Abstract: Objective To determine the correlation between nephrotoxicity and five components of Polygonum multiflorum. Methods After HK-2 cells were treated with 2.5, 10, 20, 40, 80, 120, 160 μmol·L^-1 emodin, aloe-emodin, rhein and 3.125, 12.5, 25, 50, 100, 150, 200 μmol·L^-1 physcion and chrysophanol for 24 and 48 hours, the effects of these monomers on viability of HK-2 cells were determined with the cell counting kit. After HK-2 cells were treated with 6.25, 12.5, 25, 50 and 100 μmol·L^-1 emodin, aloe-emodin, rhein, physcion and chrysophanol for 24 and 48 hours, the cell culture medium was collected to detect the release level of lactate dehydrogenase(LDH). The expression level of Kim-1 protein was detected via Elisa assay, the changes of the mitochondrial membrane potential (MMP) were detected by the JC-10 fluorescence probe, and the effects of the five anthraquinones components on apoptosis were measured by flow cytometry. Results The viability of HK-2 cells decreased with the increased concentration and administration time of emodin, aloe-emodin, rhein and chrysophanol significantly (P<0.05), but remained more than 75% after administration of 200 μmol·L^-1 physcion and chrysophanol for 48 hours. 48 hours after administration of 100 μmol·L^-1 emodin, aloe-emodin and physcion, the release level of LDH was significantly higher than in the control group (P<0.01). After administration of the five anthraquinone monomers in Polygonum multiflorum, the level of Kim-1 in the HK-2 cell supernatant didn't increase with the concentration, but increased significantly compared with the control group after 100 μmol·L^-1 administration (P<0.05). The mitochondrial membrane potential of HK-2 cells decreased with the concentration of treatment and duration of administration after the administration of the five anthraquinone components in Polygonum multiflorum. Conclusion Emodin, aloe-emodin and rhein are considered the potential anthraquinone components that causes nephrotoxicity in Polygonum multiflorum, and the nephrotoxicity risk of other components in Polygonum multiflorum needs to be studied.

Key words: HK-2 cells, Polygonum multiflorum, anthraquinones components, cytotoxicity, LDH, Kim-1, mitochondrial membrane potential, safety