Metformin improves memory via AMPK/mTOR-dependent route in a rat model of Alzheimer's disease.

Objectives: Metformin, as an insulin sensitizer, is a familiar antidiabetic drug. Increasing evidence points to metformin's protective effects against Alzheimer's disease (AD). However, the mechanism is not well understood. The present study evaluated whether inhibiting AMPK and activating mTOR could stop metformin from improving memory in rats with streptozotocin (STZ) -induced Alzheimer's disease. Materials and Methods: Twelve-week-old Wistar rats, were injected 3 mg/kg STZ intracerebroventricularly on days 1 and 3 to develop the animal model. Metformin was applied orally at 100 mg/kg (17 days). Forty-five min before the retrieval phase, dorsomorphin (DM; AMPK inhibitor, 2 M) and MHY (mTOR activator, 0.1 M) were administered. Morris Water Maze (MWM) and shuttle box were utilized to measure spatial and passive avoidance memory, respectively. Congo red staining was used to identify cortical amyloid deposition. Results: The findings exhibited a considerable enhancement in spatial learning and memory in the metformin treatment group (P≤0.05). Injection of DM and MHY alone could not significantly change MWM and passive avoidance. Additionally, co-administration of DM and MHY increased escape latency (P≤0.001) and reduced the total time spent in the target quadrant (TTS) (P≤0.05) compared to the STZ+MET group during retrieval of MWM. Also, co-injection of DM and MHY increased step-through latency (STL) and decreased time spent in the dark compartment (TDC) compared to the STZ+MET group (P≤0.001). Conclusion: Metformin appears to have a therapeutic impact by activating AMPK and inactivating mTOR. As a result, it could be used as an Alzheimer's treatment strategy.

Inhibitory effect of temozolomide on apoptosis induction of cinnamaldehyde in human glioblastoma multiforme T98G cell line.

Glioblastoma is the most common primary malignant brain tumor in adults. Temozolomide (TMZ) is an FDA-approved drug used to treat this type of cancer. Cinnamaldehyde (CIN) is a derivative of cinnamon extract and makes up 99% of it. The aim of this study was to investigate the in vitro combined effect of CIN and TMZ on human glioblastoma multiforme T98G cell line viability. In this study, we used 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl-tertazolium bromide (MTT) method to evaluate the extent of IC50, acridine orange, Giemsa and Hoechst staining to evaluate the manner of apoptosis and the Western blotting method to examine the expression change of apoptotic proteins. Our results show that TMZ has an inhibitory effect on CIN when both used in combination at concentrations of 300 and 100 µM (P<0.05) and has a cytotoxic effect when used alone at the same concentrations (P<0.05). The western blotting result showed that TMZ at concentrations of 2,000 and 1,000 µM significantly increased Bax expression and decreased Bcl2 expression (P<0.05), indicating that TMZ induced apoptosis through the mitochondrial pathway. However, CIN had no effect on Bax and Bcl2 expressions, thus causing apoptosis from another pathway. Also, the Bax:Bcl2 expression ratio at concentrations combined was lower than that for TMZ 1,000 µM and higher than that for CIN 150 and 100 µM (P<0.05), which confirms the inhibitory effect of TMZ on CIN. From the present study, we conclude that TMZ in combination with CIN has an inhibitory effect on increasing the cytotoxicity rate.

Enhanced low-gamma band power in the hippocampus and prefrontal cortex in a rat model of depression is reversed by orexin-1 receptor antagonism.

