Pungent Component Research Articles

Effect of Capsaicin on Salt Taste Sensitivity in Humans

In order to investigate the effect of pungent components on salt taste sensitivity in humans, sensory evaluation of taste intensity and palatability was performed by adding 0.5 or 1 μM capsaicin (CAP) to a 75 mM NaCl solution. The assessment results suggested that a significant number of subjects experienced stronger salt taste intensity with the CAP-added NaCl solution than that for the NaCl solution alone. A quantitative analysis performed by adding CAP to the NaCl solution revealed an increase in the salt taste intensity. At the same time, the palatability decreased with increasing concentration of CAP. The increase in salt taste intensity after the addition of CAP suggests that addition of pungent components might influence salt sensitivity in humans.

Inhibitory potential of ginger extracts against enzymes linked to type 2 diabetes, inflammation and induced oxidative stress

Ginger (Zingiber officinale Roscoe) continues to be used as an important cooking spice and herbal medicine around the world. Gingerols, the major pungent components of ginger, are known to improve diabetes, including the effect of enhancement against insulin sensitivity. In the current study, ginger sequentially extracted with different solvents—namely, hexane, ethyl acetate, methanol, 70% methanol–water and water—were screened to determine the variations in phenolic-linked active constituents. The potential of these extracts to inhibit key enzymes relevant to type 2 diabetes and inflammation was studied. Phenolic compounds—namely, gingerols and shoagols—were quantified using high-performance liquid chromatography. Ethyl acetate extract showed higher activity compared with other extracts. These studies indicate that ginger has very good potential for α-glucosidase and α-amylase inhibition relevant for type 2 diabetes management and cyclooxygenase inhibition for inflammation.

Inhibitory effects of zingerone, a pungent component of Zingiber officinale Roscoe, on colonic motility in rats.

Ginger (rhizome of Zingiber officinale Roscoe) is an herbal medicine for the treatment of gastrointestinal disorders including constipation and diarrhea. Zingerone is a likely active constituent responsible for the antidiarrheal activity of ginger. The current study was designed to characterize pharmacological actions of zingerone on colonic motility. To evaluate pharmacological effects of zingerone on colonic motility, we used isolated colonic segments from rats, in which mechanical responses were recorded in the longitudinal direction. In addition, we evaluated the effects on colonic motility in vivo by measuring intraluminal pressure changes and expelled fluid volume from the colon in anesthetized rats. Zingerone was applied to the lumen of the colon to allow the drug to access from the mucosal side. Zingerone inhibited spontaneous contractile movements in the isolated colonic segments in a dose-dependent manner. The inhibitory effects of zingerone on colonic movements were not affected by pretreatment with capsazepine, a typical antagonist of transient receptor potential vanilloid 1. In addition, tetrodotoxin, a blocker of voltage-dependent sodium channels on neurons, did not affect the suppression of colonic movements by zingerone, suggesting that zingerone acts on the smooth muscles directly. Zingerone also attenuated colonic motility in vivo without affecting blood pressure and heart rate. The effects were reversible and reproducible. Our findings suggest that zingerone can inhibit colonic motility via direct action on smooth muscles. Zingerone might exert beneficial therapeutic effects on hypermotility-induced diarrhea by abrogating excessive gastrointestinal motility.

Adiposity Suppression Effect in Mice Due to Black Pepper and Its Main Pungent Component, Piperine

We investigated energy metabolism enhancement by pepper by examining suppression of body fat accumulation in mice due to piperine (PIP) and black pepper (BP) intake. To induce adiposity, mice were fed a high-fat, high-sucrose (HFS) diet as a control diet for 4 weeks. Visceral fat weights decreased significantly in the mice fed diets of 0.03% and of 0.05% PIP. Body weight in the 0.05% PIP group also decreased significantly. In the mice fed a diet of 1.0% BP, body weight and visceral fat weights decreased significantly. For all parameters tested, the 1.0% BP group tended to show values slightly lower than those of the 0.03% PIP group. Expression of thermogenic protein uncoupling protein 1 tended to increase in the mice on the 1.0% BP diet. These results indicate that BP suppresses the effect of body fat accumulation mainly through the action of PIP.

