PubMed İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.14627/8
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Article The Gut-Kidney Axis in Calcium Oxalate Nephrolithiasis: Nutritional and Microbial Insights(Kare Publ, 2026) Sener, Goksel; Marzi, Mahdi; Sener, Tarik EmreCalcium oxalate (CaOx) nephrolithiasis is the most common type of kidney stone disease worldwide. Recent studies show that its development cannot be explained solely by renal solute handling; instead, it reflects a broader interaction between dietary habits, the intestinal microbiota, and host metabolic responses. Intestinal absorption of calcium and oxalate-two central drivers of lithogenesis-is shaped by both microbial composition and dietary patterns. Although Oxalobacter formigenes was initially regarded as the main oxalate-degrading organism, newer studies indicate that a wider disturbance of the gut microbiota, especially the loss of short-chain fatty acid (SCFA)-producing species, may increase susceptibility to stone formation. In this review, nutritional, microbial, and mechanistic evidence is brought together to examine how diet-particularly salt, animal protein, calcium, oxalate, fruits, vegetables, and water intake-modulates the gut-kidney axis. Diets high in salt or animal protein tend to shift the microbiota toward more pro-inflammatory and acidogenic profiles, while fiber-rich, plant-based diets and adequate hydration appear to support microbial diversity, SCFA production, and epithelial barrier integrity. Probiotic and synbiotic interventions have also gained attention as potential strategies to reduce stone recurrence by targeting gut microbial function. Taken together, current findings suggest that the gut-kidney axis is a dynamic metabolic link between diet, microbial ecology, and renal physiology. Future studies combining multi-omics methods with personalized nutritional approaches may help develop more effective microbiota-based prevention and treatment strategies for CaOx nephrolithiasis.Article Protective Effects of Lactobacillus Rhamnosus GG Against Methotrexate-Induced Oxidative Renal Toxicity(Springer, 2026) Yanardag, Refiye; Bayrak, Bertan Boran; Sener, Goksel; Almurad, Bade; Donmez, Muhammet OguzhanMethotrexate (MTX) is commonly prescribed for various malignant and autoimmune conditions, but it can cause significant oxidative and functional impairment in renal tissue. Lactobacillus rhamnosus GG. (LGG) is a well-known probiotic with biological activities that support antioxidant balance. This study investigated the impact of LGG on MTX-induced kidney damage. Male Sprague-Dawley rats were divided into four groups: physiological saline-treated control group; a group receiving MTX alone; a group receiving MTX alongside a low dose of LGG; and a group receiving MTX alongside a high dose of LGG. MTX was administered as single dose (20 mg/kg/bw) intraperitoneally and LGG (low dose 1 x 10(9) CFU/day and high dose 5 & times; 10(9) CFU/day, respectively) orally for five days. On day six, blood and kidney samples were collected and examined for oxidative indicators, enzymatic antioxidant responses, and renal functional markers. MTX significantly increased in glomerular filtration markers in serum and elevated key indicators of oxidative stress in renal tissues. More so, MTX demonstrated to disrupt renal ionic homeostasis, such as declined sodium/potassium-ATPase, paraoxonase, and increased lactate dehydrogenase, carbonic anhydrase, xanthine oxidase, myeloperoxidase, and arginase activities. In contrast, LGG supplementation has been shown to effectively reverse all MTX-induced biochemical alterations in both serum and renal tissue. We can suggest that LGG can provide significant protection against oxidative renal toxicity induced by MTX in rats.Article Protective Effects of L-Theanine against Bisphenol A-Induced Oxidative Stress and Gut Microbiota Disruption in Wistar Rats(Springer, 2026) Sener, Azize; Marzi, Mahdi; Sener, Goksel; Donmez, Muhammet OguzhanBackground Gut microbiota homeostasis plays a central role in maintaining intestinal