Seaweeds are marine macro algae that can be found attach to the bottom shallow coastal waters.
There are three major groups of seaweeds namely brown (Phaeophyta), red (Rhodophyta) and
green (Chlorophyta). One of the edible red seaweeds is Eucheuma cottonii. Red seaweeds have
been found of consisted several potential pharmaceutical uses such as antitumor, antiviral,
anticoagulant and immunomodulation functions. In This study, heavy metals content of E.
cottonii was determined by ICP-OES. Methanol was used as solvent for extraction. The
phenolic content of the extract was determined by Follin-Ciocalteau method and results were
expressed as gallic acid equivalents. The antioxidant activity was determined by DPPH assay.
Besides, anti-tyrosinase activity was investigated tyrosinase and L-DOPA with kojic acid as
positive control. For element test, three elements were detected (Ar, Fe and Zn). The phenolic
contents (3.40±0.013 mg GAE/g extract) and antioxidant activity (38.82±0.99 mg/mL) were
lower compared to other plants but E. cottonii shows a good tyrosinase enzyme inhibition
which achieved average 234.33μg/mL in 50% inhibition tyrosinase concentration (IC50). E.
cottonii could be the potential source of natural anti-tyrosinase.