Attenuation of smoke induced neuronal and physiological changes by bacoside rich extract in Wistar rats via down regulation of HO-1 and iNOS

[Bacosides: a study of neurobiological activity, prospects for application]

Bacosides are the main biologically active components derived from the plant bacopa monnieri (Bacopa monnieri (L.) Wettst.), which has been used as a nootropic in Indian medicine for many centuries. In recent years, these compounds have attracted attention because of their wide range of neurobiological effects. The neuroprotective effects of bacosides on brain neurons under the influence of various damaging factors (neurotoxins, oxidative stress, beta-amyloid deposition, cigarette smoke, etc.) have been established. It was shown that these substances reduce the levels of inflammatory cytokines and inhibit the processes of demyelination of neurons. The anticonvulsant effect of bacosides has been established. These compounds also improve cognitive functions, including memory and learning abilities. The effects associated with the influence on the dopaminergic and serotonergic systems of the striatum are of interest for the therapy of morphine addiction. The theoretical justifications for the future use of bacosides as a multipurpose means of complex therapy of individual diseases in neurological and psychiatric practice are presented.

Bacopa Protects against Neurotoxicity Induced by MPP+ and Methamphetamine

The neurotoxins methamphetamine (METH) and 1-methyl-4-phenylpyridinium (MPP⁺) damage catecholamine neurons. Although sharing the same mechanism to enter within these neurons, METH neurotoxicity mostly depends on oxidative species, while MPP⁺ toxicity depends on the inhibition of mitochondrial activity. This explains why only a few compounds protect against both neurotoxins. Identifying a final common pathway that is shared by these neurotoxins is key to prompting novel remedies for spontaneous neurodegeneration. In the present study we assessed whether natural extracts from Bacopa monnieri (BM) may provide a dual protection against METH- and MPP⁺-induced cell damage as measured by light and electron microscopy. The protection induced by BM against catecholamine cell death and degeneration was dose-dependently related to the suppression of reactive oxygen species (ROS) formation and mitochondrial alterations. These were measured by light and electron microscopy with MitoTracker Red and Green as well as by the ultrastructural morphometry of specific mitochondrial structures. In fact, BM suppresses the damage of mitochondrial crests and matrix dilution and increases the amount of healthy and total mitochondria. The present data provide evidence for a natural compound, which protects catecholamine cells independently by the type of experimental toxicity. This may be useful to counteract spontaneous degenerations of catecholamine cells.

Bacopa monniera extract mitigates isoproterenol-induced cardiac stress via Nrf2/Keap1/NQO1 mediated pathway

The present study was aimed to investigate the effect of standardised hydroalcoholic extract of Bacopa monniera (BME) against isoproterenol (ISO) induced cardiac stress. Isoproterenol (85 mg/kg body weight) was administered intraperitoneally to induce cardiac stress in rats. Bacopa monniera extract (BME75 and 150 mg/kg) was orally administered for 21 days followed by ISO on 22nd and 23rd experimental days. ISO caused significant cardiac damage, which was concomitant with increased apoptosis and attenuated expressions of Nrf2, HO-1, and regulating apoptotic protein expressions of Bax, Bcl2 and NOS2. Treatment with BME in rats significantly improved cardiac dysfunction by maintaining cardiac rhythm, myocardial integrity. Decreased oxidative stress by restored expressions of Nrf2, NQO1 and HO-1 followed by elevating antioxidant enzymes and total glutathione levels. Our present results suggest that the BME treatment strengthening the endogenous defence system through Nrf2 modulation and played a key role against cardiac oxidative stress induced by ISO in rats.

