Anti-Alzheimer and Antioxidant Effects of Nelumbo nucifera L. Alkaloids, Nuciferine and Norcoclaurine in Alloxan-Induced Diabetic Albino Rats

The present study is aimed to determine the efficacy and dose response of the nuciferine (1), norcoclaurine (2) and crude extract of Nelumbo nucifera in managements of diabetes, Alzheimer disease and related allergies. Experimentally, alloxan (100 mg/kg body weight (b.w.))-induced diabetic rats (200-250 g) were divided into seven groups (n = 6). Group I: normal control, Group II: diabetic control, Group III: standard treated with glibenclamide and Group lV-VII: treated with methanolic crude extracts (100, 200 mg/kg), nuciferine and norcoclaurine (10 mg/kg b.w.) for 15 days. Different tests were performed, including blood glucose, body weights and antioxidant enzyme assays, i.e., superoxide dismutase (SOD), catalase test (CAT), lipid peroxidation assay (TBARS), glutathione assay (GSH) and acetylcholinesterase (AChE) assay. Nuciferine and norcoclaurine significantly reduced blood glucose (p < 0.05) and restored body weight in diabetic rats. Moreover, nuciferine and norcoclaurine (10 mg/kg) significantly recovered the antioxidant enzymes (SOD, CAT, GPx and GSH) which decreased during induced diabetes. Significant increase in TBARS was also observed in the diabetic group and nuciferine as well as norcoclaurine (10 mg/kg) inhibited the increase in TBARS in diabetic animals (p < 0.05), as compared to glibenclamide. AChE activity was significantly recovered by nuciferine and norcoclaurine (10 mg/kg) both in the blood and brain of the diabetic group (p < 0.05). Nuciferine and norcoclaurine showed potent inhibitory effects against alpha-glucosidase and alpha-amylase with IC50, 19.06 +/- 0.03, 15.03 +/- 0.09 mu M and 24.07 +/- 0.05, 18.04 +/- 0.021 mu M, as confirmed by molecular docking studies. This study concludes that nuciferine and norcoclaurine significantly improve memory and could be considered as an effective phytomedicine for diabetes, Alzheimer's disease (AD) and oxidative stress.

Automated summary

This study aimed to determine the efficacy and dose response of nuciferine, norcoclaurine, and crude extract of Nelumbo nucifera in managing diabetes, Alzheimer's disease, and related allergies. The results showed that these substances significantly reduced blood glucose levels, restored body weight, and improved antioxidant enzyme activity.