The cytotoxicity of L-carnitine and its protective effect on H
-induced toxicity in HL7702 Cells. The upper curve: HL7702 cells were incubated with L-carnitine for 24 h. The lower curve: Cells were treated with or without L-carnitine prior to H2O2 challenge (300 μM, 12 h). Cell viability was assayed by MTT assay. The percentage of cell viability in the control group was treated as 100%. Each value represents the mean of three replicates. ΔP < 0.05, #P < 0.01 vs. control; *P < 0.05, **P < 0.01 vs. H2O2 alone.