Effect of Piper nigrum essential oil in dextran sulfate sodium (DSS)-induced colitis and its potential mechanisms.

BACKGROUND: Piper nigrum essential oil (PnEO) possesses pleasant aroma, unique flavor, and various bioactivities; however, its role against colitis remains unclear. PURPOSE: In this study, we investigated the role of PnEO in relieving colitis and explored its potential mechanisms in a mouse model of dextran sulfate sodium (DSS)-induced colitis. METHODS: Initially, we identified and quantified the components of PnEO by gas chromatography-mass spectrometry (GC-MS). Subsequently, we investigated the protective role of PnEO (50 and 200 mg/kg) in DSS-induced colitis in mice by evaluating disease activity index (DAI) scores and colon length, and performing histological analyses. Eyeball blood was collected and cytokines were determined using ELISA kits. The anti-inflammatory mechanisms of PnEO were analyzed by western blot (WB) and immunohistochemistry (IHC). The intestinal barrier function was evaluated according to tight junction (TJ) protein mRNA levels. We used 16S rRNA gene sequencing to analyze the intestinal microflora of mouse cecal contents. RESULTS: Supplementation with PnEO (50 and 200 mg/kg) increased colon length and improved colon histopathology. PnEO regulated inflammatory responses by downregulating TLR4/MAPKs activation, thereby reducing the release of cytokines and mediators. Moreover, it also protected the intestinal barrier through enhancing the expression of claudin-1, claudin-3, occludin, ZO-1, and mucin 2. 16S rRNA gene sequencing revealed that PnEO (200 mg/kg) decreased the abundance of Akkermansia in the gut microbiome. CONCLUSION: PnEO treatment (50 and 200 mg/kg) relieved DSS-induced colitis by inhibiting TLR4/MAPK pathway and protecting intestinal barrier, and high-dose PnEO exhibited better effects. Moreover, PnEO (200 mg/kg) regulated key compositions of the gut microbiome, which indicated that it had therapeutic potential for sustaining gut health to lower the risk of colitis.

Nontargeted Metabolomics for Phenolic and Polyhydroxy Compounds Profile of Pepper (Piper nigrum L.) Products Based on LC-MS/MS Analysis.

In the present study, nontargeted metabolomics was used to screen the phenolic and polyhydroxy compounds in pepper products. A total of 186 phenolic and polyhydroxy compounds, including anthocyanins, proanthocyanidins, catechin derivatives, flavanones, flavones, flavonols, isoflavones and 3-O-p-coumaroyl quinic acid O-hexoside, quinic acid (polyhydroxy compounds), etc. For the selected 50 types of phenolic compound, except malvidin 3,5-diglucoside (malvin), l-epicatechin and 4'-hydroxy-5,7-dimethoxyflavanone, other compound contents were present in high contents in freeze-dried pepper berries, and pinocembrin was relatively abundant in two kinds of pepper products. The score plots of principal component analysis indicated that the pepper samples can be classified into four groups on the basis of the type pepper processing. This study provided a comprehensive profile of the phenolic and polyhydroxy compounds of different pepper products and partly clarified the factors responsible for different metabolite profiles in ongoing studies and the changes of phenolic compounds for the browning mechanism of black pepper.

Contribution of Polyphenol Oxidation, Chlorophyll and Vitamin C Degradation to the Blackening of Piper nigrum L.

Black pepper (Piper nigrum L.) is the most widely used spice in the world. Blackening is considered to be beneficial and important in the processing of black pepper because it contributes to its color and flavor. The purpose of this paper is to investigate polyphenol oxidation as well as the chlorophyll and vitamin C (VC) degradation in the blackening of Piper nigrum L. Black pepper was produced by four methods, and changes in polyphenols, chlorophyll and VC were studied by high performance liquid chromatography (HPLC) and ultraviolet-visible and visible (UV-Vis) spectrophotometry. The results show that polyphenol oxidase activity significantly decreased during the preparation of black pepper, and the concentrations of phenolic compounds, VC, and chlorophyll a and b also significantly decreased. Polyphenol oxidation and chlorophyll and VC degradation contribute to the blackening. A crude extract of phenolic compounds from black pepper was prepared by the system solvent method. The greater the polarity of the extraction solvent, the higher the extraction rates of the phenolic compounds and the total phenol content. Pepper phenolic compounds were analyzed by HPLC analysis.

