Naglaa F. Khedr

Modulation of bone turnover in orchidectomized rats treated with raloxifene and risedronate

Osteoporosis is a reduction in bone mineral density (BMD). It develops less often in men than in women. This study aimed to evaluate the bone protective effects of raloxifene (RAL), risedronate (RIS), and their combination on osteoporotic male rats. Forty male Wister rats (12 weeks) were randomly divided into five groups: sham‐operated group (n = 8), orchidectomized (ORX) group (n = 7), RAL group (n = 9), RIS group (n = 7) and RAL + RIS group (n = 7). RAL was orally administered at 3 mg/kg three times/week, and RIS was given subcutaneously at 5 μg/kg, twice weekly. After 6 weeks of treatment, serum cathepsin‐K, alkaline (ALP) and acid phosphatase activities, serum osteocalcin, serum Ca2+, and Pi were determined. Urinary Ca2+ and deoxypyridinoline levels, BMD, and Ca2+ content of femur ash were estimated. Histochemical localization of ALP activity of tibia and histomorphometry was examined. As compared to sham, ORX rats showed a significant increase in bone turnover markers, and histochemical activity of ALP was increased markedly in proximal tibia of ORX rats, whereas BMD and Ca2+ content of femur ash were reduced after ORX. These changes were modulated after treatment with RAL and RIS or both to ORX rats; BMD of femur was improved by each treatment, and bone turnover markers were reduced as compared to ORX vehicle group. We concluded that orchidectomy induced osteoporosis and increased bone turnover in male rats because of withdrawal of sex hormones. Both RAL and RIS could treat osteoporosis in ORX rats; they reduced bone turnover markers and maintained BMD.

Curcumin Protects against Monosodium Glutamate Neurotoxicity and Decreasing NMDA2B and mGluR5 Expression in Rat Hippocampus

Background: Monosodium glutamate (MSG) is a flavor enhancer used in food industries. MSG is well documented to induce neurotoxicity. Curcumin (CUR) reportedly possesses beneficial effects against various neurotoxic insults. Hence, this present study has been designed to evaluate the neuroprotective effect of curcumin on MSG-induced neurotoxicity in rats. Methods: Thirty-two male Wister rats were divided into four groups (n=8): Control group, MSG group, CUR group and MSG + CUR group. CUR (Curcumin 150 mg/kg, orally) was given day after day for four weeks along with MSG (4 mg/kg, orally). After 4 weeks, rats were sacrificed and brain hippocampus was isolated immediately on ice. Inflammatory marker TNFα and acetylcholinesterase (AChE) activity (marker for cholinergic function) were estimated. Gene expressions of metabotropic glutamate receptor 5 (mGluR5) and N-methyl-D-aspartate receptor 2B (NMDA2B) along with glutamate concentration were assessed. Results: Treatment with CUR significantly attenuated AChE activity and TNFα in MSG-treated animals. The anti-inflammatory properties of CUR may be responsible for this observed neuroprotective action. A possible role of CUR to attenuate both glutamate level and gene expression of NMDA2B and mGLUR5 in brain hippocampus was established when compared to MSG group. Conclusion: We concluded that CUR as flavor enhancer protects against MSG-induced neurotoxicity in rats.

Metformin augments doxorubicin cytotoxicity in mammary carcinoma through activation of adenosine monophosphate protein kinase pathway

Since the incidence of breast cancer increases dramatically all over the world, the search for effective treatment is an urgent need. Metformin has demonstrated anti-tumorigenic effect both in vivo and in vitro in different cancer types. This work was designed to examine on molecular level the mode of action of metformin in mice bearing solid Ehrlich carcinoma and to evaluate the use of metformin in conjunction with doxorubicin as a combined therapy against solid Ehrlich carcinoma. Ehrlich ascites carcinoma cells were inoculated in 60 female mice as a model of breast cancer. The mice were divided into four equal groups: Control tumor, metformin, doxorubicin, and co-treatment. Metformin (15 mg/kg) and doxorubicin (4 mg/kg) were given intraperitoneally (i.p.) for four cycles every 5 days starting on day 12 of inoculation. The anti-tumorigenic effect of metformin was mediated by enhancement of adenosine monophosphate protein kinase activity and elevation of P53 protein as well as the suppression of nuclear factor-kappa B, DNA contents, and cyclin D1 gene expression. Metformin and doxorubicin mono-treatments exhibited opposing action regarding cyclin D1 gene expression, phosphorylated adenosine monophosphate protein kinase, and nuclear factor-kappa B levels. Co-treatment markedly decreased tumor volume, increased survival rate, and improved other parameters compared to doxorubicin group. In parallel, the histopathological findings demonstrated enhanced apoptosis and absence of necrosis in tumor tissue of co-treatment group. Metformin proved chemotherapeutic effect which could be mediated by the activation of adenosine monophosphate protein kinase and related pathways. Combining metformin and doxorubicin, which exhibited different mechanisms of action, produced greater efficacy as anticancer therapeutic regimen.