Galangal Pungent Component, 1′-Acetoxychavicol Acetate, Activates TRPA1

We investigated the activation of transient receptor potential cation channel (TRP) subfamily V, member 1 (TRPV1) and TRP subfamily A, member 1 (TRPA1) by 1'-acetoxychavicol acetate (ACA), the main pungent component in galangal. ACA did not activate TRPV1-expressing human embryonic kidney (HEK) cells, but strongly activated TRPA1-expressing HEK cells. ACA was more potent than allyl isothiocyanate, the typical TRPA1 agonist.

6]-Dehydroshogaol, a minor component in ginger rhizome, exhibits quinone reductase inducing and anti-inflammatory activities that rival those of curcumin

Quinone reductase (QR) inducing activity, a biomarker for Phase II enzyme induction, was detected in a crude ginger rhizome ethanolic extract using a murine hepatoma cell (Hepa 1c1c7) bioassay. An ethyl acetate-partitioned fraction became enriched in QR inducing activity with a CD value (concentration required to double QR specific activity) of 7 μg/ml and was further separated by silica flash chromatography. The four major fractions recovered exhibited CD values ranging 10–20 μg/mL for QR inducing activity. 1H NMR analysis revealed an abundance of gingerols in the first 3 fractions, and this led to a comparative assessment of QR inducing and anti-inflammatory activities among [6]-gingerol and structurally related vanilloids from ginger and other spices. [6]-Dehydroshogaol (DHSG), a minor component of fresh ginger, had QR inducing activity (CD = 8.4 μM) of comparable potency to the well known cancer preventive agent, curcumin (CD = 4.3 μM). In contrast, [6]-gingerol the major pungent component of ginger showed less potent QR inducing activity (CD = 55 μM) and capsaicin exhibited the weakest inducing activity (CD = 103 μM). [6]-Shogaol, [6]-DHSG and curcumin were also potent inhibitors of nitric oxide (NO) synthesis, inhibiting 50% NO evolution in activated macrophages at levels of 10–12 μM (IC 50 values). Comparatively, IC 50 values for [6]-gingerol and capsaicin were about an order of magnitude greater (less potent) at 90 μM and 169 μM, respectively. This appears to be the first report of biological activities of [6]-DHSG, and Phase II enzyme-inducing ability of shogoal and gingerol.

Effects of Various Fragrant Ingredients on Desmopressin-induced Fluid Retention in Mice

Although fragrances are often used in aromatherapy for the treatment of edema, few studies on their diuretic and/or antiedematous activities have been performed. In this study, the effects of four types of fragrant ingredients (d-limonene, piperitone, alpha-pinene, and cinnamaldehyde) were examined in a mouse model of fluid retention. The mice were loaded with water after treatment with desmopressin (an antidiuretic hormone). In addition, zingerone, a pungent component of ginger which is considered to be effective in the treatment of edema, was examined. Moreover, their effects were compared with those of furosemide, a representative diuretic. Among the five types of fragrant ingredients examined, all except for cinnamaldehyde increased the urine volume in the fluid retention mouse model when administered at a dose of 100 mg/kg. In particular, d-limonene and zingerone significantly increased the urine volume. Thus the effects of these two ingredients were further examined at lower doses of 10 and 30 mg/kg. d-Limonene significantly increased the urine volume in a dose-dependent manner. Zingerone resulted in a significant increase in the urine volume only at a dose of 30 mg/kg. In normal mice, d-limonene did not affect the urine volume at the same doses. In contrast, zingerone significantly increased the urine volume in normal mice at a dose of 30 mg/kg. Furosemide significantly increased the urine volume in both the fluid-retentive and normal mice. These results indicate that both d-limonene and zingerone exhibit diuretic actions; however, the former fragrance only exerted an action in the fluid-retentive state. This different action suggests that d-limonene might be promising for the treatment of edema.

