2012 Volume 18 Issue 3 Pages 461-465
Lotus plant (Nelumbo nucifera Gaertn) is well known for its therapeutic effects despite its ability to accumulate heavy metals. This study evaluates antioxidant properties and heavy metal content of seed, stem and rhizome of lotus that grown in ex-tin mining pond. Total phenolic content, DPPH-radical scavenging activity and tyrosinase inhibition activity were determined on methanol extracts. Contents of ash, lead and chromium were determined on dried, ground samples. The highest concentration of phenolic content, ash, lead and chromium is in the seeds. Tyrosinase inhibition activity is highest in the rhizome and lowest in the stem. Correlation of DPPH-radical scavenging activity is good with tyrosinase inhibition activity (P < 0.01). The concentration of lead found exceeded the permissible limits of Codex Alimentarius. Therefore, assessment of metal contamination should be a mandatory priority to utilization of abandoned ex-tin mining area for edible plant cultivation.
