Effect of Plant Extracts on Innate Immunity of Skin Cells: Investigations on Human Keratinocyte Cell Lines

Stresses caused by many factors including pathogenic bacteria result in inflamatory diseases and they are considered as a major source of skin cancers and premature ageing. Plants growing in semi-arid environments and deserts present the astonishing capacity to survive extreme conditions of drought and high temperatures. The objective of this study is to investigate the effects of extracts from two endemic plants from Saudi Arabia, namly C. myrrha and Rhamnus frangula, on the immune response of human keratinocyte cell lines (HaCaT). Our major findings are i) the extracts from both plants exhibit a significant anti-oxidant activity. The concentrations used are below the limit value of toxicity. ii) These extracts stimulate the innate immune response in HaCaT cells and iii) treatments with these extracts are not harmful to the natural cutaneous microflora. Together these findings are highly promising with regards to skin protection. It was in this work investigate the impact of plant extracts on the immune response of human keratinocyte cell lines (HaCaT). In this study, the elicitor activity of the extracts obtained from two endemic plants Arabia C. myrrha and R. frangula was evaluated. These plants were collected and provided by Dr. Samiah Hamad Al-Mijalli from (Saudia Arabia). The antioxidant activity of C. myrrha and R. frangula extracts was assessed for its ability to scavenge free radicals and to protect human keratinocytes from oxidative stress. Furthermore, the impact of such treatment was evaluated on both HaCaT cell viability and on the growth/proliferation of the natural cutaneaous microbiota.