Pterostilbene attenuates acute kidney injury in septic mice

Pterostilbene: a potential therapeutic agent for fibrotic diseases

Fibrosis is a prevailing pathology in chronic diseases and accounts for 45% of deaths in developed countries. This condition is primarily identified by the transformation of fibroblasts into myofibroblasts and the overproduction of extracellular matrix (ECM) by myofibroblasts. Pterostilbene (PTS) is a natural analogue of resveratrol and is most commonly found in blueberries. Research has shown that PTS exerts a wide range of pharmacological effects, such as antioxidant, anti-inflammatory, and anticancer effects. As a result, PTS has the potential to prevent and cure numerous diseases. Emerging evidence has indicated that PTS can alleviate myocardial fibrosis, renal fibrosis, pulmonary fibrosis, hepatic fibrosis, and colon fibrosis via the inhibition of inflammation, oxidative stress, and fibrogenesis effects in vivo and in vitro, and the potential mechanisms are linked to various pathways, including transforming growth factor-β1 (TGF-β1)/small mother against decapentaplegic proteins (Smads) signalling, the reactive oxygen species (ROS)-driven Pitx2c/mir-15b pathway, nuclear factor kappa B (NF-κB) signalling, Kelch-like epichlorohydrin-associated protein-1 (Keap-1)/NF-E2-related factor-2 (Nrf2) cascade, the NLR family pyridine structure domain 3 (NLRP3) pathway, the Janus kinase-2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway, and the Src/STAT3 pathway. In this review, we comprehensively summarize the antifibrotic effects of PTS both in vivo and in vitro and the pharmacological mechanisms, pharmacokinetics, and toxicology of PTS and provide insights into and strategies for exploring promising agents for the treatment of fibrosis.

Protective potential of pterostilbene against cyclophosphamide-induced nephrotoxicity and cystitis in rats

PURPOSE

Cyclophosphamide (CYP) is an antitumor drug. However, in addition to its antitumor affect, CYP can also lead to nephrotoxicity and hemorrhagic cystitis. The purpose of this study was to investigate the potential protective effects of Pterostilbene (Pte), a natural antioxidant as a resveratrol analog against CYP-induced nephrotoxicity and cystitis in rats.

METHODS

Twenty-one male Sprague Dawley rats were divided into 3 equal groups. The control group and the CYP group (CYPG) received 1 ml/kg sunflower oil per day, and the CYP + Pte group (CYP + PteG) 40 mg/kg per day Pte dissolved in sunflower oil once a day via the oral route for 14 days. In addition, on day 9 of the experiment, CYPG and CYP + PteG received a single dose of 200 mg/kg CYP dissolved in saline solution, while the control group received a single dose of 10 ml/kg saline solution, via the intraperitoneal route. Bladder and kidney tissues were collected for histological and biochemical evaluations.

RESULTS

Pte was observed to reduce CYP-derived increases in malondialdehyde level, total oxidant status (TOS), the oxidative stress index (OSI), and apoptosis in kidney tissues and to cause an increase in superoxide dismutase levels. It also reduced CYP-derived increases in TOS, OSI, and apoptosis in bladder tissue. Moreover, Pte also ameliorated histopathological findings associated with CYP-induced tissue damage in both the kidney and bladder.

CONCLUSION

Our study findings show that Pte may exhibit a protective effect against CYP-induced nephrotoxicity and cystitis.

