Biochemical studies on palm date seeds (Phoenix dactylifera L.) in a diabetic rat model

Abstract

Phoenix dactylifera L. seed is popularly used in Egypt for treating diabetes mellitus (DM). The antidiabetic activity of aqueous methanolic extracts of two cultivars of P. dactylifera namely Sammany (PDSE) and Hayany (PDHE) was investigated in streptozotocin (STZ)-induced DM in male albino rats. Studies were also conducted to determine the phytochemical composition of the seeds of the two cultivars.The PDSE and PDHEat doses 70, 140 and 280 mg/kg b.w. and gliclazide (10 mg/kg b.w.) were given for 14 consecutive days after a single administration of STZ (52.5 mg/kg, i.p.). Twenty four hours after the last given dose, blood samples were collected as well ashepatic and pancreatic tissues were isolated. Sera were used to determine some metabolic and oxidative stress biomarkers. Serum levels of glucose, total cholesterol (TC), triglycerides (TG), α-amylase and C-Peptide were measured for metabolic assessment while serum levels of malondialdehyde (MDA), reduced glutathione (GSH) and total antioxidant capacity (TAC) were measured for oxidative stress biomarkers assessment. In addition, histopathological examination of the hepatic and pancreatic tissues was performed. Phytochemical investigation on theseeds ofthe two studied cultivars resulted in identification of 25 different phenolic compounds. Also, the fatty acid analysis revealed that oleic acid was the most abundant unsaturated fatty acid; sugar analysis recognized glucose and arabinose as the major sugars for Sammany and Hayany cultivars, respectively. Elemental analysis revealed that sodium and potassium were the major elements for Sammany and Hayany cultivars, respectively. A dose of 280 mg/kg b.w. of PDSE and PDHE showed a marked reduction in serum glucose level by about 55.4% and 56% of STZ-induced group, respectively. Also, PDSE and PDHE succeeded to decrease serum TC, TG, α-amylase and MDA levels in a dose dependent manner, while the serum levels of C-Peptide, TAC and GSH were significantly elevated. From the histopathological studies, PDSE and PDHE showed a beneficial effect against diabetic complications that appeared in hepatic lobules and pancreatic islets. In conclusion, theobtained results in this study support the popular use of the seeds of Sammany and Hayany cultivars ofP. dactylifera in the treatment of DM.