Dose Escalation and Safety of Capsaicin for Cerebral Perfusion Augmentation: A Pilot Study

Sphenopalatine ganglion stimulation for the treatment of cerebrovascular ischemia

PURPOSE

The parasympathetic effects of the sphenopalatine ganglion (SPG) on the cerebral vasculature provide a compelling rationale for its therapeutic application in cerebrovascular ischemia. In recent years, attempts have been made to stimulate the SPG to achieve beneficial effects on cerebral circulation.

METHODS

This review synthesizes the available publications on SPG stimulation. It critically evaluates the evidence from preclinical studies and clinical trials to assess its potential as a treatment for acute cerebrovascular disorders and outlines aspects that still require more study.

RESULTS

The medical literature provides consistent evidence of the significant effects of stimulating the SPG on cerebrovascular circulation. In addition, considerable evidence supports the therapeutic role of SPG stimulation in patients with cerebral ischemia.

CONCLUSION

Given the current understanding, future research could explore the potential of SPG stimulation as a non-reperfusion intervention to improve long-term outcomes for individuals with ischemic cerebrovascular conditions.

Capsaicin: A Potential Treatment to Improve Cerebrovascular Function and Cognition in Obesity and Ageing

Impaired cognition is the primary symptom of dementia, which can lead to functional disability and reduced quality of life among an increasingly ageing population. Ageing is associated with increased oxidative stress, chronic low-grade systemic inflammation, and endothelial dysfunction, which reduces cerebrovascular function leading to cognitive decline. Chronic low-grade systemic inflammatory conditions, such as obesity, exacerbate this decline beyond normal ageing and predispose individuals to neurodegenerative diseases, such as dementia. Capsaicin, the major pungent molecule of chilli, has recently demonstrated improvements in cognition in animal models via activation of the transient receptor potential vanilloid channel 1 (TRPV1). Capsaicin-induced TRPV1 activation reduces adiposity, chronic low-grade systemic inflammation, and oxidative stress, as well as improves endothelial function, all of which are associated with cerebrovascular function and cognition. This review examines the current literature on capsaicin and Capsimax, a capsaicin supplement associated with reduced gastrointestinal irritation compared to capsaicin. Acute and chronic capsaicin treatment can improve cognition in animals. However, studies adequately assessing the effects of capsaicin on cerebrovascular function, and cognition in humans do not exist. Capsimax may be a potentially safe therapeutic intervention for future clinical trials testing the effects of capsaicin on cerebrovascular function and cognition.

Beneficial Effects of Capsaicin in Disorders of the Central Nervous System

Capsaicin is a natural compound found in chili peppers and is used in the diet of many countries. The important mechanism of action of capsaicin is its influence on TRPV1 channels in nociceptive sensory neurons. Furthermore, the beneficial effects of capsaicin in cardiovascular and oncological disorders have been described. Many recent publications show the positive effects of capsaicin in animal models of brain disorders. In Alzheimer’s disease, capsaicin reduces neurodegeneration and memory impairment. The beneficial effects of capsaicin in Parkinson’s disease and depression have also been described. It has been found that capsaicin reduces the area of infarction and improves neurological outcomes in animal models of stroke. However, both proepileptic and antiepileptic effects of capsaicin in animal models of epilepsy have been proposed. These contradictory results may be caused by the fact that capsaicin influences not only TRPV1 channels but also different molecular targets such as voltage-gated sodium channels. Human studies show that capsaicin may be helpful in treating stroke complications such as dysphagia. Additionally, this compound exerts pain-relieving effects in migraine and cluster headaches. The purpose of this review is to discuss the mechanisms of the beneficial effects of capsaicin in disorders of the central nervous system.