Effect of guava (Psidium guajava Linn.) fruit water extract on lipid peroxidation and serum lipid profiles of streptozotocin-nicotinamide induced diabetic rats

The prevalence of diabetes is rapidly increasing and it can cause a wide range of health complications affecting almost every part of the body. The aim of this study was to examine guava fruit ability in reducing blood glucose level and preventing diabetic complication ofstreptozotocin-nicotinamide induced diabetes rat. Guava fruit performance was measured byin vitro lipid peroxidation inhibition, in vivo blood glucose level, in vivo serum lipid profile, and in vivo lipid peroxidation inhibition. This study confirmed that guava fruit extracts can significantly reduce blood sugar in type 2 diabetic rats, plasma triglycerides and low density lipoprotein (LDL) concentrations. Most importantly, guava fruit water extract showed impressive efficacy against in vitro and in vivo lipid peroxidation examinations. These activities may be due to the antioxidants properties offered from phenolic and flavonoid compounds in guava fruit water extract. Guava fruit water extract was found to consist 40.13 mg GAE/g of phenolic content and 18.43 ± 1.22 mg quercetin equivalent/g of flavonoid content.   Key words: Guava fruit, lipid peroxidation, malonaldehyde, serum lipid profile, diabetes mellitus.