Punicalagin and ellagic acid containing Punica granatum L. fruit rind extract prevents vincristine-induced neuropathic pain in rats: an in silico and in vivo evidence of GABAergic action and cytokine inhibition

Treating chronic stress and chronic pain by manipulating gut microbiota with diet: can we kill two birds with one stone?

Background: Chronic stress and chronic pain are closely linked by the capacity to exacerbate each other, sharing common roots in the brain and in the gut. The strict intersection between these two neurological diseases makes important to have a therapeutic strategy aimed at preventing both to maintain mental health in patients. Diet is an modifiable lifestyle factor associated with gut-brain axis diseases and there is growing interest in its use as adjuvant to main therapies. Several evidence attest the impact of specific diets or nutrients on chronic stress-related disorders and pain with a good degree of certainty. A daily adequate intake of foods containing micronutrients such as amino acids, minerals and vitamins, as well as the reduction in the consumption of processed food products can have a positive impact on microbiota and gut health. Many nutrients are endowed of prebiotic, anti-inflammatory, immunomodulatory and neuroprotective potential which make them useful tools helping the management of chronic stress and pain in patients. Dietary regimes, as intermittent fasting or caloric restriction, are promising, although further studies are needed to optimize protocols according to patient's medical history, age and sex. Moreover, by supporting gut microbiota health with diet is possible to attenuate comorbidities such as obesity, gastrointestinal dysfunction and mood disorders, thus reducing healthcare costs related to chronic stress or pain.Objective: This review summarize the most recent evidence on the microbiota-mediated beneficial effects of macro- and micronutrients, dietary-related factors, specific nutritional regimens and dietary intervention on these pathological conditions.

Multifaceted Neuroprotective Role of Punicalagin: A Review

Millions of people worldwide are currently afflicted with neurologic conditions like a seizure, depression, stress, Alzheimer's disease, Parkinson's disease, and Huntington's disease. However, the precise etiopathology of these diseases is still unknown. Substantial studies are being conducted to discover more treatments against these disorders because many patients do not experience the therapeutic benefits that would be expected from using existing pharmaceutical strategies. Herbal medicines which have been used in traditional medicine for millennia to treat various neurological problems are also being investigated and scientifically assessed. Punicalagin is a known polyphenol that has significant antioxidant, anti-inflammatory, anti-viral, anti-proliferative, and anti-cancer properties. Around the world, traditional use of herbal drugs is gaining wider acceptance as a part of complementary and alternative medicine. The scientific community should pay attention to these many neuroprotective pharmacodynamic activities of Punicalagin to create effective pharmacotherapeutic plans, as evidenced by mounting data in pre-clinical research investigations. The current review describes the recent studies on the pharmacological effects of Punicalagin in a variety of neurological illnesses and paves the way for further study in this field.

5,7-Dimethoxycoumarin ameliorates vincristine induced neuropathic pain: potential role of 5HT3 receptors and monoamines

Vincristine is the drug of choice for Hodgkin's lymphoma, acute lymphoblastic leukemia, and non-Hodgkin lymphoma. Despite its significant anticancer effects, it causes dose-dependent neuropathy, leading to compulsive dose reduction. The available drugs used for vincristine-induced neuropathic pain (VINP) have a range of safety, efficacy, and tolerability issues prompting a search for new therapies. 5,7-Dimethoxycoumarin (5,7-DMC) also known as citropten, is a natural coumarin found in the essential oils of citrus plants such as lime, lemons, and bergamots, and it possesses both antidepressant and anti-inflammatory effects. This study was designed to investigate the possible analgesic and antiallodynic effects of 5,7-DMC in a murine model of VINP. Vincristine was administered to groups of BALB/c male mice (0.1 mg/kg intraperitoneally) once daily for 14 days to induce VINP. Thermal hyperalgesia and mechanical allodynia were quantified using the tail immersion test and von Frey filament application method. The levels of monoamine neurotransmitters and vitamin C in frontal cortical, striatal and hippocampal tissues, as well as the TNF-α level in plasma, were quantified using high performance liquid chromatography and ELISA respectively. On day 15 of the protocol, acute treatment with 5,7-DMC clearly reversed VINP thermal hyperalgesia, mechanical static allodynia, mechanical dynamic allodynia, and cold allodynia. The activity of 5,7-DMC against hyperalgesia and allodynia was inhibited by pretreatment with ondansetron but not naloxone, implicating a 5-HT3 receptor involvement. VINP vitamin C levels were restored by 5,7-DMC in the frontal cortex, and changes in serotonin, dopamine, adenosine, inosine and hypoxanthine levels caused by vincristine were reversed either fully or partially. Additionally, the vincristine-induced rise in hippocampal serotonin, dopamine, inosine and striatal serotonin was appreciably reversed by 5,7-DMC. 5,7-DMC also reversed the vincristine-induced increase in the plasma level of TNF-α. In negating the changes in the levels of some neurotransmitters in the brain caused by vincristine, 5,7-DMC showed stronger effects than gabapentin. It was concluded that, there is a potential role of 5-HT3 receptors and monoamines in the amelioration of VINP induced by 5,7-DMC, and the use of this compound warrants further investigation.

