Effects Of Capsaicin Research Articles

The Relationship Between Capsaicin in Chili Pepper and Cancer: A Comprehensive Insight

Capsicum plant consists of savage and tame types, and there is a substance named the capsaicin that causes burning sensation of the bitter peppers. Capsaicin has many effects in the body. In addition to its antioxidant and anti-inflammatory properties, it has benefits such as cancer prevention, reducing blood pressure, having analgesic effects in the body. There are different capsaicinoids such as dihydrocapsaicin, nordroydrocapsaicin, homocapsaicin in nature. These capsaicinoids provide anti cancer activities by interacting with key signal molecules. Capsaicin can suppress the growth of cancer cells by changing the expression of the relevant genes of cancer cells. In summary, the capsaicin
 ensures anticancer activity by suppressing the proliferation, growth in cancer cells and to induce apoptosis which inhibit the metastasis. This situation can provide promising new treatment approaches in common and fatal cancer species today. This article revises the relationship between capsaicin and different types of cancer, anti cancer effect of capsaicin. Therewithal, studies examining the treatment of different cancer cells with various doses of capsaicin are included. Capsaicin can suppress the growth of cancer cells by changing the expression of the relevant genes of cancer cells.

UHPLC-qTOF-MS-Based Nontargeted Metabolomics to Characterize the Effects of Capsaicin on Plasma and Skin Metabolic Profiles of C57BL/6 Mice-An In vivo Experimental Study.

Capsaicin is the main compound found in chili pepper and has complex pharmacologic effects. This study aimed to elucidate the mechanism of the effect of capsaicin on physiological processes by analyzing changes in metabolites and metabolic pathways. Female C57BL/6 mice were divided into two groups(n = 10/group) and fed with capsaicin-soybean oil solution(group T) or soybean oil(group C) for 6 weeks. Ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-qTOF-MS) based metabolomics was undertaken to assess plasma and skin metabolic profile changes and identify differential metabolites through multivariate analysis. According to the OPLS-DA score plots, the plasma and skin metabolic profiles in the group T and group C were significantly separated. In plasma, 38 significant differential metabolites were identified. KEGG pathway enrichment analysis revealed that the most significant plasma metabolic pathways included pyruvate metabolism and ABC transporters. In skin, seven significant differential metabolites were found. Four metabolic pathways with p values < 0.05 were detected, including sphingolipid metabolism, sphingolipid signaling pathway, apoptosis, and necroptosis. These findings will provide metabolomic insights to assess the physiological functions of capsaicin and contribute to a better understanding of the potential effects of a capsaicin-rich diet on health.

Histochemical Effect of Capsaicin Alone or in Combination with The Metformin on Ovaries Structure After Induced a Polycystic Ovary Syndrome by Letrozole in Rats

Histochemical Effect of Capsaicin Alone or in Combination with The Metformin on Ovaries Structure After Induced a Polycystic Ovary Syndrome by Letrozole in Rats

SAEM GRACE: Dopamine antagonists and topical capsaicin for cannabis hyperemesis syndrome in the emergency department: A systematic review of direct evidence.

Adults with cannabis hyperemesis syndrome (CHS) are increasingly presenting to the emergency department (ED), and this systematic review will evaluate the direct evidence on the effectiveness of capsaicin and dopamine antagonists in its clinical management. A bibliographic search was conducted to address the following population-intervention-control-outcome (PICO) question: (P) adults >18 years old with a diagnosis of acute CHS presenting to the ED; (I) dopamine antagonists (e.g., haloperidol, droperidol) and topical capsaicin; (C) usual care or no active comparator; and (O) symptoms improvement/resolution in ED, ED length of stay, admission rate, ED recidivism, need for rescue medication, and adverse events. This systematic review was conducted in accordance with PRISMA reporting recommendations. From 53 potentially relevant articles, seven articles were included: five observational studies and two randomized controlled trials, including a total of 492 patients. Five of these studies evaluated the efficacy of capsaicin cream (n = 386), and two examined dopamine antagonists (haloperidol, droperidol; n = 106). There was mixed evidence for the efficacy of capsaicin for reducing nausea and emesis. Both studies evaluating dopamine antagonists detected clinical benefit to usual care or no active comparator. There is limited direct evidence on the efficacy of dopamine antagonists or capsaicin for treating CHS in the ED. Current evidence is mixed for capsaicin and potentially beneficial for dopamine antagonists. Because of the small number of studies, small number of participants, lack of standardization of treatment administration, and risk of bias of the included studies, methodologically rigorous trials on both types of intervention are needed to directly inform ED management of CHS.

