RESUMO
BACKGROUND: The skin provides a predominant barrier against chemical, physical and microbial incursion. The intemperate exposure to ultraviolet A (UVA) radiation can cause excessive cellular oxidative stress, leading to skin damage, proteins damage and mitochondrial dysfunction. There is sufficient evidences supporting the proposal that mitochondria is highly implicated in skin photo-damage. METHODS: In the present study, a polysaccharide isolated from Astragalus membranaceus was further purified to be an α-glucan, which was further investigated its beneficial influence on UVA-induced photo-damage in HaCaT cells. RESULTS: Our results showed that the purified Astragalus membranaceus polysaccharide (AP) can protect HaCaT cells from UVA-induced photo-damage through reducing UVA-induced intracellular ROS production and mitochondrial membrane potential, thereby altering ATP content. It was found that the UVA induced damage in HaCaT cells could be effectively restored by co-treatment with AP. CONCLUSIONS: AP exhibited promising potential for advanced application as multifunctional skin care products and drugs.
Assuntos
Astragalus propinquus/química , Queratinócitos/efeitos dos fármacos , Queratinócitos/efeitos da radiação , Polissacarídeos/farmacologia , Protetores contra Radiação/farmacologia , Raios Ultravioleta/efeitos adversos , Trifosfato de Adenosina/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Queratinócitos/citologia , Queratinócitos/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Polissacarídeos/química , Protetores contra Radiação/química , Espécies Reativas de Oxigênio/metabolismoRESUMO
UVA radiation from the sun is the main external stimulus in the pathogenesis of skin photo-aging. This process is associated with cellular oxidative stress. Here we aim at showing the protective effect of d-Tetramannuronic Acid Tetrasodium Salt (M4), a natural product, against UVA (30J/cm2) irradiation-induced oxidative stress and photo-aging in HaCaT cells, and to reveal the molecular mechanism underlying the protective efficacy. M4 pretreatment significantly increased HaCaT cell viability and MMP, suppressing UVA-induced ROS generation. Moreover, M4 treatment prevented the UVA-induced photo-aging of HaCaT cells (the reduction of cell viability, mitochondria dysfunction, and SIRT1/pGC-1α deregulation). Notably, the anti-photo-aging potential of M4 was directly associated with the increased expression of MMP and SIRT1, which was followed by the up-regulation of pGC-1α, D-LOOP, and Mt-TFA, and the transcriptional activation of NRF1/NRF2. Therefore, M4 is useful for the protection of skin cells from UVA-induced photo-aging.
Assuntos
Ácidos Hexurônicos/farmacologia , Substâncias Protetoras/farmacologia , Envelhecimento da Pele/efeitos dos fármacos , Envelhecimento da Pele/efeitos da radiação , Raios Ultravioleta/efeitos adversos , Trifosfato de Adenosina/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Expressão Gênica , Células HaCaT , Ácidos Hexurônicos/química , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Queratinócitos/efeitos da radiação , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos da radiação , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/efeitos da radiação , Modelos Moleculares , Conformação Molecular , NAD/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/química , RNA Mensageiro , Espécies Reativas de Oxigênio , Sirtuína 1/química , Sirtuína 1/metabolismo , Relação Estrutura-AtividadeRESUMO
This study aimed to show the α-L-Hexaguluroic acid hexasodium salt (G6) protective effect against UVA-induced photoaging of human keratinocyte cells. We found that G6 localized to the mitochondria and improved mitochondrial functions. G6 increased respiratory chain complex activities, which led to increased cellular ATP content and NAD+/NADH ratio. Thus, G6 alleviated the oxidative stress state in UVA-irradiated cells. Moreover, G6 can regulate the SIRT1/pGC-1α pathway, which enhanced the cells' viability and mitochondria energy metabolism. Notably, the anti-photoaging potential of G6 was directly associated with the increased level of MMP and SIRT1, which was followed by the upregulation of pGC-1α, D-LOOP, and Mt-TFA, and with the transcriptional activation of NRF1/NRF2. Taking all of the results together, we conclude that G6 could protect HaCaT cells from UVA-induced photo-aging via the regulation of mitochondria energy metabolism and its downstream signaling pathways.
