Organic solvent and hot water extracts of freshwater macroalgae, Cladophora
glomerata and Microspora floccosa, harvested from Nan River in northern Thailand
were screened for antioxidant and anticancer activities using DPPH free radical
scavenging assay and inhibition of proliferation of the KB human oral cancer cell lines
respectively. The ethyl acetate extract of C. glomerata showed the highest total phenol
content (18.1±2.3 mg GAE/g), radical scavenging activity (49.8±2.7% DPPH scavenging
at 100 g/ml) and in vitro growth inhibition (IC50=1420.0±66 g/g) of the KB cell lines.
These results indicate that C. glomerata could be a source of valuable bioactive
materials.