In vitro and in vivo biological properties of pea pods (Pisum sativum L.)

Pea pods, a food waste by-product, was studied for its chemical composition and evaluated for its in vitro antioxidant, protein denaturating and anti-acetylcholinesterase (anti-AChE) and in vivo antidiabetic, anti-hyperlipidemic and cytoprotective properties in alloxan-induced diabetic mice. The pea pods had 51% fiber, 28.2% carbohydrates, 14.2% crude protein, 4.5% lipids and 4.5% ash which consisted mainly of K, Mg, Ca, Na, Fe, Zn and Cu (in descending order). The fatty acid (FA) profile showed that linoleic, linolenic and palmitic acids were the main components. Although its lipids are highly oxidation susceptible, the lipid fraction showed good nutritional attributes as shown by its low atherogenic, thrombogenic and hypoholestrolemic values. The pea pods methanol extract (PPE) showed very low antioxidant activity but it had a strong inhibitory effect on heat-induced BSA denaturation suggesting its possible anti-inflammatory effects. Oral administration of PPE to diabetic mice decreased serum glucose levels, alanine aminotransferase, aspartate aminotransferase, urea, creatinine, alkaline phosphatase and lactate dehydrogenase activities. It reduced lipid peroxidation, and H2O2 and SH contents, but it significantly (p < 0.05) increased the activities of antioxidant enzymes (CAT, GPX and SOD) in the liver, kidney and testis. Moreover, PPE effectively reduced serum triglycerides, cholesterol and LDL and restored the hepatic, renal and testicular FA profiles suggesting its promising anti-hyperlipidemic effect. Overall, PPE could be useful to help manage diabetes and its associated hyperlipidema, to reduce the risk of oxidative stress and to decrease liver, kidney and testis damage.