M. A. Shalaby

Safety and efficacy of Zingiber officinale roots on fertility of male diabetic rats.

The acute toxicity of methanolic and watery extracts of Zingiber officinale (ZO) roots in mice and their effects on fertility of male diabetic rats were carried out. The fertility experiment was done on six groups of male rats one of them was kept as normal control, while the others were rendered diabetic by subcutaneous injection of alloxan (120 mg kg(-1)). One group was left as diabetic control, while the others were given orally either methanolic (100 and 200 mg kg(-1)) or watery extract (150 and 300 mg kg(-1)) for 65 consecutive days. The results showed that no mortalities occur when both extracts were given orally to mice in doses up to 5 g kg(-1) b.wt. Both extracts increased fertility index, sexual organs weight, serum testosterone level and sperm motility and count. Histopathological examination of the testes of diabetic rats showed mild to moderate degenerative changes of spermatogenic cells, diffuse edema and incomplete arrest of spermatogenesis. Treatment with ZO extracts caused alleviation of the testicular lesions that appeared in non-treated diabetic rats. Conclusively, extracts of ZO have high safety in mice and intake of ZO roots as a drink may be useful for diabetic patients who suffer from sexual impotency.

Reproductive toxicity of methomyl insecticide in male rats and protective effect of folic acid.

The acute toxicity (LD(50)) of insecticide methomyl and its effects on male reproduction in rats were carried out. Methomyl was given orally to male rats daily for 65 successive days at two doses (0.5 and 1.0 mg kg(-1) b.wt., corresponding to 1/40 and 1/20 LD(50)) alone and in combination with folic acid (1.1 mg kg(-1) b.wt., corresponding to acceptable daily intake, ADI). Fertility index, weight of sexual organs, semen picture, serum testosterone level and histopathology of testes were the parameters used to evaluate the reproductive efficiency of treated rats. The reversibility of methomyl effects was also studied after 65 days post-administration. The oral LD(50) of methomyl was 20.0 mg kg(-1) b.wt. in male rats. Methomyl significantly decreased the fertility index, weight of testes and accessory male sexual glands, serum testosterone level and sperm motility and count, but increased sperm cell abnormality. It induced testicular lesions characterized by moderate to severe degenerative changes of seminiferous tubules and incomplete arrest of spermatogenesis. These toxic effects were not persistent (reversible). Coadministration of folic acid with methomyl decreased its reproductive toxicity. A great attention should be taken during field application of methomyl to avoid its deleterious effects in farm animals and occupationally exposed humans.

Etiology of sarcoplasmic reticulum calcium release channel lesions in doxorubicin-induced cardiomyopathy

Alterations in the native function of the ryanodine-sensitive Ca2+ release channel complex of sarcoplasmic reticulum (SR) isolated from rat cardiac ventricles during acute and chronic exposure to doxorubicin are examined. Compared to control SR, actively loaded SR from animals exposed to a single intravenous dose of doxorubicin exhibit faster rates of doxorubicin-induced Ca2+ release and the occupancy of [3H]ryanodine is significantly enhanced with subsequent exposure of SR membranes to doxorubicin in vitro. One week after acute exposure to doxorubicin in vitro, the EC50 for activation of the binding of [3H]ryanodine by Ca2+ is not significantly different from control SR. However, the persistence of doxorubicin-sensitized SR channels appears to be latent since repeated exposure to doxorubicin in vitro significantly enhances receptor occupancy in SR obtained from the treated rats compared to control SR. Ryanodine receptors from rats chronically exposed to doxorubicin consistently exhibit a higher sensitivity to activation Ca2+ which persists at least 4 weeks following the last injection of drug. Chronic exposure produces a concomitant reduction in the capacity of [3H]ryanodine binding sites. The marked decrease in receptor density observed with SR from doxorubicin-treated rats coincides with significant reduction in body weight, suggesting a possible influence of nutrition. However, sodium dodecyl sulfate polyacrylamide electrophoresis indicates no significant loss of the high molecular weight subunit of the ryanodine receptor, suggesting that loss of [3H]ryanodine-binding capacity may be the result of progressive and permanent channel desensitization. Consistent with desensitized receptors, membrane vesicles prepared from rats chronically exposed to doxorubicin take up significantly more Ca2+ and exhibit significantly reduced rates of doxorubicin or Ca2+/ryanodine induced Ca2+ release. The data demonstrates (i) doxorubicin inflicts cumulative SR channel lesions in vivo, (ii) a persistent sensitization of the SR channel to activation by Ca2+ and (iii) a significant and apparently irreversible reduction in the number of functional channel complexes.

