Effect of Gongronema latifolium ethanol leaf extract on gastric acid secretion and cytoprotection in streptozotocin-induced diabetic rats.

OBJECTIVES: Gongronema latifolium leaves have been used in folklore medicine to manage diabetes mellitus and alleviate dyspepsia. This study aimed to provide a pharmacological basis to the medicinal use ofGongronema latifolium as an antidiabetic and antiulcerogenic agent in diabetes mellitus. METHODS: Ethanol extract from the leaf (200 mg/kg bodyweight) of Gongronema latifolium was administered to both streptozotocin-induced diabetic and control groups orally for 14 days. Gastric acid secretion was measured and ulcer was induced using ethanol and four-hour pyloric ligation. RESULTS: The mean bodyweight was significantly lower (p < 0.01), while the mean weight of the stomach, liver and small intestine to bodyweight ratio was increased significantly (p < 0.05) in the two diabetic groups compared to control. Extract significantly (p < 0.01) reduced the blood glucose level similar to the non-diabetic control. Basal and stimulated acid secretion in diabetic control rats was significantly (p < 0.01) decreased when compared to control. Extract administration increased the stimulated gastric acid secretion to a level significantly (p < 0.05) higher than control while reduction in gastric secretion by ranitidine was similar compared with control. Gongronema latifolium treatment significantly (p < 0.05) reduced ulcer scores in both ulcer models and increased mucus weight in the diabetic group. CONCLUSION: These results suggest that Gongronema latifolium antiulcerative activity is due to its prevention of chemical-induced stomach injury.

Aqueous leaf extract of Rothmannia longiflora improves basal metabolic rate and electrolyte parameters in alloxan-induced diabetic rats.

This study evaluated the action of aqueous leaf extract of Rothmannia longiflora on basal metabolic rate and electrolyte profile of alloxan-induced diabetic rats. Fifteen male Wistar rats weighing 135-140 g were assigned to 3 groups of 5 rats each. Group 1 which served as control received placebo treatment, group 2 namely the diabetic [untreated] group also received placebo treatment whereas group 3-the extract treated diabetic group was administered extract [15 g/kg body weight] by oral administration for 14 days. Results of BMR measurement showed a significant increase [P<0.01] in BMR level of Diabetic untreated group [1.03+/-0.02 ml/hr/g] compared to the control group [0.79+/-0.07 ml/hr/g]. Extract treatment significantly [P<0.05] decreased BMR in the diabetic rats. Results of analyses of serum electrolytes and glucose showed significant decreases [P<0.01] in sodium and chloride concentrations in the diabetic untreated group when compared to the control. However, sodium and chloride concentrations in the extract treated diabetic were not significantly different from that of their control values. There was no significant difference in potassium and urea concentrations in the extract-treated diabetic rats with respect to their control values. Extract treatment significantly [P<0.05] reduced serum glucose level of the extract treated group when compared to the diabetic untreated group. This suggests that oral administration of Rothmannia longiflora might be beneficial for the restoration of basal metabolic rate and improvement of electrolyte profile in diabetes mellitus.

Phytochemistry and some haematological changes following oral administration of ethanolic root extract of Gongronema latifolium in rats.

Gongronema latifolium is a climbing perennial plant that belongs to the family of asclepidaceae. The medicinal uses of the leaves and stem bark extract of Gongronema latifolium has been reported in many scientific literatures to include anti-hyperglycaemic, anti-ulcerative etc. There is paucity in scientific reports on the medicinal properties of the root extract. This study was therefore designed to elucidate the phytochemical constituents and effect of ethanolic root extract of Gongronema latifolium on some hematological parameters. Eighteen (18) albino Wistar rats were randomly assigned into 3 groups of 6 rats each. Group 1 [control] was fed on normal rat chow, the test groups [group 2 and 3] in addition received extract treatment [p.o] at a dose of 100mg/kg and 200mg/kg respectively. The feeding regimens lasted for 14 days and all animals had access to tap water. Results show that the extract contains polyphenols, glycosides, reducing sugars and alkaloids. The mean RBC count for control was 4.44+/-0.15x10(6)cells/mm3, this did not differ significantly from the test groups. The total WBC counts were 3.79+/-0.15x10(3) cells/mm3, 3.37+/-0.19x10(3)cells/mm3 and 5.54+/-0.39x10(3)cells/mm3 for groups 1, 2, and 3 respectively. WBC was significantly [P<0.01] higher in the high dose [group 3] compared with control. Mean PCV [%] were 33.60+/-0.81, 37.20+/-0.80 and 34.80+/-1.35 for groups 1, 2, and 3 respectively. The PCV was significantly [P<0.05) higher in low dose extract recipients [group 2] than in control. Hb content, MCV and MCH did not differ significantly among the groups, but MCHC was significantly lower in the test groups compared with control group. Neutrophils were significantly [P<0.001] reduced in the test groups, while the eosinophils and monocytes count were significantly increased in the test groups than in controls. In conclusion, the extract has little or no effect on RBC count, PCV, MCV and MCH. But low doses of the extract significantly increased the Hb count while high doses significantly increased WBC count, probably due to increase in eosinophil and monocyte counts. MCHC was dose-dependently reduced. The extract was also observed to contain polyphenols, alkaloids, glycosides and reducing sugars.