Abstract

Psoriasis is a chronic inflammatory skin disease with immense physical, biological and psychological implications which puts a person at high risk for developing cancers like lung cancer. The aim of the study was to determine the effectiveness of Nigella sativa seeds as an effective antioxidant that can prevent the proliferation of psoriatic epidermal keratinocytes and lung cancer cells. Quantitative determination of phenols, flavonoids and antioxidant activities were performed using Folin-Ciocalteu colorimetric method, aluminium chloride colorimetric method and hydroxyl radical scavenging assay respectively. In vitro antiproliferative assay against psoriatic epidermal keratinocytes and A549 human lung cancer cell lines were determined using 3-(4,5-dimethylthiazol-2yl)-2,5-biphenyl tetrazolium bromide assay. Nigella sativa seeds were found to possess good amount of phenols and flavonoids. The hydroxyl radical scavenging activity was observed to be 79.15 %±0.29 % at 120 μg/ml. The maximum cytotoxicity on psoriatic keratinocytes was found to be 71.50 %±0.74% at 250 μg/ml and half-maximal inhibitory concentration was calculated to be 31.8 μg/ml. Maximum cytotoxicity on A549 human lung cancer cell lines of 72.22 %±0.80 % was observed at 160 μg/ml and half-maximal inhibitory concentration was calculated to be 71.94 μg/ml. From these observations, it is evident that Nigella sativa seeds have excellent antioxidant, antipsoriatic and anticancer activities. This makes it a promising safe herbal based therapy in the treatment of psoriasis in comparison to commercially available drugs with adverse side effects.