Rhodiola crenulata Attenuates γ-Ray Induced Cellular Injury via Modulation of Oxidative Stress in Human Skin Cells.

Skin injury is a major complication during radiation therapy and is associated with oxidative damage to skin cells. An effective and safe radioprotectant to prevent this skin damage is still unavailable. The Rhodiola crenulata root extract (RCE) has been reported to be a free radical scavenger and a potent anti-oxidant in both in vitro and in vivo models. In the current study, we investigated the effects of RCE on ionizing radiation-induced skin injury and its underlying mechanisms. HaCaT cells - a non-cancerous skin cell line together with HepG2, Caco2, A549, and OECM cancer cell lines - were pre-treated with RCE for 24[Formula: see text]h followed by exposure to 15 Gy using Caesium-137 as a γ-ray source. The cell viability was measured. In HaCaT cells, oxidative stress markers, cellular apoptosis pathways, matrix metalloproteinases (MMPs), and pro-inflammatory cytokine gene expression were studied. We found that RCE significantly protected HaCaT cells, but not cancer cells from the loss of viability induced by exposure to ionizing radiation. RCE attenuated radiation-induced oxidative stress markers, cell apoptosis, MMP levels, and expression of cytokine genes. RCE also limited the induction of p53 and p21 by radiation exposure. These findings indicate that RCE may selectively protect the skin cells from ionizing radiation without altering its ability to kill cancer cells. Therefore, we suggest that RCE or its derivatives could serve as a novel radioprotective therapy.