Molecular mechanism of polypeptides from Chlamys farreri (PCF)’s anti-apoptotic effect in UVA-exposed HaCaT cells involves HSF1/HSP70, JNK, XO, iNOS and NO/ROS

•HSF1/HSP70 is involved in PCF’s anti-apoptotic effect against UVA-induced apoptosis.•Inhibition of JNK also is involved and is likely mediated via HSF1/HSP70 activation.•Inhibition of iNOS expression is likely part of the mechanism of PCF.•Xanthine oxidase is involved in PCF’s anti-apoptotic effect.•NO/ROS release is altered by PCF treatment and is likely part of the mechanism.