Monitoring the Nanocurcumin Effect on Lead Exposure in the Huh7-1x-ARE-luc Cell Line

The human genome consists of protective genes, which contain a sequence known as the antioxidant responsive element (ARE) located in their promoter regions. ARE is specific to the transcription factor NF-E2 related factor2 (Nrf2). This signaling pathway is the major defense mechanism against oxidative stress that comprises the chemoprotective response. The cell line that expresses the ARE reporter is sensitive for the detection of ARE activating compounds. It can help to identify toxicity risk and antioxidant activity of chemicals and drugs.
We used a stable Huh7 ARE-reporter cell line in this study. Metabolic activity of these cells in different concentrations of lead (0 to 80 micromole) was evaluated by the MTT test. We assessed the effects of oxidative stress. We exposed the Huh7 ARE-reporter cell line to different concentrations of lead, an oxidative stress inducer, and nanocurcumin, an antioxidant compound, after which we investivated luciferase activity. Real-time PCR was used to detected AREKEAP1 pathway gene expression.
Lead, at 30 μM, suppressed 50% of the cells’ metabolic activity.Cells treated with both lead (30 μM) and nanocurcumin at 4 μM and 8 μM had decreased luciferase activity compared to those treated with only lead. This activity increased when we increased the nanocurcumin concentration to 16 μM. Real-time PCR analysis showed decreased NQO1 and NRF2 expressions in cells treated with both lead (30 μM) and nanocurcumin (4 μM and 8 μM) compared to just lead treated cells. However, NQO1 and NRF2 had increased expressions in cells treated with both lead (30 μM) and nanocurcumin (16 μM) compared to just lead treated cells.
Nano curcumin, as an antioxidant, significantly reduced the toxic effects of lead toxic. This effect probably occurred through the AREKEAP1 pathway. Hence, nanocurcumin could be used as an antioxidant to reduce oxidative stress.