights of rats in the treated groups when compared with the control group. In addition, hematological and biochemical parameters also revealed no toxic effects of the extract on rats. Histological sections of the heart, liver and kidney from test animals showed no signs of degen- eration. Conclusion： These results showed that AEVM at dosage levels up to 600 mg/kg is nontoxic and could also offer protection on some body tissues. AEVM could, therefore, be considered safe.