The Ayurvedic drug, Ksheerabala, ameliorates quinolinic acid-induced oxidative stress in rat brain

Sida cordifolia L. attenuates behavioral hypersensitivity by interfering with KIF17-NR2B signaling in rat model of neuropathic pain

ETHNOPHARMACOLOGICAL RELEVANCE

Sida cordifolia L., a perennial subshrub belonging to the Malvaceae family, holds noteworthy significance in the Indian Ayurvedic System and global texts. Roots of this plant are reported to be useful in neurodegenerative disorders, facial paralysis, and treating several neuropathic pain conditions such as neuralgia, and sciatica. However, despite these claims, there remains a dearth of experimental evidence showcasing the effectiveness of Sida cordifolia L. roots in mitigating neuropathic pain.

AIM OF THE STUDY

The primary objective of this study was to assess the analgesic properties of the whole extract (SCE) obtained from the roots of Sida cordifolia L., as well as its aqueous fraction (SAF) in rat model of chronic constriction injury (CCI)-induced neuropathic pain. Furthermore, in-depth phytochemical and molecular biology studies were conducted to identify the potential phytoconstituents and unveil the underlying mechanisms of action.

MATERIAL AND METHODS

DCM: Methanol (1:1) was used to extract the roots of Sida cordifolia L. to get whole extract (SCE) and was subjected to phytochemical investigations including LC-MS analysis. Analgesic potential of SCE was evaluated in chronic constriction injury (CCI) model of neuropathic pain in rats followed by its bioactivity guided fractionation using in-vitro anti-inflammatory assay and assessment of most potent fraction (SAF) in in-vivo pain model. We have also performed the detailed phytochemical and molecular biology investigations to delineate the mechanism of action of Sida cordifolia root extract.

RESULTS

Chronic constriction injury leads to significant decrease in paw withdrawal threshold and paw withdrawal latency indicating development of hypersensitivity in rodents. Treatment with SCE and its most potent aqueous fraction (SAF) leads to significant and dose-dependent reduction in pain-like behavior of nerve injured rats. Pro-inflammatory cytokines (TNF-α, IL-1β), glia cell markers (Iba1, ICAM1), neuropeptides (CGRP and Substance P), KIF-17 and NR2B expressions were found to be significantly upregulated in DRG and spinal cord of nerve injured rats. Treatment with SCE and SAF suppressed oxido-inflammatory cascade along with attenuation of KIF-17 mediated NR2B trafficking and neuroinflammation in DRG and spinal tissues of neuropathic rats. HPTLC and HR-MS analysis suggest betaine as major constituent in SAF which along with other phytoconstituents.

CONCLUSIONS

Both the whole extract (SCE) and the aqueous fraction (SAF) demonstrate a significant reduction in mechanical and thermal hypersensitivity by inhibiting KIF-17 mediated NR2B signaling in nerve injured rats and may be used as a potential alternative for the treatment of chronic pain. Our findings support the use of roots of Sida cordifolia L. in neuropathic pain conditions as acclaimed by its traditional use.

Asiatic acid prevents the quinolinic acid-induced oxidative stress and cognitive impairment

Increased accumulation of endogenous neurotoxin quinolinic acid has been found in various neurodegenerative diseases. Oxidative stress caused by quinolinic acid is considered as imperative factor for its toxicity. Asiatic acid, a natural triterpene is widely studied for its various medicinal values. In the present study the effects of asiatic acid in preventing the cognitive impairment and oxidative stress caused by quinolinic acid was investigated. Male Spraque-Dawley rats were orally administered asiatic acid (30 mg/kg/day) for 28 days, while quinolinic acid toxicity-induced animals received quinolinic acid (1.5 mmol/kg/day) from day 15 to day 28 for 14 days. Asiatic acid administration prevented the loss of spatial memory caused due to quinolinic acid-induced toxicity as determined using the novel object location test. In addition, asiatic acid administration alleviated the deleterious effect of quinolinic acid in brain such as increased oxidative stress, decreased antioxidant status and mitochondrial oxidative phosphorylation dysfunction. These data demonstrate that asiatic acid through its potent antioxidant and cognition enhancement property prevented the neuronal impairments caused by quinolinic acid.

