Effect of Thai banana (Musa AA group) in reducing accumulation of oxidation end products in UVB-irradiated mouse skin

Scope: Chronic UVB exposure causes skin disorders and cancer through DNA strand breaks and oxidation of numerous functional groups of proteins and lipids in the skin. In this study, we investigated the effects of Thai banana (Musa AA group, "Khai," and Musa ABB group, "Namwa") on the prevention of UVB-induced skin damage when fed to male ICR mice. Methods and Results: Mice were orally fed banana (Khai or Namwa) fruit pulps at dose of 1 mg/g body weight/day for 12 weeks. The shaved backs of the mice were irradiated with UVB for 12 weeks. The intensity dose of UVBexposure was increased from 54 mJ/cm(2)/exposure at week 1 to 126 mJ/cm(2)/exposure at week 12. A significant increase in skin thickness, lipid peroxidation, protein oxidation end products, and expression of MMP-1 was observed in UVB-irradiated mouse skin. A reduction in the accumulation of oxidation end products was found in the skin of UVB-irradiated mice receiving Khai. This occurred in conjunction with a reduction in MMP-1 expression, inhibition of epidermal thickening, and induction of gamma-GCS expression. Conclusion: The dietary intake of Khai prevented skin damage from chronic UVB exposure by increased gamma-GCS expression and reduced oxidation end products included carbonyls, malondialdehyde and 4-hydroxynonenal. (C) 2017 Elsevier B.V. All rights reserved.