In vitro and in vivo antioxidant properties of Phyllanthus muellerianus and its major constituent, geraniin

Abstract

Objective: Phyllanthus muellerianus (Kuntze) Exell. of the family Euphorbiaceae, is used as a wound healing agent in Ghana and other West African countries. Oxidative stress has been identified to delay wound healing process and subsequently leads to the development of chronic wounds. Hence, the aim of the present study was to investigate the in vivo and in vitro antioxidant properties of aqueous extract of the aerial parts of P.muellerianus (PLE) and its major constituent, geraniin. Methods: Wound tissues excised from rats treated with PLE (0.25, 0.5 and 1% w/w) and geraniin (0.1, 0.2 and 0.4 % w/w) incorporated in aqueous creams were assayed for the levels of superoxide dismutase (SOD), catalase (CAT), myeloperoxidase (MPO), ascorbate peroxidase (APx) and malondialdehyde (MDA). 1,1-diphenyl-2-picryl-hydrazyl (DPPH), ferric reducing antioxidant power, total phenolic content and total antioxidant capacity assays were used to measure in vitro antioxidant activity. Results: SOD, CAT and APx activity increased significantly in both PLE and geraniin-treated wound tissues compared to the untreated tissues. However, MPO activity decreased significantly in all three PLE and 0.2 and 0.4% w/w geraniin-treated wound tissues compared to the untreated tissues. MDA levels decreased significantly in all of the PLE and geraniin-treated wound tissues compared to the untreated tissues. Ferric reducing antioxidant power (FRAP) was observed to be significantly lower for PLE than geraniin.