Response to chronic sustained hypoxia: increased cytosolic gelsolin and decreased plasma gelsolin levels.

An actin binding protein, gelsolin (GSN) has two isoforms, plasma (pGSN) and cytosolic (cGSN). Changes in pGSN and/or cGSN levels have been shown to be associated with the pathogenesis of several diseases. The aim of this study was to evaluate changes in intracellular and extracellular GSNlevels with HIF-1 in animals exposed to chronic sustained hypoxia (CSH), in addition to apoptosis and the cellular redox status. The rats in the Sham group were exposed to 21% O2, and the rats in the hypoxia groups were exposed to 13 and 10% O2, respectively. Plasma pGSN, HIF-1α, Total Antioxidant Status (TAS) and Total Oxidant Status (TOS), and lung tissue pGSN, HIF-1α, TAS, TOS, GSN levels, and apoptotic cell numbers were measured. HIF-1α levels were found to increase significantly in the tissue, especially in the group with severe hypoxia, both in biochemical and histological examinations. pGSN levels were also significantly decreased in both plasma and tissue. Significant increases in tissue were observed in cGSN. It was observed that while the antioxidant activity was dominant in the tissue, the oxidant activity was dominant in the plasma. In particular, the response to hypoxia regulated by HIF-1 is very important for cellular survival. The results of this study showed that the increase in cGSN and TAS levels in the lung tissue together with HIF-1α can be considered as the activation of mechanisms for cellular protection.

Investigation of the effect of Myricetin on Cisplatin-induced liver hepatotoxicity.

OBJECTIVE: Cisplatin, a widely used anticancer agent, induces hepatotoxicity alongside organ damage. Understanding Cisplatin's toxicity mechanism and developing preventive measures are crucial. Our study explores Myricetin, a flavonoid, for its protective effects against Cisplatin-induced hepatotoxicity. METHODS: In our study, a total of 32 Wistar albino male rats were utilized, which were categorized into four distinct groups: Control, Myricetin, Cisplatin, and Myricetin+Cisplatin. For the histological assessment of hepatic tissues, hematoxylin-eosin and periodic acid Schiff staining were employed, alongside immunohistochemical measurements of TNF-α, interleukin-17, and interleukin-6 immunoreactivity. Additionally, aspartate transaminase and alanine transaminase values were examined by biochemical analysis. RESULTS: In the histological evaluation of the tissues, a normal healthy cell structure and a strong periodic acid Schiff (+) reaction were observed in the hepatocyte cells in the tissues of the Control and Myricetin groups, while intense eosinophilia, minimal vacuolization, congestion, and sinusoidal expansions were observed in the hematoxylin-eosin stainings, and a decrease in the positive reaction in the periodic acid Schiff staining was observed in the Cisplatin group. Consistent with these histological findings, an increase in TNF-α, interleukin-17, and interleukin-6 expressions (p<0.0001) and a concomitant increase in aspartate transaminase and alanine transaminase values were observed in the Cisplatin group. In the group protected by Myricetin, a significant improvement was observed in all these histological and biochemical values. CONCLUSION: Cisplatin induces notable histopathological alterations in the liver. In this context, Myricetin exhibits the potential to alleviate Cisplatin-induced damage by modulating histological parameters and biochemical processes.

Effect of vitamin B12 on methotrexate-induced cardiotoxicity in rats.

Objectives: Methotrexate (MTX) is a drug with anti-inflammatory and immunosuppressive effects and is also a folic acid antagonist. Our aim in this study is to determine the molecular mechanisms of cardiotoxicity caused by MTX, a chemotherapeutic drug, and to evaluate the protective effects of vitamin B12 on this toxicity. Materials and Methods: A total of 32 rats were used in our study and 4 groups were formed. Control group, Vit B12 group (3 µg/kg B12 for 15 days, IP), MTX group (20 mg/kg MTX single dose on day 8 of the experiment, IP), MTX +Vit B12 group (3 µg/kg, IP ), Vit B12 throughout the 15 days, and a single dose of 20 mg/kg MTX (IP) on day 8 of the experiment. Immunohistochemically, expressions of hypoxia-inducible factor 1α (HIF1-α), vascular endothelial growth factor receptor-2 (VEGFR-2), erythropoietin (EPO), and interleukin-6 (IL-6) were evaluated in the heart tissue. Total catalase (CAT), superoxide dismutase (SOD), and malondialdehyde (MDA) levels were measured in the heart tissue. At the same time, ANP and NT-proBNP levels were measured in the blood serum. Results: In the study, the expression of HIF1-α and VEGFR-2 increased significantly in the MTX group, while IL-6 and EPO significantly decreased. At the same time, CAT and SOD levels were significantly decreased and MDA levels increased significantly in the MTX group. While vitamin B12 significantly corrected all these values, it also greatly reduced the increases in ANP and NT-proBNP levels caused by MTX. Conclusion: It is important to use Vit B12 before and after MTX administration to replace the folate that MTX has reduced.

Vitamin B12 suppresses GADD153, prevents apoptosis and regulates the testicular function in methotrexate treated rat testis.

Methotrexate (MTX) is an anti-neoplastic drug that also causes testicular damage. Vitamin B12 (Vit B12) is a water soluble vitamin that is required for normal metabolism. We investigated Vit B12 as a possible protective agent against testicular damage caused by MTX treatment. We divided rats into four groups: control group, Vit B12 group treated with Vit B12 daily for 15 days, MTX group treated with MTX on day 8, MTX + Vit B12 group treated with MTX on day 8 + Vit B12 for 15 days. Serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone were measured. We also measured proliferating cell nuclear antigen (PCNA), connexin43 (Cx43) and the growth arrest- and DNA damage-inducible gene, 153 (GADD153), using immunohistochemical staining. Apoptosis was assessed using TUNEL staining. The MTX group exhibited degeneration of seminiferous tubules; decreased serum testosterone, LH and FSH levels; fewer PCNA positive cells; increased Cx43 expression; and increased GADD153 and TUNEL stained cells compared to the control group. These pathologic findings were substantially reversed In the MTX + Vit B12 group. MTX caused increased endoplasmic reticulum stress and apoptosis via GADD153. Consequently, Vit B12 potentially is a protective agent against damage caused by MTX.