The hippocampal-prefrontal cortex network dynamics is reported to be involved in various cognitive functions and in different mood disturbances including depression. It has been suggested that blocking orexin-1 receptors can be beneficial in depression. The purpose of this study is to determine whether orexin-1 receptor antagonists have an impact on changes in brain oscillations in the hippocampus and prefrontal cortex in a rat model of depression. Forty-eight male Wistar rats were divided into six experimental groups: control, chronic mild stress (CMS), acute SB-334867, a selective orexin-1 receptor antagonist, treated rats (SB), chronic SB-treated (CSB), CMS+SB, and CMS+CSB. Two stainless steel recording electrodes were placed in the coordinates of the hippocampus (HPC) and the prefrontal cortex (PFC). After behavioral verification of the model, local field potentials were recorded at 1 kHz sampling frequency. The absolute power of different frequency bands was obtained using the Fast Fourier Transform (FFT) function, and the power spectral density (PSD) of each frequency band was calculated for each animal. In the CMS- treated animals, the low-gamma band power increased both in the HPC and PFC (p ≤ 0.05), which were reversed by chronic SB-334867 treatment (p ≤ 0.05). The alterations in theta, and high-gamma band power were not significant in CMS treated rats, while acute and chronic SB-334867 treatment diminished the theta and high-gamma band power (p ≤ 0.05), respectively. The hippocampal-prefrontal coherence decreased in the delta (p ≤ 0.01), theta (p ≤ 0.01), and alpha (p ≤ 0.05) band range of the CMS exposed rats. It is concluded that CMS boosts the low-gamma band power, which is reversed by CSB treatment. The low-frequency band coherence is attenuated after CMS treatment.

Intracerebroventricular Injection of MHY1485 Blocked the Beneficial Effect of Adiponectin on Aversive Memory in the STZ Model of Dementia.

BACKGROUND: The most prominent adipokine, adiponectin (APN), has an adverse relationship with the malfunction of adipose tissue. Obesity causes a decrease in plasma APN levels, which eventually results in insulin resistance and diabetes. In this study, we assessed how the effects of APN on memory are influenced by the insulin receptor substrate-1 (IRS-1) and the mammalian target of rapamycin (mTOR) pathways. METHODS: Streptozotocin (STZ) 3 mg/kg intracerebroventricular injections on days 1 and 3 following cannulation were used to create an animal model of Alzheimer's disease. The acquisition phase was preceded by injections of MHY and adiponectin. For the passive avoidance task, the stepthrough latency and total duration in the dark compartment were recorded and evaluated, and the preference index was calculated for the novel object identification test. IRS-1 protein expression in the hippocampus was assessed by western blotting. RESULTS: STZ reduced the step-through latency (STL), which rose significantly (P≤0.001) in the APN+STZ group. The memory-improving effects of APN were reversed when MHY was administered first (P≤0.001). The STZ and APN+STZ+MHY groups both had a substantial decline in the preference index (P≤0.01). Compared to the control group, the STZ group's expression of the IRS- 1 protein was dramatically reduced (P≤0.0001). In contrast to the APN+STZ group, the MHYtreated group likewise showed decreased IRS-1 protein expression (P≤0.0001), but APN+STZ was able to enhance IRS-1 expression rate (P≤0.0001). CONCLUSION: In a rat model of AD, we found that adiponectin improved aversive and cognitive memory, which is at least partially mediated by the mTOR signaling cascade.

Lateral habenula deep brain stimulation alleviates depression-like behaviors and reverses the oscillatory pattern in the nucleus accumbens in an animal model of depression.

