Supplementation of carvacrol attenuates hippocampal tumor necrosis factor-alpha level, oxidative stress, and learning and memory dysfunction in lipopolysaccharide-exposed rats

Hibiscetin attenuates lipopolysaccharide-evoked memory impairment by inhibiting BDNF/caspase-3/NF-κB pathway in rodents

This study explores the neuroprotective potential of hibiscetin concerning memory deficits induced by lipopolysaccharide (LPS) injection in rats. The aim of this study is to evaluate the effect of hibiscetin against LPS-injected memory deficits in rats. The behavioral paradigms were conducted to access LPS-induced memory deficits. Various biochemical parameters such as acetyl-cholinesterase activity, choline-acetyltransferase, antioxidant (superoxide dismutase, glutathione transferase, catalase), oxidative stress (malonaldehyde), and nitric oxide levels were examined. Furthermore, neuroinflammatory parameters such as tumor necrosis factor-α, interleukin-1β (IL-1β), IL-6, and nuclear factor-kappa B expression and brain-derived neurotrophic factor as well as apoptosis marker i.e., caspase-3 were evaluated. The results demonstrated that the hibiscetin-treated group exhibited significant recovery in LPS-induced memory deficits in rats by using behavioral paradigms, biochemical parameters, antioxidant levels, oxidative stress, neuroinflammatory markers, and apoptosis markers. Recent research suggested that hibiscetin may serve as a promising neuroprotective agent in experimental animals and could offer an alternative in LPS-injected memory deficits in rodent models.

Therapeutic Potential of Myrtenal and Its Derivatives-A Review

The investigation of monoterpenes as natural products has gained significant attention in the search for new pharmacological agents due to their ability to exhibit a wide range in biological activities, including antifungal, antibacterial, antioxidant, anticancer, antispasmodic, hypotensive, and vasodilating properties. In vitro and in vivo studies reveal their antidepressant, anxiolytic, and memory-enhancing effects in experimental dementia and Parkinson's disease. Chemical modification of natural substances by conjugation with various synthetic components is a modern method of obtaining new biologically active compounds. The discovery of new potential drugs among monoterpene derivatives is a progressive avenue within experimental pharmacology, offering a promising approach for the therapy of diverse pathological conditions. Biologically active substances such as monoterpenes, for example, borneol, camphor, geraniol, pinene, and thymol, are used to synthesize compounds with analgesic, anti-inflammatory, anticonvulsive, antidepressant, anti-Alzheimer's, antiparkinsonian, antiviral and antibacterial (antituberculosis) properties. Myrtenal is a perspective monoterpenoid with therapeutic potential in various fields of medicine. Its chemical modifications often lead to new or more pronounced biological effects. As an example, the conjugation of myrtenal with the established pharmacophore adamantane enables the augmentation of several of its pivotal properties. Myrtenal-adamantane derivatives exhibited a variety of beneficial characteristics, such as antimicrobial, antifungal, antiviral, anticancer, anxiolytic, and neuroprotective properties, which are worth examining in more detail and at length.

Neuroprotective effects of sesamol against LPS-induced spatial learning and memory deficits are mediated via anti-inflammatory and antioxidant activities in the rat brain

Objective

Sesamol is a phenolic lignan extracted from sesame seeds, and it possesses anti-inflammatory and antioxidant activities. Lipopolysaccharide (LPS) is known to produce neuroinflammatory responses and memory impairment. The current study aimed to investigate the protective influence of sesamol against LPS-mediated neuroinflammation and memory impairment.

Materials and Methods

Sesamol (10 and 50 mg/kg) was injected to Wistar rats for two weeks. Then, animals received LPS injection (1 mg/kg) for five days, while treatment with sesamol was performed 30 min before LPS injection. Spatial learning and memory were assessed by the Morris water maze (MWM), two hours after LPS injection on days 15-19. Biochemical assessments were performed after the end of behavioral experiments.

Results

LPS-administered rats showed spatial learning and memory deficits, since they spent more time in the MWM to find the hidden platform and less time in the target quadrant. Besides these behavioral changes, tumor necrosis factor-α (TNF-α) and lipid peroxidation levels were increased, while total thiol level was decreased in the hippocampus and/or cerebral cortex. In addition, sesamol treatment (50 mg/kg) for three weeks decreased the escape latency and increased the time on probe trial. Sesamol also reduced lipid peroxidation and TNF-α level, while enhanced total thiol level in the brain of LPS-exposed rats.

Conclusion

Supplementation of sesamol attenuated learning and memory impairments in LPS-treated rats via antioxidative and anti-inflammatory activities in the rat brain.

Treadmill running and Levisticum Officinale extract protect against LPS-induced memory deficits by modulating neurogenesis, neuroinflammation and oxidative stress

Neuroinflammation plays an essential role in the pathogenesis of Alzheimer's disease. The preventive effect of physical exercise on attenuating neuroinflammation has not been completely defined. Levisticum officinale is known as a medicinal plant with antioxidant and anti-inflammatory properties. The current study was designed to investigate the neuroprotective impacts of treadmill running and Levisticum officinale on lipopolysaccharide (LPS)-induced learning and memory impairments and neuroinflammation in rats. Male Wistar rats ran on a treadmill and/or were pretreated with Levisticum officinale extract at a dose of 100 mg/kg for a week. Then, rats received intraperitoneal injection of LPS at a dose of 1 mg/kg. Treadmill running and/or treatment of extract lasted three more weeks. Behavioral, molecular, biochemical and immunohistochemical assessments were carried out after the end of the experiment. LPS administration resulted in spatial learning and memory impairments along with increased mRNA expression of interleukin-6 and malondialdehyde levels, as well as decreased superoxide dismutase activity and neurogenesis in the hippocampus. Moreover, treadmill running for four weeks, alone and in combination with Levisticum officinale extract attenuated spatial learning and memory deficits, decreased the mRNA expression of interleukin-6 and malondialdehyde levels, and enhanced superoxide dismutase activity and neurogenesis in the hippocampus. In conclusion, the advantageous effects of running exercise and Levisticum officinale extract on LPS-induced memory impairments are possibly due to the antioxidant and anti-inflammatory activity and enhancing neurogenesis.