Protective effect of phenolic extracts from two species of miracle berry leaves (Thaumatococcus daniellii and Megaphrynium macrostachyum) on some pro-oxidant induced oxidative stress in rat pancreas in vitro

Abstract

Traditionally, miracle berry leaves are mostly used as food wrappers in order to increase the shelf life of the food. Therefore, this study sought to investigate the antioxidative properties and protective effect of phenolic extracts from two species of miracle berry leaves namely; Thaumatococcus daniellii (Benn) Benth and Megaphrynium macrostachyum (Benth) Milne-Redh on some pro-oxidant induced oxidative stress in rat pancreas in vitro. The phenolic extract was prepared with 80% acetone (v/v); thereafter, ability of the extracts to inhibit some pro-oxidants (FeSO4 and Sodium nitroprusside, SNP) induced lipid peroxidation in rat's pancreas was assessed. Furthermore, antioxidative properties of the phenolic extracts were evaluated. The result revealed that both leaves extracts inhibit Fe2+ and SNP-induced lipid peroxidation on rat's pancreas in a dose dependent manner (0 - 0.5 mg/mL) and also exhibit antioxidant properties as typified by their Fe2+ chelating, DPPH and OH radical scavenging abilities, however, M. macrostachyum leaf had a significantly (P<0.05) higher Fe2+ and SNP-induced lipid peroxidation on rat's pancreas and antioxidant properties than T. daniellii leaf in vitro. The inhibition of Fe2+ and SNP-induced lipid peroxidation in rat's pancreas by both leaves could be attributed to their reducing power, chelating and radical scavenging abilities. Therefore, this antioxidative potential of both M. macrostachyum and T. daniellii leaves clearly gives us an insight that they could be used to prevent degenerative disease associated with oxidative stress. Hence, this antioxidant effect could be some possible mechanism by which they are used as food wrappers in order to increase the shelf life of food.