Studies on the effect of aqueous extract of millettia aboensis leaves on lomotil – induced constipation in wistar albino rats

Thesis Abstract

Millettia aboensis leaf is a rich source of reducing sugar, tannins, glycosides and flavonoids and has been reported to have medicinal property as well as some physiological potentials. The leaf also has been used by traditional herbalists for general healing of diseases including ulcer and laxatives. This study evaluated the effect of aqueous extract of M. aboensis leaves on lomotil-induced constipation in Wistar albino rats. The qualitative phytochemical constituents of the extract showed the relative presence of reducing sugars, tannins and flavonoids in relatively high concentrations; alkaloids, steroids and glycosides in moderately high concentrations; soluble carbohydrates, saponins and hydrogen cyanides were in low concentrations while terpernoid was not detected. The median lethal dose effect (LD50) of the extract recorded no death at dose of 5000 mg/kg b.w. Assay of Aspartate Amino transferase and Alanine Amino transferase activities in serum of treated rats (groups 2 and 3) given 100 and 1000 mg/kg b.w. of the extract showed significant increase (p<0.05) compared to the control group 1 (normal saline). The ALP activity in serum of the mice in groups 2 and 3 administered 100 and 1000 mg/kg b.w. of the extract exhibited neither significant increase nor decrease (p>0.05) compared to the control group 1 mice. Triacylglycerol and High density lipoprotein concentrations in serum of the mice treated with 100 and 1000 mg/kg b.w. of the extract showed non-significant increase (p>0.05) compared to the control group while the LDL and total cholesterol concentrations of the groups 2 and 3 given 100 and 1000 mg/kg b.w. of the extract showed non-significant decrease (p>0.05) compared to the control group. The potassium ion concentration showed a non-significant increase (p>0.05) in the groups 2 and 3 mice administered 100 and 1000 mg/kg b.w. of the extract compared to the control group while the serum level of sodium ion showed a non-significant increase (p>0.05) in group 2 mice administered 100 mg/kg b.w. of the extract and a significant increase (p<0.05) in group 3 mice that received 1000 mg/kg b.w. of the extract compared to the control mice. There was neither a significant decrease nor increase (p>0.05) in the serum level of glucose of the mice in groups 2 and 3 administered 100 and 1000 mg/kg b.w. of the extract compared to the control. rThe result of the aqueous extract of M. aboensis on the mean value of the faecal droppings on lomotil-induced constipation in rats showed neither a significant decrease nor increase (p>0.05) in groups 2 (standard drug of lomotil), 3 (100 mg/kg b.w. of extract), 5 (100 mg/kg of extract + 5 mg/ml of lomotil, 7 (5 mg/ml of lomotil + 200 mg/kg b.w. of extract) and 8 (5mg/ml of lomotil + 200 mg/kg of extract) compared to the negative control (normal saline) while group 4 mice (200 mg/kg b.w. of extract) showed a non-significant increase (p>0.05) and group 6 (200 mg/kg b.w. of extract + 5 mg/ml of lomotil) showed a significant increase (p<0.05) compared to the positive control group 2 (standard drug of 5 mg/ml of lomotil). The study of the effects of the aqueous extract of M. aboensis on transport of glucose across everted rat intestine showed significant increase (p<0.05) in the glucose influx into the everted intestinal sac (serosal compartment) in a dose-dependent manner in all the treated groups contained in groups 3, 4 and 5 everted in 100, 200 and 400 µg/ml of the extract compared to the control group 1 while in group 2 (standard drug metformin), there was a significant decrease (p<0.05) compared to the control. Sodium transport across the everted rat intestine showed a significant increase (p<0.05) in the influx of sodium ions into the serosal compartment of groups 2, 3 and 4 everted in 100, 200 and 400 µg/ml of the extract compared to the control group while potassium transport across everted rat intestine showed significant increase (p<0.05) in the efflux of potassium ions into the mucosal compartment of all the treated groups 2, 3 and 4 everted in 100, 200 and 400 µg/ml of the extract compared to the control group 1. The significant increase in the frequency of faecal droppings on the extract treated groups may prove that the extract contains some bioactive compounds that have the properties of laxative effects when administered and therefore support the claim that this plant is used in folk medicine for the treatment of constipation.