Early life trauma/stress is associated with behavioral abnormalities, memory impairment, and long-term neurodevelopmental alterations. Brain-derived neurotrophic factor (BDNF) and its associated signaling pathways have been investigated for their roles in linking stress with neurological complications. Taurine (TAU), the most abundant non-protein amino acid in the body, is known for its significant effects on the central nervous system (CNS); however, its precise mechanisms of action are vague. This study aimed to investigate the effects of TAU on the BDNF/TrkB/ERK1/CREB signaling pathway in the hippocampus and its impact on memory, cognitive deficits, and depression-like behaviors in the maternal separation and early weaning (MSEW) model. The amino acid TAU was administered to mouse offspring (50 and 100 mg/kg, s.c., started on the post-natal day; PND = 6) of the control and MSEW model. Behavioral tests revealed significant memory impairments and depression-like behavior during puberty, with no significant changes in memory indices observed in adult offspring. Notably, TAU treatment significantly ameliorated memory impairments and reduced cognitive disorder and depression markers during puberty (PND = 35). In the MSEW group, the expression/levels of BDNF, TrkB, ERK1, and CREB were markedly downregulated during puberty, while no significant changes were detected in adult animals (PND = 85). Notably, the TAU administration significantly upregulated components of the BDNF/TrkB/ERK1/CREB signaling pathway in both juvenile and adult mice. These findings suggest that TAU may have therapeutic potential in mitigating early-life trauma-induced neurodevelopmental deficits by modulating the BDNF/TrkB/ERK1/CREB pathway. Given the critical role of this signaling pathway in various CNS disorders, further investigations are warranted to explore the effects of TAU in the CNS and to elucidate its potential as a candidate for further investigation in stress-related neurodevelopmental and neurobehavioral disorders.

Aim of the study:Cholestasis is characterized by impaired bile flow from the liver to the small intestine. Beyond liver damage, cholestasis significantly affects other organs, particularly the kidneys, causing a condition known as cholemic nephropathy (CN). Sildenafil is a phosphodiesterase type 5 (PDE5) enzyme inhibitor with a wide range of pharmacological effects. Several studies have described the nephroprotective properties of sildenafil. Material and methods:Rats underwent bile duct ligation (BDL) surgery to induce cholestasis and CN. Afterward, BDL animals received sildenafil (5, 10, and 20 mg/kg/day, i.p., for 14 consecutive days). Urine, blood, and kidney samples were collected for further evaluation. Results:Elevated levels of blood urea nitrogen (BUN) and creatinine (Cr) and urinalysis revealed renal injury in this model (p < 0.001). Oxidative stress markers, including depleted antioxidant capacity, increased ROS formation, lipid peroxidation, and protein carbonylation, were evident in the kidneys of BDL rats (p < 0.001). Moreover, the activity of enzymatic antioxidant systems (CAT, SOD, GR, and GPx) was also significantly decreased in the kidney of BDL animals (p < 0.001). Tissue pro-inflammatory cytokines (TNF-a, IL-6, and IL-1b) were also considerably higher in the kidney of cholestatic rats (p < 0.001). Renal histopathological changes in BDL animals included inflammatory cell infiltration, tubular atrophy, necrosis, significant fibrotic changes, and cast formation. It was found that sildenafil significantly reduced pathological changes, mitigated oxidative stress biomarkers, and suppressed inflammation in the kidneys of BDL animals. The nephroprotective effects of sildenafil were not dose-dependent in the current study. Conclusions:The data obtained from this study revealed that sildenafil could significantly protect against renal damage in cholestasis. The effect of sildenafil on oxidative stress and the inflammatory response plays an essential role in its nephroprotective mechanisms.

