Effects of P1G10 against UVB-induced damage: Reduction of antioxidant stress, inflammation and cell proliferation

Abstract

Background

P1G10 is the proteolytic fraction from Vasconcellea cundinamarcensis latex equivalent to papain from C. papaya. It acts as healing enhancer in diverse wound scenarios. In a preliminary study P1G10 showed promising anti-inflammatory activity in lesions induced by single dose UVB irradiation.

Aim

The present study assesses the impact of P1G10 topically applied on mice lesions induced by multiple UVB doses.

Results

After repeated exposure to 240 mJ cm^-2 UVB, P1G10 decreased by ∼50 % the detected ROS, enhanced glutathione peroxidase (GPx) and catalase activities, thereby protecting against oxidative stress. The anti-inflammatory effect of the fraction was consolidated by reduction in TNF-α (∼70 %) and IL1β (∼90 %) and confirmed by histological analyses showing a reduction in cellularity and leukocyte infiltration into the hypodermis. Additionally, epidermal hyperplasia induced by UVB was reduced as shown by a decrease of PCNA immunolabeling in keratinocytes. Pathways involved in the inflammatory process and in UVB-induced production of free radicals were also affected, revealing that P1G10 application reduced phosphorylation of MAP kinase proteins (JNK and P38) and Akt, as well as MMP-9 activity.

Conclusions

These data confirm the lasting protective action of P1G10 by moderating oxidative stress and apoptosis induced by multiple doses of UV-B in the skin, suggesting a potential preventive action against the onset of carcinogenesis.