Pygeum africanum: effect on oxidative stress in early diabetes-induced bladder.
ABSTRACT To evaluate the effect of Pygeum africanum on oxidative stress and functional changes of the bladder after diabetes induction.
Thirty-two adult Wistar male rats were treated daily for 8 weeks and grouped as follows: Control group (n = 6), Streptozotocin-induced diabetic group (n = 10), diabetes plus P. africanum group (n = 10), and control plus P. africanum group (n = 6). After diabetes induction for 4 weeks, the diabetes plus P. africanum and control plus P. africanum groups were fed with P. africanum (100 mg/kg, orally) in peanut oil for another 4 weeks. The catalase, superoxide dismutase activity, and malondialdehyde levels were measured as a marker of lipid peroxidation. The levels of inducible nitric oxide synthase were also evaluated. Urodynamic studies were performed to evaluate the functional changes of diabetic bladders after P. africanum treatment.
The catalase and superoxide dismutase activities significantly increased (P < 0.05) and maleic dialdehyde levels significantly decreased from diabetic plus P. africanum group compared with diabetic group (P < 0.05). Immunohistochemical studies showed a significantly decreased number of inducible nitric oxide synthase-positive cells in diabetic plus P. africanum group compared with diabetic group (P < 0.05). In diabetic plus P. africanum group, maximal bladder volume significantly decreased, while bladder pressure and maximal bladder pressure significantly increased compared with diabetic group (P < 0.05).
Early treatment with P. africanum could effectively suppress the oxidative stress status in diabetic bladder and may slow down the process of diabetic cystopathy.
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ABSTRACT: To evaluate the gene and protein expression of nerve growth factor (NGF) and substance P (SP) in the bladder 8 weeks after diabetes induction and investigate the pathogenesis of diabetic cystopathy. Thirty Wistar rats were divided into three groups: control (n = 10), streptozotocin-induced diabetic group (n = 10) and Pygeum africanum (P. africanum) group (n = 10; diabetic rats were given P. africanum (100 mg/kg/day)). Eight weeks later, the bladders were dissected. We measured the expression of NGF and SP in the bladders using RT-PCR, ELISA and immunohistochemistry. We found a significantly reduced expression of NGF in the bladders from the diabetic group compared with the control. Immunohistochemical studies showed a statistically significant reduction of SP in the bladders from the diabetic group compared with the control (P < 0.05). Expression of NGF was greatly increased in the P. africanum group compared with that of the diabetic group. Immunohistochemical studies showed an increased level of SP in the bladders from the P. africanum group compared with the control (P < 0.05). Our findings indicated that the decrease in NGF and SP may be a contributory factor in diabetic cystopathy. In addition, P. africanum could significantly upregulate the expression of NGF and SP in diabetic rats.International Urology and Nephrology 03/2011; 43(1):109-16. · 1.33 Impact Factor
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ABSTRACT: This study investigated the inhibitory effect of grape seed proanthocyanidin extract (GSPE) on selenite-induced cataract formation in rats and the possible mechanism. Eighty 8-day-old Sprague-Dawley rats were divided randomly into 5 groups: control group, model group, three GSPE groups (low dose, medium dose and high dose). Control group received subcutaneous injection of physiological saline. Model group was given subcutaneous injection of sodium selenite (20 μmol/kg body weight) on the postpartum day 10, and once every other day for consecutive three times thereafter. GSPE treated groups were respectively administered GSPE at doses of 50, 100, and 200 mg/kg body weight intragastrically 2 days prior to the selenite injection (that was, on the postpartum day 8), and once daily for fourteen consecutive days thereafter. The opacity of lenses was observed, graded and photographed under the slit lamp microscopy and the maximal diameter of the nuclear cataract plaques was measured. The lenses were analyzed for superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-PX), malondialdehyde (MDA), calcium (Ca(2+)), nitric oxide (NO) and anti-hydroxyl radical ability (anti-OH(-)). The histomorphology of lenses was observed with HE staining under a light microscope. The levels of calpainII, and iNOS protein and mRNA expression in lenses were detected by using immunohistochemistry and real-time quantitative RT-PCR. The results showed subcutaneous injection of sodium selenite led to severe nuclear cataract in model group, and the achievement ratio of model group was 100%. As compared with model group, the degree of lenses opacity and the maximal diameter of nuclear cataract plaques were significantly reduced in GSPE-treated groups. Moreover, we observed selenite treatment caused a significant decrease in the activities of antioxidative enzymes (SOD, CAT, GSH-PX) and anti-OH(-) ability, accompanied by a significant increase in the levels of MDA, NO, Ca(2+) as well as iNOS, and calpainII protein and mRNA expression. Administration of GSPE could dose-dependently preserve the activities of these antioxidative enzymes and anti-OH(-) ability, accompanied by a significant reduction in the levels of MDA, NO, Ca(2+) as well as iNOS, and calpainII protein and mRNA expression. These results suggested that GSPE markedly prevented selenite-induced cataract formation probably by suppressing the generation of lipid peroxidation and free radicals as well as the activation of iNOS, and calpainII in the lenses.Journal of Huazhong University of Science and Technology 08/2012; 32(4):613-9. · 0.58 Impact Factor
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ABSTRACT: Partial bladder outlet obstruction (PBOO) in rabbits causes free radical production through ischemia and reperfusion within the bladder smooth muscle and mucosa. We had previously shown that pretreatment of rabbits with a combination of α-lipoic acid (αLA) and coenzyme Q10 (CoQ) protected the bladder from contractile and metabolic dysfunctions mediated by PBOO. In this study, we examined the ability of pretreatment with αLA and CoQ combination in rabbits to protect the bladder from contractile damage mediated by either hydrogen peroxide (H(2)O(2)) or in vitro ischemia-reperfusion (I/R) which represents two in vitro models of oxidative damage. Eight adult male New Zealand white rabbits were pretreated with CoQ and αLA orally for four weeks. Eight adult male control rabbits were given vehicle. Eight full-thickness bladder strips were isolated from each of 4 treated and 4 control rabbit bladders, and a dose-response curve to H(2)O(2) (0.1-0.8%) was generated. Similarly, isolated strips of bladder from the remaining 4 control and 4 treated rabbits were subjected to 1 h of ischemia (no oxygen without glucose) followed by 2 h of incubation in oxygenated buffer with glucose. The effects on the contractile responses to field stimulation (FS) at 2, 8, and 32 Hz, carbachol, and potassium chloride (KCl) were determined. H(2)O(2) reduced the contractile responses to KCl and carbachol to a significantly greater degree than to FS, whereas I/R reduced the contractile responses to FS to a significantly greater degree than to KCl and carbachol. Pretreatment of the rabbits with the combination of CoQ and αLA significantly protected the bladder from the damaging effects of I/R, but had virtually no effect on the damaging effects of H(2)O(2). Although both H(2)O(2) and I/R are in vitro models of oxidative free radical damage to bladder smooth muscle, they have significantly different methods of action and different sensitivities to antioxidants.International Urology and Nephrology 03/2011; 43(1):91-7. · 1.33 Impact Factor