PRE-084 ameliorates adenine-induced renal fibrosis in rats.

2-(4-morpholinoethyl)- 1-phenylcyclohexane-1-carboxylate hydrochloride (PRE-084) is a selective sigma 1 receptor agonist. It has been shown that PRE-084 protected various tissues from experimental injury. However, no reports are available on its effect on renal fibrosis. Rat model of adenine-induced chronic kidney disease was chosen to study this. Adenine feeding in rats caused renal dysfunction as shown by increased serum creatinine and reduced creatinine clearance along with increased high molecular weight (HMW) urine protein excretion. Further, adenine feeding induced profibrotic changes in the kidney as reflected by increased expression of alpha-smooth muscle actin (α-SMA), fibroblast specific protein-1 (FSP-1) and matrix metalloproteinase-2 (MMP-2) activity; reduced cytokeratin expression. Further, there was excess deposition of extracellular matrix in the kidney, a striking character of fibrosis. However, administration of PRE-084 to adenine fed rats led to reduction in creatinine and proteinuria parameters partly. This was accompanied by reduced expression of α-SMA, FSP-1 and MMP-2 activity and slight restoration of cytokeratin levels leading to reduced extracellular matrix deposition in the kidney. These data demonstrate that PRE-084 partly ameliorated renal dysfunction and exhibited anti-fibrotic potential in the kidney of adenine fed rats.

Fat augments leptin-induced uterine contractions by decreasing JAK2 and BKCa channel expressions in late pregnant rats.

Altered lipid metabolism in obesity causes pregnancy complications in humans and animals. Leptin levels increase in pregnancy, as well as obesity. However, the effect of obesity on uterine leptin receptors and its distal signaling is not clear. The present study aimed to understand the effect of increased fat on leptin signaling in rat uterus. Wistar female rats were fed with an HF diet (40% Fat, 17% Sucrose, 1.25% Cholesterol, 0.75% Cholic acid) for 6 weeks before the mating and during pregnancy. HF diet significantly increased the fat depots, liver weight, serum, and tissue cholesterol levels. It produced fatty degeneration in the liver and caused infiltration of inflammatory cells, cystic endometrial glands, and sub endometrial fibrosis of the uterus. In isometric tension experiments, leptin caused a significant increase in uterine contractions in high fat-fed animals compared to control animals. Analysis of receptor expressions revealed no significant difference between the groups. However, a significant decrease in the JAK2 and BKCaα mRNA expression was observed in the uterus of high fat-fed rats. No change in the BKCaß, eNOS, iNOS, MLCP, and MLCK mRNA expressions was noticed in the HF group compared to the control. The findings of the present study suggest that the contractile response to leptin in the uterus of high fat-fed rats may be attributed to reduced signaling through JAK2 and, lowered expressions of BKCa channel α subunits.

Topical bilirubin-deferoxamine hastens excisional wound healing by modulating inflammation, oxidative stress, angiogenesis, and collagen deposition in diabetic rats.

AIM OF THE STUDY: The study was performed to understand the detailed mechanism of diabetic wound healing by bilirubin-deferoxamine (DFO) combination on topical application. MATERIALS AND METHODS: There were two study groups, control, and treatment. The granulation tissues collected on different days (3, 7, 14, and 19) were studied in detail for inflammatory mediators, angiogenesis markers, epithelialization, and oxidative stress parameters. RESULTS: A significant increase in wound contraction percentage was observed from day 7 in the bilirubin-DFO treatment group. The combinatorial treatment significantly reduced tumour necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1ß), and enhanced IL-10 levels. Upregulated mRNAs of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1 alpha (HIF-1 α) along with CD31 immunohistochemistry showed the pro-angiogenesis potential of the combination. Hematoxylin and Eosin (H and E) staining and Masson's trichrome staining showed reduced inflammatory cell infiltration, enhanced fibroblast proliferation, well-organized collagen fibers, and the development of new blood vessels. Collagen deposition is further supported by immunohistochemistry studies and Masson's trichrome staining. Bilirubin-DFO combination also reduced lipid peroxidation and elevated antioxidative enzymes. CONCLUSION: Topical application of bilirubin-DFO showed immense potential in augmenting skin wound regeneration in diabetes by upregulating the antioxidant status as well as increasing angiogenesis, collagen deposition, and modulating cytokines.

Differential Expression of Prostaglandin Receptors in Canine Uterus With Pyometra.

