Paricalcitol protects against hydrogen peroxide-induced injury in endothelial cells through suppression of apoptosis.

The vascular endothelium is one of the main targets of oxidative stress which plays an important role in the pathophysiology of vascular damage. Recent studies show that vitamin D can positively regulate endothelial functions in various chronic diseases and in cases of increased oxidative stress. In our study, we investigated the restorative and protective potentials of paricalcitol which is frequently used in patients with chronic renal failure, a vitamin D analogue, in human umbilical vein endothelial cells (HUVEC) before and after H2O2-induced oxidative stress. Paricalcitol treatment after the oxidative stress induced by H2O2 increased cell viability in endothelial cells depending on the dose that was used. While paricalcitol (500 nM) decreased caspase-3 activity and mitochondrial membrane potential loss, it increased nitric oxide (NO) production and reduced glutathione (GSH) levels. Paricalcitol treatment before oxidative stress increased cell viability. It increased NO production and mitochondrial membrane potential while significantly reducing caspase-3 activity. While paricalcitol caused a significant inhibition of protein disulfide isomerase (PDI) reductase activity in healthy endothelial cells, it did not cause a significant change on the PDI reductase activity under oxidative stress conditions. Present study showed that paricalcitol has restorative and protective effects on endothelial cells against oxidative injury, but these effects occur at high concentrations of paricalcitol.

The antioxidant, anti-inflammatory, and antiplatelet effects of Ribes rubrum L. fruit extract in the diabetic rats.

The prothrombotic and inflammatory state plays a significant role in the occurrence of cardiovascular complications in type 2 diabetes mellitus. In this study, the antidiabetic, anti-inflammatory, and antiplatelet potentials of the extracts obtained from Ribes rubrum were investigated. The antidiabetic, anti-inflammatory, and antioxidant activities of the ethanol and water extracts of R. rubrum were evaluated by in vitro methods. The total phenolic and flavonoid contents were also determined. The experimental diabetes model in rats was induced with streptozotocin (STZ). After hyperglycemia occurred, the ethanol extracts of R. rubrum (RRE, at 100 mg/kg and 500 mg/kg doses) were administered to the treatment groups for 14 days. Blood glucose, lipid profile, plasma, and pancreas tumor necrosis factor-α (TNF-α) levels were determined and compared at the end of the experiments. P-selectin levels and mitochondrial membrane polarization (MMP) of platelets were also measured. In vitro study, the RRE showed potent anti-inflammatory activity. Administration of RRE (at 100 mg/kg doses) to diabetic rats lowered blood glucose level insignificantly. The results showed that there was an increment in levels of TNF-α in plasma and pancreas tissue of the diabetic group compared to the control group. R. rubrum extract regulated and normalized their levels in plasma and pancreatic tissue. RRE at both doses significantly decreased platelet P-selectin levels and prevented STZ-induced loss of MMP in platelets. The results of current research indicate that RRE extract has potent anti-platelet and anti-inflammatory effects and may be beneficial in preventing diabetic complications. PRACTICAL APPLICATIONS: Hyperglycemia causes dyslipidemia, advanced oxidative stress, platelet activation, and inflammation in diabetes mellitus. Plants with various medicinal properties are of worldwide interest for the treatment of diseases due to their biological activities. In this study, the antidiabetic, anti-inflammatory, and antioxidant effects of extracts of Ribes rubrum (%100 ethanol, 50% ethanol, water) were evaluated by in vitro and in vivo methods. The diabetes model was induced with streptozotocin (STZ). The rats were divided into control, diabetic control, R. rubrum-100 mg/kg, and R. rubrum-500 mg/kg doses groups. Blood glucose levels, tumor necrosis factor-α (TNF-α), platelet P-selectin levels, mitochondrial membrane polarization of platelets were examined. The present study has shown that R. rubrum has anti-inflammatory and antiplatelet activity. R. rubrum may be beneficial in the prevention and treatment of DM complications due to its anti-inflammatory and antithrombotic effects.

Evaluation of biochemical parameters in Rubus tereticaulis treated rats and its implications in wound healing.

