Tiger's Milk Medicinal Mushroom, Lignosus rhinocerotis (Agaricomycetes) Sclerotium Inhibits Nitric Oxide Production in LPS-Stimulated BV2 Microglia

Abstract

In Malaysia and China, the sclerotium of Lignosus rhinocerotis is used by local communities and traditional medicine practitioners as a general tonic and remedy to treat a variety of ailments, including inflammation-associated disorders. In this study, 10 samples from different preparations of L. rhinocerotis sclerotium, including a hot aqueous extract (HAE), an ethanol extract (EE), fractions from the HAE and EE, and crude polysaccharides, were tested for their in vitro cytotoxic and nitric oxide (NO) inhibitory activities in lipopolysaccharide (LPS)--stimulated BV2 microglia. Of the 10 samples tested, HAE was the least cytotoxic toward BV2 microglia, with a half-maximal inhibitory concentration of 176.23 ± 2.64 mg/mL at 24 hours of incubation and 20.01 ± 1.69 mg/ mL at 48 hours of incubation. The inhibition of NO production was explored by pretreatment of BV2 microglia with samples at 2 incubation time points (4 and 24 hours) before the stimulation by LPS for 24 hours. After 24 hours of pretreatment, 8 of the 10 samples inhibited NO production by 50% or more, and cytotoxic effects were not observed. Among the 8 active samples, 500 µg/mL of HAE, 250 µg/mL of an n-butanol fraction of the HAE, and 250 µg/mL of an ethyl acetate fraction of HAE showed maximum inhibition of NO production by 88.95%, 86.50%, and 85.93%, respectively. These results suggest that the L. rhinocerotis sclerotium may contain secondary metabolites that have the potential to inhibit NO production.

A Status Review of the Bioactive Activities of Tiger Milk Mushroom Lignosus rhinocerotis (Cooke) Ryvarden

“…Treatment with linoleic acid significantly suppressed iNOS and COX2 expression by 1.2-fold as compared to the control. In another study, LPS-induced BV2 cells pretreated with hot aqueous extract (500 μg/mL), n-butanol fraction of hot aqueous extract (250 μg/mL), and ethyl acetate fraction of hot aqueous extract (250 μg/mL), showed maximum inhibition of NO production by 88.95, 86.50, and 85.93%, respectively (Seow et al, 2017 ). These studies represent the first evidence of anti-inflammatory properties of L. rhinocerotis using brain microglial BV2 cells.…”

Neuroprotective effects of a novel peptide from Lignosus rhinocerotis against 6‐hydroxydopamine‐induced apoptosis in PC12 cells by inhibiting NF‐κB activation

“…In contrast to the mushroom polysaccharide (which can be extracted using a standard approach), the extraction of mushroom peptides requires further investigation. Polysaccharides are one of the most representative fungal active substances from L. rhinocerotis , which have been proven by many researchers to have antioxidant, antitumor, anti‐inflammatory, and immune‐enhancing activities (Keong et al, 2016 ; Lee et al, 2014 ; Seow et al, 2017 ). However, in this study, we have isolated a novel peptide, LRP, and it was shown to contain no polysaccharides as determined by the phenol–sulfuric acid method.…”

Mushroom nutriceuticals in Malaysia

“…The freeze-dried cultivated sclerotium marketed as Ligno TM02 ® by Ligno Biotech Sdn Bhd, were reported to elicit immunomodulation, neuritogenesis 3 and antineuroinflammatory effects. 4 Ganoderma lucidum, also known by the Japanese name Reishi and Chinese name Ling zhi, is the most revered mushroom in Traditional Chinese Medicine documented in Shen Nong Ben Cao Jing. Ling zhi is consumed in the form of concoctions by Asian populations for promoting health and longevity.…”