The objective of the study was to ascertain the role of prostaglandins Viz., PGE2 and PGF2α, and their respective receptors in the pathophysiology of canine pyometra. Normal (n = 6) and pyometra (n = 8) affected uterus were collected from bitches undergoing ovariohysterectomy. Pyometra was graded according to histopathological alterations. The levels of PGE2 and PGF2α were estimated in the endometrium. The differential expression in the mRNA of PGF2α receptor (FP) and PGE2 receptors (EP1, EP2, EP3, and EP4) were studied in the endometrium and myometrium of the pyometra-affected uterus. Normal uterus served as calibrator. Elevation of both PGE2 and PGF2α levels in the endometrium of pyometra-affected bitches was observed. The FP receptor gene in the endometrium and myometrium of pyometra-affected bitches was downregulated (P < .05). Out of all EP receptors, only EP2 receptor has shown upregulation in both endometrium and myometrium of pyometra affected uterus. EP3 receptor got downregulated in both endometrium and myometrium in pyometra. Thus, downregulation of FP, EP3 receptors in the myometrium reinforces the lack of contractility in pyometra-affected bitches favoring bacterial proliferation and subsequent pus accumulation. Moreover, upregulation of EP2 receptors in the pyometra bitches suggests the scope of selective pharmacological inhibition of EP2 receptors as an adjunct therapy in the treatment of pyometra.

Leptin receptor stimulation in late pregnant mouse uterine tissue inhibits spontaneous contractions by increasing NO and cGMP.

The adipokine, leptin exerts inhibitory effect on both spontaneous and oxytocin-induced contractions in myometrium. However, the mechanisms involved in leptin-induced effect are not clear. In the present study, we studied the altered characteristics of uterine contractions in the presence of leptin and the possible mechanisms of its effect in late pregnant (18.5 day) mouse uterus. We conducted functional, biochemical and molecular biology studies to demonstrate the mechanism of leptin-induced response. Leptin exerted an inhibitory response (Emax 40.5 ± 3.99%) on basal uterine contractions. The extent of inhibition was less than that obtained with known uterine relaxants, salbutamol (Emax103 ± 8.66%) and BRL-37344 (Emax 84.79 ± 8.12%). Leptin-induced uterine response was inhibited by leptin receptor antagonist SHLA and JAK-STAT pathway inhibitor, AG-490. The relaxant response was also subdued by NO-cGMP-PK-G pathway blockers L-NAME, 1400W, ODQ and KT-5823. Further, leptin enhanced the levels of NO and cGMP in uterine tissues. Also, SHLA, AG-490 and a combination of 1400 W and L-NAME prevented leptin-induced increase in NO. Similar effect was observed on cGMP levels in presence of leptin and SHLA. However, leptin did not influence CaCl2-induced response in potassium-depolarized tissues. We also detected leptin receptor protein in late pregnant mouse uterus located in endometrial luminal epithelium and myometrial layers. Real-time PCR studies revealed significantly higher expression of short forms of the receptor (ObRa and ObRc) in comparison to the long form (ObRb). In conclusion, the results of the present study suggest that leptin inhibits mouse uterine contraction by stimulating short forms of the leptin receptors and activating NO pathway in a JAK-STAT-dependent manner.

Current therapeutic applications and pharmacokinetic modulations of ivermectin.

Ivermectin is considered to be a wonder drug due to its broad-spectrum antiparasitic activity against both ectoparasites and endoparasites (under class of endectocide) and has multiple applications in both veterinary and human medicine. In particular, ivermectin is commonly used in the treatment of different kinds of infections and infestations. By altering the vehicles used in the formulations, the pharmacokinetic properties of different ivermectin preparations can be altered. Since its development, various vehicles have been evaluated to assess the efficacy, safety, and therapeutic systemic concentrations of ivermectin in different species. A subcutaneous route of administration is preferred over a topical or an oral route for ivermectin due to superior bioavailability. Different formulations of ivermectin have been developed over the years, such as stabilized aqueous formulations, osmotic pumps, controlled release capsules, silicone carriers, zein microspheres, biodegradable microparticulate drug delivery systems, lipid nanocapsules, solid lipid nanoparticles, sustained-release ivermectin varnish, sustained-release ivermectin-loaded solid dispersion suspension, and biodegradable subcutaneous implants. However, several reports of ivermectin resistance have been identified in different parts of the world over the past few years. Continuous use of suboptimal formulations or sub-therapeutic plasma concentrations may predispose an individual to resistance toward ivermectin. The current research trend is focused toward the need for developing ivermectin formulations that are stable, effective, and safe and that reduce the number of doses required for complete clinical cure in different parasitic diseases. Therefore, single-dose long-acting preparations of ivermectin that provide effective therapeutic drug concentrations need to be developed and commercialized, which may revolutionize drug therapy and prophylaxis against various parasitic diseases in the near future. The present review highlights the current advances in pharmacokinetic modulation of ivermectin formulations and their potent therapeutic applications, issues related to emergence of ivermectin resistance, and future trends of ivermectin usage.