We evaluated the effects of Rubus tereticaulis in healing process by determining the total carbonyl content, collagen synthesis, and total protein level on rat wounded tissues. Wounds were performed in the back of 54 Wistar rats, using a biopsy punch instrument with 0.6 mm in diameter. Rats were randomly divided into three groups: (i) un-treatment wounds group served as "controls", (ii) Madecassol® used as "positive control" group, and (iii) the application of topical cream of R. tereticaulis served as "treatment" group of wound healing. The animals were killed at the end of experiment under anesthesia with ketamine, and tissue samples were collected for the evaluation at three times intervals (3rd, 7th, and 14th day). The wounded areas were analyzed for total carbonyl content, collagen, and total protein levels by HPLC, ELISA, and spectrophotometric methods, respectively. Total carbonyl content in the treatment group was significantly lower in comparison with control group on 3rd day (2.839 ± 0.438 vs. 3.216 ± 0.216 nmol carbonyl/mol protein; p < 0.5) and 14th days (4.222 ± 0.128 vs. 4.784 ± 0.077 nmol carbonyl/mol protein; p < 0.05), respectively. New collagen formation on the wound sites after the initial injury was noted in the treated and positive control groups (5.310 ± 0.331 vs. 5.164 ± 0.377 mg collagen/g wet tissue) at the 3rd day than control group (2.180 ± 0.718 mg collagen/g wet tissue, p < 0.01), and in treated and positive control groups at 7th day (9.654 ± 0.201, 9.053 ± 1.062 mg collagen/g wet tissue, p < 0.01); and in treated and positive control groups at 14th day (8.469 ± 0.236, 5.631 ± 0.531 mg collagen/g wet tissue, respectively; p < 0.05) in comparison with the control group. Total protein level of samples did not change significantly between the groups. Thus, application of R. tereticaulis ameliorated the wound healing process in rats as it facilitated collagen formation through healing of the wound. Evaluating total carbonyl content by HPLC could be useful as an advance procedure for quantification of healing.

Protective effects of resveratrol on hepatic ischemia reperfusion injury in streptozotocin-induced diabetic rats.

Resveratrol (RSV) is a natural polyphenolic compound having antioxidant effects. This study was designed to investigate the protective effects of resveratrol against oxidative stress in hepatic ischemia-reperfusion (I/R) injury in streptozotocin (STZ)-induced diabetic rats. STZ was injected intraperitonally (i.p.) to 18 Sprague-Dawley albino rats, which were divided into three groups, each having six rats. First group was non-treated diabetic group (D), second diabetic group was subjected to 30 min of hepatic ischemia followed by a 45-min reperfusion period (D + I/R), and third diabetic group was subjected to 30 min of hepatic ischemia followed by a 45-min reperfusion period and treated with 20 mg/kg/day oral RSV before 30 min I/R injury (D + I/R + RSV). At the end of the experimental period, animals were decapitated, and blood samples were collected to determine tissue tumor necrosis factor-α (TNF-α) levels. Liver and lung tissue samples were obtained for the evaluation of biochemical parameters including malondialdehyde (MDA) and glutathione (GSH) levels and histopathological examinations. Compared to control, I/R injury resulted in decreases in GSH levels and increases in MDA levels. Tissue TNF-α levels were also increased in the D + I/R group compared to D group. Treatment with RSV prevented the alterations on biochemical parameters and histopathological changes induced by I/R. We demonstrate that in diabetic rats, hepatic I/R injury is associated with an augmented inflammatory response and oxidative stress, while RSV pre-treatment significantly decreased these responses. Larger clinical studies are desirable to determine the exact role(s) of RSV on hepatic I/R injury among diabetic subjects.

Effect of Horse-chestnut seed extract on matrix metalloproteinase-1 and -9 during diabetic wound healing.

The effects of aqueous-ethanol extract of Horse chestnut (HCE) on MMP-1 and MMP-9 expressions during cutaneous wound healing in diabetic rats were investigated in this study. The expressions of MMP-1 and MMP-9, wound closure, myeloperoxidase (MPO) activity, hydroxyproline, and malondialdehyde (MDA) levels in wound tissue were measured. Quercetin glucuronide in HCE was identified as main compound using a LC-MS/MS. The hydroxyproline level was significantly increased in the treated group versus control after the 3rd and 7th days (p < 0.05). The MDA level and MPO activity were significantly lower in the treatment group (p < 0.05). MMP-1 gene expression level in treated rats was increased in the 7th day while it was reduced in 14th day. MMP-9 gene expression level in treated rats was decreased in 7th, and 14th days compared to control (p < 0.05). These results show that HCE accelerated the cutaneous wound-healing process in diabetic rats via MMP-1 and MMP-9 regulation. PRACTICAL APPLICATIONS: The main function of MMPs is to degrade and deposite the various components of the extracellular matrix. Also, they participate physiological processes such as inflammation, angiogenesis, and tissue remodeling. Horse chestnut seeds (HC) are known to be rich in saponins and flavonoids. HC are used for the treatment of abdominal pain, stomach ache, cold, hemorrhoids, arterial stiffness, rheumatism, oedema, diarrhea, chronic venous insufficiency and also as an antihemorrhagic and antipyretic in traditional medicine. It has been shown that HC has anti-inflammatory, antioedema, vessel protective, and free radical scavenging properties. This study indicates that HCE could be an effective agent for wound healing in diabetic wound model via its ability to suppress the MMP-9 gene expression and regulates MMP-1 gene expression besides its antioxidative, anti-inflammatory effects.

