Capsicum and capsaicin--a review: case report of the use of hot peppers in child abuse

Capsaicin, the active principle of hot peppers of the genus Capsicum, exhibits broad bioactivity. It targets neuronal structures which contain substance P, clinically seen as gastrointestinal and dermatologic irritation, bronchospasm and fibrinolysis. As a research tool, capsaicin profoundly alters neurologic anatomy and function. We review the toxicity of capsaicin and comment briefly on the use of hot peppers in child abuse.     

In vivo and in vitro evaluation for nutraceutical purposes of capsaicin, capsanthin,lutein and four pepper varieties

The purpose of this study is to determine the nutraceutic potential of different Capsicum sp, capsaicin, capsanthin and lutein and provide data in order to clarify the conflicting results obtained for capsaicin by different authors. To achieve these objectives, in vivo (geno/antigenotoxicity and lifespan assays in the animal model Drosophila) and in vitro (cytotoxicity and DNA-fragmentation assays in HL60 promyelocytic cell line) assays were carried out. Results showed that i) none of the tested substances were genotoxic except green hot pepper and capsaicin at the highest tested concentration (5 mg/mL and 11.5 μM respectively), ii) all tested substances except green hot pepper are antimutagenic against H₂O₂-induced damage, iii) only red sweet pepper significantly extend the lifespan and healthspan of D. melanogaster at 1.25 and 2.5 mg/mL, iv) all pepper varieties induce dose-depended cytotoxic effect in HL60 cells with different IC₅₀, and v) all pepper varieties and capsaicin exerted proapoptotic effect on HL60 cells. In conclusion: (i) sweet peppers could be suggested as nutraceutical food, (ii) hot peppers should be moderately consumed, and (iii) supplementary studies are necessary to clarify the synergic effect of the carotenoids and capsaicinoids in the hot pepper food matrix.     

Effects of Capsaicin on the Pharmacokinetics of Antipyrine,Theophylline and Quinine in Rats

Abstract— Capsaicin is the active principal of capsicum fruits, such as hot peppers. The influence of 1-week pretreatment of capsaicin (25 mg kg^?1) on the pharmacokinetics of antipyrine, theophylline and quinine was investigated in rats. The drugs were given as an intravenous bolus dose. The control rats received the vehicle solvent (polyethylene glycol) only. Clearance of antipyrine in the capsaicin-pretreated rats was significantly lower than that observed in the control rats (0·241 ± 0·029 vs 0·344 ± 0·034 L h^?1 kg^?1, P < 0·05). This is consistent with a prolongation in the elimination half-life of antipyrine in animals pretreated with capsaicin (2·06 ± 0·30 vs 1·61 ± 0·27 h), as the volume of distribution was not significantly changed. In contrast, capsaicin pretreatment had no significant effect on the pharmacokinetics of theophylline and quinine.     

Beneficial influence of capsaicin on lipid peroxidation, membrane-bound enzymes and glycoprotein profile during experimental lung carcinogenesis

This study was designed to examine the impact of a principal component of hot red peppers and chilli peppers, capsaicin, on alterations in lipid peroxidation, membrane-bound enzyme profiles and glycoprotein levels during benzo(a)pyrene (BP)-induced lung cancer in Swiss albino mice. BP (50 mgkg(-1)) induced deleterious changes that were that revealed by alterations in lipid peroxidation, membrane-bound enzyme (Na+/K+ ATPase, Ca2+ ATPase and Mg2+ ATPase) activity, levels of total protein and protein-bound carbohydrate components (sialic acid, hexose, hexosamine, hexuronic acid and fucose). Pre-co-treatment with capsaicin (10 mg kg(-1)) restored the detrimental effects induced by BP, indicating its protective role in BP-induced lung cancer.     

Topical capsaicin in the treatment of cutaneous disorders

Capsaicin, the primary pungent principle in hot peppers, produces marked alterations in the function of unmyelinated sensory afferent fibers, which are believed to signal pain and to initiate inflammatory responses. Capsaicin first excites and then desensitizes these nerves to subsequent stimulation both by itself and by a variety of physiocochemical stimuli. Accordingly, capsaicin is finding increasing use as a topical therapy for a variety of cutaneous disorders that involve pain and inflammation. Although topical capsaicin has shown therapeutic potential, the utility of capsaicin appears to be limited at present primarily by its irritant properties and secondarily by less than optimal therapeutic response, perhaps resulting from insufficient drug delivery. A capsaicin analogue with diminished irritant properties that retained the critical pharmacologic activities might present a reasonable alternative.     

Capsaicin impairs proliferation of neural progenitor cells and hippocampal neurogenesis in young mice

Capsaicin (N-vanillyl-8-methyl-1-nonenamide) is a major pungent ingredient in hot peppers and induces apoptosis in malignant carcinoma cell lines. However, the adverse effects of capsaicin on neuronal development have not been fully explored. The aim of this study was to determine whether capsaicin affected murine-derived cerebellar multi-potent neural progenitor cells (NPC) or adult hippocampal neurogenesis in vivo. Capsaicin dose-dependently suppressed NPC proliferation, and higher concentrations were cytotoxic. Capsaicin decreased the activation of extracellular signal-regulated kinases (ERK) without markedly affecting p38 kinases. Capsaicin reduced the number of newly generated cells in the dentate gyrus of the hippocampus but did not significantly alter learning and memory performance in young adult mice. Interestingly, capsaicin decreased ERK activation in the hippocampus, suggesting that reduced ERK signaling may be involved in the capsaicin-mediated regulation of hippocampal neurogenesis.     

