Effect of UV-C radiation on chemical profile and pharmaceutical application in vitro of Aloe vera oil.

The uncontrolled exposure to ultra violet (UV) radiation have many adverse impacts on human health. UV could be divided into three main classes according to wave length range where UV-C (200-280) is one of these classes. Aloe vera oil is a common product in markets with many cosmetic and medicinal applications. The purpose of this investigation is to expose the oil to UV-C at a dose of 17.0 mJ/cm² (254 nm) for 0, 30, and 60 min to examine the impact of change of exposure periods on the alteration in chemical composition of Aloe vera oil as well as its various biological activities. GC-MS examination of various oil forms reveled the proportional elevation in the number of compounds in the oil with increasing time of exposure to UV-C where linoleic acid ethyl ester and ethyl oleate were the most common compounds in oil forms with emergence of trace molecules and their derivatives from various chemical classes especially in the exposed oil to radiation especially after 60 min. The antimicrobial action towards Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumonia, and Salmonella typhi) and fungi (Aspergillus niger and Candida albicans) reflecting the successive to boost the activity versus examined microbes except for A. niger with inhibition zones ranged from 16 ± 1 to 24 ± 1mm, 18 ± 1 to 25 ± 1mm, and 22 ± 1 to 26 ± 1 mm using unexposed A. vera oil, exposed A. vera oil to UV for 30, and 60 min, respectively against tested microorganisms. Moreover, exposure to radiation at various time points resulted in substantial reduction of minimal inhibitory concentration (MIC) as well as minimal bactericidal concentration (MBC) for the applied oil forms. For instance the MIC values were 62.5 ± 0.1, 31.25 ± 0.1, and 15.62 ± 0.1 µg/ml for S. aureus, 125 ± 0.2, 62.5 ± 0.2, and 31.25 ± 0.2 µg/ml for B. subtilis, moreover MBC values were 125 ± 0.1, 125 ± 0.2, and 31.25 ± 0.3 µg/ml for S. aureus, 250 ± 0.3, 125 ± 0.2, and 31.25 ± 0.3 µg/ml for B. subtilis using unexposed A. vera oil, exposed A. vera oil to UV for 30, and 60 min, respectively. There is a notable improvement of anti-biofilm action of examined oil especially upon using 25% of MBC. Furthermore, antioxidant, anti-inflammatory, anticancer, and wound healing capabilities of the tested oils dramatically raised with increase time of exposure. Future studies are required to detect the maximal beneficial gain upon exposure to various natural oils UV-C.