Accelerated lipid peroxidation in a rat model of gentamicin nephrotoxicity

Kidney disease represents a burden for the health care system worldwide. As the prevalence continues to rise, discovering new biomarkers of early kidney damage has become crucial. Oxidative stress (OS) represents one of the main factors involved in the early stages of many syndromes leading to kidney damage. Therefore, it must be studied in detail. To date, many studies have focused on OS in advanced stages of acute kidney injury (AKI), with great success. The aim of the present study was to ascertain whether even mild renal function impairment can be linked to specific systemic markers of OS and systemic antioxidants in order to pinpoint certain biomarkers for early kidney damage. We used male rats (Rattus norvegicus) in which we induced kidney damage by injecting gentamicin for 7 days. Blood was collected 24 h after the last dose of gentamicin. Urea, creatinine, 3-nitrotyrosine (3-NT), nitric oxide (NO), malondialdehyde (MDA), thiols (TS), total oxidative stress (TOS), and interferon-γ (IFN-γ) were determined. In addition, for the antioxidant status we measured total antioxidant capacity (TAC) and interleukin-10 (IL-10). Our results demonstrated that the rats had mild renal impairment consistent with a pre-AKI stage due to the nephrotoxic effect of gentamicin. However, TOS, MDA and NO were significantly higher in the gentamicin group compared to the control group. In addition, TAC was higher in the control group. Hence, OS markers reach higher levels and may potentially be used as markers of kidney damage even in cases of mild renal function impairment.

The Effect of miR-361-3p Targeting TRAF6 on Apoptosis of Multiple Myeloma Cells

microRNA-361-3p (miR-361-3p) is involved in the carcinogenesis of oral cancer and pancreatic catheter adenocarcinoma, and has anti-carcinogenic effects on non-small cell lung cancer (NSCLC). However, its effect on multiple myeloma (MM) is less reported. Here, we found that upregulating the expression of miR-361-3p inhibited MM cell viability and promoted MM apoptosis. We measured expressions of tumor necrosis factor receptor-associated factor 6 (TRAF6) and miR-361-3p in MM cells and detected the viability, colony formation rate, and apoptosis of MM cells. In addition, we measured expressions of apoptosis-related genes Bcl-2, Bax, and Cleaved caspase-3 (C caspase-3). The binding site between miR-361-3p and TRAF6 was predicted by TargetScan. Our results showed that miR-361-3p was low expressed in the plasma of MM patients and cell lines, while its overexpression inhibited viability and colony formation of MM cells and increased the cell apoptosis. Furthermore, TRAF6, which was predicted to be a target gene of miR-361-3p, was highexpressed in the plasma of patients and cell lines with MM. Rescue experiments demonstrated that the effect of TRAF6 on MM cells was opposite to that of miR-361-3p. Upregulation of miR-361-3p induced apoptosis and inhibited the proliferation of MM cells through targeting TRAF6, suggesting that miR-361-3p might be a potential target for MM therapy.

Pterostilbene administration improves the recovery potential of extremely low-frequency magnetic field in acute renal ischemia-reperfusion injury: an FTIR spectroscopic study

Renal ischemia-reperfusion (I/R) injury, one of the drastic outcomes of renal failure and organ transplantation, tends to deteriorate over time; therefore, noninvasive therapeutic strategies will avail the progression-free survival of the patients. Magnetic field has been proposed as a noninvasive treatment strategy; however, with recent scientific advances, many controversies have arisen regarding its efficacy. Pterostilbene, a natural analog of resveratrol, was documented to be effective in treatment of I/R injuries. This study aims to assess the acute therapeutic effects of combined extremely low-frequency magnetic field (ELF-MF) and pterostilbene treatment on renal I/R injury. After induction of renal I/R in Wistar rats, treatments of 50 Hz, 1 mT ELF-MF applied alone or in combination with pterostilbene were applied for 5 consecutive days. Kidney homogenates were analyzed by Fourier transform infrared spectroscopy. I/R injury resulted in an altered protein and lipid structure with the dominance of longer acyl chains; a slight decrease in lipid, protein, unsaturated lipid, and unsaturated/saturated lipid content; and an increase in membrane fluidity and lipid peroxidation in rat kidneys. Although ELF-MF treatment alone was not sufficient to restore all ischemia-induced alterations, the combined treatment strategy of pterostilbene administration in the presence of ELF-MF was successful and warrants further investigation.