<p>Induction of Autophagy by Baicalin Through the AMPK-mTOR Pathway Protects Human Skin Fibroblasts from Ultraviolet B Radiation-Induced Apoptosis</p>

Abstract

These authors contributed equally to this work Background: Baicalin, a natural product isolated from Scutellaria radix, has been reported to exert anti-oxidant and anti-apoptotic effects on skin, but the underlying mechanism remains poorly understood. This study aimed to investigate the possible mechanism of anti-UVB effect of baicalin in human skin fibroblasts. Methods: Cell proliferation was estimated by CCK-8 Kit. Apoptotic incidence was detected by flow cytometry with Annexin V-PE/PI apoptosis detection kit. Autophagy was determined by the evaluation of fluorescent LC3 puncta and Western blotting. Cell signalling was analysed by Western blotting. Results: Baicalin exerted cytoprotective effects in UVB-induced HSFs. Moreover, baicalin increased autophagy and suppressed UVB-induced apoptosis of HSFs. Pretreatment with 3-MA, an autophagy inhibitor, attenuated baicalin-induced HSFs autophagy and promoted apoptosis. Baicalin activated AMPK, which leads to suppression of basal mTOR activity in cultured HSFs. Administration of compound C, an AMPK inhibitor, abrogated AMPK phosphorylation and increased mTOR phosphorylation and apoptosis compared with baicalin alone. Conclusion: Taken together, these results indicate the important role of mTOR inhibition in UVB protection by baicalin and provide a new target and strategy for better prevention of UV-induced skin disorders.

Baicalin improves the functions of granulosa cells and the ovary in aged mice through the mTOR signaling pathway

“…The study of HK-2 proximal tubule epithelial cells from the human renal cortex found that Baicalin pretreatments could activate the downstream Nrf2 pathway to inhibit the cytotoxic effects of hydrogen peroxide on HK-2 [ 41 ]. It was reported that the mTOR pathway played an important role in follicular development, and that Baicalin could regulate the mTOR signaling pathway of human skin fibroblasts and lung cancer cells [ 42 ]. Our results showed that Baicalin treatments could affect the mTOR pathway, and its activation or inhibition could affect the actions of Baicalin on the granulosa cells.…”

HSP27 Protects Skin From Ultraviolet B -Induced Photodamage by Regulating Autophagy and Reactive Oxygen Species Production

“…Although the specific mechanism is unclear, existing research shows that in terms of either keratinocytes or fibroblasts, UVB exposure can cause autophagy changes in either keratinocytes or fibroblasts ( Chen et al, 2018 ; J. A.; Zhang et al, 2020 ). Inhibited autophagy may accelerate cell aging, and activated autophagy may have powerful anti-aging effect (J.…”

Natural Baicalein-Rich Fraction as Radiosensitizer in Combination with Bismuth Oxide Nanoparticles and Cisplatin for Clinical Radiotherapy

“… 84 The stability of the Sestrins (SESN)-2 gene after irradiation stimulated AMPK signaling in MCF-7 cells, and it was initiated in dermal fibroblast cells following baicalin treatment. 85 , 86 However, following irradiation, AMPK expression in MDA-MB-231 cells had various effects, including inhibiting apoptosis, inducing G1 cell cycle arrest, and promoting cell growth. 87 , 88 The contradicting effects of AMPK pathways in different cell lines might be the causal mechanisms that occurred during electron irradiation at 6 MeV in the MCF-7, MDA-MB-231, and NIH/3T3 cells.…”