Neuroprotection induced by vitamin E against oxidative stress in hippocampal neurons: Involvement of TRPV1 channels

Pretreatment of cultured hippocampal neurons with a low concentration of alpha-tocopherol (alpha-TP), the major component of vitamin E, results in a long-lasting protection against oxidative damages, via genomic effects. This neuroprotection is associated with the attenuation of a calcium influx triggered by oxidative agents such as Fe(2+) ions. This Ca(2+) influx is supported by a TRP-like channel, also partly involved in capacitive calcium entry within neurons. Here, we evidence the contribution of TRPV1 channels in this mechanism. TRPV1 channels are activated by various agents including capsaicin, the pungent component of hot chili peppers and blocked by capsazepine (CPZ) or 5'-iodo-resiniferatoxin. Both TRPV1 inhibitors strongly reduced Fe(2+) ion-mediated toxicity and Ca(2+) influx, in the same way as to alpha-TP pretreatment. Moreover, CPZ also decreased capacitive calcium entry in hippocampal neurons. Finally, both CPZ and 5'-iodo-resiniferatoxin reduced spontaneous excitatory synaptic transmission; this depression of synaptic transmission being largely occluded in alpha-TP-pretreated neurons. In conclusion, in our experimental model, TRPV1 channels are involved in the Fe(2+) ion-induced neuronal death and a negative modulation of this channel activity by alpha-TP pretreatment may account, at least in part, for the long-lasting neuroprotection against oxidative stress.

Lowering Effects of Allyl Isothiocyanate on the Number of Lymphocyte and Its Subsets in Rats

The purpose of this study was to elucidate the effects of a main pungent component of wasabi, allyl isothiocyanate (AITC), on the number of lymphocytes, T-lymphocyte, B-lymphocyte and natural killer (NK) cells and plasma corticosterone concentrations in rats. AITC was given as either single dosage [20 mg/kg body weight per day; subcutaneous (s.c.) and oral] or as a daily dosage (10 mg and 20 mg/kg body weight per day; s.c.) for 4 days for the hourly and daily assessment of changes in the numbers of lymphocytes, respectively. A single s.c. injection or oral administration of AITC significantly reduced the number of lymphocytes at 4 hr to approximately 0.68 times, indicating that decreased effects of AITC on the number of lymphocytes are independent on the administration route. Administration of AITC for 4 days reduced dose-dependently the number of lymphocytes, and significantly reduced the number of T-lymphocyte and B-lymphocyte to 0.79 and 0.60 times, respectively. However, the number of NK cells did not change by AITC. Administration of AITC increased plasma corticosterone concentrations at 4 day of post s.c. injection to 5.4-6.0 times. These results suggest that AITC-mediated immunosuppresion is at least in part attributable to changes in the number and distribution of lymphocyte and its subsets.

Genetic variants involved in gallstone formation and capsaicin metabolism, and the risk of gallbladder cancer in Chilean women

To determine the effects of genetic variants associated with gallstone formation and capsaicin (a pungent component of chili pepper) metabolism on the risk of gallbladder cancer (GBC). A total of 57 patients with GBC, 119 patients with gallstones, and 70 controls were enrolled in this study. DNA was extracted from their blood or paraffin block sample using standard commercial kits. The statuses of the genetic variants were assayed using Taqman SNP Genotyping Assays or Custom Taqman SNP Genotyping Assays. The non-ancestral T/T genotype of apolipoprotein B rs693 polymorphism was associated with a decreased risk of GBC (OR: 0.14, 95% CI: 0.03-0.63). The T/T genotype of cholesteryl ester transfer protein (CETP) rs708272 polymorphism was associated with an increased risk of GBC (OR: 5.04, 95% CI: 1.43-17.8). Genetic variants involved in gallstone formation such as the apolipoprotein B rs693 and CETP rs708272 polymorphisms may be related to the risk of developing GBC in Chilean women.

