ABSTRACT
Aims: To evaluate the anti-hyperglycaemic efficacy and safety of the methanol extract of the combination of Senecio biafrae leaf, Xylopia aethiopica fruit, Carica papaya seed and Spondias mombin stem bark mixed together in ratio 1:1:1:1 Study Design: Extract of medicinal plants was assayed using glucose and streptozotocin-induced herperglycaemic rats model. Place and Duration of Study: Department of Pharmacognosy, Obafemi Awolowo University, IleIfe, Nigeria, between May, 2019 and January, 2022. Methodology: The extract of the combined plant parts was tested for toxicity in rats while its effects on glucose level, blood and biochemical components were also assessed. Its in-vitro anti-hyperglycaemic activity was assayed in ?-amylase and ?-glucosidase inhibitory models while its in-vivo effects were tested in glucose and streptozotocin-induced hyperglycaemic rats. The antioxidant activity of the extract was also carried out. Results: The extract did not show any adverse effects on blood sugar levels, haematological and biochemical parameters in normal rats in sub acute toxicity tests. The extract gave comparable (p > 0.05) ?-amylase and ?-glucosidase inhibitory effects to acarbose. In glucose-induced hyperglycaemic rats, its 100 mg/kg was the most effective dose with 19, 40, 43, and 57% activity that was significantly higher (p < 0.05) than the 10, 18, 24, and 40% activity given by glibenclamide (5 mg/kg) at the same time points. In streptozotocin-induced diabetic assay, its 50 mg/kg showed 31, 85, 85 and 82 % effects on days 4, 7, 10 and 14, respectively that was significantly higher than its 100 mg/kg and glibenclamide on days 7 and 10. The extract also elicited high free radical scavenging effects in all the antioxidant assays. Conclusion: The extract of the combination of four Nigerian antidiabetic plants mixed together in equal ratio gave significantly better antidiabetic activity at low doses than the individual plants without toxic effects.
ABSTRACT
Aims: To evaluate blood glucose-lowering ability of leaf ashes and compare anti-hyperglycaemic activities of Annona muricata leaf extract and ash. Study Design: Ashes and extract of medicinal plants were assayed using glucose-loaded rats model. Place and Duration of Study: Department of Pharmacognosy, Obafemi Awolowo University, Ile-Ife, Nigeria, between March 2017 and February 2020. Methodology: Adequately prepared ashes of seven plants and A. muricata methanol extract were assayed for anti-hyperglycaemic potentials, using glucose-loaded (10 g/kg, p.o.) Wistar rats that were hyperglycaemic [blood glucose levels ? 7.0 mmol/L] thirty minutes thereafter (T0.0). Groups of 5 rats each, were administered 100, 150, 200 mg/kg of different ashes and A. muricata extract (200 mg/kg). Normal saline and glibenclamide (5 mg/kg) were negative and positive controls, respectively. Their blood glucose levels were determined at 0-4 hours post-extract/ash/drug administration; results analysed using ANOVA followed by the Student-Newman-Keuls’ and Dunnett post-hoc tests. P ? .05 was considered significantly different. Results: 100 mg/kg of Momordica charantia, Azadirachta indica and Eugenia malaccensis leaf ashes was their most active dose, indicating significantly higher extrapancreatic activity. 32, 37, 54, 59 and 36, 43, 50, 48 % reductions elicited by Chromolaena odorata (COLA) and A. muricata (AMLA) ashes (200 mg/kg) at 0.5, 1, 2 and 4 hours, respectively made them the most active ashes. Also, blood glucose levels in glibenclamide (5 mg/kg)-, COLA-, AMLA- and its extract (200 mg/kg)-treated rats were comparable (P > .05) and their anti-hyperglycaemic activity was suggested to be due to the pancreatic (insulinotropic) and extra-pancreatic actions of their constituents. Conclusion: Study justified anti-diabetic ethnomedicinal use of plant-ashes in Nigeria, while doses were recommended for the optimum folkloric usage of these leaf ashes in managing diabetes in the rural areas of Nigeria. The leaf ashes may contain elements with glucose postprandial tolerance factor and insulin stimulating properties.
ABSTRACT
Heliotropium indicum of the family Boraginaceae is used locally in Nigeria to treat ailments such as ulcer and fever. In this study, ulceration of the gastric mucosa in Wistar rats was induced via the oral administration of 80mg/kg/bodyweight of Indomethacin. Histological analyses of the stomach body wall in the rats of Groups 2 and 4 (which received 100mg/kg/bodyweight of extract before oral administration of 80mg/kg/bodyweight Indomethacin and 80mg/kg/bodyweight Indomethacin only respectively) showed erosion of the mucus-secreting cells, gastric pit, upper and middle parts of gastric glands and some of the parietal cells. Histological observations of the stomach body wall in rats of Group 5 (which received 200mg/ kg/bodyweight of extract before oral administration of 80mg/kg/bodyweight of Indomethacin) showed erosion of the mucus-secreting cells, gastric pit and the upper most part of the gastric gland. Histological observations of the stomach body wall in rats of Groups 1, 6 and 3 (which received 50mg/kg/bodyweight of Ranitidine and 400mg/kg/bodyweight of extract before oral administration of 80mg/ kg/bodyweight Indomethacin; and only 80mg/kg/bodyweight of Normal Saline respectively) showed normal morphological appearance of the different components of the mucosa layer. Thus, the aqueous extracts of the dried leaves of Heliotropium indicum have dose dependent histo-gastroprotective effects.