Some pharmacological effects of cinnamon and ginger herbs in obese diabetic rats.

Aims: The present study was designed to assess some pharmacological effects of cinnamon (CAE) and ginger (GAE) aqueous extracts in obese diabetic rats, and to elucidate the potential mechanisms. Materials and Methods: Forty-two Sprague-Dawley rats were randomized into 6 equal groups. Group 1 was a negative control and the other groups were rendered obese by feeding rats on high-fat diet for 4 weeks. The obese rats were subcutaneously injected with alloxan for 5*days to induce diabetes. Group 2 was a positive control, and Groups 3, 4, 5 and 6 were orally given CAE in doses 200 and 400 mg/kg and GAE in the same doses, respectively for 6 weeks. Blood samples were collected for serum biochemical analyses. Kidneys were dissected out to assay activity of tissue antioxidant enzymes: Superoxide dismutase, glutathione peroxidase and catalase. Results: CAE and GAE significantly reduced body weight and body fat mass; normalized serum levels of liver enzymes; improved lipid profile; decreased blood glucose and leptin and increased insulin serum levels in obese diabetic rats. Both extracts also increased activity of kidney antioxidant enzymes. Conclusion: CAE and GAE exhibit anti-obesity, hepatoprotective, hypolipidemic, antidiabetic and anti-oxidant effects in obese diabetic rats. These results confirm the previous reports on both extracts. The potential mechanisms underlying these effects are fully discussed and clarified. Our results affirm the traditional use of cinnamon and ginger for treating patients suffering from obesity and diabetes. The obese diabetic rat model used in this study is a novel animal model used in pharmacology researches.

Analgesic, anti-inflammatory and anti-hyperlipidemic activities of Commiphora molmol extract (Myrrh).

Aim: The aim was to evaluate the analgesic, anti-inflammatory, and anti-hyperlipidemic activities of Commiphora molmol extract (CME) and its effects on body weight and blood lipids. Materials and Methods: The analgesic effect was assessed using thermal (hot plate test) and chemical (writhing test) stimuli to induce central and peripheral pain in mice. The anti-inflammatory activity was determined using formalin-induced paw edema in rats. For anti-hyperlipidemic effect, 25 rats were randomly divided into five groups (n = 5). Group 1 was fed on basal diet (normal control), while the other four groups were fed on high-fat diet for 6 weeks to induce obesity and hyperlipidemia. Thereafter, Group 2 was kept obese hyperlipidemic, and Groups 3, 4 and 5 were orally given CME in doses of 125, 250, and 500 mg/kg for 6 weeks, respectively. Body weight gains of rats were calculated, and blood samples were collected for analysis of blood lipids. Results: CME produced a dose-dependent analgesic effect using both hot plate and writhing tests in mice. The hot plate method appeared to be more sensitive than writhing test. CME exhibited an anti-inflammatory activity as it decreased volume of paw edema induced by formalin in rats. The extract decreased body weight gain; normalized the high levels of blood lipids and decreased atherogenic index low-density lipoprotein/ high-density lipoprotein in obese hyperlipidemic rats. Conclusion: The results denote that C. molmol extract (myrrh) has significant analgesic, anti-inflammatory and anti-hyperlipidemic effects and reduces body weight gain and improves blood lipids profile. These results affirm the traditional use of C. molmol for the treatment of pain, inflammations, and hyperlipidemia.

Assessment of protective and anti-oxidant properties of Tribulus terrestris fruits against testicular toxicity in rats.

