CHANGES IN SECONDARY METABOLITES PROFILES AND BIOLOGICAL ACTIVITY OF THE FRESH FRUITING BODIES OF Stereum hirsutum EXPOSED TO HIGH-DOSE UV-B RADIATION

Abstract

The present study aims to investigate the effects of ultraviolet radiation (type B) on the steroid and fatty acids content, phenolic compounds and biological activities of Stereum hirsutum wild fruiting bodies, which has been used by both Chinese and Korean folk medicine to treat cancer and recently as functional food. From another perspective, the distribution of steroid derivatives as well as fatty acids underwent significant changes after UV exposure over time. In our model of study UV-B radiation induced a decrease in the relative abundance of ergosterol derivatives while squalene increased. We also detected that UVB radiation (1.2 W m -2 ) enhanced the antioxidant activity of Stereum hirsutum, with the acetonic extract after 48 hours of radiation the most efficient with a half-maximal inhibitory concentration (IC 50 ) of 339.9 μg/mL. Gas-mass chromatography (GC-MS) analysis at this 48 hours stage revealed a high content of phenolic compounds (70%). We observed a decrease in the antibacterial activity against Escherichia coli, Salmonella typhi and Salmonella typhimurium compared to their respective controls. The study concludes that UV-B influences the pathway of secondary metabolites to induce changes metabolic in the composition of sterols and fatty acids and increasing the abundance of antioxidant compounds in S. hirsutum.

Mushroom Species Stereum hirsutum as Natural Source of Phenolics and Fatty Acids as Antioxidants and Acetylcholinesterase Inhibitors

“…[36] In addition, linoleic acid showed strong anti-neuroinflammatory, anti-amyloidogenic, and anti-apoptotic effects, as well as improved neuronal survival and memory deficits in the Aß-infused mouse model. , [37] In comparison, S. hirsutum from Chile showed much lower content of unsaturated linoleic (4.70 %) and oleic acids (1.00 %) [32] than S. hirsutum analyzed in this study (40.00 % and 26.81 %, respectively). Biochemical adaptation of the lipid complex of mushrooms to stressful environmental conditions is based on changing the degree of unsaturation of FA.…”

“…S. rugosum exhibited twice lower content of linoleic acid (19.64 %), [14] while GC analysis of S. hirsutum from Chile exhibited that the major FA was palmitic acid with 7.20 %. [32] In in S. sanguinolentum species 39.14 % of palmitic acid was detected, [14] while in this study the concentration of palmitic acid was 14.13 %. The most abundant FA in S. rugosum was oleic acid with 34.23 %.…”

UV-B Radiations and Secondary Metabolites

“…The accumulation of tannin, salicylate and flavonoids in the leaf, induced by UV-B radiations, was more pronounced in male, as compared with female plants. Exposure to UV-B radiation changed the composition of sterols and fatty acids and increased the abundance of antioxidants in Stereum hirsutum (Torres et al 2016). In a study on aquatic plants such as Alternanthera sessilis (Klein et al, 2018) the highest estimated flavonoid levels were noted UV-B exposure for 8 h, followed by a 24 h recovery period.…”

“…Ultraviolet wavelength (400-200 nm) refers to electromagnetic radiations between visible light and Xrays, with significant influence on the living organisms, including plants (Katerova et al, 2012;Mao et al, 2017). Climate change refers to seasonal variations, defined as increased atmospheric temperatures, carbon dioxide concentrations and intensity of Ultraviolet-B radiations, having significant influences on plants (Teramura et al, 1990;Torres et al, 2016). UV-B (280-315 nm) radiations reach the Earth as a result of stratospheric ozone depletion due to pollutants.…”

Molecular identification of Shiitake [Lentinula edodes Berk (Pegler)] and production of secondary metabolites with biotechnological potential

“…However, little is known about the genetic origin of Colombian Shiitake, genetic diversity, and parent strains, as well as the contents of bioactive compounds of shiitakes cultured under the tropical conditions of Colombia. Since the genetic instability has been frequently observed in edible mushrooms 6 , environmental conditions might generate genetic and/or biochemical changes and differences in the secondary metabolite profile 7 . These could influence the potential of Colombian shiitakes usability in biotechnological processes, considering that the mushroom potential to produce secondary metabolites has been already demonstrated 8 .…”