Allyl isothiocyanate-induced changes in the distribution of white blood cells in rats

The main pungent component of wasabi (Eutrema japonica) is known to be isothiocyanate and its derivatives, volatile substances. Allyl isothiocyanate (AITC) accounts for more than half of isothiocyanate derivatives. However, there is a little information on the effects of AITC on the immune system by analyzing the number of white blood cells (WBCs) over the course of days of AITC administration. In the present study, we studied the effects of AITC (dose=20 mg/kg body weight/day for 10 days, subcutaneous: s.c.) on the number of WBCs (total WBCs, lymphocytes, monocyte, neutrophil, basophil and eosinophil) and plasma corticosterone concentrations in adult male rats. Administration of AITC decreased significantly the number of total WBCs on days 1-4 post s.c. injection by 25-27%. Administration of AITC also decreased the number of lymphocytes on days 1-10 by 21-36% and monocyte on days 1-8 by 28-78%. However, administration of AITC increased the number of neutrophil on days 8-10 by 61-112%. AITC did not change the number of eosinophil and basophil. Plasma corticosterone concentrations during the experimental period were 4.7-8.4 times significantly higher in the AITC group than in the control group, indicating that AITC induced stress-responses. The relative weights of thymus and adrenals per body weight were significantly lower and clearly higher in the AITC group than in the control group, respectively. These results suggest that AITC-mediated stress-responses are at least in part attributable to changes in the number of circulating WBCs.

Capsaicin Induced the Upregulation of Transcriptional and Translational Expression of Glycolytic Enzymes Related to Energy Metabolism in Human Intestinal Epithelial Cells

Capsaicin is the major pungent component in hot chili pepper. It is known that capsaicin induces the increase of energy metabolism through adrenaline activation. The aim of this study was to investigate the mechanism underlying the effect of capsaicin on energy metabolism in human intestinal epithelial cells (Caco-2). To clarify the mechanism, we performed proteomics, real time-PCR, ATP measurement, and MTT in this study. Glycolytic enzymes, namely, phosphoglycerate mutase (PGM) and triosephosphate isomerase (TPI), were overexpressed in capsaicin-treated Caco-2 cells. mRNA expression levels of TPI and PGM were also increased in capsaicin-treated Caco-2 cells. Furthermore, intracellular adenosine triphosphate (ATP) content, which is the end product of glycolysis, was increased. To demonstrate the intracellular ATP production and ATP accumulation, the viability of Caco-2 cells incubated with glucose free medium was measured. The viability of capsaicin pretreated cells was higher than that of untreated cells. All these observations strongly indicate that capsaicin increases energy metabolism in human epithelial cells through the activation of glycolytic enzymes.

Synthesis and elucidation of deuterated vanillylamine hydrochloride and capsaicin

AbstractCapsaicin is the major pungent component of hot peppers, which belong to the plant genus Capsicum. Although the biosynthesis of capsaicin is known to involve the condensation of vanillylamine and 8‐methylnonenoic acid by capsaicin synthase, the mechanism of biosynthesis is still not fully understood. In this study, deuterium labelled versions of capsaicin and the precursor vanillylamine were synthesized in order to investigate the biosynthesis of capsaicin in hot peppers. Copyright © 2009 John Wiley & Sons, Ltd.

Extraction of pungent components from Japanese pepper ( Xanthoxylum piperitum DC.) using supercritical CO 2

Supercritical CO 2 extraction of pungent components from immature and mature Japanese pepper has been conducted in order to study the effect of extraction condition on the yield of extract and composition of pungent components in the extract. Extraction was carried out in semi-continuous extractor at pressure of 9–45 MPa, temperature of 40–80 °C and CO 2 flow rate of 1–3 mL/min. Composition of pungent compounds in the extract was analyzed by GC–MS, while sanshool compounds was qualitatively analyzed by HPLC–DAD. Extraction condition significantly affected the yield of extract and the composition of pungent components in the extract. In general, extraction yield of mature Japanese pepper was higher than immature one. Extraction condition can be tuned to obtain higher content of the target pungent components. The extract was mainly contained hydroxy-α-sanshool as the most abundant of sanshool compounds followed by α- and δ-sanshool. As comparison with the conventional methods, supercritical CO 2 extraction effectively extracted the pungent components of Japanese pepper in high yield.

