MATERIALS AND METHODS: Sprague-Dawley rats were randomly divided into 5 groups, namely: normal control (NC), diabetic control (DC), diabetic on 300 mg/kg b.w. MP, diabetic on 300 mg/kg b.w. metformin, and diabetic on MP and metformin combined therapy. Treatment was done orally for 4 weeks, and NC and DC groups received distilled water as vehicle.
KEY FINDINGS: Results showed increased fasting blood glucose and serum markers of hepatic lesion (aspartate aminotransferase, alkaline phosphatase, alanine aminotransferase and gamma-glutamyl transferase), increased hepatic lactate dehydrogenase activity, decreased hepatic superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase and glutathione reductase activities, increased immunoexpressions of nuclear factor kappa B, tumor necrosis factor-α, interleukin(IL)-1β and caspase-3, and decreased immunoexpressions of IL-10 and proliferating cell nuclear antigen in the liver of DC group. Histopathology of the liver revealed numerous hepatocytes with pyknotic nuclei and inflammatory infiltration, while periodic acid-schiff staining decreased in the liver of DC group. Treatment with MP attenuated these negative effects and was comparable to metformin. Furthermore, these effects were better attenuated in the combined therapy-treated diabetic rats.
SIGNIFICANCE: Malaysian propolis attenuates hepatic lesion in DM and exerts a synergistic protective effect with the anti-hyperglycemic medication, metformin.
OBJECTIVES: To investigate the effect of metformin on the expression of testicular steroidogenesis-related genes, spermatogenesis, and fertility of male diabetic rats.
MATERIALS AND METHODS: Eighteen adult male Sprague Dawley rats were divided into three groups, namely normal control (NC), diabetic control (DC), and metformin-treated (300 mg/kg body weight/day) diabetic rats (D+Met). Diabetes was induced using a single intraperitoneal injection of streptozotocin (60 mg/kg b.w.), followed by oral treatment with metformin for four weeks.
RESULTS: Diabetes decreased serum and intratesticular testosterone levels and increased serum but not intratesticular levels of luteinizing hormone. Sperm count, motility, viability, and normal morphology were decreased, while sperm nuclear DNA fragmentation was increased in DC group, relative to NC group. Testicular mRNA levels of androgen receptor, luteinizing hormone receptor, cytochrome P450 enzyme (CYP11A1), steroidogenic acute regulatory (StAR) protein, 3β-hydroxysteroid dehydrogenase (HSD), and 17β-HSD, as well as the level of StAR protein and activities of CYP11A1, 3β-HSD, and 17β-HSD, were decreased in DC group. Similarly, decreased activities of epididymal antioxidant enzymes and increased lipid peroxidation were observed in DC group. Consequently, decreased litter size, fetal weight, mating and fertility indices, and increased pre- and post-implantation losses were recorded in DC group. Following intervention with metformin, we observed increases in serum and intratesticular testosterone levels, Leydig cell count, improved sperm parameters, and decreased sperm nuclear DNA fragmentation. Furthermore, mRNA levels and activities of steroidogenesis-related enzymes were increased, with improved fertility outcome.
DISCUSSION AND CONCLUSION: Diabetes mellitus is associated with dysregulation of steroidogenesis, abnormal spermatogenesis, and fertility decline. Controlling hyperglycemia is therefore crucial in preserving male reproductive function. Metformin not only regulates blood glucose level, but also preserves male fertility in diabetic state.
OBJECTIVE: To examine the effects of metformin on parameters involved in testicular lactate production, transport/utilisation, and sexual behaviour in diabetic state.
METHODS: Male Sprague-Dawley rats were assigned into normal control (NC), diabetic control (DC), and metformin-treated diabetic group (n = 6/group). Metformin (300 mg/kg b.w./day) was administrated orally for 4 weeks.
RESULTS: Intra-testicular glucose and lactate levels, and lactate dehydrogenase (LDH) activity increased, while the mRNA transcript levels of genes responsible for testicular glucose and lactate transport/utilisation (glucose transporter 3, monocarboxylate transporter 4 (MCT4), MCT2, and LDH type C) decreased in DC group. Furthermore, penile nitric oxide increased, while cyclic guanosine monophosphate decreased, with impaired sexual behaviour in DC group. Treatment with metformin improved these parameters.
CONCLUSIONS: Metformin increases testicular lactate transport/utilisation and improves sexual behaviour in diabetic state.
METHODS: Wistar rats employed for this study consisted of normoglycaemic and diabetic rats in nine experimental groups. The normoglycaemic and diabetic rats were either treated with metformin (500 mg/kg b.w.), quercetin (10 mg/kg b.w.), or ethanol extract of H. verticillata leaf (250 mg/kg b.w. and 500 mg/kg b.w.) administered orally for 28 days.
KEY FINDINGS: Results revealed that H. verticillata significantly lowered blood glucose level, attenuated dyslipidaemia, decreased atherogenic coefficient, atherogenic and coronary risk indices, and increased cardioprotective index in diabetic rats. Also, H. verticillata significantly decreased serum urea, creatinine, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and unconjugated bilirubin levels, relative to untreated diabetic rats. Further, H. verticillata increased serum superoxide dismutase, catalase and glutathione peroxidase activities and glutathione level, and decreased malondialdehyde level in diabetic rats in a manner similar to metformin and quercetin. Histopathological investigation of the liver and kidney revealed restored hepatocytes and amelioration of congested interstitial blood vessel of the Bowman's space of the kidneys upon intervention with H. verticillata.