Aims: This study was carried out to assess the protective and anti-oxidant activities of the methanolic extract of Tribulus terrestris fruits (METT) against sodium valproate (SVP)-induced testicular toxicity in rats. Materials and Methods: Fifty mature male rats were randomly divided into five equal groups (n = 10). Group 1 was used normal (negative) control, and the other four groups were intoxicated with SVP (500 mg/kg–1, orally) during the last week of the experiment. Group 2 was kept intoxicated (positive) control, and Groups 3, 4 and 5 were orally pre-treated with METT in daily doses 2.5, 5.0, and 10.0 mg/kg–1 for 60 days, respectively. Weights of sexual organs, serum testosterone, follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels, semen picture, testicular anti-oxidant capacity and histopathology of testes were the parameters used in this study. Results: Oral pre-treatment with METT significantly increased weights of testes and seminal vesicles; serum testosterone, FSH and LH levels and sperm motility, count and viability in SVP-intoxicated rats. METT enhanced the activity of testicular anti-oxidant enzymes and partially alleviated degenerative changes induced by SVP in testes. Conclusion: The pre-treatment with METT has protective and anti-oxidant effects in SVP-intoxicated rats. Mechanisms of this protective effect against testicular toxicity may be due to the increased release of testosterone, FSH and LH and the enhanced tissue anti-oxidant capacity. These results affirm the traditional use of T. terrestris fruits as an aphrodisiac for treating male sexual impotency and erectile dysfunction in patients. The study recommends that T. terrestris fruits may be beneficial for male patients suffering from infertility.

THE ROLE OF LIVER IN LEPTIN METABOLISM IN EXPERIMENTAL NEPHROTIC SYNDROME

Leptin is a hormone influencing food intake, energy expenditure and body weight. It is produced by adipocytes, exerts its effects on brain, endocrine pancreas and other organs by activating trans-membrane receptors and is cleared from plasma mainly by the kidneys. Several studies have suggested that leptins effects on metabolism are mediated by the liver. Our aim was to evaluate the role of the liver in the metabolism of leptin by comparing the serum leptin level in the portal vein with that in inferior vena cava and to study the relationship between leptin and lipoprotein levels in healthy and nephrotic rats. Experimental nephrotic syndrome was conducted in rats by intraperitoneal injection of the supernatant from the kidney suspension obtained by previous unilateral nephrectomy of the same rat and complete Freunds adjuvant. There was a highly significant rise in leptin and lipid profile levels in the nephrotic rats compared with the normal rats. A highly significant increase in leptin in the inferior vena cava was detected compared with the level in the portal veins of nephrotic rats, while insignificant difference was observed in normal rats. This work has stressed the role of liver in leptin and lipid metabolism in nephrotic rats.

Phytochemical, antioxidant and hepatoprotective effects of different fractions of Moringa oleifera leaves methanol extract against liver injury in animal model

Objective: To evaluate the potential antioxidant and hepatoprotective effects of n-hexane, dichloromethane(DCM), ethyl acetate(EtOAc), n-butanol and aqueous fractions of Moringa oleifera(M. oleifera) leaves methanol extract against carbon tetrachloride(CCl4)-induced liver injury in rats. Methods: These fractions were prepared from the M. oleifera leaves methanol extract by solubilization in water and partitioning in n-hexane, EtOAc, DCM and n-butanol. Their phyto-components were identified by GC-MS analysis. The in vitro antioxidant effect of these fractions was carried out by assessment of 1,1-diphenyl-2-picrylhydrazyl scavenging activity. A total of 40 Sprague Dawley rats were allocated into 8 equal groups: group 1 given olive oil (1 mL/kg b.wt.), group 2 injected with CCl4, group 3 to 7 administered with n-hexane, DCM, EtOAc, n-butanol and aqueous fractions, respectively after CCl4, group 8 administered with silymarin after CCl4. The activities of aspartate aminotransferase, alanine aminotransferase, and the levels of total cholesterol, triglycerides, glucose, total proteins and albumin in serum were determined spectrophotometrically. Glutathione reduced, lipid peroxide by-products levels, glutathione-s-transferase and catalase enzyme activities in the liver homogenate were determined by spectrophotometer. Liver specimens were also examined for histopathological alterations under light microscope. Results: The GC-MS analysis of different fractions of the M. oleifera leaves methanol extract revealed that n-hexane, DCM, EtOAc, n-butanol, and aqueous fractions contained 17, 22, 23, 19 and 32 compounds, respectively. The percent and the molecular structure of each component in each fraction were identified. The n-butanol and EtOAc fractions exhibited the strongest in vitro antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl. CCl4 significantly decreased glutathione reduced and total proteins concentration and glutathione-s-transferase and catalase activities but increased lipid peroxide by-products and total cholesterol levels. The n-hexane followed by aqueous and DCM fractions were the most potent to regulate serum enzyme activities and lipid peroxide by-products levels in the liver homogenate. Conclusions: n-hexane, DCM, and aqueous fractions have the highest effectiveness against CCl4-induced hepatotoxicity. Isolation and purification of the active constituents require further experiments.