Depression is a series of symptoms that influence mood, thinking, and behavior and create unpleasant emotions like hopelessness and apathy. Treatment-resistant depression (TRD) affects 30 % of depression patients despite the availability of several non-invasive therapies. Deep brain stimulation (DBS) is a novel therapy for TRD. The aim of the current study was to evaluate the effect of LHb-DBS by recording local field potentials (LFP) and conducting behavioral experiments. Thirty-two mature male Wistar rats were randomly divided into four groups: control, chronic mild stress (CMS), CMS+DBS, and DBS. After surgery and electrode placement in the lateral habenula (LHb), nucleus accumbens (NAc), and prelimbic cortex (PrL), the CMS protocol was applied for 3 weeks to create depression-like models. The open field test (OFT), sucrose preference test (SPT), and forced swim test (FST) were also performed. In the DBS groups, the LHb area was stimulated for four consecutive days. Finally, on the 22nd day, LFP was recorded from the NAc and PrL and analyzed using MATLAB software. Analyzing the findings using ANOVA and P-values ≤ 0.05 was considered. LHb-DBS alleviated depression-like behaviors in chronic moderate stress model rats (P ≤ 0.05). Three weeks of CMS enhanced almost all band powers in the NAc, while LHb-DBS decreased the power of the theta, alpha, beta, and gamma bands in the NAc (P ≤ 0.05), and the low-gamma band in the PrL. CMS also boosted the NAc-PrL coherence in low-frequency bands, while LHb-DBS increased beta and low gamma band coherence (P ≤ 0.05). In sum, the results of the present study showed that depression enhances low-frequency coherence between NAc and PrL cortex. Depression also potentiates many brain oscillations in the NAc, which can be mainly reversed by LHb-DBS.

Stem cell-conditioned medium is a promising treatment for Alzheimer's disease.

BACKGROUND AND AIM: Alzheimer's disease (AD), a prevalent progressive neurodegenerative disease, is mainly characterized by dementia, memory loss, and cognitive disorder. Rising research was performed to develop pharmacological or non-pharmacological approaches to treat or improve AD complications. Mesenchymal stem cells (MSCs) are stromal cells that can self-renew and exhibit multilineage differentiation. Recent evidence suggested that some of the therapeutic effects of MSCs are mediated by the secreted paracrine factors. These paracrine factors, called MSC- conditioned medium (MSC-CM), may stimulate endogenous repair, promote angio- and artery genesis, and reduce apoptosis through paracrine mechanisms. The current study aims to systematically review the advantages of MSC-CM to the development of research and therapeutic concepts for AD management. MATERIAL AND METHODS: The present systematic review was performed using PubMed, Web of Science, and Scopus from April 2020 to May 2022 following the "Preferred Reporting Items for Systematic Reviews" (PRISMA) guidelines. The keywords, including "Conditioned medium OR Conditioned media OR Stem cell therapy" AND "Alzheimer's," was searched, and finally, 13 papers were extracted. RESULTS: The obtained data revealed that MSC-CMs might positively affect neurodegenerative diseases prognosis, especially AD, through various mechanisms, including a decrease in neuro-inflammation, reduction of oxidative stress and Aß formation, modulation of Microglia function and count, reduction of apoptosis, induction of synaptogenesis and neurogenesis. Also, the results showed that MSC-CM administration could significantly improve cognitive and memory function, increase the expression of neurotrophic factors, decrease the production of pro-inflammatory cytokines, improve mitochondrial function, reduce cytotoxicity, and increase neurotransmitter levels. CONCLUSION: While inhibiting the induction of neuroinflammation could be considered the first therapeutic effect of CMs, the prevention of apoptosis could be regarded as the most crucial effect of CMs on AD improvement.

Chronic orexin-1 receptor blockage attenuates depressive behaviors and provokes PSD-95 expression in a rat model of depression.

Depression is a devastating mood disorder affecting more than 300 million people worldwide. Almost 30 % of patients still suffer from treatment resistant depression. Although many reports support the involvement of orexin in the pathophysiology of depression, the precise role of orexin is still unclear. In this study, we evaluated the role of the orexin 1 receptor (Orx1R) on depressive behaviors and the alterations in postsynaptic density-95 (PSD-95) protein in the chronic mild stress (CMS) model of depression. Fifty-four male Wistar rats were randomly allocated to 6 groups; Control, CMS, acute SB-334867 (SB), CMS+SB, chronic SB (CSB) and CMS+CSB. Rats were exposed to one or two unpredictable stressors each day for three weeks for the induction of CMS. Intracerebroventricular (icv) injection of SB-334867, a selective Orx1R antagonist, was performed either 30 min before behavioral tests (acute) or once daily for 14 days (chronic). Behavioral despair was assessed by immobility time in the forced swim test (FST), sucrose consumption in sucrose preference test (SPT), and the number of crosses in the open field test (OFT) on days 1, 11, and 22 of the experiment. Finally, rats were decapitated, and brain tissue of the hippocampus (HPC) and prefrontal cortex (PFC) were collected, and the relative expression of PSD-95 was evaluated by western blotting. The CMS model rats showed a significant increase in FST immobility time (P = 0.001) and a decrease in locomotion (P = 0.04) and sucrose preference (P = 0.039). Chronic application of SB decreased immobility time to the control values (P = 0.001) and diminished locomotion (P = 0.047) and sucrose preference (P = 0.042) in comparison to the CMS group. Acute SB reversed just the immobility time (P ≤ 0.006). Chronic SB treatment increased the relative PSD-95 expression in PFC (P = 0.001). Hence, chronic antagonism of Orx1R alleviates depressive behaviors induced by CMS and improves PSD-95 expression in PFC.

