Antimicrobial, antioxidant, anticancer property and chemical composition of different parts (corm, stem and leave) of Colocasia esculenta extract

Abstract

This study was carried out to reveal antimicrobial, antioxidant and anti-cancer activities of extracts from different parts of Colocasia esculenta namely the corm, stem and leaf. The chemical composition of each part of C. esculenta was also characterized. Antimicrobial property of C. esculenta extracts against Aeromonas hydrophila, Escherichia coli, Edwardsiella tarda, Flavobacterium sp., Klebsiella sp., Salmonella sp., Vibrio alginolyticus, V. parahaemolyticus, V. cholerae and Pseudomonas aeruginosa was revealed by using broth micro-dilution method whereas antioxidant activity of the plant extracts was characterized by using α, α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging method. Anticancer activity of the extracts was determined with Colorimetric MTT (tetrazolium) assay against human breast adenocarcinoma (MCF-7). Compounds of the plant extracts were screened and identified by using gas chromatography - mass spectrometry (GC-MS). The minimum inhibitory concentration (MIC) values of different parts of C. esculenta extracts ranged from 7.81 to 500 mg/l against the tested bacteria. In terms of antioxidant activity, the inhibition concentration of stem extract of C. esculenta against 50% of DPPH (IC₅₀) was 0.125 ppt whereas IC₅₀ of C. esculenta leaf extract was 0.28 ppt and the IC₅₀ of corm extract was 4.8 ppt. At the concentration of 20 µg/ml and onward, root extract of C. esculenta was found to inhibit 30% of cancer cell growth whereas stem extract of C. esculenta at 30 µg/ml can inhibit 30% of cancer cell growth. On the other hand, no anticancer activity was found in the leaf extract of C. esculenta. A total of 6 compounds were identified in the C. esculenta corm extract with the 8 major compounds, 11-Octadecadienoic acid, methyl ester (54.62%) and Hexadecanoic acid, methyl ester (20.55%) whereas, 12 compounds were successfully identified in C. esculenta stem extract in which Acetic acid 24.70% was the major compound. Eight compounds were identified in the extract of C. esculenta leaf in which Cyclohexanol, 5-methyl-2-(1-methylethyl)-, [1S-(1 α., 2 β, 5 β)]- (54.73%) was the major compound. This study revealed that the potential of C. esculenta to be used as medicinal drug is promising.