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The possible protective effect of betulinic acid on renal ischemia/reperfusion (I/R) injury was studied. Wistar Albino rats were unilaterally nephrectomized and subjected to 45 min of renal pedicle occlusion followed by 6 h of reperfusion. Betulinic acid (250 mg/kg, i.p.) or saline was administered at 30 min prior to ischemia and immediately before the reperfusion. Creatinine, blood urea nitrogen (BUN), lactate dehydrogenase (LDH) and TNF-alpha as well as the oxidative burst of neutrophil and leukocyte apoptosis were assayed in blood samples. Malondialdehyde (MDA), glutathione (GSH) levels, Na+, K+-ATPase and myeloperoxidase (MPO) activities were determined in kidney tissue which was also analysed microscopically. I/R caused significant increases in blood creatinine, BUN, LDH and TNF-alpha. In the kidney samples of the I/R group, MDA levels and MPO activity were increased significantly, however, GSH levels and Na+, K+-ATPase activity were decreased. Betulinic acid ameliorated the oxidative burst response to both formyl-methionyl-leucyl-phenylalanine (fMLP) and phorbol 12-myristate 13-acetate (PMA) stimuli, normalized the apoptotic response and most of the biochemical indices as well as histopathological alterations induced by I/R. In conclusion, these data suggest that betulinic acid attenuates I/R-induced oxidant responses, improved microscopic damage and renal function by regulating apoptotic function of leukocytes and inhibiting neutrophil infiltration. Copyright (C) 2009 John Wiley & Sons, Ltd.

This study was designed to determine the possible protective effect of grape seed extract (GSE), a widely used antioxidant dietary supplement, on hepatic ischemia/reperfusion (I/R) injury. Wistar albino rats were subjected to 45 min of hepatic ischemia, followed by a 60 min reperfusion period. GSE was administered in a dose of 50 mg/kg/day orally for 15 days before (I/R) injury and repeated before the reperfusion period. Liver samples were taken for histological examination or determination of hepatic malondialdehyde (MDA), glutathione (GSH) and myeloperoxidase (MPO) activity. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were determined to assess liver functions. Lactate dehydrogenase (LDH) and cytokines (TNF-alpha and IL-1 beta) were also assayed in serum samples for the evaluation of generalized tissue damage. Ischemia/reperfusion caused a significant decrease in hepatic GSH, and significant increases in MDA level, and MPO activity. Serum AST and ALT levels, as well as LDH activity and plasma TNF-alpha and IL-1 beta levels were also elevated in the I/R group. Treatment with GSE reversed all these biochemical parameters as well as histological alterations induced by I/R. In conclusion, GSE reduced I/R-induced organ injury through its ability to balance the oxidant-antioxidant status, to inhibit neutrophil infiltration and to regulate the release of inflammatory mediators. Copyright (c) 2007 John Wiley & Sons, Ltd.

Spermatogenesis is a long, complex and finely tuned process. During this process, the developing sperm cell is sensitive to endogenous and exogenous factors. Exposure to reproductive cytotoxic agents may damage somatic testicular cells or germ cells at different stages of differentiation, leading to a temporary or permanent impairment of fertility (Take et al. 2009). Many studies have shown that irradiation (IR) and hyperthermia (HT) lead to infertility due to decrease in spermatogenic colony growth, decrease in the number of sperm and in the weight of the testis in rats (Moore & Chase 1923; Brinkworth & Handelsman 2000). Moreover, short-term exposure of the testis to heat (Lue et al. 1999; Xu et al. 2003) and radiation (Allan et al. 1988; Hasegawa et al. 1997) causes apoptosis-related loss of germ cells in the adult rat. It is evident that significant permanent tissue hypoplasia can result following ionizing IR exposure in late foetal development. Exposure to ionizing IR in early development causes infertility by affecting the gonocytes (Jensh & Brent 1988). Ionized radiation triggers the apoptosis of the spermatogenic cells (Allan et al. 1988; Hasegawa et al. 1997). Depending on the dose and duration of ionizing radiation, spermatogenic cell damage can be irreversible (Brinkworth & Handelsman 2000). Another environmental factor causing infertility in males is high-temperature. Experimental studies have shown that HT leads to spermatogenic cell death depending on its duration and amplitude (Collins & Lacy 1969). All germ cells are associated with adjacent spermatogenic cells and with Sertoli cells. This dynamic relation is mediated by tight, gap and anchoring junctions (Russell 1993). Tight junctions between Sertoli cells and epididymal epithelia are important for the formation and functioning of the blood-testis and blood-epididymal barriers. Sertoli cell tight junctions in the seminiferous epithelium are close to the basement membrane. These junctions at the basal domain of Sertoli cells break down to allow the passage of preleptotene and leptotene spermatocytes across the blood-testis barrier, while new tight junction fibrils are formed under the migrating preleptotene and leptotene spermatocytes (Pelletier 2001). During this process, tight junctions have a coordinating role in the movement of early spermatocytes to the adluminal compartment of the seminiferous epithelium. Epithelial tight junctions are multimolecular membrane specializations comprising multiple integral membrane proteins such as zonula occludens-1 (ZO-1) and occludin. ZO-1, a 225-kDa protein, is an integral membrane protein found in the most superficial region of the tight junctions. Occludin, a 65-kDa protein, was the first tight junction–associated integral membrane protein identified in different types of epithelia (Furuse et al. 1993), including the rat testis and epididymis (Moroi et al. 1998). ZO-1 is necessary for the localization of occludin in tight junction. The main roles of tight junctions are to act as a physical barrier to prevent solutes and water from passing freely through the intercellular spaces and to create and maintain cell polarity (Tsukita & Furuse 1999). In the testis, tight junctions between Sertoli cells form part of the blood-testis barrier, which is important for the maintenance of a special physiological milieu for spermatogenesis and for the protection of germ cells from the immune system (Russell & Peterson 1985). Gonocytes are radiosensitive between 15–19 gestational days, and gonocytes proliferate and differentiate to the type A spermatogonia at postnatal first week (Moreno, 2001). The effects of ionizing radiation are reversible at 6 months after exposure in adults (Brinkworth & Handelsman 2000). Moreover, hyperthermia causes apoptosis in spermatogenic cells over long term (Xu et al. 2003). In this study, we aimed to show the ultimate stem cell death and blood-testes barrier damage due to the synergistic effect of in utero ionizing radiation and postnatal hyperthermia using histopathological and ultrastructural analysis, TUNEL assay for cell death, flow cytometry for DNA ploidy ratio, ZO-1 and occludin immunohistochemistry at 3 and 6 months in rat testes.