Preclinical models of atherosclerosis: An overview.

Atherosclerosis is a primary cause of illness and death globally and its mechanism is still unclear. Different animal models have been created to evaluate the progression of atherosclerosis, allowing researchers to carefully control the circumstances of the experiment as well as the nutrition and environmental risk factors. To investigate the negative effects of various interventions, pathophysiological alterations might be generated utilizing genetic or pharmacological methods. These models' molecular and pathophysiological mechanisms have been clarified through experiments, and they have served as platforms for the creation of new drugs. Different models can be employed to address various research problems, each with its own benefits and drawbacks. In the current review study, various species of atherosclerosis models are discussed, along with the viability of using them in experiments.

Hidden attributes of zymosan in the pathogenesis of inflammatory diseases: A tale of the fungal agent.

Inflammation triggers immune system-mediated actions that contribute to the development of multiple diseases. Zymosan, a polysaccharide derived from the Saccharomyces cerevisiae cell wall, is mainly made up of glucan and mannan residues and is used as an inflammatory agent. Zymosan is a fungal product that activates the immune system through the activation of inflammatory signaling pathways, and releases a variety of harmful chemicals including pattern recognition receptors, reactive oxygen species (ROS), and the excitatory amino acid glutamate, cytokines, adhesion molecules, etc. Furthermore, we will dive into the molecular mechanistic insights through which this fungal agent induces and influences various inflammatory diseases such as cardiovascular, neuroinflammation, diabetes, arthritis, and sepsis. Based on the evidence, zymosan appears to be a promising inflammatory-inducing agent. Nonetheless, more animal data is the need of the hour to catch a glimpse and unravel the capacity of zymosan.

Pentylenetetrazole Induced Kindling Model of Refractory Epilepsy: A Proof-of-concept Study to Explore Dose and Time Range of Phenobarbital in Rats.

Introduction: Drug-resistant epilepsy is an unmet medical condition that impacts 30% of epileptic patients. Numerous antiseizure drugs have already been developed but they provide only symptomatic relief and do not target the underlying pathogenesis. Preclinical models provide opportunities to gain insights into obscure mechanisms of drug-resistant epilepsy. Current animal models possess lacunae that need rectification and validation to discover novel antiepileptic drugs. The present study aims to validate 3 different doses of phenobarbital at 2 different periods. Methods: Pentylenetetrazole was given at a sub-convulsive dose (30 mg/kg/day/intraperitoneal [IP]) for 28 days to develop kindling in male Wistar rats. Further, kindled rats were divided into the following four groups: Pentylenetetrazole control, pentylenetetrazole and phenobarbital (20 mg/kg), pentylenetetrazole and phenobarbital 40 mg/kg, and pentylenetetrazole and phenobarbital (60 mg/kg). They were assessed on days 14 and 28 post-kindling. Seizure scoring, oxidative stress, phenobarbital plasma levels, and histopathology of hippocampal neurons were analyzed. Results: The results showed that the combination of pentylenetetrazole and phenobarbital (40 and 60 mg/kg) remarkably decreased seizure score, elucidated higher antioxidant effect, and prevented neuronal injury on day 14, whereas increased seizure score, oxidative stress, and neuronal death was observed with chronic administration of pentylenetetrazole and phenobarbital in kindled rats at day 28. Moreover, phenobarbital levels in blood were significantly increased at day 28 of phenobarbital treatment compared to day 14. Conclusion: The adapted protocol with phenobarbital 40 mg/kg dose could be of great potential in screening antiseizure drugs in refractory epilepsy.

Efficacy of Ferulic Acid in an Animal Model of Drug-Resistant Epilepsy: Beneficial or Not?

Background Lamotrigine (LTG) and subconvulsive doses of pentylenetetrazol (PTZ) as a model mimic drug-resistant epilepsy (DRE), which is a serious unmet medical condition. Previous evidence suggests an imperative role of neuroinflammation in the development of DRE. Various preclinical models of brain injury have reported potent anti-inflammatory and antioxidant properties of ferulic acid (FA). Therefore, its efficacy against intractable epilepsy is worthwhile to study. Materials and methods The present study evaluated the efficacy of FA in LTG and PTZ-induced refractory seizures in mice. On every alternate day for 38 days, LTG (5mg/kg) was injected before PTZ (30-40mg/kg) to establish a murine model of DRE. Animals were treated with two doses of FA (40, 80 mg/kg). All the animals were assessed for seizure score and the latency of seizures every alternate day till the end of the study. Histopathological score and the levels of pro-inflammatory mediators, interleukin-1ßeta (IL-Iß), tumor necrosis factor-alpha (TNF-α), and matrix metalloproteinase-9 (MMP-9) were quantified in the brain tissue of these mice.  Results Ferulic acid (FA) neither decreases the LTG and PTZ-induced refractory seizures score nor increases the latency to develop seizures. In addition, the injury to hippocampal neurons and the levels of pro-inflammatory cytokines were comparable with two doses of FA in treated mice. Conclusion In the present study, single-dose FA treatment does not show any beneficial effect against the LTG/PTZ model of DRE. Therefore, its single-dose administration might not be beneficial against the DRE model.

Dimethyl Fumarate Ameliorates Paclitaxel-Induced Neuropathic Pain in Rats.