The Impact of Catechins, Capsaicin, and Gingerol in Managing Diabetes and Reducing the Risk of Atherosclerosis

Background: Diabetes mellitus and atherosclerosis are significant contributors to global morbidity and mortality, with their prevalence escalating alongside the increasing incidence of obesity and sedentary lifestyles. Traditional therapeutic approaches have had limited success in fully managing these conditions, prompting interest in natural compounds such as capsaicin and gingerol. These compounds have been identified for their potential therapeutic effects, including anti-inflammatory, antioxidant, and metabolic regulatory properties. Objective: This review aims to critically assess the impact of capsaicin and gingerol on the management of diabetes and atherosclerosis, highlighting their mechanisms of action, therapeutic potential, and clinical applications. Methods: A comprehensive literature search was conducted across multiple databases, including PubMed, Scopus, Web of Science, and Google Scholar, focusing on studies that evaluated the effects of capsaicin and gingerol on diabetes and atherosclerosis. The search strategy incorporated a combination of keywords and MeSH terms related to the compounds and diseases of interest. Studies were selected based on predefined inclusion and exclusion criteria, with data extraction and quality assessment conducted according to standardized protocols. Results: The review synthesized evidence from both animal models and human clinical trials, demonstrating that capsaicin and gingerol exhibit significant potential in improving metabolic health, reducing inflammation, and mitigating the risk factors associated with diabetes and atherosclerosis. Capsaicin was found to enhance weight management and cardiovascular health through mechanisms involving the sympathetic nervous system and TRPV1 activation. Gingerol showed potent anti-inflammatory effects and improved glucose and lipid metabolism. However, the clinical applicability of these findings requires further investigation to determine optimal dosages and long-term effects. Conclusion: Capsaicin and gingerol present promising natural therapeutic options for the management of diabetes and atherosclerosis, with potential benefits extending beyond traditional treatment modalities. Further clinical trials are necessary to fully elucidate their therapeutic potential and integrate them into clinical practice.

Essential Oils from the Genus Piper Promote Antinociception by Modulating TRP Channels and Anti-Inflammatory Effects in Adult Zebrafish.

The Piper genus, known for its pharmacological potential, comprises 2,263 species primarily found in tropical regions. Despite recent advancements in pain therapies, the demand for more effective and well-tolerated analgesics and anti-inflammatories, particularly for chronic pain, remains. This study assessed the effects of essential oils from Piper caldense, Piper mosenii, and Piper mikanianum on nociceptive behavior induced by formalin and capsaicin, as well as their anti-inflammatory impact induced by carrageenan, using adult zebrafish models. Results indicated non-toxic essential oils with antinociceptive properties in both neurogenic and inflammatory phases of formalin-induced nociception through interaction with the TRPA1 receptor. Additionally, P. mosenii essential oil also blocked the nociceptive effect of capsaicin, a TRPV1 receptor agonist. Furthermore, essential oils from P. caldense and P. mikanianum exhibited significant anti-inflammatory effects by reducing carrageenan-induced abdominal edema. These findings highlight the pharmacological potential of Piper's essential oils as antinociceptive and anti-inflammatory agents.

Spice Up Your Kidney: A Review on the Effects of Capsaicin in Renal Physiology and Disease.

Capsaicin, the organic compound which attributes the spicy flavor and taste of red peppers and chili peppers, has been extensively studied for centuries as a potential natural remedy for the treatment of several illnesses. Indeed, this compound exerts well-known systemic pleiotropic effects and may thus bring important benefits against various pathological conditions like neuropathic pain, rhinitis, itching, or chronic inflammation. Yet, little is known about the possible biological activity of capsaicin at the kidney level, as this aspect has only been addressed by sparse experimental investigations. In this paper, we aimed to review the available evidence focusing specifically on the effects of capsaicin on renal physiology, as well as its potential benefits for the treatment of various kidney disorders. Capsaicin may indeed modulate various aspects of renal function and renal nervous activity. On the other hand, the observed experimental benefits in preventing acute kidney injury, slowing down the progression of diabetic and chronic kidney disease, ameliorating hypertension, and even delaying renal cancer growth may set the stage for future human trials of capsaicin administration as an adjuvant or preventive therapy for different, difficult-to-treat renal diseases.

