ABSTRACT

In this study the micronutrient, phytochemicals composition, acute toxicity and antidiabetic activity of the ethanolic extracts of Alternanthera brasiliana stem, Asystesia gangetica and Abutilon mauritianum leaf were evaluated. The micronutrient and phytochemical composition were carried with standard methods of analysis. Acute toxicity study of the ethanol extracts was carried out using 30 albino mice randomly assigned into 6 groups for the treatment. For the acute and sub acute antidiabetic study, 50 adult rats were randomly divided into 5 groups and were used for each plant sample treatment. The rats were made diabetic with alloxan monohydrate. Blood glucose levels of the rats were determined. The effect of these plant samples on the hematological profile, biochemical profile, lipid profile and histopathology parameters of the rats were measured. The thiamine, riboflavin, niacin and ascorbic acid for the plant samples ranged from 0.33 to 0.07 mg/100 g, 1.96 to 0.02 mg/100 g, 0.72 to 0.01 mg/100 and 26.96 to 8.65 mg/100 g, respectively. The calcium, magnesium, phosphorous, potassium and iron content for the plant samples ranged from 14.37 to 1.94 %, 3.83 to 2.08 %, 1.74 to 0.41 mg/100 g, 5.01 to 1.15 mg/100 g and 2.10 to 0.12 mg/100 g, respectively. The saponins, steroids, tannins, alkaloids, flavonoids and hydrogen cyanide contents of the plant samples ranged from 2.88 to 6.65 %, 12.37 to 0.22 %, 6.84 to 0.01 %, 2.91 to 0.09 %, 10.86 to 1.56 % and 10.81 to 0.67 mg/g, respectively. The acute toxicity study indicated no death with and signs of toxicity in any of the groups for the 3 samples, while that of the antidiabetic study showed significant (p˂0.05) rise in the plasma glucose level in the diabetic rats when compared with the normal rats. Treatment of the diabetic rats with 400 and 800 mg/kg of the extract significantly (p˂ 0.05) reduced the blood glucose level of the diabetic rats both in acute and sub-acute treatment. The activity of the extract during acute study was incomparable to that of the reference standard drug except at 0 and 2 hour for A. brasiliana stem, 4 and 6 hours for A. gangetica sample, but was only comparable to that of the standard drug during sub-acute treatment at 7, 14 and 21 days for A. gangetica sample and at 14 day for Abutilon mauritianum sample at both doses. It was observed that the treatment with the plants extract had high % fall than the treatment done with glybenclamide. Interestingly, the treatment with 800 mg/kg had the highest value of % fall in glucose for the A. mauritianum leaf (52 %). This implied that the extract rate of lowering potentials are dose-dependent and plant type; and could replace the drug in the management of diabetes since it is safe. Also, significant (p˂0.05) differences were observed in serum lipid profile, biochemical study and hematology study while at histopathology had no significant (p˃0.05) difference when compared with diabetic control.