Capsaicin intake and oral carcinogenesis: A systematic review

Unlocking the potential of capsaicin in oral health (Review)

Capsaicin is a bioactive compound found prominently in Capsicum annuum L. plants and takes on a pivotal role in their characteristic spiciness. Previous studies have delved into the potential analgesic effect of capsaicin in various oral conditions, such as oral neuropathic pain, trigeminal neuralgia, oral mucositis, temporomandibular joint disorders and burning mouth syndrome. Capsaicin has also demonstrated promise in inhibiting the proliferation of different oral cancer cell lines. Its antimicrobial properties have also been shown to inhibit the growth of oral pathogens associated with dental caries, periodontitis and oral candidiasis. However, to harness its benefits effectively, more studies are required to establish optimal dosages for pain relief while minimizing adverse effects. In addition, investigation of the effect of capsaicin on nonpathogenic oral bacteria and viruses is warranted. Human-based research is crucial for elucidating the biomolecular mechanisms underlying the properties of capsaicin, potentially leading to the development of more effective interventions for oral health problems.

Dietary patterns suggest that dark chocolate intake may have an inhibitory effect on oral cancer: a Mendelian randomization study

Background

Previous studies reported that variations in dietary intake patterns substantially impact human health, specifically tumorigenesis. However, confounding factors in previous cohort studies have obscured the relationship between dietary differences and the risk of oral cancer (OC).

Materials and methods

We developed an outcome dataset from genome-wide association studies (GWAS) data on three OCs within the GAME-ON project, using GWAS-META merging. We extracted 21 dietary exposures, including 10 dietary patterns, 6 vitamins, and 5 micronutrients, from the UK Biobank database, using the inverse variance weighting method as the primary statistical method. Sensitivity analysis was conducted to detect heterogeneity and pleiotropy. Serum metabolite concentrations were adjusted using multivariate Mendelian randomization.

Results

Of the 10 analyzed dietary patterns, 8 showed no significant association with the risk of developing OC. Consumption of dark chocolate (inverse variance weighted [IVW]: Odds ratio (OR) = 0.786, 95% confidence interval [CI]: 0.622-0.993, p = 0.044) and sweet pepper exhibited an inverse relationship with OC risk (IVW: OR = 0.757, 95% CI: 0.574-0.997, p = 0.048). Reverse MR analysis revealed no reverse causality. Furthermore, no significant correlation was observed between the intake of 6 vitamins and 5 micronutrients and the risk of developing OC. After using multivariable MR to adjust for serum caffeine, linoleate, theophylline, and theobromine metabolism levels, consuming dark chocolate was unrelated to a decreased risk of OC. After adjusting each serum metabolite individually, the observed p-values deviated from the original values to varying degrees, indicating that the components of dark chocolate could have different effects. Among these components, theophylline demonstrated the most significant inhibitory effect.

Conclusion

This study demonstrated a causal relationship between the intake of dark chocolate and sweet peppers and a lower risk of OC. The components of dark chocolate could have different effects.

Capsaicin: A chili pepper bioactive phytocompound with a potential role in suppressing cancer development and progression

Cancer profoundly influences morbidity and fatality rates worldwide. Patients often have dismal prognoses despite recent improvements in cancer therapy regimens. However, potent biomolecules derived from natural sources, including medicinal and dietary plants, contain biological and pharmacological properties to prevent and treat various human malignancies. Capsaicin is a bioactive phytocompound present in red hot chili peppers. Capsaicin has demonstrated many biological effects, including antioxidant, anti-inflammatory, antimicrobial, and anticarcinogenic capabilities. This review highlights the cellular and molecular pathways through which capsaicin exhibits antineoplastic activities. Our work also depicts the synergistic anticancer properties of capsaicin in conjunction with other natural bioactive components and approved anticancer drugs. Capsaicin inhibits proliferation in various cancerous cells, and its antineoplastic actions in numerous in vitro and in vivo carcinoma models impact oncogenesis, tumor-promoting and suppressor genes, and associated signaling pathways. Capsaicin alone or combined with other phytocompounds or approved antineoplastic drugs triggers cell cycle progression arrest, generating reactive oxygen species and disrupting mitochondrial membrane integrity, ultimately stimulating caspases and promoting death. Furthermore, capsaicin alone or in combination can promote apoptosis in carcinoma cells by enhancing the p53 and c-Myc gene expressions. In conclusion, capsaicin alone or in combination can have enormous potential for cancer prevention and intervention, but further high-quality studies are needed to firmly establish the clinical efficacy of this phytocompound.

Anti(angiogenic) food components: can be a major source of bias in the investigation of angiogenesis inhibitors

Background

Natural and diet-derived angiogenesis inhibitors/promotors are widely found in diets. These compounds can in several ways impact the results of oncological research of angiogenesis inhibitors.

