Diabetes mellitus is a potentially morbid condition with high prevalence worldwide thus being a major medical concern. Experimental induction of diabetes mellitus in animal models is essential for the advancement of our knowledge and understanding of the various aspects of its pathogenesis and ultimately finding new therapies and cure. Experimental diabetes mellitus is generally induced in laboratory animals by several methods that include: chemical, surgical and genetic (immunological) manipulations. Most of the experiments in diabetes are carried out in rodents, although some studies are still performed in larger animals. The present review highlights the various methods of inducing diabetes in experimental animals in order to test the newer drugs for their anti-diabetic potential.

Aim of the study: This study was made to investigate the antidiabetic, antioxidant and hypolipidemic potential of Cinnamomum tamala, (Buch.-Ham.) Nees & Eberm (Tejpat) oil (CTO) in streptozotocin (STZ) induced diabetes in rats along with evaluation of chemical constituents. Materials and methods: The GC-MS (Gas chromatography–mass spectrometry) analysis of the oil showed 31 constituents of which cinnamaldehyde was found the major component (44.898%). CTO and cinnamaldehyde was orally administered to diabetic rats to study its effect in both acute and chronic antihyperglycemic models. The body weight, oral glucose tolerance test and biochemical parameters viz. glucose level, insulin level, liver glycogen content, glycosylated hemoglobin, total plasma cholesterol, triglyceride and antioxidant parameters were estimated for all treated groups and compared against diabetic control group. Results: CTO (100 mg/kg and 200 mg/kg), cinnamaldehyde (20 mg/kg) and glibenclamide (0.6 mg/kg) in respective groups of diabetic animals administered for 28 days reduced the blood glucose level in streptozotocin induced diabetic rats. There was significant increase in body weight, liver glycogen content, plasma insulin level and decrease in the blood glucose, glycosylated hemoglobin and total plasma cholesterol in test groups as compared to control group. The results of CTO and cinnamaldehyde were found comparable with standard drug glibenclamide. In vitro antioxidant studies on CTO using various models showed significant antioxidant activity. In vivo antioxidant studies on STZ induced diabetic rats revealed decreased malondialdehyde (MDA) and increased reduced glutathione (GSH). Conclusion: Thus the investigation results that CTO has significant antidiabetic, antioxidant and hypolipidemic activity.

Salvadora persica (kharijal) is a large, well-branched, and evergreen shrub or a tree resembling Salvadora oleoides (meethijal) found in the dry and arid regions of India. Chewing sticks have been used for centuries for tooth cleaning, and are recommended by the World Health Organization in areas where their use is customary. Salvadora persica has enormous reported activities. It has potential medicinal and research activities. Salvadora persica is a promising product and is useful to produce antiplaque, analgesic, anticonvulsant, antibacterial, antimycotic, cytotoxic, antifertility, deobstruent, carminative, diuretic, astringent, and also used in biliousness, and rheumatism. This review highlights the pharmacologic effects and therapeutic effects of Salvadora persica. The chemical constituents present in different parts of the plant are also discussed.

Diabetes mellitus is a chronic metabolic disorder characterized by hyperglycaemia and other symptoms like polyuria (frequent urination), polydipsia (increased thirst) and polyphagia (increased hunger) which ultimately causes various other complications like retinopathy, neuropathy, nephropathy and microangiopathy. The antidiabetic and antihyperlipidemic potential of oil from Piper longum (PLO) and piperine was investigated with their possible mechanism using α-glucosidase, aldose reductase (AR), and pancreatic lipase inhibitory activity. The biochemical parameters, viz. glucose level, insulin level, liver glycogen content, glycosylated hemoglobin, total plasma cholesterol, triglyceride, and antioxidant parameters, were estimated for all treated groups in acute and chronic antihyperglycemic animal models. PLO (100 and 200 mg/kg), piperine (25 and 50 mg/kg), and glibenclamide (0.6 mg/kg) in respective groups of diabetic animals administered for 28 days reduced the blood glucose level in streptozotocin-induced diabetic rats. There was significant increase in body weight, liver glycogen content, plasma insulin, and high-density lipoprotein and decrease in glycosylated hemoglobin, triglyceride, and total plasma cholesterol in PLO-administered groups as compared to control group. The IC50 value of PLO for α-glucosidase, AR, and pancreatic lipase was found to be 150 ± 2.5, 120 ± 1.2, and 175 ± 1.2 μg/ml, respectively, which was found comparable with the standard drugs acarbose (90 ± 2.3 μg/ml), quercetin (80 ± 2.3 μg/ml), and orlistat (25 ± 0.5 μg/ml), respectively. The investigation done reveals that PLO has significant antidiabetic and antihyperlipidemic activity.