Fungal metabolite isolated from Mycosphaerella nawae AM20 and its protective role in cerebral ischemia

Abstract

Usnic acid is one of the important metabolites showed cardiovascular protective properties. The main aim of the study was to analyze antioxidant and cerebral ischemia preventive role in experimental Albino rats. The amount of usnic acid in the Mycosphaerella nawae AM20 culture extract was determined by High Performance Liquid Chromatography. Antioxidant property was evaluated by various methods and usnic acid has potential Fe2+ chelating activity. The influence of usnic acid on special learning and memory was studied in vivo using Albino rats. Morris water maze (MWM) analysis revealed that the experimental ischemic rats treated with usnic acid reached the platform at minimum time than ischemic rats without usnic acid treatment. At 0.1 mL usnic acid concentration, hydroxy-3-methyl-glutaryl-CoA reductase (HMGR) inhibition activity was 18.4 ± 1.1% and it increased as 80.3 ± 2.4% at 0.5 mL concentration in the reaction mixture. Likewise, acetylcholinesterase (ACE) inhibitor activity was observed and was dose dependent. At 0.2 mL concentration, 21.8 ± 1.7% enzyme activities inhibited and it increased as 48.3 ± 1.8% at 0.5 mL sample concentration. Fibrinolytic analysis revealed 13 ± 0 mm zone of clearance at 0.5 mL sample concentration and the standard plasmin showed 17 ± 2 mm zone of clearance. Biochemical analysis revealed that the amount of malondialdehyde (MDA) was higher in the hippocampal region of ischemia group animal (59.4 ± 3.5 μM). Moreover, usnic acid treated ischemia group showed reduced MDA content (29.8 ± 3.5 μM). Superoxide dismutase (SOD) activity was reduced in ischemic albino rat and improved SOD activity was observed in the treated animal.

Keywords

• Fungi
• Metabolites
• Usnic acid
• Cerebral ischemia
• Stroke prevention