Assessment of anti-diabetic activity of an ethnopharmacological plant Nerium oleander through alloxan induced diabetes in mice

Ethnopharmacological relevance: Nerium oleander L. (syn. Nerium indicum Mill. and Nerium odorum Aiton.) is used for its anti-diabetic properties in Pakistan, Algeria, Morocco and is also recognized in Ayurveda. The present study was undertaken to investigate the anti-diabetic capacity of a standardized hydromethanolic extract of Nerium oleander in alloxan induced diabetes in mice. Materials and methods: Nerium oleander leaf extract (NOLE) was orally administered at 50 and 200 mg/kg body weight (BW) dose to alloxanized mice (blood glucose >200 mg/dl). After 20 consecutive days of treatment, various diabetic parameters were studied and compared with untreated mice. Furthermore, gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography (HPLC) analysis was employed to reveal the phytochemical composition of the plant extract. Results: NOLE demonstrated antihyperglycaemic activity by reducing 73.79% blood glucose level after 20 days of treatment. Oral glucose tolerance test (OGTT) revealed increase in glucose tolerance as evident by 65.72% decrease in blood glucose in 3 h post treatment. Percentage decrease in different liver marker enzymes were significant along with decrease in triglyceride and cholesterol levels, displaying potent antihyperlipidemic activity. Peroxidase and catalase activity in liver, kidney and skeletal muscle were significantly restored besides marked reduction in lipid peroxidation and normalization of hepatic glycogen level in the NOLE treated alloxanized mice. Different bioactive phytocompounds with potent anti-diabetic activity were identified by GC-MS and HPLC analysis. Conclusion: The present investigation revealed that Nerium oleander possess potent anti-diabetic activity as claimed in different ethnopharmacological practices. (C) 2014 Elsevier Ireland Ltd. All rights reserved.