SIGNIFICANCE: H. verticillata in addition to its anti-hyperglycaemic activity ameliorates oxidative stress, dyslipidaemia, atherogenicity and hepatorenal lesions in DM.
OBJECTIVES: We explored the possible preventive/therapeutic effects of orlistat (a medication prescribed for weight loss) on obesity-induced steroidogenesis and spermatogenesis decline.
MATERIALS AND METHODS: Twenty-four adult male Sprague Dawley rats weighing 250-300 g were randomized into four groups (n = 6/group), namely; normal control, high-fat diet, high-fat diet plus orlistat preventive group and high-fat diet plus orlistat treatment group. Orlistat (10 mg/kg/b.w./d suspended in distilled water) was either concurrently administered with high-fat diet for 12 weeks (high-fat diet plus orlistat preventive group) or administered from week 7-12 post- high-fat diet feeding (high-fat diet plus orlistat treatment group). Thereafter, serum, testes and epididymis were collected for analyses.
RESULTS: Obesity increased serum leptin and decreased adiponectin levels, decreased serum and intra-testicular levels of follicle stimulating hormone, luteinising hormone and testosterone, sperm count, motility, viability, normal morphology and epididymal antioxidants, but increased epididymal malondialdehyde level and sperm nDNA fragmentation. Testicular mRNA transcript levels of androgen receptor, luteinizing hormone receptor, steroidogenic acute regulatory protein, cytochrome P450 enzyme (CYP11A1), 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase were significantly decreased in the testes of the high-fat diet group. Further, the levels of steroidogenic acute regulatory protein protein and enzymatic activities of CYP11A1, 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase were also significantly decreased in the testes of the high-fat diet group. Treatment with orlistat significantly decreased leptin and increased adiponectin levels, improved sperm parameters, decreased sperm DNA fragmentation, increased the levels of steroidogenic hormones, proteins and associated genes in high-fat diet-induced obese male rats, with the preventive group (high-fat diet plus orlistat preventive group) having better results relative to the treatment group (high-fat diet plus orlistat treatment group).
DISCUSSION AND CONCLUSION: Orlistat attenuated impaired spermatogenesis and steroidogenesis decline by up-regulating steroidogenic genes. This may not be unconnected to its significant effect in lowering serum leptin levels, since the hormone is known to dampen fertility potential. Therefore, orlistat may improve fertility potential in overweight/obese men.
MATERIALS AND METHODS: Whole ethanol extract (WE) of the nuts, and its liquid-liquid fractions-ethyl acetate (ET) and residue (RES) were separately administered to obese rats for 6 weeks. The normal (NC) and obese (OC) controls received normal saline and the standard control (SC), orlistat (5.14 mg/kg b.w.), during the same period. Thereafter, the animals were euthanized and the adipose, brain, kidneys and heart tissues were studied.
RESULTS: The change in body weight to naso-anal length which increased by 63.52 % in OC compared to NC (p < 0.05), decreased by 57.88, 85.80 and 70.20 % in WE, ET and RES-treated groups, respectively, relative to the OC (p < 0.05). Also, adipose tissue weights were lowered upon treatment with the extracts and fractions versus OC (p < 0.05). Total lipids, phospholipids, triacylglycerol and cholesterol concentrations in the studied tissues which were higher in OC (p < 0.05) were lowered (p < 0.05) and compared favorably with SC. Further, malondialdehyde levels in the tissues were lowered upon treatment, compared to the OC (p < 0.05). Glutathione level and activities of glutathione peroxidase, superoxide dismutase and glutathione-S-transferase which were decreased (p < 0.05) in OC, were restored upon treatment with the extracts, relative to the obese control (p < 0.05).
SIGNIFICANCE: African walnuts assuaged lipogenesis, oxidative stress and peroxidation in extra-hepatic tissues of obese rats, hence, may attenuate ectopic fat accumulation and its associated pathogenesis.
OBJECTIVE: The study aimed to investigate the effect of African walnuts (Tetracarpidium conophorum) on lipids storage and the regulatory enzymes of hepatic lipid metabolism in obese rats.
METHODS: Nuts were extracted in ethanol (WE) and further separated to obtain the ethyl-acetate fraction (ET) and the residue (RES). These were administered orally to 3 groups of monosodium glutamate- obese rats (n = 6), respectively, for 6 weeks. Other groups in the study were: normal (NC), obese control (OC) and standard control (SC) which received orlistat. Hepatic total lipids, total phospholipids, triacylglycerol (TG), total cholesterol (TCHOL), 3-hydroxyl-3-methylglutaryl-CoA (HMG-CoA) reductase and paraoxonase were studied.
RESULTS: Total lipids, TG and TCHOL which increased in OC compared to NC group, decreased. HMG-CoA reductase activity decreased in the 3 study groups relative to OC. Paraoxonase activity which decreased in OC was up-regulated, while the magnitude of hepatic cholesterol decreased from 94.32 % in OC to 52.19, 65.43 and 47.04 % with WE, ET and RES, respectively. Flavonoids, alkaloids, glycosides, tannins and saponins were detected in the nut. GC-MS analysis revealed 16, 18 and 10 volatile components in WE, ET and RES, respectively. Unsaturated fatty acids (linolenic acids: 33.33, 47.95 and 50.93 %, and α-linolenic acids: 25, 19.66 and 26.63 %) in WE, ET and RES, respectively, are the most abundant, and likely to be responsible for the observed activity.
CONCLUSION: African walnuts can prevent hepatic lipid accumulation through reciprocal actions on HMG-CoA reductase and paraoxonase in obesity.