Ngozi G

Antinutrients are important phytochemicals that also determine the safety of medicinal and nutritional plant parts. The antinutrients of Moringa oleifera and Vernonia amygdalina (bitter leaf) leaves were extracted by soaking, using water, ethanol and hydromethanol (1:1) as solvents. The phytochemical analyses were done both qualitatively and quantitatively (using Spectrophotometer: UV-V15). This study showed that Moringa and bitter leaf contain some antinutritional constituents, including Tannins, Oxalates, Saponins and Alkaloids. Hydromethanol extracted the highest concentration of Tannins (65.91%) from bitter leaf extract. Ethanol extracted the highest concentrations of Oxalates (5.2 x 103 Mg/100g) and Saponins (7,616.84 µg/g) from both medicinal leaves and the highest concentration of Alkaloids from Bitter leaves only. Water extracted the highest concentrations of Alkaloids and Tannins from Moringa leaves only. Generally, ethanol solvent yielded highest crude extraction of antinutrients in the herbs. Therefore, it is also necessary to consider the antinutritional yield of a solvent in the choice of solvents for herbal production.

The leaves of Ocimum gratissimum (OG) and Vernonia amygdalina (VA) had been of medicinal interest mainly due to their respective antioxidant and antihyperglycaemic properties. A daily dose of 0.5gKg-1 body weight aqueous leaf extracts of OG, VA and 50:50 (OG+VA) was orally administered to three different rabbit groups for 28 days, fed ad libitum. The control group was given only 2mlKg-1 of normal saline daily. Fasting blood glucose concentration was monitored with a digital glucometer. From the SPSS (version 15) multivariate analysis (p=.05), results showed that the mean fasting blood glucose concentrations of normal rabbits used was 5.98±0.5 mMolL-1. Only VA lowered fasting blood glucose within 24 hours and maintained the hypoglycaemia for 72 hours; VA potentiated OG after 72 hours and later synergistically lowered fasting blood glucose concentration. This study suggested that VA and (OG+VA) were time-dependent hypoglycaemic: while consumption of VA had acute effect, (OG+VA) could preferably be used for longer prophylaxis of diabetes. Therefore, further researches are recommended on the efficacy of this herbal combination therapy.