Effects of procaine and two of its metabolites on cisplatin-induced kidney injury in vitro: Mitochondrial aspects

Procaine-The Controversial Geroprotector Candidate: New Insights Regarding Its Molecular and Cellular Effects

Since its discovery in 1905 and its employment in everyday medical practice as a local anesthetic, to its highly controversial endorsement as an "anti-aging" molecule in the sixties and seventies, procaine is part of the history of medicine and gerontoprophylaxis. Procaine can be considered a "veteran" drug due to its long-time use in clinical practice, but is also a molecule which continues to incite interest, revealing new biological and pharmacological effects within novel experimental approaches. Therefore, this review is aimed at exploring and systematizing recent data on the biochemical, cellular, and molecular mechanisms involved in the antioxidant and potential geroprotective effects of procaine, focusing on the following aspects: (1) the research state-of-the-art, through an objective examination of scientific literature within the last 30 years, describing the positive, as well as the negative reports; (2) the experimental data supporting the beneficial effects of procaine in preventing or alleviating age-related pathology; and (3) the multifactorial pathways procaine impacts oxidative stress, inflammation, atherogenesis, cerebral age-related pathology, DNA damage, and methylation. According to reviewed data, procaine displayed antioxidant and cytoprotective actions in experimental models of myocardial ischemia/reperfusion injury, lipoprotein oxidation, endothelial-dependent vasorelaxation, inflammation, sepsis, intoxication, ionizing irradiation, cancer, and neurodegeneration. This analysis painted a complex pharmacological profile of procaine: a molecule that has not yet fully expressed its therapeutic potential in the treatment and prevention of aging-associated diseases. The numerous recent reports found demonstrate the rising interest in researching the multiple actions of procaine regulating key processes involved in cellular senescence. Its beneficial effects on cell/tissue functions and metabolism could designate procaine as a valuable candidate for the well-established Geroprotectors database.

The Use of Porcine Proximal Tubular Cells for Studying NephrotoxicityIn Vitro:The Role of Oxidative Stress in Cisplatin-induced Cell Death

The effects of a widely used antitumour drug, cisplatin, on freshly isolated porcine proximal tubular cells (PPTC) in suspension were investigated. Incubation of the PPTC with 5-500μM cisplatin resulted in a decrease in mitochondrial membrane potential (MMP) and in cell death. In addition, the formation of reactive oxygen species (ROS) was observed within 20 minutes. Prevention of ROS formation with the antioxidants diphenyl- p-phenylene-diamine (DPPD) or desferrioxamine had no effect on the cisplatin-induced effects on MMP and cell death, implying that cisplatin-induced ROS formation is not a cause of cell death. In order to investigate whether the ROS formation was related to mitochondrial damage, we determined the effects of cisplatin on the enzymatic activities of NADP:ubiquinone reductase (Complex I) and succinate:ubiquinone reductase (Complex II) of the respiratory chain. Exposure of the PPTC to cisplatin resulted in a time-dependent and dose-dependent inhibition of the activities of both Complex I and Complex II. The inhibition of these activities and the depletion of ATP could not be prevented by the antioxidants, indicating that these effects are not a consequence of ROS formation. We propose that damage to the mitochondria could be a key event in cisplatin-induced cell death.

Protective effect of procaine hydrochloride on cisplatin-induced alterations in rat kidney

Efforts have been made to reduce the undesirable side effects of cisplatin, mainly nephro- and neurotoxicity, but their reduction is usually accompanied by a concomitant inhibition of antitumor activity. The local anesthetic procaine hydrochloride (P.HCl) improves the therapeutic index of cisplatin not only by the reduction of its nephro- and hemotoxicity, but also by an increase of its antitumor activity. We therefore investigated the effects of a combined treatment of cisplatin and P.HCl on rat kidneys and compared this to kidneys from rats treated with a toxic dose of cisplatin or P.HCl alone. Treatment with a saline solution was used as control. Dehydrogenase activities [succinate dehydrogenase (SDH) and NADPH diaphorase reaction demonstrating nitric oxide synthase (NOS/NADPHd)] and phosphatase activities [K -nitrophenyl phosphatase (K pNPPase), alkaline phosphatase (AlPase) and acid phosphatase (AcPase)] were studied on cryostatic sections of kidneys from controls and treated rats. Evidence of heavy morphological damage and altered AlPase and AcPase activities induced by cisplatin were observed in the S3 segment of the proximal tubules. In addition, SDH and K pNPPase activities showed some changes in the distal tubule cells. The NOS/NADPHd activity in macula densa was drastically reduced. Combined treatment of cisplatin and P.HCl greatly attenuated morphological alterations of the rat kidney and reduced the changes in enzyme activities, except for NOS/NADPHd activity, compared to the cisplatin-treated group of animals. The study indicates that, in cisplatin-induced nephrotoxicity, a significant role is played by enzyme activities, in particular K pNPPase and NOS/NADPHd, and that P.HCl can mitigate the nephrotoxicity of cisplatin, possibly by influencing some enzyme activities involved in important renal metabolic pathways.