redox balance and immune regulation. Bisphenol A (BPA), a widely distributed environmental contaminant, has been associated with oxidative stress, inflammatory responses, and disturbances in intestinal microbial communities. L-theanine (LTN), a bioactive amino acid naturally present in green tea, possesses well-documented antioxidant and anti-inflammatory properties; however, its potential protective role against BPA-induced intestinal injury has not been fully clarified. Methods and Results In the present study, female Wistar albino rats were randomly allocated into three groups: control, BPA (50 mg/kg/day), and BPA + LTN (100 mg/kg/day) and treated for 30 days. Oxidative stress and inflammatory responses in intestinal and colonic tissues were assessed by measuring malondialdehyde (MDA), reduced glutathione (GSH) levels and myeloperoxidase (MPO), catalase (CAT) activities. BPA exposure significantly increased MDA (p < 0.001) level and MPO (p < 0.001) activity while reducing GSH content (p < 0.001) and CAT activity (p < 0.001) compared with the control group. Compared to the BPA group, LTN treatment led to significant changes in MDA, MPO, and GSH levels in both tissues. MDA and MPO levels were significantly reduced in the intestine and colon tissues of the BPA + LTN group (p < 0.001). GSH and CAT levels were significantly increased in both the intestine and colon compared to the BPA group (p < 0.001). In addition, fecal microbiota composition was analyzed using 16 S rRNA gene sequencing, with taxonomic profiling performed at the phylum, genus and species levels. BPA exposure was associated with reduced microbial stability and compositional shifts within the gut microbiota, whereas LTN treatment partially restored microbial richness and community structure. Conclusions Collectively, these findings indicate that LTN alleviates BPA-induced intestinal oxidative stress and microbiota dysbiosis, suggesting its potential as a protective dietary compound against environmental toxicant-related intestinal injury.Article Protective Effects of Panax Ginseng against Bisphenol A-Induced Testicular Toxicity in Rats(Springer Nature, 2026) Cesur, Yasemin; Cam, Kamil; Pazarbasi, Seren Ede; Dorucu, Dogancan; Sener, Goksel; Abas, Burcin Irem; Cevik, OzgeBisphenol A (BPA) is an endocrine-disrupting chemical known to cause testicular toxicity through oxidative stress and apoptosis. Panax ginseng (PG) is a natural product with anti-inflammatory effects. This study aimed to evaluate the protective effect of PG against BPA-induced testicular damage in rats. Thirty-two Wistar Albino rats aged 10-12 weeks were divided into four groups: Control, PG, BPA, and BPA + PG. BPA (50 mg/kg/day) and PG (100 mg/kg/day) were orally administered for 6 weeks. BPA significantly increased serum total oxidant status and decreased antioxidant status (p < 0.001, p < 0.001). Also, the levels of superoxide dismutase (an antioxidant enzyme) (p = 0.0005) and androgen receptor-mRNA (an androgen signaling marker) decreased (p = 0.014). However, caspase 3 (an apoptosis marker) (p = 0.0067), 8-hydroxy-2'-deoxyguanosine (a marker of oxidative DNA damage) (p < 0.001), and tumor necrosis factor-alpha (a proinflammatory cytokine) (p < 0.001) levels increased in testicular tissues. Rats treated with PG showed improvements in all oxidative and inflammatory markers and significantly restored androgen receptor expression. Histopathological examination revealed degeneration in seminiferous tubules and reduced spermatozoa in the BPA group, while the BPA + PG group showed marked improvement. These findings suggest that PG may alleviate oxidative stress-related testicular damage at both molecular and histological levels and may offer insights for future clinical studies.Article Montelukast Attenuates Abdominal Aortic Aneurysm in Rats: Anti-Inflammatory and Antioxidant Effects(Elsevier, 2026) Tekin, Gozde; Cevik, Ozge; Cetinel, Sule; Sener, Goksel; Kizilay, MehmetObjective: Oxidative stress and inflammation are widely recognized as central mechanisms in the pathogenesis of abdominal aortic