A comparative study of a preclinical survival model of smoke inhalation injury in mice and rats

Smoke inhalation injury increases morbidity and mortality. Clinically relevant animal models are necessary for the continued investigation of the pathophysiology of inhalation injury and the development of therapeutics. The goal of our research was threefold: 1) to develop a reproducible survival model of smoke inhalation injury in rats that closely resembled our previous mouse model, 2) to validate the rat smoke inhalation injury model using a variety of laboratory techniques, and 3) to compare and contrast our rat model with both the well-established mouse model and previously published rat models to highlight our improvements on smoke delivery and lung injury. Mice and rats were anesthetized, intubated, and placed in custom-built smoke chambers to passively inhale woodchip-generated smoke. Bronchoalveolar lavage fluid (BALF) and lung tissue were collected for confirmatory tests. Lung sections were hematoxylin and eosin stained, lung edema was assessed with wet-to-dry (W/D) ratio, and inflammatory cell infiltration and cytokine elevation were evaluated using flow cytometry, immunohistochemistry, and ELISA. We confirmed that our mouse and rat models of smoke inhalation injury mimic the injury seen after human burn inhalation injury with evidence of pulmonary edema, neutrophil infiltration, and inflammatory cytokine elevation. Interestingly, rats mounted a more severe immunological response compared with mice. In summary, we successfully validated a reliable and clinically translatable survival model of lung injury and immune response in rats and mice and characterized the extent of this injury. These animal models allow for the continued study of smoke inhalation pathophysiology to ultimately develop a better therapeutic.

Dammarane triterpenoid glycosides in Bacopa monnieri: A review on chemical diversity and bioactivity

Bacopa monnieri (L.) is a reputed medicinal herb in traditional system of medicine of India, where it is used as nervine tonic to sharpen intellect and memory. This review discusses chemical characterization of dammarane triterpenoid glycosides which are well accepted for improvement in memory and for potential pharmacological activities. In addition, this review provides information on the chemical composition of specialized metabolites of B. monnieri and in the formulations by different analytical techniques. This comprehensive review covers literature up to 2019 with an emphasis on structural characterization of dammarane triterpenoid glycosides by spectroscopic techniques, chemical composition by analytical methods and pharmacological activities.

Emerging therapies for smoke inhalation injury: a review

Background

Smoke inhalation injury increases overall burn mortality by up to 20 times. Current therapy remains supportive with a failure to identify an optimal or targeted treatment protocol for smoke inhalation injury. The goal of this review is to describe emerging therapies that are being developed to treat the pulmonary pathology induced by smoke inhalation injury with or without concurrent burn injury.

Main body

A comprehensive literature search was performed using PubMed (1995–present) for therapies not approved by the U.S. Food and Drug Administration (FDA) for smoke inhalation injury with or without concurrent burn injury. Therapies were divided based on therapeutic strategy. Models included inhalation alone with or without concurrent burn injury. Specific animal model, mechanism of action of medication, route of administration, therapeutic benefit, safety, mortality benefit, and efficacy were reviewed. Multiple potential therapies for smoke inhalation injury with or without burn injury are currently under investigation. These include stem cell therapy, anticoagulation therapy, selectin inhibition, inflammatory pathway modulation, superoxide and peroxynitrite decomposition, selective nitric oxide synthase inhibition, hydrogen sulfide, HMG-CoA reductase inhibition, proton pump inhibition, and targeted nanotherapies. While each of these approaches shows a potential therapeutic benefit to treating inhalation injury in animal models, further research including mortality benefit is needed to ensure safety and efficacy in humans.

Conclusions

Multiple novel therapies currently under active investigation to treat smoke inhalation injury show promising results. Much research remains to be conducted before these emerging therapies can be translated to the clinical arena.

Chemical composition of Ocimum sanctum by LC-ESI-MS/MS analysis and its protective effects against smoke induced lung and neuronal tissue damage in rats