Methods

We very briefly overview some of the most important examples to show how these compounds can create a bias in current research of cancer. Implications of this expert opinion cover similar angiogenesis-related diseases.

Results

Significant intra-individual differences in terms of dietary intake and differential effect of food processing techniques result in differential bioactivity and bioavailability of these compounds. There are only a handful of validated dietary questionnaire to quantify natural angiogenesis inhibitors/promotors. A corollary consequence is that participants in non-randomized clinical trials will have different baseline levels of serum/plasma/tissue/organ diet-derived angiogenesis inhibitors/promotors. This will lead to creation of clinical uncertainty and a hidden bias and consequently creation of translational efficiency bias, sampling efficiency, and waste of resources. We call for developing and validating a semi-quantitative food frequency questionnaire (FFQ) to gather data on these agents, specifically designed for oncological research because there is a clear gap in the literature of oncology.

Conclusions

This might facilitate the discovery of better prognostic, diagnostic, preventive measures, and therapeutic agents for the management of different cancers. Implications of this paper cover similar settings like ophthalmologic research.

Association between spicy food and hypertension among Han Chinese aged 30-79 years in Sichuan Basin: a population-based cross-sectional study

BACKGROUND

While spicy food is believed to have cardiovascular-protective effects, its impact on hypertension remains uncertain due to conflicting findings from previous studies. This study aimed to explore the association between spicy food and hypertension in Sichuan Basin, China.

METHODS

The baseline data of 43,657 residents aged 30-79 in the Sichuan Basin were analyzed including a questionnaire survey (e.g., sociodemographics, diet and lifestyle, medical history), medical examinations (e.g., height, body weight, and blood pressure), and clinical laboratory tests (e.g., blood and urine specimens). Participants were recruited by multi-stage, stratified cluster sampling in consideration of both sex ratio and age ratio between June 2018 and February 2019. Multivariable logistic regression was performed to explore the effect of spicy food on hypertension and multivariable linear regression was applied to estimate the effect of spicy food on systolic and diastolic blood pressure (SBP/DBP).

RESULTS

Concerning hypertension, negative associations with spicy food consumption were observed only in females: compared to those who do not eat spicy food, the odds ratios of consuming spicy food 6-7 days/week, consuming spicy food with strong strength, and years of eating spicy food-to-age ratio were 0.886 (0.799, 0.982), 0.757 (0.587, 0.977), 0.632 (0.505, 0.792), respectively. No significant association was found in males (All P trends > 0.05). In the stratified analyses, participants in the subgroup who were 50 to 79 years old (OR, 95%CI: 0.814, 0.763, 0.869), habitually snored (OR, 95%CI: 0.899, 0.829, 0.976), had a BMI < 24 kg/m2 (OR, 95%CI: 0.886, 0.810, 0.969), had a normal waist circumference (OR, 95%CI: 0.898, 0.810, 0.997), and had no dyslipidemia (OR, 95%CI: 0.897, 0.835, 0.964) showed a significantly stronger association. For SBP, consuming spicy food had negative effects in both genders, but the effect was smaller in males compared to females: among males, the β coefficients for consuming spicy food 1-2 days/week, weak strength, and years of eating spicy food-to-age ratio were 0.931 (-1.832, -0.030), -0.639 (-1.247, -0.032), and - 2.952 (-4.413, -1.492), respectively; among females, the β coefficients for consuming spicy food 3-5 days/week, 6-7 days/week, weak strength, moderate strength, and years of eating spicy food-to-age ratio were - 1.251 (-2.115, -0.388), -1.215 (-1.897, -0.534), -0.788 (-1.313, -0.263), -1.807 (-2.542, -1.072), and - 5.853 (-7.195, -4.512), respectively. For DBP, only a positive association between the years of eating spicy food-to-age ratio and DBP was found in males with β coefficient (95%CI ) of 1.300 (0.338, 2.263); Little association was found in females (all P trends > 0.05), except for a decrease of 0.591 mmHg ( 95%CI: -1.078, -0.105) in DBP among participants who consumed spicy food 1-2 days/week, compared to those who did not consume spicy food.

CONCLUSION

Spicy food may lower SBP and has an antihypertensive effect, particularly beneficial for women and individuals with fewer risk factors in the Sichuan Basin. Spicy food consumption may decrease DBP in women but increase it in men. Further multicenter prospective cohort studies are needed to confirm these findings.

Explainable ensemble learning model improves identification of candidates for oral cancer screening

OBJECTIVES

Artificial intelligence could enhance the use of disparate risk factors (crude method) for better stratification of patients to be screened for oral cancer. This study aims to construct a meta-classifier that considers diverse risk factors to identify patients at risk of oral cancer and other suspicious oral diseases for targeted screening.