Effects of dapagliflozin in experimental sepsis model in rats.

BACKGROUND: The aim of this study was to evaluate the possible protective effects of dapagliflozin in an experimental sepsis model in rats. METHODS: Saline (1 mL/kg, p.o.) or dapagliflozin (10 mg/kg, p.o.) was administered to Sprague-Dawley rats for 5 days prior to the surgical procedures. Under anesthesia, sepsis was induced by cecal ligation puncture, while sham control groups underwent laparotomy only. Blood urea nitrogen, creatinine, and glucose levels were measured in serum samples and the levels of malondialdehyde (MDA), glutathione (GSH), myeloperoxidase (MPO), tumor necrosis factor alpha, interleukin 1 beta, caspase 8, and caspase 9 were determined in tissue samples (kidney, liver, and lung). Histological evaluation was also performed. RESULTS: The administration of dapagliflozin in a sepsis model reduced oxidative stress (MDA), increased antioxidant levels (GSH), and reduced inflammation (MPO) in the kidney (p<0.05). Dapagliflozin also decreased oxidative stress (MDA) in lung tissue and decreased inflammation (MPO) in lung and liver tissue (p<0.05). Caspase 8 and 9 levels in kidney, lung, and liver tissue were increased (p<0.05) in the dapagliflozin group compared with the sepsis group. According to the histopathological results, sepsis was moderately improved in renal tissue and slightly attenuated in lung and liver tissue with the administration of dapagliflozin. CONCLUSION: Dapagliflozin had a preventive effect on sepsis-induced kidney damage, but the protective effect was mild in lung and liver tissue in the present study.

Protective effect of ferulic acid on cisplatin induced nephrotoxicity in rats.

This study aims to determine the potential protective effects of ferulic acid against cisplatin-induced nephrotoxicity and to compare its effect with curcumin, a well-known protective agent against cisplatin- induced toxicity in rats. Administration of cisplatin resulted in high BUN (Blood Urea Nitrogen), creatinine, MDA (Malondialdehyde), MPO (Myeloperoxidase), TOS (Total Oxidative Status), PtNT (Protein Nitrotyrosine) levels (p<0.05). Histological observations showed abnormal morphology of kidney; in addition with appearance of TUNEL positive cells indicating apoptosis in cisplatin administered group. HO-1 (Heme Oxygenase-1) levels measured by RT-PCR (Real Time Polymerase Chain Reaction), and TAS (Total Antioxidative Status) revealed antioxidant depletion due to cisplatin toxicity in animals (p<0.05). All parameters showed improvement in groups treated with ferulic acid (p<0.05). Ferulic acid treatment was found significant in preventing oxidative stress, increasing antioxidative status and regaining histological parameters to normal, indicating nephroprotective and antioxidant effects of this phenolic compound.

Ethanol extract of Cotinus coggygria leaves accelerates wound healing process in diabetic rats.

CONTEXT: Cotinus coggygria Scop. (Anacardiaceae) leaves that were used as wound healing in traditional Balkan and Anatolian folk medicine, could be potentially effective in treating diabetic wounds. OBJECTIVE: This study investigates biochemical and histological effects of ethanol extract of C. coggygria (CCE) on excision wound model in diabetic rats. MATERIALS AND METHODS: This study was conducted on diabetic Wistar albino rats, which were injected by a single dose (50 mg/kg i.p.) streptozotocin. Afterward an excision wound model was created in all animals; diabetic control rats were applied topically simple ointment and diabetic treatment rats were applied topically 5% (w/w) ointment with CC, once a day during the experimental period. Malondialdehyde, glutathione and hydroxyproline levels in wound tissues were investigated at the end of 3rd, 7th, and 14th days. Histopathological examination was also performed. RESULTS: Hydroxyproline content was significantly increased in the CCE treated group versus control after the 3rd and 7th days (15.33 versus 11.83; 19.67 versus 15.67 mg/g, p < 0.05; respectively). A statistically significant elevation in glutathione at the end of 3rd, 7th, and 14th days (5.13 versus 1.58, p < 0.05; 4.72 versus 1.88, p < 0.05; 3.83 versus 1.88 µmol/g, p < 0.05, respectively) and a statistically significant decrease in malondialdehyde level at the end of 7th day (4.49 versus 1.48 nmol/g, p < 0.05) were determined in the treated group versus control group. These results were also supported by histological analyses. DISCUSSION AND CONCLUSION: These findings indicate that CCE accelerated the cutaneous wound healing process in diabetic wounds, in confirmation of its traditional use.