Smoke induced oxidative stress is known to cause various cancers and associated health problems including lung cancer. Herbal extracts have been reported as antioxidant supplements which attenuate free radical induced oxidative damage of tissues, among which Ocimum sanctum has been reported as the elixir of life due to its innumerable health benefits. In the present study, we investigated the protective effect of O. sanctum against cracker smoke induced lung and brain tissue damage. The results of the study demonstrate that O. sanctum regulates the hematological and serum biochemical parameters such as RBC, WBC, blood urea nitrogen and creatinine kinase. O. sanctum supplementation inhibited oxidative stress as analyzed by SOD, CAT enzyme levels and i-NOS, HSP-70 protein expression. O. sanctum administration also regulated neurotransmitter levels, such as serotonin, dopamine, and regulated acetylcholine esterase levels which play a vital role in neuronal function. Further O. sanctum treatment also preserved the morphology of lung and brain tissues of smoke stress induced rats as observed by histopathology and transmission electron microscope analysis. The biodistribution of O. sanctum was showed its accumulation in key tissues such as kidney, liver, lungs and heart. The LC-ESI-MS/MS analysis of O. sanctum showed the presence of polyphenols, flavonoids and fatty acids which might be responsible for the observed anti-stress effects.

Standardized Bacopa monnieri extract ameliorates acute paraquat-induced oxidative stress, and neurotoxicity in prepubertal mice brain

OBJECTIVES

Bacopa monnieri (BM), an ayurvedic medicinal plant, has attracted considerable interest owing to its diverse neuropharmacological properties. Epidemiological studies have shown significant correlation between paraquat (PQ) exposure and increased risk for Parkinson's disease in humans. In this study, we examined the propensity of standardized extract of BM to attenuate acute PQ-induced oxidative stress, mitochondrial dysfunctions, and neurotoxicity in the different brain regions of prepubertal mice.

METHODS

To test this hypothesis, prepubertal mice provided orally with standardized BM extract (200 mg/kg body weight/day for 4 weeks) were challenged with an acute dose (15 mg/kg body weight, intraperitoneally) of PQ after 3 hours of last dose of extract. Mice were sacrificed after 48 hours of PQ injection, and different brain regions were isolated and subjected to biochemical determinations/quantification of central monoamine (dopamine, DA) levels (by high-performance liquid chromatography).

RESULTS

Oral supplementation of BM for 4 weeks resulted in significant reduction in the basal levels of oxidative markers such as reactive oxygen species (ROS), malondialdehyde (MDA), and hydroperoxides (HP) in various brain regions. PQ at the administered dose elicited marked oxidative stress within 48 hours in various brain regions of mice. However, BM prophylaxis significantly improved oxidative homeostasis by restoring PQ-induced ROS, MDA, and HP levels and also by attenuating mitochondrial dysfunction. Interestingly, BM supplementation restored the activities of cholinergic enzymes along with the restoration of striatal DA levels among the PQ-treated mice.

DISCUSSION

Based on these findings, we infer that BM prophylaxis renders the brain resistant to PQ-mediated oxidative perturbations and thus may be better exploited as a preventive approach to protect against oxidative-mediated neuronal dysfunctions.

The Molecular Links of Re-Emerging Therapy: A Review of Evidence of Brahmi (Bacopa monniera)

The convolution associated with memory is being resolved with advancement in neuroscience. According to the concurrent assumptions, synaptic plasticity forms one of the basis of memory formation, stabilization and strengthening. In Alzheimer's disease (AD), which is generally characterized by memory dysfunction, connections amongst the cells in the brain are attenuated or lost leading to degeneration of neural networks. Numerous attempts have been made to find new therapies for memory dysfunction with increasing attention and investments being laid on herbal drugs. Many herbal plants and extracts have already documented beneficial results when tested for antiamnesic effects. Brahmi (Bacopa monniera) is one such common herbal drug, which is employed for a long time in the Indian and Chinese medical system in order to treat several disorders. Previous research has shown that Brahmi exerts many pharmacological effects including memory boosting capacity in the treatment of Alzheimer's disease and Schizophrenia, exhibiting antiparkinsonian, antistroke, and anticonvulsant potentials. The present review discusses the chemical constituents of Brahmi along with in vitro and in vivo studies based on the pharmacological effects exerted by it. The efficacy of Brahmi in treating various disorders has evoked sufficient research in recent years and now it is a time to launch multiple clinical trials.