Optimized production of vanillin from green vanilla pods by enzyme-assisted extraction combined with pre-freezing and thawing.

Production of vanillin from natural green vanilla pods was carried out by enzyme-assisted extraction combined with pre-freezing and thawing. In the first step the green vanilla pods were pre-frozen and then thawed to destroy cellular compartmentation. In the second step pectinase from Aspergillus niger was used to hydrolyze the pectin between the glucovanillin substrate and ß-glucosidase. Four main variables, including enzyme amount, reaction temperature, time and pH, which were of significance for the vanillin content were studied and a central composite design (CCD) based on the results of a single-factor tests was used. Response surface methodology based on CCD was employed to optimize the combination of enzyme amount, reaction temperature, time, and pH for maximum vanillin production. This resulted in the optimal condition in regards of the enzyme amount, reaction temperature, time, and pH at 84.2 mg, 49.5 °C, 7.1 h, and 4.2, respectively. Under the optimal condition, the experimental yield of vanillin was 4.63% ± 0.11% (dwb), which was in good agreement with the value predicted by the model. Compared to the traditional curing process (1.98%) and viscozyme extract (2.36%), the optimized method for the vanillin production significantly increased the yield by 133.85% and 96%, respectively.

Comparison of four kinds of extraction techniques and kinetics of microwave-assisted extraction of vanillin from Vanilla planifolia Andrews.

Vanillin yield, microscopic structure, antioxidant activity and overall odour of vanilla extracts obtained by different treatments were investigated. MAE showed the strongest extraction power, shortest time and highest antioxidant activity. Maceration gave higher vanillin yields than UAE and PAE, similar antioxidant activity with UAE, but longer times than UAE and PAE. Overall odour intensity of different vanilla extracts obtained by UAE, PAE and MAE were similar, while higher than maceration extracts. Then, powered vanilla bean with a sample/solvent ratio of 4 g/100 mL was selected as the optimum condition for MAE. Next, compared with other three equations, two-site kinetic equation with lowest RMSD and highest R²(adj) was shown to be more suitable in describing the kinetics of vanillin extraction. By fitting the parameters C(eq), k1, k2, and f, a kinetics model was constructed to describe vanillin extraction in terms of irradiation power, ethanol concentration, and extraction time.

[Comparison of green coffee beans volatiles chemical composition of Hainan main area].

Chemical component of Hainan green coffee beans was analyzed with solid phase microextraction-gas chromatography-mass spectrometry, and the discrepancy between two green coffee beans was differentiated through the spectrum database retrieval and retention index of compound characterization. The experimental results show that: the chemical composition of Wanning coffee beans and Chengmai coffee beans is basically the same. The quantity of analyzed compound in Wanning area coffee is 91, and in Chengmai area coffee is 106, the quantity of the same compound is 66, and the percent of the same component is 75.52%. The same compounds accounted for 89.86% of the total content of Wanning area coffee, and accounted for 85.70% of the total content of Chengmai area coffee.

Optimization of enzymatic process for vanillin extraction using response surface methodology.

Vanillin was extracted from vanilla beans using pretreatment with cellulase to produce enzymatic hydrolysis, and response surface methodology (RSM) was applied to optimize the processing parameters of this extraction. The effects of heating time, enzyme quantity and temperature on enzymatic extraction of vanillin were evaluated. Extraction yield (mg/g) was used as the response value. The results revealed that the increase in heating time and the increase in enzyme quantity (within certain ranges) were associated with an enhancement of extraction yield, and that the optimal conditions for vanillin extraction were: Heating time 6 h, temperature 60 °C and enzyme quantity 33.5 mL. Calculated from the final polynomial functions, the optimal response of vanillin extraction yield was 7.62 mg/g. The predicted results for optimal reaction conditions were in good agreement with experimental values.