Capsaicin as an in vitro inhibitor of benzo(a)pyrene metabolism and its DNA binding in human and murine keratinocytes

Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide), the active principle of capsicum fruits, such as hot peppers, is a known inhibitor of substance P. This substance was also found to be a potent in vitro inhibitor of human and murine epidermal metabolism of benzo(a)pyrene (BP) and the enzyme-mediated binding of BP metabolites to DNA. In both untreated and 3-methylcholanthrene-treated neonatal rat epidermal microsomes, capsaicin resulted in a dose-dependent inhibition of aryl hydrocarbon hydroxylase activity with an I50 value of 3.0 X 10(-4)-3.6 X 10(-4) M. A Lineweaver-Burk plot of the inhibition of aryl hydrocarbon hydroxylase activity suggested that the inhibition is of the noncompetitive type with Ki value of 50 microM. Capsaicin also inhibited BP metabolism and the binding of 3H-BP to DNA in BALB/c mouse and human keratinocytes. The formation of BP-7,8-diol was also substantially diminished in both systems in the presence of capsaicin (180-300 microM). Our results indicate that the substance P inhibitor, capsaicin, is also an inhibitor of epidermal BP metabolism and DNA binding of its metabolites. Therefore, in addition to its neurological effects, capsaicin may represent a new category of compound with anti-carcinogenic effects.     

Gastroprotective effect of the mixture of alpha- and beta-amyrin from Protium heptaphyllum: role of capsaicin-sensitive primary afferent neurons

This investigation evaluated the role of capsaicin-sensitive afferent neurons in the gastroprotective effect of alpha- and beta-amyrin, a triterpenoid mixture isolated from Protium heptaphyllum resin. Gastric mucosai damage was induced in mice by intragastric ethanol and assessed by planimetry. Mice pretreated orally with the amyrin mixture (50 and 100 mg/kg) or capsaicin (2.5 and 5 mg/kg), the pungent principle from red hot peppers, showed a significantly lower intensity of ethanol-associated gastric mucosal damage, in relation to vehicle-treated controls. At higher doses both these agents produced either a diminished protection or no significant effect. The maximal gastroprotection that was observed at the dose of 100 mg/kg amyrin mixture was almost abolished in mice with their sensory afferents chemically ablated by a neurotoxic dose of capsaicin, suggesting that the gastro-protective mechanism of alpha- and beta-amyrin mixture involves at least in part the activation of capsaicin-sensitive primary afferent neurons.     

Capsaicin induced apoptosis of B16-F10 melanoma cells through down-regulation of Bcl-2.

Capsaicin (8-methyl-N-vanillyl-6-nonenamide), a pungent ingredient of hot chili peppers, has been reported to possess substantial anticarcinogenic and antimutagenic activities. In the present study, we investigated the effect of capsaicin on induction of apoptosis in highly metastatic B16-F10 murine melanoma cells. Capsaicin inhibited growth of B16-F10 cells in a concentration-dependent manner. Proapoptotic effect of capsaicin was evidenced by nuclear condensation, internucleosomal DNA fragmentation, in situ terminal nick-end labeling of fragmented DNA (TUNEL), and an increased sub G1 fraction. Treatment of B16-F10 cells with capsaicin caused release of mitochondrial cytochrome c, activation of caspase-3, and cleavage of poly (ADP-ribose) polymerase in a dose-dependent manner. Furthermore, Bcl-2 expression in the B16-F10 cells was slightly down-regulated by capsaicin treatment. In contrast, there were no alterations in the levels of Bax in capsaicin-treated cells. Collectively, these findings indicate that capsaicin-induces apoptosis of B16-F10 melanoma cells via down-regulation the Bcl-2.     

Effects of capsaicin and dihydrocapsaicin on human and rat liver microsomal CYP450 enzyme activities in vitro and in vivo

Capsaicin and dihydrocapsaicin, the two most abundant members of capsaicinoids in chili peppers, are widely used as food additives and for other purposes. In this study, we examined the inhibitory potentials of capsaicin and dihydrocapsaicin against CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4/5 activities in human liver microsomes. The effects of these two capsaicinoids on CYP450 enzymes were also evaluated in vivo in rats. The results demonstrated that capsaicin and dihydrocapsaicin moderately inhibited five isozymes (IC₅₀ values ranging from 4.4 to 61.8 μM), with the exception of CYP2E1 (IC₅₀>200 μM). Both capsaicinoids exhibited competitive, mixed, and noncompetitive inhibition on these isozymes (K _i = 3.1 ± 0.5 ? 78.6 ± 8.4 μM). Time-dependent inhibition of CYP3A4/5 by capsaicin was found. After multiple administrations of capsaicin and dihydrocapsaicin (1, 4, and 10 mg/kg) to rats, chlorzoxazone 6-hydroxylase activity and the expression of CYP2E1 were increased in liver microsomes. Our findings indicated that the possibility of food–drug interactions mediated by capsaicin and dihydrocapsaicin could not be excluded, and provided the useful information for evaluating the anticarcinogenic potentials of these two capsaicinoids.