Capsaicin Shows Species and Strain-specific Activity: Investigation of the Antibacterial Effects on the Oral Pathogen Streptococcus mutans and the Oral Probiotics Streptococcus salivarius M18 and K12

Extensive research has investigated capsaicin (CAP), the primary bioactive compound in chili peppers, to explore its diverse pharmacological and physiological properties. Recently, the focus has shifted to understanding the potential effects of CAP on gut microbiota due to the strong link between gut bacterial profile and diet. However, there has been no research on the effects of CAP on oral microbiota. Therefore, our study aimed to explore the antibacterial effects of CAP on two oral probiotics, Streptococcus salivarius M18, and S. salivarius K12, along with the oral pathogen S. mutans. Previously, the anti-cancer activity of CAP had been demonstrated, and in accordance with these findings, here, we show its growth inhibitory activity on colorectal cancer cell lines. However, this study is the first to examine the impact of CAP on specific oral microorganisms while considering the oral consumption of CAP and the interconnectedness of the oral and gut microbiomes. The findings revealed that CAP exhibited antibacterial properties against the M18 strain at concentrations exceeding 100 µg/mL. Surprisingly, it did not show any growth-inhibitory effects on S. salivarius K12, even at a concentration of 2 mg/mL. Similarly, CAP did not inhibit the growth of S. mutans, a significant factor in dental caries. These results suggest that CAP's effects are species and strain-specific, indicating potential changes in the oral microbiota upon CAP consumption.

Capsaicin Attenuates LPS-Induced Acute Lung Injury by Inhibiting Inflammation and Autophagy Through Regulation of the TRPV1/AKT Pathway.

Acute lung injury (ALI) is a severe pulmonary disease characterized by damage to the alveoli and pulmonary blood vessels, leading to severe impairment of lung function. Studies on the effect of capsaicin (8-methyl-N-geranyl-6-nonamide, CAP) on lipopolysaccharide (LPS)-induced ALI in bronchial epithelial cells transformed with Ad12-SV40 2B (BEAS-2B) are still limited. This study aimed to investigate the effect and specific mechanism by which CAP improves LPS-induced ALI. The present study investigated the effect of CAP and the potential underlying mechanisms in LPS-induced ALI in vitro and vivo via RNA sequencing, Western blotting (WB), quantitative real-time reverse transcription PCR (qRT‒PCR), enzyme-linked immunosorbent assay (ELISA), and transmission electron microscopy (TEM). The TRPV1 inhibitor AMG9810 and the AKT agonist SC79 were used to confirm the protective effect of the TRPV1/AKT axis against ALI. The autophagy agonist rapamycin (Rapa) and the autophagy inhibitors 3-methyladenine (3-MA) and bafilomycin A1 (Baf-A1) were used to clarify the characteristics of LPS-induced autophagy. Our findings demonstrated that CAP effectively suppressed inflammation and autophagy in LPS-induced ALI, both in vivo and in vitro. This mechanism involves regulation by the TRPV1/AKT signaling pathway. By activating TRPV1, CAP reduces the expression of P-AKT, thereby exerting its anti-inflammatory and inhibitory effects on pro-death autophagy. Furthermore, prior administration of CAP provided substantial protection to mice against ALI induced by LPS, reduced the lung wet/dry ratio, decreased proinflammatory cytokine expression, and downregulated LC3 expression. Taken together, our results indicate that CAP protects against LPS-induced ALI by inhibiting inflammatory responses and autophagic death through the TRPV1/AKT signaling pathway, presenting a novel strategy for ALI therapy.

Effect of Capsaicin Stress on Aroma-Producing Properties of Lactobacillus plantarum CL-01 Based on E-Nose and GC-IMS.