aneurysm. This study sought to examine the potential protective properties of montelukast in a rat model of aortic aneurysm. Methods: Male Sprague-Dawley rats were randomly allocated into three experimental groups. Abdominal aortic aneurysm was induced using the calcium chloride (CaCl2) model, in which gauze soaked in 0.5 M CaCl2 was placed directly onto the adventitial surface of the infrarenal abdominal aorta for 15 minutes. After induction, the treatment group received daily intraperitoneal injections of montelukast (10 mg/kg) for 4 consecutive weeks. At the study end point, animals were euthanized, and infrarenal aortic tissues were harvested for biochemical and histological evaluations. Measured parameters included matrix metalloproteinase (MMP)-2 and MMP-9 expression, myeloperoxidase (MPO) activity, and 8-hydroxy-2 '-deoxyguanosine levels. Antioxidant capacity was assessed through superoxide dismutase (SOD) activity assays. Histopathological examinations were performed, and statistical analysis was conducted using GraphPad Prism v.5. Results: Exposure to CaCl2 triggered pronounced oxidative injury and inflammation, as evidenced by elevated 8-hydroxy-2 '-deoxyguanosine levels, increased MPO activity, reduced SOD activity, and upregulated MMP-2 and MMP-9 expression. Montelukast administration markedly attenuated these changes, normalizing oxidative and inflammatory markers while improving histopathological architecture. Conclusions: Montelukast effectively counteracted CaCl2-induced aortic damage. The protective effects of montelukast appear to be mediated through suppression of MMP activity, restoration of SOD levels, and reduction of MPO-driven oxidative injury. By mitigating both inflammatory and oxidative mechanisms, montelukast contributes to the preservation of aortic wall structure. Clinical Relevance: Abdominal aortic aneurysm remains a major vascular disorder without an effective pharmacological therapy to slow its progression. In this experimental study, montelukast, a leukotriene receptor antagonist widely used in asthma, attenuated abdominal aortic aneurysm formation in rats and was associated with increased superoxide dismutase activity, reduced myeloperoxidase levels, and suppressed matrix metalloproteinase activation. These combined antioxidant, anti-inflammatory, and matrix-stabilizing effects preserved aortic wall integrity. Given montelukast's established safety and clinical availability, these findings support its potential for future clinical investigation as a pharmacological approach to limit aneurysm progression. (JVS-Vascular Science 2026;7:100405.)Article The Therapeutic Role of Ginseng in Promoting Hippocampal Neurogenesis and Ameliorating Cognitive Function Following Whole Brain Radiotherapy in Rats(Springer/Plenum Publishers, 2025) Sahin, Sevim; Bayindir, Nihan; Ertas, Busra; Ceylan, Cemile; Elibol, Birsen; Ozkan, Alper; Sener, GokselWhole-brain radiotherapy (WBRT) is a prevalent technique for managing multiple intracranial metastases, however, the cognitive damage in long-term survivors due to WBTR is a critical concern that impacts patients' quality of life. Panax ginseng, a bioactive compound recognized for its neuroprotective benefits, also enhances cognitive functions, including memory and learning. This study aims to examine the potential protective effects of Panax ginseng supplementation on cognitive dysfunction and the levels of neurogenesis-related proteins in the hippocampus of rats that underwent WBRT, which was delivered as 3 fractions of 6 Gy (total dose 18 Gy) using a linear accelerator. Thirty-six male Sprague-Dawley rats were divided into three groups: radiation, ginseng treatment, and control. After 60 days of Panax ginseng administration (100 mg/kg), behavior tests (Morris water maze and novel object recognition) were performed, followed by western blot analysis of the hippocampus. Results indicated that Panax ginseng supplementation ameliorated radiation-induced cognitive impairments. Additionally, western blot analyses revealed that Panax ginseng promoted neuronal recovery and