Protective effects of 6-hydroxy-1-methylindole-3-acetonitrile on cisplatin-induced oxidative nephrotoxicity via Nrf2 inactivation.

We previously demonstrated the ethanol extract of the roots of Brassica rapa protects against cisplatin-induced nephrotoxicity by attenuating oxidative stress. Here, we investigated the nephroprotective effects of 6-hydroxy-1-methylindole-3-acetonitrile (6-HMA), which was isolated from the roots of B. rapa, on cisplatin-induced toxicity in renal epithelial LLC-PK1 cells and in rats with acute renal injury. Pretreatment of LLC-PK1 cells with 6-HMA ameliorated cisplatin-induced cytotoxicity caused by oxidative stress, as was demonstrated by reductions in the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) and increased levels of glutathione (GSH). In addition, 6-HMA inhibited cisplatin-induced heme oxygenase-1 (HO-1) expression, possibly due to the suppression of the nuclear translocation and binding activity of NF-E2-related factor 2 (Nrf2). Furthermore, 6-HMA administered rats showed lower levels of blood urea nitrogen (BUN), creatinine, and urinary lactate dehydrogenase (LDH) than cisplatin alone-treated rats in cisplatin-induced renal injury model. Moreover, 6-HMA inhibited the cisplatin-induced formation of MDA and GSH depletion and increased the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR). Taken together, these findings indicate 6-HMA is a major active constituent from the roots of B. rapa to have a protective effect against cisplatin-induced nephrotoxicity by attenuating oxidative stress.

Donepezil, a potent acetylcholinesterase inhibitor, induces caspase-dependent apoptosis in human promyelocytic leukemia HL-60 cells.

Although donepezil, a potent acetylcholinesterase (AChE) inhibitor, has been used to treat Alzheimer's disease (AD) due to its neuroprotective effects, its mode of action to inhibit the growth of cancer cells is poorly understood. In the present study, we investigated the pro-apoptotic activities of donepezil in HL-60 human promyelocytic leukemia cells and the underlying molecular mechanism involved. It was found that donepezil induced the apoptosis of HL-60 and U937 cells in a dose- and time-dependent manner, as evidenced by the formation of DNA fragmentation and the accumulation of positive cells for Annexin V. In addition, the activations of caspase-8, -9, and -3 were significantly increased 36 h after donepezil treatment. Furthermore, the broad caspase inhibitor (z-VAD-fmk) blocked donepezil-induced apoptosis. In addition, donepezil was found to cause the loss of mitochondrial membrane potential (DeltaPsi(m)), to increase the release of cytochrome c to the cytosol, and to alter the expressions of Bcl-2 family proteins. Taken together, these results demonstrate for the first time that donepezil displayed an induction of apoptosis in HL-60 cells via a mitochondria-mediated caspase-dependent pathway.