The Effect of 40-Hz White LED Therapy on Structure-Function of Brain Mitochondrial ATP-Sensitive Ca-Activated Large-Conductance Potassium Channel in Amyloid Beta Toxicity.

Photobiomodulation therapy has become the focus of medical research in many areas such as Alzheimer's disease (AD), because of its modulatory effect on cellular processes through light energy absorption via photoreceptors/chromophores located in the mitochondria. However, there are still many questions around the underlying mechanisms. This study was carried out to unravel whether the function-structure of ATP-sensitive mitoBKCa channels, as crucial components for maintenance of mitochondrial homeostasis, can be altered subsequent to light therapy in AD. Induction of Aß neurotoxicity in male Wistar rats was done by intracerebroventricular injection of Aß1-42. After a week, light-treated rats were exposed to 40-Hz white light LEDs, 15 min for 7 days. Electrophysiological properties of mitoBKCa channel were investigated using a channel incorporated into the bilayer lipid membrane, and mitoBKCa-ß2 subunit expression was determined using western blot analysis in Aß-induced toxicity and light-treated rats. Our results describe that conductance and open probability (Po) of mitoBKCa channel decreased significantly and was accompanied by a Po curve rightward shift in mitochondrial preparation in Aß-induced toxicity rats. We also showed a significant reduction in expression of mitoBKCa-ß2 subunit, which is partly responsible for a leftward shift in BKCa Po curve in low calcium status. Interestingly, we provided evidence of a significant improvement in channel conductance and Po after light therapy. We also found that light therapy improved mitoBKCa-ß2 subunit expression, increasing it close to saline group. The current study explains a light therapy improvement in brain mitoBKCa channel function in the Aß-induced neurotoxicity rat model, an effect that can be linked to increased expression of ß2 subunit.

Co-treatment of AMPA endocytosis inhibitor and GluN2B antagonist facilitate consolidation and retrieval of memory impaired by ß amyloid peptide.

BACKGROUND: Glutamate neurotransmission stands as an important issue to minimize memory impairment. We investigated the effects of an inhibitor of α-amino-3-hydroxy-5-methyl-4-isozazole propionic acid receptors (AMPA) endocytosis and GluN2B subunit of N-methyl-d-aspartate receptors (NMDA), either isolated or combined, on memory impairments induced by Amyloid beta1-42 (Aß). METHODS: Eighty male Wistar rats were used for two experiments of consolidation and retrieval of memory. Memory impairment was induced by intracerebroventricular (ICV) injection of Aß1-42 (2 µg/µl), and evaluated using Morris Water Maze (MWM). Each experiment consisted of 5 groups: Saline + Saline, Aß + Saline, Aß + Ifenprodil (Ifen, 3 nmol/ICV), Aß +Tat-GluR23Y (3 µmol/kg/IP), and Aß1 +Ifen + Tat-GluR23Y. Then, hippocampal cAMP-response element-binding protein (CREB) was measured by western blotting. Data were analyzed by Analysis of variance (ANOVA) repeated measure, and one-way Anova followed by Tukey's post hoc test. RESULTS: During retrieval, Aß+ Tat-GluR23Y showed significant improvement in total time spent (TTS) in the target quadrant (p = 0.009), escape latency to a platform (p = 0.008) and hippocampal level of CREB (p = 0.006) compared with Aß + saline. Also, coadministration of Tat-GluR23Yand Ifen similar to Tat-GluR23Y alone caused significant improvement in TTS (p = 0.014) and latency to platform (p = 0.013). During consolidation, shorter escape latency (p = 0.001), longer TTS (p = 0.002) and higher level of hippocampal CREB were observed in the Aß + Tat-GluR23Y (p = 0.001) and Aß+ Tat-GluR23Y + Ifen (p = 0.017), respectively. CONCLUSION: The present study provides pieces of evidence that inhibition of AMPARs endocytosis using Tat-GluR23Y facilitates memory consolidation and retrieval in Aß induced memory impairment via the CREB signaling pathway.