Cisplatin-induced changes in adenine nucleotides in rat kidney slices: amelioration by tiopronin and procaine

The adenine nucleotides (ATP, ADP and AMP) in rat renal cortical slices exposed in-vitro to cisplatin, an anticancer drug, were determined by HPLC. Cisplatin had no effect on total adenine nucleotides in the slices but caused a time- and concentration-dependent decrease in ATP levels with a concomitant increase in ADP and AMP levels. The decrease in ATP and increases in ADP and AMP concentrations became statistically significant after incubation with cisplatin (2 mM) for 90 min or after cisplatin (1 mM) for 120 min. Both tiopronin, a sulphydryl-containing drug, and procaine, an antioxidant, protected against cisplatin-induced changes in the adenine nucleotides. The results indicate a cisplatin-induced defect in cellular energetics that occurs at a relatively late stage in the process of toxicity to the slices in this in-vitro model. Cisplatin-induced depletion of ATP in the slices might result from an increase in catabolism of ATP to ADP and AMP. Maintenance of the normal concentration of ATP in the slices might be involved in the protection afforded by tiopronin and procaine against cisplatin-induced nephrotoxicity.

Differential effects of cisplatin on the production of NADH-dependent superoxide and the activity of antioxidant enzymes in rat renal cortical slices in vitro

Cisplatin-induced cytotoxicity has been investigated with rat renal cortical slices in vitro. Incubation of renal slices with cisplatin caused an unexpected decrease in NADH-dependent. lucigenin-enhanced chemiluminescence in the homogenate of the slices in a time- and concentration-dependent fashion. Cisplatin caused a concentration-related (0.2 1 mM) decrease in the formation of NADH-dependent superoxide anion. Cisplatin (2 mM) significantly suppressed the chemiluminescence to 70% of control as early as 15 min, and to 15% after 90 min. of incubation. A decrease was also observed 90 min. after incubation of slices with 0.25 mM cisplatin. In addition, the activities of superoxide dismutase (SOD) and catalase in the slices were significantly increased after 60 min. of exposure to cisplatin (2 mM) while decreases in the activities of glutathione (GSH) peroxidase and GSSG reductase became significant at 90 and 120 min. of incubation respectively. SOD and catalase activities were increased by 1.6 and 1.5 fold respectively after 90 min. of incubation and the activities of GSH peroxidase and GSSG reductase were decreased to 82% and 72% of control, respectively at 120 min. Both dithiothreitol (2 mM), a sulphydryl agent and diphenylphenylenediamine (5 microM), an antioxidant, protected against cisplatin-induced leakage of lactate dehydrogenase, lipid peroxidation and decreases of GSH peroxidase and GSSG reductase but had no effect on the decrease of chemiluminescence caused by cisplatin. The results suggest that neither an increase in the production of NADH-dependent superoxide anion nor a decrease in activity of several antioxidant enzymes were directly responsible for cisplatin-induced lipid peroxidation.

Comparison of the toxicities of cisplatin and a new cisplatin-procaine complex to rat renal cortical slices

1. Procaine has previously been shown to diminish the nephrotoxicity of cisplatin and the nephrotoxic effects of cisplatin and a new cisplatin complex (cis-diamminechloro-[2-(diethylamino) ethyl-4-aminobenzoate, N4]-chlorideplatinum (II) monohydrochloride monohydrate; DPR), that contains procaine hydrochloride were compared with rat renal cortical slices. 2. Cisplatin at 1 mM caused toxicity to the slices, as shown by an increase in the leakage of aspartate aminotransferase and lactate dehydrogenase from the slices into the incubation medium and a decrease in the reduction of a tetrazolium dye (MTT assay). Addition of procaine (1 mM) protected against cisplatin-induced toxicity. DPR either at 1 mM or at 4 mM had no effect either on the enzyme leakage or MTT reduction by the renal slices, but DPR at 10 mM produced a similar magnitude of enzyme leakage to cisplatin (1 mM). 3. DPR lowered the concentration of ATP and glutathione (GSH) in the slices but was less potent than cisplatin. Thiobarbituric acid reactive substances, indicators of lipid peroxidation, released into the medium were increased by the highest concentration of DPR (10 mM), which suggests that DPR has the potential to cause oxidative stress. 4. The results suggest that DPR was far less toxic than either cisplatin alone or a mixture of cisplatin and procaine.