Acute pancreatitis (AP) is a severe inflammatory disorder with a significant risk of mortality. However, restricted pharmacological treatments are available against this complication. Carnosine is an endogenous dipeptide with various pharmacological effects, including antioxidative and anti-inflammatory properties. The current study was designed to evaluate the impact of carnosine in an experimental model of AP. For this purpose, mice received arginine (two 4 g/kg doses, one-hour intervals, i.p) to induce AP. Then, animals received carnosine (50, 250, and 500 mg/kg, i.p). Serum levels of amylase, lipase, and glucose were significantly increased (P<0.001) in the current AP model. Moreover, alterations in oxidative stress biomarkers in the pancreas, including ROS formation, decreased antioxidant capacity, lipid peroxidation, and glutathione depletion, were detected in the AP group (P<0.001). A significant increase in the pancreatic level of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) was also evident in the l-arginine-treated mice (P<0.001). The major pancreatic tissue histopathological changes in the current AP model were the infiltration of inflammatory cells to the pancreas tissue, fluid accumulation, and acinar cell vacuolization/necrosis (P<0.05). Carnosine significantly reduced serum biomarkers of pancreas injury, alleviated oxidative stress, decreased pro-inflammatory cytokine levels, and improved histopathological changes in the pancreas of mice with AP (P<0.001). These findings suggest that carnosine is a protective agent in pancreatitis, with its antioxidative and anti-inflammatory properties playing a pivotal role in its mechanisms of action. Further research is needed to confirm these protective effects in clinical studies and assess carnosine safety in AP.

BACKGROUND:Taurine (TAU) is the most abundant non-protein amino acid in the central nervous system (CNS). However, the molecular mechanism of TAU in the CNS is still poorly understood. Meanwhile, disruption in mitochondrial dynamics is evident in CNS disorders. This study aimed to investigate the effect of TAU on mitochondrial dynamics. METHODS:TAU (0.25, 0.5 and 1% in drinking water) was administered to young mice for six months. Several memory/cognition parameters and indices of anxiety/depression were assessed. Meanwhile, various mitochondrial indices and the expression/activity of genes involved in mitochondrial biogenesis and dynamics (Akt, CREB, NRF1, TFAM, PGC-1α, Mfn1, Mfn2, UCP2, PINK1, OPA1, Drp1 and Fis1) were examined. RESULTS:TAU significantly enhanced memory performance, suppressed anxiety and depression-like behaviour, increased mitochondrial biogenesis/dynamics and improved mitochondrial indices. It should be mentioned that there was no significant difference between different concentrations of TAU in changing most brain mitochondrial dynamic biomarkers in the current study. CONCLUSIONS:These findings offer more insights into the molecular mechanism for TAU's action in the CNS. However, there is a need for further research to confirm these effects in humans. Overall, this study suggests the potential application of TAU in various neurological disorders and the need for clinical studies on the effects of this amino acid in the brain.

Taurine (TAU) is a sulfur-containing amino acid abundantly found in the human body. Endogenously, TAU is synthesized from cysteine in the liver. However, newborns rely entirely on TAU's dietary supply (milk). There is no investigation on the effect of long-term TAU administration on next-generation neurological development. The current study evaluated the effect of long-term TAU supplementation during the maternal gestational and litter weaning time on several neurological parameters in mice offspring. Moreover, the effects of TAU on mitochondrial function and oxidative stress biomarkers as plausible mechanisms of its action in the whole brain and hippocampus have been evaluated. TAU (0.5 % and 1 % w/v) was dissolved in the drinking water of pregnant mice (Day one of pregnancy), and amino acid supplementation was continued during the weaning time (post-natal day; PND = 21) until litters maturity (PND = 65). It was found that TAU significantly improved cognitive function, memory performance, reflexive motor activity, and emotional behaviors in F1-mice gener-ation. TAU measurement in the brain and hippocampus revealed higher levels of this amino acid. TAU and ATP levels were also significantly higher in the mitochondria isolated from the whole brain and hippocampus. Based on these data, TAU could be suggested as a supplement during pregnancy or in pediatric formula. The effects of TAU on cellular mitochondrial function and energy metabolism might play a fundamental role in the positive effects of this amino acid observed in this investigation.

Zoledronic acid (ZLD) is a bisphosphonate drug widely administered against pathological conditions such as hypercalcemia of malignancy, osteoporosis, bone metastases from solid tumors, and multiple myeloma. Unfortunately, renal injury is a serious and dose-limiting adverse effect of ZLD. There is no specific mechanism for ZLD-induced renal damage. The current study aimed to assess the effects of ZLD (10 and 15 mg/kg, i.p., single dose) on the rat kidney. In this regard, several parameters, including oxidative stress biomarkers, serum level of BUN and creatinine, inflammatory cytokines, kidney histopathology, and indices of mitochondrial function were assessed. A significant increase in serum Cr and BUN revealed renal injury. Moreover, kidney histopathological changes, including interstitial inflammation, tissue necrosis, and tubular atrophy, were detected in ZLD-treated rats. Biomarkers of oxidative stress, including a significant increase in reactive oxygen species (ROS), depletion of kidney glutathione (GSH) stores, increased lipid peroxidation, and suppression of the total antioxidant capacity, were detected in ZLD-treated animals. ZLD also significantly increased renal levels of TNF-α, IL-6, and IL-1β. ZLD exposure was also associated with significantly decreased mitochondrial dehydrogenases activity, mitochondrial depolarization, mitochondrial permeabilization, and ATP depletion. These data highlight mitochondrial dysfunction, inflammatory response, and oxidative stress as potential mechanisms in ZLD-induced kidney injury.

