Kevin Austin L. Ona¹, Paul Mark B. Medina^2,

Lead commonly contaminates water systems and causes acute and chronic toxicity, and indirectly produces ROS causing oxidative stress, to organisms. In response, organisms produce antioxidant enzymes for protection from oxidative stress, and uptake antioxidants in the environment. Ballatinao black rice is rich in antioxidants, particularly anthocyanins, and this study examined the effect of the Crude Anthocyanin Extract (CAE) of Ballatinao black rice on the acute lead toxicity to Daphnia magna through acute toxicity assays. D. magna were exposed to 10, 15 and 20 ug/mL concentrations of CAE for 24-hours with and without 4.0 mg/L lead nitrate. Number of deaths were recorded each hour for 24 hours. Three additional treatment strategies of the same parameters were also designed. Heartbeat counts in relation to lead toxicity were also measured. A significant increase in D. magna survival (α=.01) was observed when exposed to increasing CAE concentrations both in untreated and lead-treated set-ups. Variations in pre- and post-exposure treatments to CAE and lead were also performed and found to be insignificant. Heartbeat counts during the toxicity assays dropped in the first hour and normalized at 12- and 24-hour time points. The study demonstrated that Ballatinao black rice CAE can reduce the toxic effects of lead exposure to Daphnia magna.

Ballatinao black rice, anthocyanin, acute lead toxicity, daphnia magna, heartbeat count