The Ayurvedic drug Ksheerabala (101) ameliorates alcohol-induced neurotoxicity by down-regulating the expression of transcription factor (NFkB) in rat brain

Introduction:

Most of the pharmaceutical effects of alcohol are due to its accumulation in the brain. Ksheerabala (101) an Ayurvedic formulation mainly used against central nervous system disorders.

Aim:

To determine the antioxidant and neuroprotective effect of Ksheerabala (101) on alcohol-induced oxidative stress in rats.

Materials and Methods:

Male Albino rats of Sprague-Dawley strain were grouped into four; control, alcohol (4 g/kg), Ksheerabala (15 μL/1 ml milk/100 g) and Ksheerabala (15 μL/1 ml milk/100 g) + alcohol (4 g/kg). After the experimental period (90 days), the animals were sacrificed and the effect of Ksheerabala (101) was studied on oxidative stress, inflammatory markers, and induction of transcription factor in brain. Results were statistically analyzed by one-way ANOVA.

Results:

The activities of antioxidant enzymes and reduced glutathione which were decreased in alcohol-treated rats, increased significantly in co-administered groups. The lipid peroxidation products and protein carbonyls which were increased significantly in alcohol-treated rats decreased significantly in co-administered groups. The expression of gamma-glutamyl cysteine synthase decreased significantly in alcohol-treated rats and increased significantly in co-administered groups. The transcription factor nuclear factor-κB (NFκB) which was up-regulated in alcohol-treated rats was down-regulated in co-administered rats. The histopathology reinforced these results.

Conclusion:

Ksheerabala (101) attenuates alcohol-induced oxidative stress and down-regulates the expression of NFκB in rat brain.

Sesamol, a lipid lowering agent, ameliorates aluminium chloride induced behavioral and biochemical alterations in rats

Background:

Sesame oil from the seeds of Sesamum indicum Linn. (Pedaliaceae) has been used traditionally in Indian medical practice of Ayurveda in the treatment of central nervous system disorders and insomnia. A few published reports favor the anti-dementia effect of sesamol (SML), an active constituent of sesame oil.

Objective:

Thus, the present study was aimed to explore the anti-dementia effect and possible mechanism (s) of SML in aluminium chloride (AlCl₃)-induced cognitive dysfunction model in rodents with special emphasis on memory centers viz., hippocampus and frontal cortex.

Methods:

Male Wistar rats were exposed to AlCl₃ (175 mg/kg p.o.) for 60 days. SML (10 and 20 mg/kg) and rivastigmine (1 mg/kg) were administered orally 45 min before administration of AlCl₃ for 60 days. Spatial memory was assessed using Morris water maze test. After 60 days of treatment animals were sacrificed, hippocampus and frontal cortex were collected and analyzed for acetylcholinesterase (AChE) activity, tumor necrosis factor (TNF-α) level, antioxidant enzymes (Glutathione, catalase), lipid peroxidation, and nitrite level. The circulating triglycerides, total cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) levels were also analyzed.

Results:

SML significantly prevented behavioral impairments in aluminium-exposed rats. Treatment with SML reversed the increased cholesterol, triglycerides and LDL while raised the HDL levels. SML significantly corrected the effect of AlCl₃ on AChE activity. Further, SML reversed the elevated nitric oxide, TNF-α and reduced antioxidant enzymes in hippocampus and frontal cortex.

Conclusion:

The present study suggests the neuro-protection by SML against cognitive dysfunction induced by environmental toxin (AlCl₃) in hippocampus and frontal cortex.

Quinolinic acid: an endogenous neurotoxin with multiple targets

Quinolinic acid (QUIN), a neuroactive metabolite of the kynurenine pathway, is normally presented in nanomolar concentrations in human brain and cerebrospinal fluid (CSF) and is often implicated in the pathogenesis of a variety of human neurological diseases. QUIN is an agonist of N-methyl-D-aspartate (NMDA) receptor, and it has a high in vivo potency as an excitotoxin. In fact, although QUIN has an uptake system, its neuronal degradation enzyme is rapidly saturated, and the rest of extracellular QUIN can continue stimulating the NMDA receptor. However, its toxicity cannot be fully explained by its activation of NMDA receptors it is likely that additional mechanisms may also be involved. In this review we describe some of the most relevant targets of QUIN neurotoxicity which involves presynaptic receptors, energetic dysfunction, oxidative stress, transcription factors, cytoskeletal disruption, behavior alterations, and cell death.