Background Paclitaxel (PTX)-induced peripheral neuropathy (PIPN) is nonresponsive to the currently available analgesics. Previous studies have shown the role of oxidative stress and central sensitization in the development of peripheral neuropathy. Dimethyl fumarate (DMF) acts as a nuclear factor erythroid-2-related factor 2 (Nrf2) activator with neuroprotective benefits and is approved for use in multiple sclerosis. Materials and methods In the current research, we evaluated the efficacy of DMF on paclitaxel-induced peripheral neuropathy in rats. Every alternate day for one week, paclitaxel 2 mg/kg dose was injected to establish a rat model of PIPN. Animals were treated with 25 mg/kg and 50 mg/kg of DMF. All the animals were assessed for thermal hyperalgesia, cold allodynia, and mechanical allodynia once a week. The gene expression of Nrf2 and the levels of pro-inflammatory mediators (interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α), and IL-1ß) were quantified in the sciatic nerves of these rats. The levels of p38 mitogen-activated protein kinase (MAPK) and brain-derived neurotrophic factor (BDNF) were quantified in the dorsal horn of the spinal cord. Results DMF significantly attenuated paclitaxel-induced thermal hyperalgesia and cold/mechanical allodynia. A significant decrease in the levels of pro-inflammatory cytokines with the levels of p38 MAPK and BDNF was observed in the DMF-treated animals. DMF treatment significantly upregulated the gene expression of Nrf2 in the sciatic nerve. Conclusion These findings suggest that DMF prevented the development of PIPN in rats through the activation of Nrf2 and the inhibition of p38 MAPK and BDNF.

Piperlongumine inhibits diethylnitrosamine induced hepatocellular carcinoma in rats.

BACKGROUND: Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. Piperlongumine (PL) has been claimed to have cytotoxic and HCC inhibitory effects in various cancer cell lines and xenograft models, but the chemopreventive potential of PL has not been studied in experimentally induced HCC yet. RESEARCH DESIGN: Twenty-four Wistar male rats were divided into four groups of six each, Group A: untreated control; Group B: Diethylnitrosamine (DEN) control (200 mg/kg), Group C: DEN + PL 10 mg/kg; and Group D: DEN + PL 20 mg/kg. Rats from all groups were assessed for liver cancer progression or inhibition by evaluating biochemical, cytokines, tumor markers, lipid peroxidation, and histological profiles. RESULTS: The liver enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP) levels, and lipid peroxidation were significantly decreased in Group C and Group D compared to Group B. Upregulation in the level of pro-inflammatory cytokines IL-1B, TNF-α, inflammatory mediator (NF-κB) and tumour marker alpha-fetoprotein (AFP) in Group B were brought down upon treatment with piperlongumine in a dose-dependent manner. Antitumor cytokine (IL-12) was upregulated in PL-treated rats compared to DEN control rats. DEN treated group (Group B) showed histological features of HCC, and in rats treated with PL (Groups C, D) partial to complete reversal to normal liver histoarchitecture was observed. CONCLUSIONS: The potential chemopreventive actions of piperlongumine may be due to its free radical scavenging and antiproliferative effect. Therefore, piperlongumine may serve as a novel therapeutic agent for the treatment of hepatocellular carcinoma.

Reconnoitering the transformative journey of minocycline from an antibiotic to an antiepileptic drug.

Minocycline, a second-generation tetracycline antibiotic is being widely tested in animals as well as clinical settings for the management of multiple neurological disorders. The drug has shown to exert protective action in a multitude of neurological disorders including spinal-cord injury, stroke, multiple sclerosis, amyotrophic lateral sclerosis, Huntington's disease, and Parkinson's disease. Being highly lipophilic, minocycline easily penetrates the blood brain barrier and is claimed to have excellent oral absorption (~100% bioavailability). Minocycline possesses anti-inflammatory, immunomodulatory, and anti-apoptotic properties, thereby supporting its use in treating neurological disorders. The article henceforth reviews all the recent advances in the transformation of this antibiotic into a potential antiepileptic/antiepileptogenic agent. The article also gives an account of all the clinical trials undertaken till now validating the antiepileptic potential of minocycline. Based on the reported studies, minocycline seems to be an important molecule for treating epilepsy. However, the practical therapeutic implementations of this molecule require extensive mechanism-based in-vitro (cell culture) and in-vivo (animal models) studies followed by its testing in randomized, placebo controlled and double-blind clinical trials in large population as well as in different form of epilepsies.

A Review on Potential Footprints of Ferulic Acid for Treatment of Neurological Disorders.

Ferulic acid is being screened in preclinical settings to combat various neurological disorders. It is a naturally occurring dietary flavonoid commonly found in grains, fruits, and vegetables such as rice, wheat, oats, tomatoes, sweet corn etc., which exhibits protective effects against a number of neurological diseases such as epilepsy, depression, ischemia-reperfusion injury, Alzheimer's disease, and Parkinson's disease. Ferulic acid prevents and treats different neurological diseases pertaining to its potent anti-oxidative and anti-inflammatory effects, beside modulating unique neuro-signaling pathways. It stays in the bloodstream for longer periods than other dietary polyphenols and antioxidants and easily crosses blood brain barrier. The use of novel drug delivery systems such as solid-lipid nanoparticles (SLNs) or its salt forms (sodium ferulate, ethyl ferulate, and isopentyl ferulate) further enhance its bioavailability and cerebral penetration. Based on reported studies, ferulic acid appears to be a promising molecule for treatment of neurological disorders; however, more preclinical (in vitro and in vivo) mechanism-based studies should be planned and conceived followed by its testing in clinical settings.