Pharmacological screening of silibinin for antischizophrenic activity along with its acute toxicity evaluation in experimental animals

Toxicological profiling and diuretic potential of arbutin via aldosterone synthase gene inhibition

AIMS

Arbutin (ARB), a natural polyphenol isolated from the bearberry plant Arctostaphylos uva-ursi, has been studied for its diverse pharmacological activities including anti-diabetic, cardioprotective and anti-inflammatory effects. This study aimed to evaluate arbutin's diuretic activity, focusing on its impact on aldosterone synthase gene expression and its toxicity profile.

MATERIAL AND METHODS

Acute toxicity was assessed using single doses ranging from 500 to 9000 mg/kg and sub-acute toxicity with doses of 375 and 750 mg/kg over 14 days. To evaluate acute diuretic activity, ARB was administered in three doses (25, 50 and 75 mg/kg i.p) alongside standard groups, furosemide (FUR) 10 mg/kg i.p and Spironolactone (SPIR) 25 mg/kg i.p. In sub-acute diuretic study, treatment was administered for seven days, followed by blood collection and adrenal dissection for gene expression analysis.

KEY FINDINGS

Acute toxicity studies revealed that ARB is well-tolerated up to 7000 mg/kg with no significant changes in organ and body weight. However, sub-acute studies showed minor changes in leukocyte count, alkaline phosphatase (ALP), alanine aminotransferase (ALT) and triglycerides (TGs) at high doses while histopathological evaluations revealed no severe organ damage. The diuretic index and electrolyte analysis confirmed the potential of ARB as diuretic and saluretic with reduced risk of hyperuricemia and hyperkalemia. Gene expression studies showed non-selective downregulation of aldosterone synthase gene (CYP11B2) and 11β-hydroxylase (CYP11B1). While the effects on 17α-hydroxylase (CYP17A1) were less pronounced than SPIR, indicating fewer possible anti-androgenic effects.

SIGNIFICANCE

Our findings suggest that ARB is a promising diuretic agent with a favorable safety profile.

Novel Strategies Enhancing Bioavailability and Therapeutical Potential of Silibinin for Treatment of Liver Disorders

Silibinin, a bioactive component found in milk thistle extract (Silybum marianum), is known to have significant therapeutic potential in the treatment of various liver diseases. It is considered a key element of silymarin, which is traditionally used to support liver function. The main mechanisms of action of silibinin are attributed to its antioxidant properties protecting liver cells from damage caused by free radicals. Experimental studies conducted in vitro and in vivo have confirmed its ability to inhibit inflammatory and fibrotic processes, as well as promote the regeneration of damaged liver tissue. Therefore, silibinin represents a promising tool for the treatment of liver diseases. Since the silibinin molecule is insoluble in water and has poor bioavailability in vivo, new perspectives on solving this problem are being sought. The two most promising approaches are the water-soluble derivative silibinin-C-2',3-dihydrogen succinate, disodium salt, and the silibinin-phosphatidylcholine complex. Both drugs are currently under evaluation in liver disease clinical trials. Nevertheless, the mechanism underlying silibinin biological activity is still elusive and its more detailed understanding would undoubtedly increase its potential in the development of effective therapeutic strategies against liver diseases. This review is focused on the therapeutic potential of silibinin and its derivates, approaches to increase the bioavailability and the benefits in the treatment of liver diseases that have been achieved so far. The review discusses the relevant in vitro and in vivo studies that investigated the protective effects of silibinin in various forms of liver damage.

NMDA receptor modulation by Esculetin: Investigating behavioral, biochemical and neurochemical effects in schizophrenic mice model

Schizophrenia, a global mental health disorder affecting approximately 1 % of the population, is characterized by neurotransmitter dysregulation, particularly dopamine, serotonin, and glutamate. Current antipsychotic therapies, despite their efficacy, are accompanied by adverse effects, which has motivated researchers to investigate more secure substitutes. This study examines the potential antipsychotic effects of esculetin, a natural coumarin derivative recognized for its wide-ranging pharmacological activities (anti-inflammatory, antioxidant, anti-pathogenic, anticancer, and neuroprotective), in animal model of schizophrenia induced by ketamine. In order to induce disease, acute and chronic ketamine administration was performed on Swiss albino mice, supplemented with esculetin (as the test substance) and clozapine (as the reference standard). Behavioral studies and biochemical assays were performed to evaluate positive, negative, and cognitive symptoms of schizophrenia, as well as antioxidant and oxidant levels in various brain regions. Esculetin demonstrated significant improvements in behavioral symptoms, attenuated oxidative stress and neuroinflammation, and modulated neurotransmitter levels. Afterwards, ELISA was performed to evaluate levels of schizophrenia biomarkers AChE, BDNF. Moreover, proinflammatory cytokines (IL-6 and TNF-α) and NF-κB were also determined. Histopathological parameters of under study brain parts i.e., hippocampus, cortex and striata were also assessed. Esculetin and clozapine significantly (***p < 0.0001) altered ketamine induced behavioral symptoms and attenuated ketamine induced oxidative stress and neuroinflammation. Additionally, esculetin significantly (***p < 0.0001) altered neurotransmitter (dopamine, serotonin, glutamate) levels. ELISA analysis depicts ketamine reduced BDNF levels in hippocampus, cortex and striata while esculetin significantly (***p < 0.0001) increased BDNF levels in under study three parts of brain. Histopathological changes were seen in test groups. The findings of this study indicate that esculetin may have therapeutic potential in the treatment of schizophrenia induced by ketamine. As a result, esculetin may have the potential to be utilized as a treatment for schizophrenia.