Cholestasis is a clinical complication that primarily influences the liver. However, it is well known that many other organs could be affected by cholestasis. Lung tissue is a major organ influenced during cholestasis. Cholestasis-induced lung injury could induce severe complications such as respiratory distress, serious pulmonary infections, and tissue fibrosis. Unfortunately, there is no specific pharmacological intervention against this complication. Several studies revealed that oxidative stress and inflammatory response play a role in cholestasis-induced lung injury. Carnosine (CARN) is a dipeptide found at high concentrations in different tissues of humans. CARN’s antioxidant and antiinflammatory properties are repeatedly mentioned in various experimental models. This study aimed to assess the role of CARN on cholestasis-induced lung injury. Rats underwent bile duct ligation (BDL) to induce cholestasis. Broncho-alveolar lavage fluid (BALF) levels of inflammatory cells, pro-inflammatory cytokines, and immunoglobulin were monitored at scheduled intervals (7, 14, and 28 days after BDL). Moreover, lung tissue histopathological alterations and biomarkers of oxidative stress were evaluated. A significant increase in BALF inflammatory cells, TNF-α, IL-1β, IL-6, and immunoglobulin-G (IgG) was detected in the BALF of BDL rats. Moreover, lung tissue histopathological changes, collagen deposition, increased TGF-β, and elevated levels of oxidative stress biomarkers were evident in cholestatic animals. It was found that CARN (100 and 500 mg/kg, i.p.) significantly alleviated lung oxidative stress biomarkers, inflammatory response, tissue fibrosis, and histopathological alterations. These data indicate the potential protective properties of CARN in the management of cholestasis-induced pulmonary damage. The effects of CARN on inflammatory response and oxidative stress biomarkers seems to play a crucial role in its protective properties in the lung of cholestatic animals.

Acute kidney injury (AKI) is an emergency condition that requires restrictive and appropriate clinical interventions. Identifying mechanisms of organ injury is a critical step in developing clinical interventions. Unilateral ureter obstruction (UUO) is widely used as an animal model for investigating AKI. The current study was designed to evaluate the role of mitochondrial impairment and oxidative stress in the pathogenesis of renal injury in UUO model. Mice underwent UUO surgery. Then, kidney tissue histopathological changes, plasma biomarkers of renal injury, oxidative stress, and different renal mitochondrial indices were evaluated at scheduled time intervals (3, 7, 14, and 21 days after UUO surgical procedure). Significant increase in plasma creatinine and blood urea nitrogen levels was evident in UUO mice. The UUO surgery induced severe kidney tissue histopathological alterations, including necrosis, severe tubular atrophy, and interstitial inflammation. Moreover, kidney biomarkers of oxidative stress included reactive oxygen species formation, lipid peroxidation, protein carbonylation, decreased glutathione reservoirs (GSH), and increased oxidized glutathione (GSSG) observed in UUO mice. On the other hand, significant mitochondrial depolarization, decreased mitochondrial dehydrogenases activity, mitochondrial permeabilization, and decreased adenosine triphosphate and GSH/GSSG levels were discovered in mitochondria isolated from the kidneys of UUO mice. The data obtained from the current study demonstrated a pivotal and interconnected role for oxidative stress and mitochondrial dysfunction in the pathogenesis of renal injury in UUO model. Therefore, these directions could serve as therapeutic targets in animal models or patients of acute renal failure.

