Inhibitory effects of fruit peel extracts on free radicals and proliferation of lung cancer cells / Nurul Nadiah Saripshah

Fruits contain minerals and vitamins that are important for the body. Fruits are usually peeled off before consuming and the peels are thrown away. Instead of being thrown away, it was used in this study to explore the potential biological ability. In this study, the fruit peels were tested to determine the free radicals scavenging potential using DPPH and nitric oxide scavenging assay as well as anti proliferative on A549 lung cancer cells. Three types of fruit peel namely mangoes, papayas and honeydews were collected and extracted using 95% ethanol. In nitric oxide scavenging assay, gallic acid and quercetin were used as positive control and ultrapure water was used as negative control. Extracts showed potential scavenging activity against nitric oxide as the K'so was 67.93µg/ml. The nitric oxide scavenging activity of extracts (ICso = 67.93µg/ml) was higher than quercetin (ICso = 95.04µg/ml) but lower than gallic acid (ICso = 55.30µg/ml). The extract also showed scavenging activity against DPPH with the ICso equals to l 83.84µg/ml. The DPPH free radical scavenging activity of extract was the highest compared to quercetin (ICso = 267.9lµg/ml) and gallic acid (ICso = 186.06µg/ml). MTT assay was carried out to determinate the anti proliferative activity of the extract. Two types of cell lines were used, which were A549 lung cancer cell and CRL2522 normal skin cell. Quercetin was used as positive control. Extracts show high anti proliferative activity on cancer cells with the average ICso is 57.96µg/m1 ± 36.01 but low on normal skin cells with the average ICso is 108.84µg/ml ± 69.64. Compared to quercetin, extracts have lower activity on cancer cells but higher activity on normal cells. In conclusion, fruit peels extract consists of honeydew, mango and papaya showed potential free radicals scavenging and anti proliferative activity on cancer cells.