Sapium ellipticum (Hochst) Pax ethanol leaf extract modulates glucokinase and glucose-6-phosphatase activities in streptozotocin induced diabetic rats

• Published in: Asian Pacific Journal of Tropical Biomedicine
• Main Authors: Osasenaga Macdonald Ighodaro, Oluseyi Adeboye Akinloye, Regina Ngozi Ugbaja, Samuel Olatunbosun Omotainse
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wolters Kluwer Medknow Publications 2017
• Subjects: Sapium ellipticum; Glucose homeostasis; Diabetes; Glucokinase; Glucose-6-phosphatase; Arctic medicine. Tropical medicine; RC955-962; Biology (General); QH301-705.5; Arctic
• Online Access: https://doi.org/10.1016/j.apjtb.2017.05.009; https://doaj.org/article/87de70918f794d24893aa8f1b4bdd26a

Objective: To examine the effects of Sapium ellipticum (SE) leaf extract on the hepatic activities of glucokinase and glucose-6-phosphatase in streptozotocin-induced diabetic Wistar rats. Methods: STZ-induced diabetic Wistar rats (four groups, n = 8) were used in this study. SE was assessed at two different doses, 400 and 800 mg/kg BW, in comparison with metformin (METF) (12 mg/kg BW) as a reference antidiabetic drug. All treatments were done orally (p.o), twice daily at 8 h interval for a period of 21 days. Glucokinase and glucose-6-phosphatase activities were respectively determined using standard protocols. Hepatic and muscle glycogen contents were estimated as well. Results: STZ caused significant decrease in glucose-6-phosphatase activity and concomitant increase in glucokinase activity. SE extract especially at 400 mg dosage significantly reversed the alterations by increasing glucokinase activity by 40.31% and inhibiting glucose-6-phosphatase activity by 37.29% compared to diabetic control animals. However, the effects were significantly lower than that of METF which enhanced glucokinase activity by 94.76% and simultaneously inhibited glucose-6-phosphatase activity by 49.15%. The extract also improved hepatic glycogen level by 32.37 and 27.06% at 400 and 800 mg dosage respectively. HPLC-MS analysis of some SE fractions in dynamic MRM mode (using the optimized compound-specific parameters) revealed among other active compounds, the presence of amentoflavone, which has been associated with antidiabetic function. Conclusions: The ability of SE extract to concurrently inhibit glucose-6-phosphatase and activate glucokinase in this study suggests that it may be a treatment option for type 2 diabetes patients, and the presence of amentoflavone in the plant extract may account for its anti-diabetic potential.