Capsaicin stress, along with salt stress, could be considered the main stressors for lactic acid bacteria in traditional fermented pepper products. Until now, insufficient attention has been paid to salt stress, while the effect of capsaicin on the aroma-producing properties of Lactobacillus plantarum (L. plantarum) is unclear. The present study attempted to illustrate the effect of capsaicin stress on the aroma-producing properties of L. plantarum CL-01 isolated from traditionally fermented peppers based on E-nose and GC-IMS. The results showed that E-nose could clearly distinguish the overall flavor differences of L. plantarum CL-01 under capsaicin stress. A total of 48 volatile compounds (VOCs) were characterized by means of GC-IMS, and the main VOCs belonged to acids and alcohols. Capsaicin stress significantly promoted L. plantarum CL-01 to produce alpha-pinene, ethyl crotonate, isobutyric acid, trans-2-pentenal, 2-methyl-1-butanol, 3-methyl-3-buten-1-ol, 1-penten-3-one, 2-pentanone, 3-methyl-1-butanol-D, and 2-heptanone (p < 0.05). In addition, under capsaicin stress, the contents of 1-penten-3-one, 3-methyl-3-buten-1-ol, 5-methylfurfuryl alcohol, isobutanol, 2-furanmethanethiol, 2,2,4,6,6-pentamethylheptane, 1-propanethiol, diethyl malonate, acetic acid, beta-myrcene, 2-pentanone, ethyl acetate, trans-2-pentenal, 2-methylbutyl acetate, and 2-heptanone produced by L. plantarum CL-01 were significantly increased along with the fermentation time (p < 0.05). Furthermore, some significant correlations were observed between the response values of specific E-nose sensors and effective VOCs.

Alterations in descending brain-spinal pathways regulating colorectal motility in a rat model of Parkinson's disease.

Patients with Parkinson's disease (PD) often have constipation. It is assumed that a disorder of the regulatory mechanism of colorectal motility by the central nervous system is involved in the constipation, but this remains unclear. The aim of this study was to investigate whether central neural pathways can modulate colorectal motility in a rat model of PD. PD model rats were generated by injection of 6-hydroxydopamine into a unilateral medial forebrain bundle and destruction of dopaminergic neurons in the substantia nigra. Colorectal motility was measured in vivo in anesthetized rats. Intraluminal administration of capsaicin, as a noxious stimulus, induced colorectal motility in sham-operated rats but not in PD rats. Intrathecally administered dopamine (DA) and serotonin (5-HT), which mediate the prokinetic effect of capsaicin, at the L6-S1 levels enhanced colorectal motility in PD rats similarly to that in sham-operated rats. In PD rats, capsaicin enhanced colorectal motility only when a GABAA receptor antagonist was preadministered into the lumbosacral spinal cord. Capsaicin-induced colorectal motility was abolished by intrathecal administration of a D2-like receptor antagonist but not by administration of 5-HT2 and 5-HT3 receptor antagonists. These findings demonstrate that the inhibitory GABAergic component becomes operative and the stimulatory serotonergic component is suppressed in PD rats. The alteration of the central regulatory mechanism of colorectal motility is thought to be related to the occurrence of constipation in PD patients. Our findings provide a new insight into the pathogenesis of defecation disorders observed in PD.NEW & NOTEWORTHY In a rat model of Parkinson's disease, the component of descending brain-spinal pathways that regulate colorectal motility through a mediation of the lumbosacral defecation center was altered from stimulatory serotonergic neurons to inhibitory GABAergic neurons. Our findings suggest that chronic constipation in Parkinson's disease patients may be associated with alterations in central regulatory mechanisms of colorectal motility. The plasticity in the descending pathway regulating colorectal motility may contribute to other disease-related defecation abnormalities.