Protective effect of mirtazapine and hesperidin on cyclophosphamide-induced oxidative damage and infertility in rat ovaries.

Cyclophosphamide (CP) causes infertility due to ovarian toxicity. The toxicity mechanism suggests oxidative stress. We assessed whether mirtazapine (MTZ) and hesperidin (HSP) could promote ovarian protection against damage due to CP chemotherapy. Female Wistar rats aged 14 weeks were used. Animals were divided into four groups: control vehicle group (n = 8); CP group (n = 8, rats received 150 mg/kg of CP, single intraperitoneal [i.p.] injection); CP + MTZ group (n = 8, rats received same dose of CP + 30 mg/kg of MTZ, orally, daily); and HSP + CP group (n = 8, rats received same dose of CP + 100 mg/kg of HSP, orally, daily). After eight days of medication, ovaries were removed and ovarian toxicity was assessed by counting follicles and corpora lutea. Nitric oxide (NO) and malondialdehyde (MDA) levels, myeloperoxidase (MPO), glutathione peroxidase (GPx), and superoxide dismutase (SOD) activities were estimated in ovarian tissue. NO level, MDA level, and MPO activity were increased (P < 0.001), while, GPx and SOD activities were lowered significantly (P < 0.001) in CP-treated group compared with control vehicle. In addition, ovulation, number of follicles, and ovarian weight were reduced by CP treatment. On the contrary, rats pretreated with MTZ and HSP showed significant decrease in NO, MDA levels, and MPO activity, while, activities of SOD and GPx were increased (P < 0.001). Oxidative stress induced by CP in the rat ovary causes infertility in the female rats. HSP and MTZ could reverse this effect and provide protection of fertility against CP-induced toxicity.

Branched Chain Amino Acids Supplementation Modulates TGF-β1/ Smad Signaling Pathway and Interleukins in CCl4 – Induced Liver Fibrosis

The alterations and low levels of circulating branched chain amino acids (BCAAs), leucine, isoleucine, and valine, are associated with liver diseases. The study was designed to evaluate hepatoprotective effect of BCAAs on CCl4‐induced liver fibrosis and to investigate the molecular mechanisms underlying these effects in rats. In all, 30 male rats were divided into three groups. Control group (n = 10) and CCl4 group (n = 10), where rats were injected with CCl4 (1 mL/kg of 0.5 : 1 v/v injected i.p. twice weekly for 12 weeks). In CCl4 + BCAAs group (n = 10), rats were injected with similar doses of CCl4 and supplemented with a mixture of 600 mg/kg BCAAs (2 : 1 : 1.2 leucine : isoleucine : valine) by oral gavage, three times/week for 12 weeks. Liver fibrosis was assessed by measuring total bilirubin, total protein, alanine aminotransferase, and aspartate aminotransferase, hydroxyproline content, and serum IL‐6 and IL‐10. Histopathologic studies and α‐smooth muscle actin (α‐SMA) were detected immunohistochemically in liver. Serum insulin level, blood glucose, liver malodialdehyde concentration (MDA), glutathione peroxidase, and superoxide dismutase (SOD) activities were quantified. TGF‐β1, Smad3, and Smad7 gene expressions were estimated by qRT‐PCR. BCAAs suppressed liver fibrosis induced by CCl4 treatment. BCAAs modulated liver indices and downregulated TGF‐β1, Smad3, and Smad7 expressions in hepatocytes. BCAAs enhanced liver antioxidant enzyme activities (P < 0.001), reduced serum levels of TGF‐β1, IL‐6, and IL‐10 compared to CCL4 group and ameliorated histopathologic changes in rat liver. BCAAs may have a protective role against liver fibrosis via antioxidant and anti‐inflammatory mechanisms.

Roflumilast, type 4 phosphodiesterase inhibitor, attenuates inflammation in rats with ulcerative colitis via down-regulation of iNOS and elevation of cAMP