Background: of the study: Hepatic encephalopathy (HE) is a complication in which brain ammonia (NH4+) levels reach critically high concentrations because of liver failure. HE could lead to a range of neurological complications from locomotor and behavioral disturbances to coma. Several tactics have been established for subsiding blood and brain NH4+. However, there is no precise intervention to mitigate the direct neurological complications of NH4+.Purpose: It has been found that oxidative stress, mitochondrial damage, and neuro-inflammation play a fundamental role in NH4+ neurotoxicity. Piracetam is a drug used clinically in neurological complications such as stroke and head trauma. Piracetam could significantly diminish oxidative stress and improve brain mitochondrial function.Research methods: In the current study, piracetam (100 and 500 mg/kg, oral) was used in a mice model of HE induced by thioacetamide (TA, 800 mg/kg, single dose, i.p).Results: Significant disturbances in animals' locomotor activity, along with increased oxidative stress biomarkers, including reactive oxygen species formation, protein carbonylation, lipid peroxidation, depleted tissue glutathione, and decreased antioxidant capacity, were evident in the brain of TA-treated mice. Meanwhile, mitochondrial permeabilization, mitochondrial depolarization, suppression of dehydrogenases activity, and decreased ATP levels were found in the brain of the TA group. The level of pro-inflammatory cytokines was also significantly high in the brain of HE animals.Conclusion: It was found that piracetam significantly enhanced mice's locomotor activity, blunted oxidative stress biomarkers, decreased inflammatory cytokines, and improved mitochondrial indices in hyperammonemic mice. These data suggest piracetam as a neuroprotective agent which could be repurposed for the management of HE.

INTRODUCTION:Cholestasis is the stoppage of bile flow, leading to the accumulation of potentially cytotoxic bile components in the liver. These cytotoxic molecules affect many organs. Cholestasis-induced lung injury is a severe complication that could lead to tissue fibrosis and respiratory distress. Substantial evidence indicates the role of oxidative stress and inflammatory response in the pathogenesis of cholestasis-associated pulmonary damage. Agmatine (AGM; 1-amino-4-guanidinobutane) is a biogenic amine endogenously synthesized in the human body. This amine provides potent anti-inflammatory and antioxidant properties.METHODS:In the current study, a series (six C57BL/6J male mice/group) of bile duct-ligated (BDL) animals were monitored at scheduled intervals (7, 14, and 28 days after the BDL operation) to ensure inflammatory response in their lung tissue (by analyzing their bronchoalveolar lavage fluid [BALF]). It was found that the level of inflammatory cells, pro-inflammatory cytokines, and IgG in the BALF reached their maximum level on day 28 after the BDL surgery. Therefore, other research groups were selected as follows: 1) Sham-operated (2.5 mL/kg normal saline, i.p., for 28 consecutive days), 2) BDL, 3) BDL + AGM (1 mg/kg/day, i.p., for 28 consecutive days), and 4) BDL + AGM (10 mg/kg/day, i.p., for 28 consecutive days). Then, the BALF was monitored at scheduled time intervals (7, 14, and 28 days post-BDL).RESULTS:It was found that pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β), bile acids, bilirubin, and inflammatory cells (monocytes, neutrophils, and lymphocytes) were significantly increased in the BALF of BDL mice. Moreover, biomarkers of oxidative stress were significantly increased in the pulmonary tissue of cholestatic animals. Lung tissue histopathological changes, tissue collagen deposition, and increased TGF-β were also detected. It was found that AGM significantly ameliorated cholestasis-induced lung injury.CONCLUSION:The effects of AGM on inflammatory indicators, oxidative stress biomarkers, and tissue fibrosis seem to play a pivotal role in its protective properties.

Taurine (TAU) is a free amino acid abundant in the human body. Various physiological roles have been attributed to TAU. At the subcellular level, mitochondria are the primary targets for TAU function. Meanwhile, it has been found that TAU depletion is associated with severe pathologies. Cholestasis is a severe clinical complication that can progress to liver fibrosis, cirrhosis, and hepatic failure. Bile duct ligation (BDL) is a reliable model for assessing cholestasis/cirrhosis and related complications. The current study was designed to investigate the effects of cholestasis/cirrhosis on tissue and mitochondrial TAU reservoirs. Cholestatic rats were monitored (14 and 42 days after BDL surgery), and TAU levels were assessed in various tissues and isolated mitochondria. There was a significant decrease in TAU in the brain, heart, liver, kidney, skeletal muscle, intestine, lung, testis, and ovary of the BDL animals (14 and 42 days after surgery). Mitochondrial levels of TAU were also significantly depleted in BDL animals. Tissue and mitochondrial TAU levels in cirrhotic animals (42 days after the BDL operation) were substantially lower than those in the cholestatic rats (14 days after BDL surgery). These data indicate an essential role for tissue and mitochondrial TAU in preventing organ injury induced by cholestasis/cirrhosis and could justify TAU supplementation for therapeutic purposes.