Capsaicin supplementation prevents western diet-induced hyperleptinemia by reducing endoplasmic reticulum stress in apolipoprotein E-deficient mice

Background: Endoplasmic reticulum (ER) stress implicated in leptin resistance in the diet-induced obesity, which can accelerate the development of atherosclerosis forms the background of this study.&#x0D; Objective: This study aimed to investigate the effect of capsaicin on hyperleptinema by inhibiting ER stress in apolipoprotein E-deficient (ApoE-/-) mice fed a western diet (WD).&#x0D; Design: ApoE -/- mice were assigned one of three experimental diets: WD (60% kcal from fat, n = 10), WD + 0.015% capsaicin (n = 10, w/w), and WD + 1% PBA (n = 10, w/w) for 12 weeks.&#x0D; Results: In metabolic parameters, supplementation of dietary capsaicin displayed marked reduction of body weight gain and adipose tissue weight, plasma leptin, total cholesterol, and hepatic triglyceride levels without change in the plasma insulin level compared with WD fed ApoE-/- mice after 12 weeks. Capsaicin supplementation also attenuated the protein expression of ER stress markers such as eukaryotic translational initiation factor 2α and C/EBP homology protein in the liver, as well as glucose-related protein 78 localization in the aorta, indicating that capsaicin inhibits diet-induced hyperleptinemia in part by regulating the protein expression involved in ER stress.&#x0D; Conclusion: Capsaicin, therefore, may have potential as a therapeutic agent for individuals with diet-induced hyperleptinemia

The Therapeutic Effect of Capsaicin and/or Steroids on Inflammation in an Experimental Allergic Rhinitis Model

The Therapeutic Effect of Capsaicin and/or Steroids on Inflammation in an Experimental Allergic Rhinitis Model

Single-cell RNA sequencing reveals the effects of capsaicin in the treatment of sepsis-induced liver injury.

Sepsis is a difficult-to-treat systemic condition in which liver dysfunction acts as both regulator and target. However, the dynamic response of diverse intrahepatic cells to sepsis remains poorly characterized. Capsaicin (CAP), a multifunctional chemical derived from chilli peppers, has recently been shown to potentially possess anti-inflammatory effects, which is also one of the main approaches for drug discovery against sepsis. We performed single-cell RNA transcriptome sequencing on 86,830 intrahepatic cells isolated from normal mice, cecal ligation and puncture-induced sepsis model mice and CAP-treated mice. The transcriptional atlas of these cells revealed dynamic changes in hepatocytes, macrophages, neutrophils, and endothelial cells in response to sepsis. Among the extensive crosstalk across these major subtypes, KC_Cxcl10 shared strong potential interaction with other cells when responding to sepsis. CAP mitigated the severity of inflammation by partly reversing these pathophysiologic processes. Specific cell subpopulations in the liver act collectively to escalate inflammation, ultimately causing liver dysfunction. CAP displays its health-promoting function by ameliorating liver dysfunction induced by sepsis. Our study provides valuable insights into the pathophysiology of sepsis and suggestions for future therapeutic gain.

Capsaicin ameliorates myocardial injury in diabetic rats via upregulating Nrf-2, HO-1 and iNOS tissue concentrations besides normalizing the distribution of structural proteins desmin and α-SMA

Myocardial injury remains the leading cause of morbidity and mortality in diabetic patients. On the other hand, scientists have noticed that capsaicin has a distinctive pharmacological effect on the cardiovascular system. Hence, the present study aimed to investigate the potential ameliorative effects of capsaicin on the development of myocardial injury in diabetic rats and to identify the underlying mechanisms. Forty-eight animals were divided into four groups: control, diabetic, diabetic + rosuvastatin, and diabetic + capsaicin. Capsaicin was found to have a significant hypoglycemic and hypolipidemic effect compared to the other diabetic groups. Capsaicin also significantly increased the levels of the antioxidant enzymes catalase, superoxide dismutase, and glutathione peroxidase, as well as reduced glutathione. This was likely due to the upregulation of the cytoplasmic content of its key regulators Nrf-2 and HO-1, as found by immunostaining and western blot analysis. Additionally, capsaicin significantly increased the levels of cardioprotective nitric oxide, which could be stimulated by the upregulation of iNOS. Capsaicin also had a significant anti-inflammatory effect by reducing the high levels of TNF-α and IL-1β. Capsaicin was able to significantly inhibit myocardial structural damage, as found by histopathological examination using Hematoxylin and eosin (H&E), Masson trichrome, and immunostaining of desmin and α-smooth actin. This was further confirmed on the biochemical level by the attenuation of cardiac enzymes, MDA, carbonyl content, and heat shock proteins (HSP) 70 upregulation. Finally, capsaicin was able to attenuate myocardial injury by decreasing the myocardial concentration of the apoptotic protein cleaved caspase-3. In conclusion, this study has introduced capsaicin as a promising naturally derived agent that can attenuate the development of myocardial damage in diabetics through its hypoglycemic, hypolipidemic, antioxidant, anti-inflammatory, and anti-apoptotic effects.

