Resveratrol protects against ultraviolet A-mediated inhibition of the phagocytic function of human retinal pigment epithelial cells via large-conductance calcium-activated potassium channels.
This study was undertaken to examine the protective effect of resveratrol on human retinal pigment epithelial (RPE) cell phagocytosis against ultraviolet irradiation damage. Cultured RPE cells were exposed to ultraviolet A (UVA, 20 minutes) irradiation, and treated with meclofenamic acid (30 microM, 20 minutes), paxilline (100 nM, 20 minutes) or resveratrol (10 microM, 20 minutes). Meclofenamic acid and resveratrol were given after exposure to UVA. Pretreatment with meclofenamic acid, resveratrol or paxilline before UVA irradiation was also performed. Fluorescent latex beads were then fed for 4 hours and the phagocytotic function was assessed by flow cytometry. UVA irradiation inhibited the phagocytic function of human RPE cells. The large-conductance calcium-activated potassium channel activator meclofenamic acid ameliorated the damage caused by UVA irradiation. Pretreatment with resveratrol acid also provided protection against damage caused by UVA. Posttreatment with meclofenamic acid offered mild protection, whereas resveratrol did not. In conclusion, the red wine flavonoid resveratrol ameliorated UVA-mediated inhibition of human RPE phagocytosis. The underlying mechanism might involve the large-conductance calcium-activated potassium channels.
Sheu
Shwu-Jiuan
SJ
Department of Ophthalmology, Kaohsiung Veterans General Hospital, and Yuhing Junior College of Health Care and Management, Kaohsiung, Taiwan. sjsheu@vghks.gov.tw
Wu
Tsung-Tien
TT
D002460:Cell Line; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D051036:Large-Conductance Calcium-Activated Potassium Channels / Q000819:agonists* / Q000378:metabolism*; D008469:Meclofenamic Acid / Q000494:pharmacology; D010587:Phagocytosis / Q000187:drug effects* / Q000528:radiation effects*; D000077185:Resveratrol; D013267:Stilbenes / Q000494:pharmacology*; D014466:Ultraviolet Rays
D004791:Enzyme Inhibitors; D007211:Indoles; D051036:Large-Conductance Calcium-Activated Potassium Channels; D013267:Stilbenes; C048220:paxilline; D008469:Meclofenamic Acid; D000077185:Resveratrol