Description: |
Capsaicin, the main pungent ingredient in 'hot' chilli peppers, is a TRPV1 agonist with EC50 of 0.29±0.05 μM in HEK293 cells, which elicits a sensation of burning pain by selectively activating sensory neurons that convey information about noxious stimuli to the central nervous system, it may used as a pain therapy by the long-lasting and inhibitory effects on persistent pain. Capsaicin has antioxidant activity , it is more effective than melatonin in suppressing the formation of lipid hydroperoxides, it also reduces anxiety-like behaviours in rats and may be an admissible drug candidate for treating endometriosis. |
Targets: |
Akt | PI3K | mTOR | Autophagy | TRPV1 |
In vitro: |
PLoS One. 2015 May 1;10(5):e0121538. | Capsaicin Enhances the Drug Sensitivity of Cholangiocarcinoma through the Inhibition of Chemotherapeutic-Induced Autophagy.[Pubmed: 25933112] | Cholangiocarcinoma (CCA), a devastating cancer with a poor prognosis, is resistant to the currently available chemotherapeutic agents. Capsaicin, the major pungent ingredient found in hot red chili peppers of the genus Capsicum, suppresses the growth of several malignant cell lines. Our aims were to investigate the role and mechanism of capsaicin with respect to the sensitivity of CCA cells to chemotherapeutic agents.
METHODS AND RESULTS:
The effect of capsaicin on CCA tumor sensitivity to 5-fluorouracil (5-FU) was assessed in vitro in CCA cells and in vivo in a xenograft model. The drug sensitivity of QBC939 to 5-FU was significantly enhanced by capsaicin compared with either agent alone. In addition, the combination of capsaicin with 5-FU was synergistic, with a combination index (CI) < 1, and the combined treatment also suppressed tumor growth in the CCA xenograft to a greater extent than 5-FU alone. Further investigation revealed that the autophagy induced by 5-FU was inhibited by capsaicin. Moreover, the decrease in AKT and S6 phosphorylation induced by 5-FU was effectively reversed by capsaicin, indicating that capsaicin inhibits 5-FU-induced autophagy by activating the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway in CCA cells.
CONCLUSIONS:
Taken together, these results demonstrate that capsaicin may be a useful adjunct therapy to improve chemosensitivity in CCA. This effect likely occurs via PI3K/AKT/mTOR pathway activation, suggesting a promising strategy for the development of combination drugs for CCA. | Gynecol Obstet Invest. 2008;66(1):59-62. | Capsaicin inhibits proliferation of endometriotic cells in vitro.[Pubmed: 18391504 ] | Treatment of immortalized stromal-like and epithelial-like endometriotic cells with capsaicin resulted in inhibition of proliferation in a concentration-dependent manner. In addition, endometriotic cells are more sensitive to capsaicin treatment than immortalized endometrial cells, suggesting that capsaicin may be an admissible drug candidate for treating endometriosis. |
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In vivo: |
Mol Pain. 2015 Apr 22;11(1):22. | Experimental evidence for alleviating nociceptive hypersensitivity by single application of capsaicin.[Pubmed: 25896608] | The single application of high-concentration of capsaicin has been used as an analgesic therapy of persistent pain. However, its effectiveness and underlying mechanisms remain to be further evaluated with experimental approaches. METHODS AND RESULTS: The present study provided evidence showing that the single application of capsaicin dose-dependently alleviated nociceptive hypersensitivity, and reduced the action potential firing in small-diameter neurons of the dorsal root ganglia (DRG) in rats and mice. Pre-treatment with capsaicin reduced formalin-induced acute nocifensive behavior after a brief hyperalgesia in rats and mice. The inhibitory effects of capsaicin were calcium-dependent, and mediated by the capsaicin receptor (transient receptor potential vanilloid type-1). We further found that capsaicin exerted inhibitory effects on the persistent nociceptive hypersensitivity induced by peripheral inflammation and nerve injury.
CONCLUSIONS:
Thus, these results support the long-lasting and inhibitory effects of topical capsaicin on persistent pain, and the clinic use of capsaicin as a pain therapy. | Molecules . 2016 Jun 25;21(7):835. | The Effect of Capsaicin on Salivary Gland Dysfunction[Pubmed: 27347918] | Abstract
Capsaicin (trans-8-methyl-N-vanilyl-6-nonenamide) is a unique alkaloid isolated from hot chili peppers of the capsicum family. Capsaicin is an agonist of transient receptor potential vanilloid subtype 1 (TRPV1), which is expressed in nociceptive sensory neurons and a range of secretory epithelia, including salivary glands. Capsaicin has analgesic and anti-inflammatory properties in sensory neurons. Recently, increasing evidence has indicated that capsaicin also affects saliva secretion and inflammation in salivary glands. Applying capsaicin increases salivary secretion in human and animal models. Capsaicin appears to increase salivation mainly by modulating the paracellular pathway in salivary glands. Capsaicin activates TRPV1, which modulates the permeability of tight junctions (TJ) by regulating the expression and function of putative intercellular adhesion molecules in an ERK (extracelluar signal-regulated kinase) -dependent manner. Capsaicin also improved dysfunction in transplanted salivary glands. Aside from the secretory effects of capsaicin, it has anti-inflammatory effects in salivary glands. The anti-inflammatory effect of capsaicin is, however, not mediated by TRPV1, but by inhibition of the NF-κB pathway. In conclusion, capsaicin might be a potential drug for alleviating dry mouth symptoms and inflammation of salivary glands.
Keywords: Capsaicin; NF-κB; Salivary glands; TRPV1. |
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