Synergistic effect of ellagic acid and gabapentin in a rat model of neuropathic pain

BACKGROUND

Neuropathic pain is a subtype of chronic pain characterized by a primary lesion or dysfunction of the peripheral or central nervous system. The current pain management of neuropathic pain is inadequate and needs new medications.

AIM

We studied the effects of 14 days of intraperitoneal ellagic acid (EA) and gabapentin administration in a rat model of neuropathic pain induced by chronic constriction injury (CCI) of the right sciatic nerve.

METHODS

Rats were divided into six groups: (1) control, (2) CCI, (3) CCI + EA (50 mg/kg), 4) CCI + EA (100 mg/kg), 5) CCI + gabapentin (100 mg/kg), and 6) CCI + EA (100 mg/kg) + gabapentin (100 mg/kg). Behavioral tests, including mechanical allodynia, cold allodynia, and thermal hyperalgesia, were conducted on days - 1(pre-operation), 7, and 14 post-CCI. In addition, at day 14 post-CCI, spinal cord segments were collected to measure the expression of inflammatory markers, including tumor necrosis factor-alpha (TNF-α), nitric oxide (NO), and oxidative stress markers, including malondialdehyde (MDA) and thiol.

RESULTS

CCI increased mechanical allodynia, cold allodynia, and thermal hyperalgesia in rats which were reduced by treatment with EA (50 or 100 mg/kg), gabapentin, or their combination. CCI increased TNF-α, NO, and MDA levels and decreased thiol content in the spinal cord, which all were reverted by administration of EA (50 or 100 mg/kg), gabapentin, or their combination.

CONCLUSION

This is the first report on ellagic acid's ameliorative effect in rats' CCI-induced neuropathic pain. This effect can be attributed to its anti-oxidative and anti-inflammatory, thus making it potentially useful as an adjuvant to conventional treatment.

A Systematic Review and Meta-Analysis on the Role of Nutraceuticals in the Management of Neuropathic Pain in In Vivo Studies

The control of neuropathic pain is a leading challenge in modern medicine. Traditional medicine has, for a long time, used natural compounds such as nutraceuticals for this purpose, and extensive evidence has supported their role in controlling oxidative stress and persistent pain-related inflammation. Nutraceuticals are natural products belonging to the food sector whose consumption could be related to physiological benefits. Indeed, they are used to improve health, prevent chronic diseases, and delay the aging process. Here, we report a systematic review and meta-analysis to provide a more comprehensive report on the use of nutraceuticals in neuropathic pain, including evaluating confounding factors. A search of the literature has been conducted on principal databases (PubMed, MEDLINE, EMBASE, and Web of Science) following the PRISMA statement, and we retrieved 484 articles, 12 of which were selected for the meta-analysis. The results showed that administration of natural drugs in animals with neuropathic pain led to a significant reduction in thermal hyperalgesia, measured in both the injured paw (SMD: 1.79; 95% CI: 1.41 to 2.17; p < 0.0001) and in the two paws (SMD: −1.74; 95% CI: −3.36 to −0.11; p = 0.036), as well as a reduction in mechanical allodynia and hyperalgesia (SMD: 1.95, 95% CI: 1.08 to 2.82; p < 0.001) when compared to controls. The results of the review indicate that nutraceutical compounds could be clinically relevant for managing persistent neuropathic pain.

Pharmacotherapeutic potential of pomegranate in age-related neurological disorders

Age-related neurological disorders [AND] include neurodegenerative diseases [NDDs] such as Alzheimer's disease [AD] and Parkinson's disease [PD], which are the most prevalent types of dementia in the elderly. It also includes other illnesses such as migraine and epilepsy. ANDs are multifactorial, but aging is their major risk factor. The most frequent and vital pathological features of AND are oxidative stress, inflammation, and accumulation of misfolded proteins. As AND brain damage is a significant public health burden and its incidence is increasing, much has been done to overcome it. Pomegranate (Punica granatum L.) is one of the polyphenol-rich fruits that is widely mentioned in medical folklore. Pomegranate is commonly used to treat common disorders such as diarrhea, abdominal pain, wound healing, bleeding, dysentery, acidosis, microbial infections, infectious and noninfectious respiratory diseases, and neurological disorders. In the current review article, we aimed to summarize the data on the pharmacotherapeutic potentials of pomegranate in ANDs.