Anticancer and antioxidant effects of selected Sri Lankan marine algae

Abstract

For the investigation of bioactive components
from Sri Lankan seaweeds, three species of red algae
(Chondrophycus ceylanicus, Gelidiella acerosa, Gracilaria
corticata), two species of green algae (Chaetomorpha
crassa, Caulerpa racemosa) and one species of brown algae
(Sargassum cassifolium) were evaluated. For the bioactivity
evaluations, total phenol content (TPC), free radical scavenging
activity using electron spin resonance (ESR) spectroscopy and
anticancer activity against different cancer cell lines including
a human promyelocytic leukemia (HL-60), a human lung
carcinoma (A549) and a mouse melanoma (B16F10) were
assessed in vitro. Among the extracts, C. racemosa showed
significantly higher radical scavenging activity against DPPH
(34.34 %), alkyl (85.17 %) and hydroxyl radicals (81.16 %),
respectively. The MTT assay confirmed that all the extracts
were not cytotoxic at 50 and 100 µg/mL concentrations against
vero cells in vitro. In addition, a significant cancer cell growth
inhibitory effect (IC50 value 30.17 µg/mL) was observed by
C. racemosa methanol extract against HL-60 cells and it was
the highest anticancer effect compared to the other extracts.
Apoptotic body formation in HL-60 cells and the accumulation
of DNA in sub-G1 phase were determined by C. racemosa
extract in a dose-dependent manner. This study is the first report
of Sri Lankan seaweeds with the potential of pharmacological
effects including antioxidant and anticancer activity in vitro.