Capsaicinoids in Chili Pepper (Capsicum annuum L.) Powder as Affected by Heating and Storage Methods

Loss of capsaicin and dihydrocapsaicin is a problem in the preparation and storage of dehydrated peppers. In this study, the effects of heating (100C to 260C, 15 min) and storage conditions (vacuum vs. non-vacuum package, room temperature vs. refrigeration temperature) on the content of capsaicin and dihydrocapsaicin in chili pepper powder were studied with pungent components assayed by HPLC. Heating between 100C and 190C for 15 min did not seriously affect the content of capsaicinoids (<10% reduction). However, at temperatures greater than 190C, capsaicin and dihydrocapsaicin degraded rapidly. Low-temperature storage improved retention of capsaicinoids, and vacuum packaging provided little if any extra benefit. Capsaicin and dihydrocapsaicin had very similar stability and showed similar reduction rates during heating and storage, which indicates that the C=C bond in capsaicin is relatively stable and does not account for its decomposition during heating and storage.

Plasma pharmacokinetics and tissue distribution of [6]‐gingerol in rats

[6]-Gingerol is one of the pungent components in ginger which has been found to possess various pharmacological effects. However, there is insufficient information on the properties of [6]-gingerol based on controlled pharmacokinetic studies. The aim of this study was to clarify distribution profiles of [6]-gingerol in blood and biological tissues of experimental rats. Rats were administered a 240 mg/kg dose of Gs (a ginger extract, containing 53% [6]-gingerol) by oral ingestion. Plasma samples were collected at 2.5, 5, 7.5, 10, 15, 20, 30, 45 min, and 1, 1.5, 2, 3, 4 h after dosing (eight samples per time point), and brain, heart, lung, spleen, liver, kidney, stomach and small intestine tissues were collected at 5, 15, 30 min and 1, 2, 4 h after dosing (five animals per time point). Samples were prepared by a liquid-liquid extraction procedure and the extracts were assayed by HPLC-UV. After per oral application, [6]-gingerol was absorbed rapidly into the plasma, and the maximal concentration (4.23 microg/ml) was reached after 10 min post dosing. [6]-Gingerol plasma concentrations declined with time in a biexponential pattern. The elimination half-time at the terminal phase was 1.77 h and the apparent total body clearance was 40.8 l/h. When administered orally, [6]-gingerol was well distributed to the tissues examined, with the highest concentrations found in the gastrointestinal tract. Maximal concentrations of [6]-gingerol were reached in most tissues at 0.5 h post-dosing. The concentrations of [6]-gingerol in tissues all were higher than in plasma with corresponding tissue to plasma ratios greater than 1 after 0.25 h post-dose, showing high tissue partitioning and extensive distribution.

Dihydrocapsaicin (DHC), a saturated structural analog of capsaicin, induces autophagy in human cancer cells in a catalase-regulated manner

Although capsaicin, a pungent component of red pepper, is known to induce apoptosis in several types of cancer cells, the mechanisms underlying capsaicin-induced cytotoxicity are unclear. Here, we showed that dihydrocapsaicin (DHC), an analog of capsaicin, is a potential inducer of autophagy. DHC was more cytotoxic than capsaicin in HCT116, MCF-7 and WI38 cell lines. Capsaicin and DHC did not affect on the sub-G1apoptotic peak, but induced G0/G1 arrest in HCT116 and MCF-7 cells. DHC caused the artificial autophagosome marker GFP-LC3 to redistribute and upregulated expression of autophagy-related proteins. Blocking of autophagy by 3-methyladenine (3MA) as well as siRNA Atg5 induced a high level of caspase-3 activation. Although pretreatment with zVAD completely inhibited caspase-3 activation by 3MA, it did not prevent cell death. DHC-induced autophagy was enhanced by zVAD pretreatment, as shown by increased accumulation of LC3 II protein. DHC attenuated basal ROS levels through catalase induction; this effect was enhanced by antioxidants, which increased both LC3 II expression and caspase-3 activation. The catalase inhibitor 3-amino-1,2,4-triazole (3AT) abrogated DHC-induced expression of LC3 II, overexpression of the catalase gene increased expression of LC3 II protein, and knockdown decreased it. Additionally, DHC-induced autophagy was independent of p53 status. Collectively, DHC activates autophagy in a p53-independent manner and that may contribute to cytotoxicity of DHC.