Investigation of vascular endothelial growth factor receptor-dependent neuroplasticity on rat nucleus tractus solitarius and phrenic nerve after chronic sustained hypoxia.

The neuronal system that controls respiration creates plasticity in response to physiological changes. Chronic sustained hypoxia causes neuroplasticity that contributes to ventilatory acclimatization to hypoxia (VAH). The purpose of this study is to explain the potential roles of the VAH mechanism developing because of chronic sustained hypoxia on respiratory neuroplasticity of vascular endothelial growth factor (VEGF) receptor activation on the nucleus tractus solitarius (NTS) and phrenic nerve. In this study 24 adult male Sprague-Dawley rats were used. Subjects were separated into four groups, a moderate-sham (mSHAM), severed-sham (sSHAM), moderate chronic sustained hypoxia (mCSH), and severed chronic sustained hypoxia (sCSH). Normoxic group (mSHAM and sSHAM) rats were exposed to 21% O2 level (7 days) in the normobaric room while hypoxia group (mCSH and sCSH) rats were exposed to 13% and 10% O2 level (7 days). Different protocols were applied for normoxic and hypoxia groups and ventilation, respiratory frequency, and tidal volume measurements were made with whole-body plethysmography. After the test HIF-1α, erythropoietin (EPO), and VEGFR-2 expressions on the NTS region in the medulla oblongata and phrenic nerve motor neurons in spinal cord tissue were analyzed using the immunohistochemical stain method. Examinations on the medulla oblongata and spinal cord tissues revealed that HIF-1α, EPO, and VEGFR-2 expressions increased in hypoxia groups compared to normoxic groups while a similar increase was also seen when respiratory parameters were assessed. Consequently, learning about VAH-related neuroplasticity mechanisms developed as a result of chronic continuous hypoxia will contribute to developing new therapeutical approaches to various diseases causing respiratory failure using brain plasticity without recourse to medicines.

Thymoquinone has a neuroprotective effect against inflammation, oxidative stress, and endoplasmic reticulum stress in the brain cortex, medulla, and hippocampus due to doxorubicin.

Although doxorubicin (DOX) is used in many cancer treatments, it causes neurotoxicity. In this study, the effect of thymoquinone (THQ), a powerful antioxidant, on DOX-induced neurotoxicity was evaluated. In total, 40 rats were used and 5 groups were formed. Group I: control group (n = 8); Group II: olive oil group (n = 8); Group III: the THQ group (n = 8); THQ 10 mg/kg per day was given intraperitoneally (i.p.) throughout the experiment; group IV: DOX group (n = 8); On Day 7 of the experiment, a single dose of 15 mg/kg intraperitoneally DOX injected; group V: DOX + THQ group (n = 8); Throughout the experiment, 10 mg/kg THQ per day and intraperitoneally 15 mg/kg DOX on Day 7 were injected. Immunohistochemically, tumor necrosis factor-α (TNF-α), interleukin-17 (IL-17), hypoxia-inducible factor 1α (HIF1-α), glucose regulatory protein 78 (GRP78), and the gene inducible by growth arrest and DNA damage 153 (GADD153) proteins were evaluated in the brain cortex, medulla, and hippocampus regions. Total oxidant status (TOS) levels and total antioxidant status (TAS) in the brain tissue were measured. TNF-α, IL-17, HIF1-α, GRP78, and GADD153 immunoreactivities significantly increased in the DOX group in the study. THQ significantly reduced these values. THQ increased the TAS level significantly and decreased the TOS level significantly compared to the DOX group. THQ may play a role as a neuroprotective agent in DOX-induced neurotoxicity in the cortex, medulla, and hippocampus regions of the brain.

Effects of vitamin B12 on methotrexate hepatotoxicity: evaluation of receptor-interacting protein (RIP) kinase.

In the study, we aimed to show the effects of vitamin B12 on the necrosis caused by methotrexate (MTX), a folic acid antagonist. Thirty-two rats were randomly assigned to four groups of eight rats per group. Control (n = 8), Vit B12 (n = 8) 3 µg/kg/ip B12 (15 days) per day throughout the experiment, MTX (n = 8) injected with a single dose of 20 mg/kg/ip MTX on 8th day of experiment, MTX + Vit B12 (n = 8) injected with a single dose of 20 mg/kg ip methotrexate on 8th day of experiment + 3 µg/kg/ip Vit B12 (15 days) per day throughout the experiment. Oxidant (TOS)/antioxidant (TAS) system, TNF-α and TGF-ß levels, AST and ALT, serum vitamin B12 levels were determined in the tissue. Cyclooxygenase-2 (Cox-2), receptor-interacting protein kinase 1 (RIP1) and 3 (RIP3) immunohistochemistry were applied to the liver tissue. TOS increased; TAS decreased; TNF-α and TGF-ß levels increased; AST and ALT levels changed after MTX hepatotoxicity. Vit B12 decreased significantly. COX-2, RIP1, and RIP3 immunoreactivity increased. Vit B12 showed improvement in all of the negative results. Vit B12 is an important supplement to be used against necrosis in tissue after MTX hepatotoxicity.