Protective effects of tiger milk mushroom extract (xLr®) against UVB irradiation in Caenorhabditis elegans via DAF-16 anti-oxidant regulation

BACKGROUND AND AIM: A critical causative factor of oxidative stress and inflammation leading to several skin complications is ultraviolet-B (UVB) irradiation. Lignosus rhinocerus (LR), or tiger milk mushroom, is native to Southeast Asia. Cold water extract of an LR cultivar, TM02® (xLr®) is a promising anti-oxidant and anti-inflammatory source. However, the effects of xLr® on UVB-induced photoaging have never been elucidated.

EXPERIMENTAL PROCEDURE: This study investigated the protective effects of xLr® and its high, medium, and low molecular weight (HLR, MLR, and LLR, respectively) fractions against UVB irradiation using in vivo Caenorhabditis elegans (C. elegans) model.

RESULTS AND CONCLUSION: The investigation revealed a significant lifespan extension of xLr® and its fractions in UVB-irradiated C. elegans, which could be mediated by the regulation of genes associated with anti-oxidant (daf-16 and sod-3) and apoptosis (cep-1, hus-1, ced-13, and egl-1) pathways. xLr® significantly reduced the ROS production in C. elegans and increased the DAF-16 nuclear translocation compared to untreated worms. Additionally, the SOD-3 expression was increased in the xLr®-treated worms. Hence, it suggests that the different components in xLr® work synergistically to protect against UVB irradiation. Our findings may be beneficial for the application of xLr® as a treatment against UVB-induced cellular damage and photoaging.