Pelargonium sidoidesextract mediates nephrotoxicity through mitochondrial malfunction and cytoskeleton destabilization

We investigated the cytotoxic effect of Pelargonium sidoidesextract on Madin–Darby canine kidney (MDCK) cells. P. sidoidesextract decreased the cell viability in a dose dependent manner (> 0.2%). The extract of P. sidoidesdecreased the mitochondrial action potential, increased the number of reactive oxygen species (ROS) inside the cell, and caused nicotinamide adenine dinucleotide hydride (NADH) to be released, all of which are signs of mitochondrial dysfunction. The results of unbiased mRNA sequencing showed that 0.3% P. sidoidesextract upregulates the apoptosis-related gene (BBC3). This finding was supported by immunoblot analysis of apoptosis signal pathways, which included Bcl-2, Bax, cytochrome C (CytC), cleaved caspase 3 (CC3), cleaved caspase 7 (CC7), cleaved caspase 9 (CC9) and cleaved PARP (CP). It is interesting to note that the elevated levels of Bax, CytC, CC3, CC7, and CC9, as well as CP, were suppressed by N-acetyl-L-cysteine (NAC) pretreatment, which points to ROS-mediated apoptosis. The small GTPases, RhoA, and Rac1/cdc42-GTP-bound active form were all lowered when P. sidoides extract was used. Also, RhoA-related cytoskeleton signals (ROCK, p-LIMK1/2, p-cofilin) and Rac1/cdc42-related signals (N-WASP, WAVE-2) were inhibited by P. sidoidesextract. NAC or RhoA/Rac1/cdc42 activator pretreatment reduced P. sidoidesextract-induced actin destabilization. In this work, P. sidoidesextract promotes apoptosis by causing mitochondrial dysfunction and cytoskeleton disassembly.