Effects of Zingerone on Fat Storage in Ovariectomized Rats

We reported that ginger prevented obesity in mice fed a high-fat diet in previous study. In this experiment, we examined the effects of zingerone, the major pungent component of ginger on fat storage in ovariectomized (Ovx) rats. Oral administration of 170 mg/kg zingerone significantly reduced body weight and the final parametrail adipose tissue weight in ovariectomized rats. Blood glucose levels after oral administration of glucose were lower in zingerone-treated Ovx-rats than in the Ovx-rats (control). Basal lipolysis in zingerone-treated Ovx-rats was increased compared with that in the Ovx-rats. Zingerone significantly increased norepinephrine-induced lipolysis associated with the translocation of hormone-sensitive lipase (HSL) from the cytosol to lipid droplets in adipocytes. These results indicate that zingerone may prevent the fat storage through increasing norepinephrine-induced lipolysis in adipocytes.

Oral administration of capsaicin protects mice from autoimmune diabetes by inhibition of cross‐presentation of self antigens.

Capsaicin (CP) is the pungent component of chili peppers. We have observed previously that dendritic cells (DCs), a key cell type in immune responses, have the receptor for CP, and engagement of this receptor has powerful immune consequences. As CP can be used as a powerful adjuvant in enhancement of an immune response, we tested its immunomodulatory activity by oral administration in treatment of Type 1 diabetes (T1D) in non‐obese diabetic (NOD) mice. Here we demonstrate that oral administration of CP delays the onset of diabetes in NOD mice in a dose dependent manner and adoptive transfer of splenocytes from CP treated mice can transfer protection in recipient NOD mice. Further, CP administration attenuates OVA specific naïve T cell (OT1) proliferation in pancreatic lymph nodes (PLN) of RIP‐OVA mice. These results reflect the immunological potency of a neurological ligand in modulating cross‐presentation ability of islet DCs in the draining PLNs.

Inhibitory effect of gingerol on the proliferation and invasion of hepatoma cells in culture

Effect of [6]-gingerol, a major pungent component in ginger, on the proliferation of a rat ascites hepatoma AH109A cells was investigated by measuring [(3)H]thymidine incorporation into acid-insoluble fraction of the cultured cells and that on the invasion by co-culturing the hepatoma cells with rat mesentery-derived mesothelial cells. [6]-Gingerol inhibited both the proliferation and invasion of hepatoma cells in a dose-dependent manner at concentrations of 6.25-200 muM (proliferation) and 50-200 muM (invasion). [6]-Gingerol accumulated cells in S phase and elongated doubling time of hepatoma cells, and increased the rate of apoptosis. Hepatoma cells previously cultured with hypoxanthine (HX) and xanthine oxidase (XO) or with hydrogen peroxide showed increased invasive activities. [6]-Gingerol suppressed the reactive oxygen species-potentiated invasive capacity by simultaneously treating AH109A cells with [6]-gingerol, HX and XO or with [6]-gingerol and hydrogen peroxide. Furthermore, [6]-gingerol reduced the intracellular peroxide levels in AH109A cells. These results suggest that the suppression of hepatoma cell proliferation by [6]-gingerol may be due to cell cycle arrest and apoptosis induction. They also suggest that the anti-oxidative property of [6]-gingerol may be involved in its anti-invasive activity of hepatoma cells.