The evaluation of antioxidant and anti-inflammatory activities of Parmotrema hypotropa lichen extract

Abstract

Lichens are used since antiquity for multiple therapeutic purposes, treating infections, fever, convulsions, and wounds. This study was designed to evaluate the antioxidant and anti-inflammatory effects of the lichen Parmotrema hypotropa (NYL.) Hale. The total phenolics and flavonoids content were determined in ethanol extract; the antioxidant activity was assessed by different chemical assays DPPH (1,1-diphenyl-2-picrylhydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), β-carotene-linoleic acid, reducing power, and Cupric reducing antioxidant capacity (CUPRAC). The lichen extract was further tested in vitro, for its anti-inflammatory effect through the bovine serum albumin denaturation assay; also the inflammatory response was investigated on the LPS-stimulated human keratinocyte cell line (HaCaT) by measuring intercellular ROS (Reactive Oxygen Species) and TNF-α (Tumor necrosis factor-alpha) production; the amount of usnic acid in the extract was determined by High-Performance Liquid Chromatography (HPLC). The results showed that the tested extract contained high levels of total phenolics than flavonoids, and had an antioxidant effect; it prevented the protein denaturation in a dose-dependent manner, also reduced the intracellular ROS and TNF-α production by HaCaT cells. Furthermore, it did not affect the viability of HaCaT cells; the extract contained small amounts of usnic acid. Based on the different findings, P.hypotropa can constitute a potential source of bioactive compounds with antioxidant and anti inflammatory effects.