Adenosine monophosphate activated protein kinase (AMPK) is essential for the memory improving effect of adiponectin.

Adiponectin (APN) plays a major role in the regulation of insulin sensitivity and glucose homeostasis. Insulin and APN have a positive effect on memory. In this study, we examined whether the inhibition of AMPK could block the memory improving effect of APN or affect the IRS1 expression. Animal model of AD was developed by intracerebroventricular (icv) injection of 3 mg/kg streptozotocin (STZ), in 12 weeks old Wistar rats, on days 1 and 3 after cannulation. Dorsomorphin (DM) and APN (600 nM) were injected 30 and 20 min before the acquisition phase, respectively. DM was applied in 3 different doses (0.2, 2 and 20 µM). All behavioral tests were performed on days 15 and 16; the Preference Index (PI) was calculated for novel object recognition (NOR) test, while the step through latency (STL) and total time in dark compartment (TDC) were recorded and analyzed for the passive avoidance task. Relative expression of insulin receptor substrate-1 (IRS-1) protein in the hippocampus was measured by western blotting. In early retrieval test, STZ + APN treatment increased STL (P < 0.0001) and decreased TDC (P < 0.05) in comparison to STZ group, while STZ + APN + DM (2µM) caused a decrease in STL (P < 0.05) and increase in TDC (0.2µM and 2µM DM; P < 0.05). Icv injection of DM (0.2µM and 2µM) before APN decreased the PI significantly (P < 0.05) in comparison to STZ + APN group. APN treatment raised the IRS-1 expression and DM reversed this increment, significantly (P < 0.0001). It is concluded that the memory improving effect of APN is mediated, at least in part, by the AMPK pathway. APN is also able to boost insulin signaling by overexpression of IRS-1 in the hippocampus.

Chronic administration of Tat-GluR23Y ameliorates cognitive dysfunction targeting CREB signaling in rats with amyloid beta neurotoxicity.

Alzheimer's disease (AD) is behaviorally characterized by memory impairments, and pathologically by amyloid ß1-42 (Aß1-42) plaques and tangles. Aß binds to excitatory synapses and disrupts their transmission due to dysregulation of the glutamate receptors. Here we hypothesized that chronic inhibition of the endocytosis of AMPA receptors together with GluN2B subunit of NMDA receptors might improve cognition deficit induced by Aß(1-42) neurotoxicity. Forty male Wistar rats were used in this study and divided into 5 groups: Saline + Saline, Aß+Saline, Aß+Ifen (Ifenprodil, 3 nmol /2 weeks), Aß+GluR23Y (Tat-GluR23Y 3 µmol/kg/2 weeks) and Aß+Ifen+GluR23Y (same doses and durations). Aß(1-42) neurotoxicity was induced by intracerebroventricular (ICV) injection of Aß1-42 (2 µg/µl/side), and then animals received the related treatments for 14 days. Cognitive performance of rats and hippocampal level of cAMP-response element-binding (CREB) were evaluated using Morris Water Maze (MWM), and western blotting respectively. Obtained data from the acquisition trials were analyzed by two way Anova and Student T test. Also one way Analysis of variance (ANOVA) with post hoc Tuckey were used to clarify between groups differences in probe test. The Group receiving Aß, showed significant cognition deficit (long latency to platform and short total time spent in target quadrant (TTS), parallel with lower level of hippocampal CREB, versus vehicle group. While, Aß+ GluR23Y exhibited the shortest latency to platform and the longest TTS during the probe test, parallel with the higher hippocampal level of CREB compared with other groups. The present study provides evidence that chronic administration of Tat-GluR23Y; an inhibitor of GluA2-AMPARs endocytosis, successfully restores spatial memory impaired by amyloid beta neurotoxicity targeting CREB signaling pathway.