Background: Roflumilast (Rof), a phosphodiesterase 4 (PDE4) inhibitor, has been shown to be an effective agent in inflammatory diseases and marketed for chronic obstructive pulmonary disease. Objective: This study was conducted to examine the potential anti‐inflammatory effects of Rof in dextran sulphate sodium (DSS)–induced ulcerative colitis (UC) in rats and to investigate the molecular mechanisms underlying these effects. Methods: Forty male Wistar rats were divided into four groups: normal control, colitis group (rats received 5% DSS in their drinking water continuously for 7 days), Rof group, and sulfasalazine (SLZ) group. The Rof (5 mg/kg) and SLZ (500 mg/kg) groups underwent pretreatment with DSS one week ahead of DSS challenge and parallel with DSS. Colitis was determined by assessing colon length, weight loss, histologic colon score, quantifying the concentration of tumor necrosis factor alpha (TNF‐&agr;), nitric oxide (NO), cyclic adenosine monophosphate (cAMP), myeloperoxidase (MPO) activity and inducible nitric oxide synthase (iNOS) gene expression in colon tissue. Results: Rof attenuated the severity of colitis as evidenced by increased colon length, prevention of body weight loss, and improved colon histologic score compared to DSS group. Rof also suppressed the inflammatory response induced in DSS colitis group by decreasing colon concentration of TNF‐&agr;, NO and MPO activity and down‐ regulation of iNOS gene expression. The level of cAMP was increased by Rof compared to DSS group. The obtained results of Rof were comparable to those exerted by SLZ. Conclusion: These findings revealed the beneficial effects of Rof in alleviating inflammation in DSS colitis.

Suppression of inducible nitric oxide synthase and tumor necrosis factor-alpha level by lycopene is comparable to methylprednisolone in acute pancreatitis

BACKGROUND Oxidative stress and inflammation may play a key role in the pathogenesis of acute pancreatitis (AP). Lycopene, a natural carotenoid, has antioxidant scavenger capacity and inhibits inflammation in many experimental models. AIM The study was designed to investigate whether lycopene can ameliorate l-arginine-induced pancreatitis in rats and to elucidate the underlying molecular mechanisms of these effects. METHODS Forty-eight adult male Wistar rats were divided into: control group (vehicle, orally, 10 days), AP group (3 g/kg l-arginine, single i.p. injection, on day 10th of the experiment), lycopene group (50 mg/kg) and methylprednisolone group (30 mg/kg). Lycopene and methylprednisolone were given orally, once daily for 10 days prior to l-arginine injection. Rats were sacrificed 24 h after l-arginine injection. Inflammation/oxidative stress and pancreatic markers were assessed. Pancreatic histopathological studies were done. RESULTS Lycopene group showed a significant reduction in tumor necrosis factor alpha (TNF-α), myeloperoxidase activity, and down-regulation of inducible nitric oxide synthase (iNOS) gene expression. Pancreatic nitric oxide concentration was reduced and pancreatic GSH was increased in lycopene group. Serum α-amylase and lipase activities were reduced by lycopene treatment. The histology of pancreas was improved in lycopene group as well as methylprednisolone group. CONCLUSION Lycopene prior treatment proved anti-inflammatory and antioxidant effects against AP rat model via different mechanisms.

Upregulation of PPAR-γ mediates the renoprotective effect of omega-3 PUFA and ferulic acid in gentamicin-intoxicated rats

Ferulic acid (FrA) is a natural product containing phenolic compounds. ω-3 PUFA is the major constituent of fish oil. The aim of this study was to investigate the renoprotective role of FrA and FO in gentamicin (GM)-induced nephrotoxicity in rats. Forty four male rats were divided equally into 4 groups: Control group, GM group, FrA + GM group and FO + GM group. Each of the treated groups was injected with GM (40 mg/kg) i.p. for 9 consecutive days. FrA (100 mg/kg) and FO (5 mL/kg) were given to rats orally daily for 10 days prior to GM and then concomitantly with GM for additional 9 days. Kidney function was assessed by serum BUN and creatinine, urinary albumin excretion and N-acetyl-beta-D-glucosaminidase (NAG) activity and histopathological examination. The anti-inflammatory property was evaluated by measuring renal resolvin E1 and gene expression of PPAR-γ. The antioxidant activity was indicated by renal catalase (CAT) activity. GM-induced nephrotoxicity was evidenced by the renal histopathological changes along with increased renal indices. Prior and concomitant treatment with FrA or FO ameliorated nephrotoxic effect of GM as indicated by the significant decrease of serum BUN and creatinine, urinary albumin excretion and urinary NAG activity. Both treatments significantly enhanced CAT activity and gene expression of PPAR-γ. Resolvin E1 was significantly elevated in FO but not in FrA group. FrA and FO proved anti-inflammatory and renoprotective effects, which could be through their PPAR-γ agonist activity. Because FrA and FO are natural products, they could provide a safe intervention strategy in cases of exposure to nephrotoxins.

Fish Oil and Wheat Germ Oil Supplementation Modulates Brain Injury in Streptozotocin-Induced Diabetic Rats.

Uncontrolled diabetes mellitus causes neuronal damage because of increased intracellular glucose. Natural products as complementary therapy may reduce neuronal complications. This study investigated whether fish oil (FO) and wheat germ oil (WGO) supplementation protects the brain in streptozotocin (STZ)‐induced diabetic rats by estimating lipid peroxidation and the inflammatory and anti‐oxidant status of the brain.