Effect of Capsaicin and Dihydrocapsaicin in Capsicum on Myofibrillar Protein in Duck Meat.

Spice and its extracts have gained widespread utilization as natural and eco-friendly additives, imparting enhancements in flavor, color, and antioxidative attributes to meat-based products. This work aims to study the effect mechanism of capsaicin (CA) and dihydrocapsaicin (DI) in capsicum (chili pepper) on the structure and function of myofibrillar proteins (MPs) in duck meat during thermal treatment. The results showed that at a CA-DI to MP ratio of 1:500 (g/g) following a 12 min heat treatment, the carbonyl content of MPs in duck meat decreased by 48.30%, and the sulfhydryl content increased by 53.42%. When the concentration was 1:500 (CA-DI, g/g) after 24 min of heat treatment, the •OH and DPPH radical scavenging rates were highest at 59.5% and 94.0%, respectively. And the initial denaturation temperature of MPs was the highest at 96.62 °C, and the thermal absorption was lowest at 200.24 J g-1. At the parameter, the smallest particle size and size distribution range of MP were 190 nm (9.51%). Furthermore, the interplay between CA-DI and MPs contributed to a reduction in the protein particle size and intrinsic fluorescence. In summary, the combination of CA-DI and MPs played a crucial role in inducing protein unfolding and disintegration.

More spice, less salt: How capsaicin affects liking for and perceived saltiness of foods in people with smell loss

People who lose their sense of smell self-report consuming more salt to compensate for a lack of flavor and enhance eating enjoyment. However, this may contribute to excess sodium intake. Capsaicin may help increase salt taste intensity and eating enjoyment in people with smell loss, but this has not been studied in this population. The purpose of this study was to determine 1) whether salt intake in those with smell loss differs from population averages, 2) whether capsaicin increases flavor and salt taste intensity, and 3) if adding spice to foods increases liking in individuals with smell loss. Thirty-three participants 18–65 years old with confirmed smell loss for at least 12 weeks completed two sets of replicate test sessions (four total). In two sessions participants rated overall flavor intensity, taste qualities' intensities, spicy intensity, and liking for model tomato soups with low or regular sodium content and three levels of capsaicin (none, low, or moderate). In the other two sessions, participants rated the same sensory attributes for model food samples with three levels of added spice (none, low, or moderate). 24-hour urine samples were collected to determine sodium intake. Results indicate that although sodium intake is higher than recommended (<2300 mg/day) in those with smell loss (2893 ± 258 mg/day), they do not consume more sodium than population averages (3039 ± 100 mg/day; p = 0.3). Adding low and moderate amounts of capsaicin to a model tomato soup increased the intensity of overall flavor (p < 0.001) and saltiness (p = 0.004) compared to a model tomato soup without capsaicin. However, capsaicin's effect on liking differed by food type. Thus, capsaicin can improve flavor, salt taste intensity, and eating enjoyment in people with smell loss.

Neuropharmacological Study on Capsaicin in Scopolamine-injected Mice.