MATERIALS AND METHODS

A retrospective dataset from a community oral cancer screening program was used to construct and train the novel voting meta-classifier. Comprehensive risk factor information from this dataset was used as input features for eleven supervised learning algorithms which served as base learners and provided predicted probabilities that are weighted and aggregated by the meta-classifier. Training dataset was augmented using SMOTE-ENN. Additionally, Shapley additive explanations (SHAP) values were generated to implement the explainability of the model and display the important risk factors.

RESULTS

Our meta-classifier had an internal validation recall, specificity, and AUROC of 0.83, 0.86, and 0.85 for identifying the risk of oral cancer and 0.92, 0.60, and 0.76 for identifying suspicious oral mucosal disease respectively. Upon external validation, the meta-classifier had a significantly higher AUROC than the crude/current method used for identifying the risk of oral cancer (0.78 vs 0.46; p = 0.001) Also, the meta-classifier had better recall than the crude method for predicting the risk of suspicious oral mucosal diseases (0.78 vs 0.47).

CONCLUSION

Overall, these findings showcase that our approach optimizes the use of risk factors in identifying patients for oral screening which suggests potential clinical application.

The Utility of Capsicum annuum L. in Internal Medicine and In Dentistry: A Comprehensive Review

Capsaicin is a chili peppers extract, genus Capsicum, commonly used as a food spice. Since ancient times, Capsaicin has been used as a "homeopathic remedy" for treating a wild range of pathological conditions but without any scientific knowledge about its action. Several studies have demonstrated its potentiality in cardiovascular, nephrological, nutritional, and other medical fields. Capsaicin exerts its actions thanks to the bond with transient receptor potential vanilloid subtype 1 (TRPV1). TRPV1 is a nociceptive receptor, and its activation starts with a neurosensitive impulse, responsible for a burning pain sensation. However, constant local application of Capsaicin desensitized neuronal cells and leads to relief from neuropathic pain. In this review, we analyze the potential adjuvant role of Capsaicin in the treatment of different pathological conditions either in internal medicine or dentistry. Moreover, we present our experience in five patients affected by oro-facial pain consequent to post-traumatic trigeminal neuropathy, not responsive to any remedy, and successfully treated with topical application of Capsaicin. The topical application of Capsaicin is safe, effective, and quite tolerated by patients. For these reasons, in addition to the already-proven beneficial actions in the internal field, it represents a promising method for the treatment of neuropathic oral diseases.

The Antifibrotic and the Anticarcinogenic Activity of Capsaicin in Hot Chili Pepper in Relation to Oral Submucous Fibrosis

A burning sensation on eating spicy foods purportedly supports the role of capsaicin, an active component of chili peppers, in the etiology of oral submucous fibrosis (OSF). Although the mast cell mediators and activated P2X receptors induce a constant burning sensation through an ATP-dependent mechanism, it is the activation of the transient receptor potential vanilloid 1 (TRPV-1) receptor by capsaicin that aggravates it. The molecular basis for the burning pain in OSF is thus attributable to the activation of TRPV1. There is overwhelming evidence that confirms capsaicin has more of a protective role in attenuating fibrosis and is potentially therapeutic in reversing conditions linked to collagen accumulation. The activation of TRPV-1 by capsaicin increases intracellular calcium ([Ca²⁺]_i), upregulates AMP-activated protein kinase (AMPK) and Sirtuin-1 (SIRT-1), to enrich endothelium-dependent vasodilation via endothelial nitric oxide synthase (eNOS). The induction of vasodilation induces antifibrotic effects by alleviating hypoxia. The antifibrotic effects of capsaicin are mediated through the upregulation of antioxidant enzymes, downregulation of inflammatory genes and suppression of new collagen fibril formation. Capsaicin also demonstrates an anticarcinogenic effect by upregulating the cytotoxic T cells and downregulating regulatory T cells through the inhibition of angiogenesis and promotion of apoptosis. Judicious administration of capsaicin with an appropriate delivery mechanism may have therapeutic benefits in reducing pain sensation, rendering antifibrotic effects, and preventing the malignant transformation of OSF. This paper provides an overview of the molecular basis of capsaicin and its therapeutic application as an antifibrotic and anticarcinogenic agent for the treatment of OSF.

Applications of capsaicin in food industry: functionality, utilization and stabilization

As a bioactive component in Capsicum species, capsaicin is a compound of hot chili peppers which is known as the main substance responsible for the spiciness of these fruits. Besides its taste and physiological effects, it exhibits good antioxidant activity in food matrix and antimicrobial activity against foodborne pathogens and viruses. Considering its low stability and bioaccessibility, and also regarding its irritation, the entrapment methods of capsaicin are fully developed. To compensate the limitations of capsaicin, various encapsulation methods have been used so far, including coacervation, emulsion, spray chilling, and liposomal delivery. Capsaicin has been widely used as a flavoring and preservative agent in food formulations and even as an active compound in packaging film and functional foods. This review provides an overview of the techno-functional properties, stabilization procedures, and burgeoning usages of capsaicin in the latest studies of the food sector. So, it may introduce new windows for the application of this compound.