Neuregulin1ß improves both spatial and associative learning and memory in Alzheimer model of rats possibly through signaling pathways other than Erk1/2.

BACKGROUND: Neuregulin-1ß (NRG1 ß) is associated with various neurological disorders such as schizophrenia, depression and Parkinson's disease. However, its role in Alzheimer's (AD) has not been understood yet. Here, we have studied the effect of NRG1 ß and extracellular-signal-regulated kinase (ERK) signaling on special and associative memories and emotional stress in AD model of rats. METHODS: Fifty six male Wistar rats were divided into eight groups of: Saline + Saline, Aß + Saline, Aß + NRG1ß (5 µg/5 ul), Aß + PBS, Aß + NRG1ß + PD98059 (PD, 5 µg/2 µl), Aß + NRG1ß + Saline and Saline + PD. AD model was induced by intracerebroventricular (ICV) injection of beta-amyloid protein (Aß1-42, 4 µg/2 µl). The cognitive performances of rats were evaluated using Morris Water Maze (MWM) and Step through passive avoidance. Also locomotors activity and emotionality of animals were considered in an Open field test. Data were analyzed by one way Anova one way, repeated measure and T-test. RESULTS: Significant improvement was found in spatial learning and memory assessed by total time spent in target quadrant [F (4, 32) = 12.4, p = 0.001], escape latency [F (4, 32) = 15.767, p = 0.001] and distance moved [F (4, 32) = 5.55, p = 0.002], in Aß + NRG1ß compared with Aß + Saline in MWM. Also Aß + NRG1ß showed long latencies to enter into the dark compartment [F (4, 32) = 6.43, p = 0.001], but short time spent [F (4, 32) =6.93, p = 0.001] compared with control. Administration of an ERK inhibitor (PD98059, 5 µg, 15 min before NRG1ß) didn't completely block learning memory restored by NRG1ß in AD model (p = 0.7). No significant between groups differences was found in emotional stress characteristics in open field, except the grooming numbers which were higher in Saline + PD compared with Saline + Saline (p = 0.02). CONCLUSION: Our findings indicate that NRG1ß restores cognitive dysfunctions induced by amyloid ß through signaling pathways possibly other than Erk1/2, with no significant change in anxiety, locomotion and vegetative activities.

Kaempferol attenuates cognitive deficit via regulating oxidative stress and neuroinflammation in an ovariectomized rat model of sporadic dementia.