neuroplasticity processes in the hippocampus, simultaneously exhibiting a neuroprotective mechanism by reducing apoptosis and neurotoxicity markers. Panax ginseng ameliorates cognitive dysfunction after WBRT by enhancing neurogenesis and diminishing cell death in the hippocampus.Article Protective Effect of Artichoke (Cynara scolymus L.) Leaf and Receptaculum Extracts Against Hepatic Encephalopathy in Bile Duct Ligated Rats(Springer/Plenum Publishers, 2025) Kam, Ozkan; Bebitoglu, Berna Terzioglu; Sener, Goksel; Oguz, Elif; Erdogan, Nurettin Fatih; Kilickap, Andac; Hatiboglu, NebileHepatic encephalopathy (HE), complication of liver dysfunction, leads to neurocognitive impairments. Artichoke (Cynara scolymus L.) has been traditionally used for its antioxidant, anti-inflammatory and hepatoprotective properties. This study evaluates artichoke leaf and receptaculum extracts in cholestasis and HE in a rat model. Wistar rats were divided into 6 groups: sham-control, bile duct ligation (BDL), and BDL with low/high-dose leaf or receptaculum extracts. After BDL, physiological saline and extracts (250/500 mg/kg) were administered orally for 28 days. Cognitive activity was evaluated using Morris water maze and novel object recognition tests on day 28. Artichoke extract regulated liver enzymes and bilirubin at high-doses and significantly increased antioxidant enzyme activities reduced by BDL. Elevated 8-Hydroxyguanosine (8-OHdG) levels decreased in liver and brain tissues. Similarly, artichoke extracts reduced cytokine and hydroxyproline (HP) levels elevated by cholestasis. Following BDL, Na+/K+-ATPase levels in brain and liver tissues decreased, while artichoke extract reversed this. Artichoke, particularly high-dose receptaculum, improved impaired performance and increased time in the target quadrant after BDL. Both artichoke leaf and receptaculum extracts improved recognition. Artichoke treatments, especially high-dose receptaculum, reduced hepatic and neuronal damage and improved histological appearance. These findings highlight the therapeutic potential of artichoke extracts for liver fibrosis and related neurocognitive disorders.Article Synergistic Effects of Amniotic Membrane and Human Milk Exosomes on Burn Wound Healing(Elsevier Sci Ltd, 2025) Isik, Ferda; Tufan, Elif; Sivas, Guzin Goksun; Ak, Esin; Muhan, Aleyna; Sener, Goksel; Tunali-Akbay, TugbaBackground: Thermal burns are one of the most common burns. Studies are ongoing to develop synthetic or biological wound dressings to ensure painless and scarless healing of burn wounds. Objectives: This study aimed to combine the human amniotic membrane with breast milk-based exosomes and investigate their effects on burn wound healing. Methods: 24 Wistar Albino rats weighing 200-250 g and of both genders were used. Rats were divided into control, burn, burn+human amniotic membrane (hAM) and burn+hAM+Exosomes (hAM+Exo) groups. Burn injury was induced by exposing the back of rats to 90 degrees C water for 10 s. Rats were treated with hAM and hAM+ Exo for seven days after injury. At the end of the 7th day, the skin samples were taken and analyzed biochemically and histologically. TNF-alpha, IL-1(i, type III collagen, malondialdehyde (MDA), glutathione (GSH), total protein, superoxide dismutase (SOD), and tissue factor (TF) activity were determined in skin samples. Results: In the burn group, skin TNF-alpha levels increased, IL-1(i and type III collagen levels decreased. Wound healing therapy reversed these results. In the hAM+Exo group, the TNF-alpha level was lower, and IL-1 beta and type III collagen levels were higher than in the hAM group. MDA and total protein levels increased, and GSH, tissue factor, and SOD activities decreased in the burn group. In hAM and hAM+Exo groups, MDA levels decreased, and GSH and SOD activity increased compared to the burn group. The GSH levels were significantly higher in the hAM+Exo group compared to the hAM group. Conclusion: In conclusion, combining exosomes and amniotic membrane induced changes consistent with better wound healing than amniotic membrane alone.
