Anacardium occidentale nut shell liquid which is mostly known as cashew nut shell liquid has been used for decades especially by natives of South America, Asia and Africa in the treatment of topical skin diseases, skin abrasion and cancerous ulcers amongst others. Some previous studies attempted to link pharmacological activities to the antibacterial, antioxidant and anti-proliferative properties of CNSL. Chronic exposure to sunlight can lead to skin damages including erythema, edema, hyperplasia, formation of sunburn cells, photoaging, suppression of the immune system and skin cancer. This study was aimed at evaluating the effect of methanol extract of Anacardium occidentale nut shell liquid on UV induced skin damage and cancer initiation.Gas chromatography and mass spectroscopic analysis was carried out on the extract. Skin damage was induced by exposing the hairless part of the experimental animals (albino rats) directly to UVR for 42 days alongside treatment with methanol extract of cashew nut shell following the experimental design. Percentage weight gain, relative organ weight, lipid peroxidation and histological studies were carried out to evaluate the impact of the UVR exposure and the chemopreventive effect of the extract. The methanol extract of CNS as determined by GC-MS analysis contains 1,2,3-Benzenetriol and benzofuran. A normal skin tissue and hepatocyte was observed in the normal control, severe wrinkling of skin epithelium with actinic keratosis of the dermal collagen and marked venous congestion in the liver of the negative control and complete recovery in the group treated with 300mg/kg of the extract was observed. Marked serboheic keratosis and venous congestion in the liver was seen in the untreated groups. This study suggest that the administration of methanol extract of CNS exhibited a chemopreventive effect against skin damage which could lead to cancer initiation stage resulting from ultraviolet radiation by preventing its detrimental impact on the epidermis which could in turn lead to DNA damage and subsequently skin cancer initiation. 1,2,3-Benzenetriol and benzofuran which according to previous studies, exhibits anticancer, antioxidant and antibacterial activity were present in the extract, these compounds amongst others are believed to be responsible for the pharmacological activities observed in the study.
Keywords: Anacardium occidentale (Cashew), Bioactive Compounds, Skin Damage and Ultra-violet Radiation