In-vitro Cytotoxicity, Anti-bacterial and Anti-inflammatory Activities of Ecklonia radiata and Jania verrucosa from Eastern Cape, South Africa

Abstract

Seaweeds are marine floras constituting in part to over 90% of the oceanic biomass. Despite the enrichments of seaweeds, their potentials are largely unexplored. Hence, this study evaluated the phytochemical screening, antimicrobial, anti-inflammatory and cytotoxicity activities of methanolic extracts of Ecklonia radiata and Jania verrucosa. E. radiata and J. verrucosa were collected from sites on the rocky shores of the Mbashe and Port St. John rivers on the Eastern Cape coast of South Africa during spring low tides. Qualitative phytochemical screening was carried out using standard protocol. The assessment of anti-inflammatory activity was done by inhibition of albumin denaturation assay and antimicrobial analysis was performed against six different pathogenic clinical isolates. The cytotoxicity effect of the methanolic extracts were further investigated on MDA-MB-231, HepG2, CaCo-2 and KMST-6 by (3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium reduction assay (MTT assay). Phytochemical analysis revealed the presence of tannins, phenols, glycosides, and alkaloid for both extracts. The methanolic extracts of both seed weeds also possess anti-inflammatory activity by inhibiting albumin denaturation. The average minimum inhibitory concentration (MIC) values of the plantextracts ranged from 160-10000 µg/mL. J. verrucosa methanolic extract had the most significant biological activity with the lowest MIC value (160 µg/ml). The cytotoxicity result showed that cells treated with the methanolic extracts of E. radiata and J. verrucosa have more cytotoxicity effect on MDA-MB-231 treated cells followed by HepG2 and CaCo-2. Non-cancerous cell line (KMST-6) however showed some selectivity in their activities. Among the cancer cell lines, HepG2 treated cells were significantly suppressed (p < 0.05) with both extracts compared to 5µM camptothecin (standard drug). In conclusion, E. radiata and J. verrucosa have potential for chemoprevention of human breast, good anti-inflammatory and antibacterial activities.