Antioxidant and nitric oxide synthase activation properties of water soluble polysaccharides from Pleurotus florida

Abstract

Context: Cellular damage caused by reactive oxygen species has been implicated in several diseases, and, at the same time, nitric oxide is recognized as an important messenger molecule for several pathophysiological conditions. Hence, a novel antioxidant and nitric oxide synthase (NOS) activator from natural sources have significant importance in human health. Aims: The present study was conducted to evaluate the free radical‑scavenging activity and NOS activation properties of water‑soluble crude polysaccharide (Floridan) from Pleurotus florida. Materials and Methods: Crude polysaccharide was precipitated from hot water extract of P. florida, and their physicochemical parameters were determined. Then, α and β glucan were estimated using mushroom and yeast β glucan assay kit and Fourier transform infrared spectroscopy (FT‑IR). Floridan was analyzed for their free radical scavenging activity in different test systems, namely hydroxyl and superoxide radical scavenging activity, ferrous ion chelating ability, determination of reducing power and inhibition of lipid peroxidation. Floridan was also tested for NOS activation using oxyhaemoglobin method. Statistical Analysis: The results were statistically analyzed using the Student’s t‑test. Results: Results showed that Floridan was rich in water‑soluble β glucan with very low amount of protein and phenols. The EC50 for hydroxyl and superoxide radical‑scavenging activity were 140 and 320 μg/ml, respectively, 450 μg/ml for chelating ability, 300 μg/ml for inhibition of lipid peroxidation and 2 mg/ml for reducing power. Floridan also increased nitric oxide production significantly. Conclusions: The present results revealed that this mushroom polysaccharide may be utilized as a promising dietary supplement to combat several killer diseases. Key words: Mushroom, nitric oxide, physicochemical parameters, polysaccharide, reactive oxygen species