Alzheimer's disease (AD) is associated with oxidative stress, and ultimately results in cognitive deficit. Despite existing literature on the pathophysiology of AD, there is currently no cure for AD. The present study investigated the effects of kaempferol (Kmp) isolated from the extract of Mespilus germanica L. (medlar) leaves on cognitive impairment, hippocampal antioxidants, apoptosis, lipid peroxidation and neuro-inflammation markers in ovariectomized (OVX) rat models of sporadic AD. Kaempferol, as the main flavonoid of medlar extract has been previously known for anti-oxidative, anti-inflammatory and anti-neurotoxic effects. Thirty-two female Wistar rats were ovariectomized, and randomly divided into four groups: sham, OVX + saline, OVX + streptozotocin (STZ) + saline, OVX + STZ + Kmp. Animals received intracerebroventricular injection of STZ (3 mg/kg, twice with one day interval) to establish models of sporadic AD. Intraperitoneal injection of Kmp (10 mg/kg) for 21 days was performed in the OVX + STZ + Kmp group. Spatial learning and memory of rats were evaluated using a Morris water maze. Finally, brain homogenates were used for biochemical analysis by enzyme-linked immunosorbent assay. The results showed a significant improvement in spatial learning and memory as evidenced by shortened escape latency and searching distance in Morris water maze in the OVX + STZ + Kmp group compared with the OVX + STZ group. Kmp also exhibited significant elevations in brain levels of antioxidant enzymes of superoxide dismutase and glutathione, while reduction in tumor necrosis factor-α and malondialdehyde. Our results demonstrate that Kmp is capable of alleviating STZ-induced memory impairment in OVX rats, probably by elevating endogenous hippocampal antioxidants of superoxide dismutase and glutathione, and reducing neuroinflammation. This study suggests that Kmp may be a potential neuroprotective agent against cognitive deficit in AD.

The role of flaxseed and vitamin E on oxidative stress in prepubertal rats with experimental varicocele: An experimental study.

BACKGROUND: Prepubertal varicocele has the most devastating effects on the testes. Oxidative stress is the major cause leading to infertility in varicocele. The antioxidant properties of Flaxseed (FS) treatment in some oxidative diseases have been reported. OBJECTIVE: This study aimed to evaluate the antioxidant effect of FS in prepubertal rats with experimental varicocele. MATERIALS AND METHODS: Forty two male prepubertal rats were divided into 6 groups: the varicocele group were either fed with 10% FS, or with regular diet, or with Vit E, the group with sham operation fed with 10% FS, or had regular diet, and control rats who had not been operated but received regular diet. Varicocele was created by Koksal method. After 6 weeks sperm superoxide anion and H2O2 were evaluated by flowcytometery. Semen total antioxidant capacity (TAC) by Koracevic method and testes malondialdehyde (MDA) by thiobarbituric acid with spectrophotometry was measured. RESULTS: While superoxide anion and H2O2 were significantly higher in varicocele grop with regular diet (p=0.0001), FS significantly decreased the previously-mentioned parameters (p=0.0001). There were no significant differences for seminal TAC between 6 groups (p=0.07). Left testicular MDA concentration were lower in varicocele or group that were fed with 10% FS compared with other groups (p=0.001). CONCLUSION: Reactive oxygen species (ROS) may cause sperm oxidative damage. FS as a fat soluble antioxidant can scavenge intracellular ROS production in varicocele.

Flow cytometric evaluation of sperm superoxide anion production in rats with experimental varicocele.

OBJECTIVES: To determine whether intracellular superoxide anion production changes in the sperm of rats with experimental varicocele and to study mitochondrial membrane potential (MMP), sperm viability, antioxidant activity, Bax and Bcl-2 changes, and sperm count and motility in these rats. METHODS: The study groups consisted of 32 male rats divided into the following 4 groups: control, sham, varicocele-1, and varicocele-2. Experimental varicocele was established by partial ligation of the left renal vein in the latter 2 groups. Animals were killed 2 and 6 months after surgery, and dilation of the internal spermatic veins was observed. Then, superoxide anion production, MMP, antioxidant activity, and sperm characteristics were evaluated. Flow cytometry was used to study sperm superoxide anion production, assessed by dihydroethidium and MMP with rhodamine 123. RESULTS: Our results showed intracellular superoxide anion production significantly increased, and MMP, sperm viability, sperm count, and motility decreased in rats with experimental left varicocele. More Bax-positive cells were seen in the varicocele groups. However, there was no significant difference for seminal plasma antioxidant activity among all groups. CONCLUSIONS: These findings suggest that a main source of reactive oxygen species production in varicocele condition is intracellular.