To evaluate the potential beneficial role of Capsaicin in cognitive dysfunction, mitochondrial impairment, and oxidative damage induced by scopolamine in mice. Capsaicin is the chief phenolic component present in red chili and is responsible for its pungent and spicy flavor. It affects TRPV1 channels in nociceptive sensory neurons and is present in the hippocampus, and hypothalamus of the brains of rodents and humans. The main objective is to investigate the effective role of capsaicin in attenuating cognitive dysfunction, mitochondrial impairment, and oxidative damage induced by scopolamine in mice and examine the feasible mechanisms. Various doses of capsaicin (5, 10, and 20 mg/kg) were given orally to mice daily for 7 consecutive days after the administration of scopolamine. Various behavioral tests (motor coordination, locomotor counts, hole board test) and biochemical assay (Pro-inflammatory cytokines, catalase, lipid peroxidation, nitrite, reduced glutathione, and superoxide dismutase), mitochondrial complex (I, II, III, and IV) enzyme activities, and mitochondrial permeability transition were evaluated in the distinct regions of the brain. Scopolamine-treated mice showed a considerable reduction in the entries and duration in the light zone as well as in open arms of the elevated plus maze. Interestingly, capsaicin at different doses reversed the anxiety, depressive-like behaviors, and learning and memory impairment effects of scopolamine. Scopolamine-administered mice demonstrated substantially increased pro-inflammatory cytokines levels, impaired mitochondrial enzyme complex activities, and increased oxidative damage compared to the normal control group. Capsaicin treatment reinstated the reduced lipid peroxidation, nitric oxide, catalase, superoxide dismutase, reduced glutathione activity, decreasing pro-inflammatory cytokines and restoring mitochondrial complex enzyme activities (I, II, III, and IV) as well as mitochondrial permeability. Moreover, the IL-1β level was restored at a dose of capsaicin (10 and 20 mg/kg) only. Capsaicin reduced the scopolamine-induced acetylcholinesterase activity, thereby raising the acetylcholine concentration in the hippocampal tissues of mice. Preservation of neuronal cell morphology was also confirmed by capsaicin in histological studies. From the above experimental results, capsaicin at a dose of 10 mg/kg, p.o. for seven consecutive days was found to be the most effective dose. The experiential neuroprotective effect of capsaicin through the restoration of mitochondrial functions, antioxidant effects, and modulation of pro-inflammatory cytokines makes it a promising candidate for further drug development through clinical setup.

Inhibition of pyroptosis and apoptosis by capsaicin protects against LPS-induced acute kidney injury through TRPV1/UCP2 axis in vitro.

Acute kidney injury is a fatal disease characterized by a rapid deterioration of kidney function. Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide) is a natural product extracted from Capsicum. The aim of this study was to explore the protective effect of capsaicin on inflammation, apoptosis, and mitochondrial dysfunction in an in vitro model of acute kidney injury. Lipopolysaccharide (LPS)-induced acute kidney injury model was established in HK-2 cells to investigate the protective effect of capsaicin. Cell viability was assessed using CCK-8 assay, and protein expression was detected using western blot and immunofluorescence assay. Intracellular reactive oxygen species (ROS) level and mitochondrial membrane potential were analyzed by flow cytometry. Cell apoptosis was detected by propidium iodide staining. The results showed that capsaicin ameliorated LPS-induced cytotoxicity in vitro and attenuated the release of interleukin (IL)-1β and IL-18. Intriguingly, genipin abolished the protective effect of capsaicin. Molecularly, capsaicin activated transient receptor potential cation channel subfamily V member 1 -mitochondrial uncoupling protein 2 axis and inhibited caspase-1-mediated pyroptosis. In addition, capsaicin alleviated LPS-induced ROS production and mitochondrial membrane potential disruption and inhibited apoptosis. These findings suggest that capsaicin shows a protective effect in in vitro acute kidney injury model.

Recent advances in analysis of capsaicin and its effects on metabolic pathways by mass spectrometry.

Capsaicin is the main food active component in Capsicum that has gained considerable attention due to its broad biological activities, including antioxidation, anti-inflammation, anti-tumor, weight regulation, cardiac protection, anti-calculi, and diurnal-circadian regulation. The potent biological effects of capsaicin are intimately related to metabolic pathways such as lipid metabolism, energy metabolism, and antioxidant stress. Mass spectrometry (MS) has emerged as an effective tool for deciphering the mechanisms underlying capsaicin metabolism and its biological impacts. However, it remains challenging to accurately identify and quantify capsaicin and its self-metabolites in complex food and biological samples, and to integrate multi-omics data generated from MS. In this work, we summarized recent advances in the detection of capsaicin and its self-metabolites using MS and discussed the relevant MS-based studies of metabolic pathways. Furthermore, we discussed current issues and future directions in this field. In-depth studies of capsaicin metabolism and its physiological functions based on MS is anticipated to yield new insights and methods for preventing and treating a wide range of diseases.