Discoloration Investigations of Yellow Lantern Pepper Sauce (Capsicum chinense Jacq.) Fermented by Lactobacillus plantarum: Effect of Carotenoids and Physiochemical Indices.

Color is one of the important indicators affecting the quality of fermented pepper sauces, and it is closely related to carotenoid composition. This study systematically analyzed the changes in carotenoids and related physiochemical indices during the fermentation of yellow lantern pepper sauce. The CIELab color values indicated that L* and C* displayed a significant decreasing trend during fermentation. After 35 days of fermentation, the total carotenoid content significantly reduced from 3446.36 to 1556.50 µg/g DW (p < 0.05), and the degradation rate was 54.84%. Among them, the total content of carotene decreased by 56.03% during fermentation, whereas the degradation rate of xanthophylls and their esters was 44.47%. According to correlation analysis, violaxanthin myristate and lutein played a pivotal role in L*, a *, b *, chroma (C*), and yellowness index (YI). Moreover, PCA analysis indicated that lactic acid and acetic acid were the important qualities affecting the stability of pigment in fermented yellow lantern pepper sauce, which might also be the inducement of the color change. This work gives additional information concerning the discoloration of yellow lantern pepper sauce during fermentation and provides theory evidence regulating and improving the sensory qualities of yellow lantern pepper sauce.

De novo transcriptome profiling unveils the regulation of phenylpropanoid biosynthesis in unripe Piper nigrum berries.

BACKGROUND: Black pepper (Piper nigrum L.) is rich in bioactive compounds that make it an imperative constituent in traditional medicines. Although the unripe fruits have long been used in different Ayurvedic formulations, the mechanism of gene regulation resulting in the production of the bioactive compounds in black pepper is not much investigated. Exploring the regulatory factors favouring the production of bioactive compounds ultimately help to accumulate the medicinally important content of black pepper. The factors that enhance the biosynthesis of these compounds could be potential candidates for metabolic engineering strategies to obtain a high level production of significant biomolecules. RESULTS: Being a non-model plant, de novo sequencing technology was used to unravel comprehensive information about the genes and transcription factors that are expressed in mature unripe green berries of P. nigrum from which commercially available black pepper is prepared. In this study, the key gene regulations involved in the synthesis of bioactive principles in black pepper was brought out with a focus on the highly expressed phenylpropanoid pathway genes. Quantitative real-time PCR analysis of critical genes and transcription factors in the different developmental stages from bud to the mature green berries provides important information useful for choosing the developmental stage that would be best for the production of a particular bioactive compound. Comparison with a previous study has also been included to understand the relative position of the results obtained from this study. CONCLUSIONS: The current study uncovered significant information regarding the gene expression and regulation responsible for the bioactivity of black pepper. The key transcription factors and enzymes analyzed in this study are promising targets for achieving a high level production of significant biomolecules through metabolic engineering.

Viphyllin™, a standardized extract from black pepper seeds, mitigates intestinal inflammation, oxidative stress, and anxiety-like behavior in DSS-induced colitis mice.

Inflammatory bowel diseases (IBD) are the common health concern in populations across the world. Clinical evidence suggests that IBD, characterized by intestinal inflammation, is associated with neuronal manifestations to a greater extent. In this study, we have investigated the protective effects of Viphyllin™, a standardized black pepper (Piper nigrum) seed extract containing 30% ß-caryophyllene against dextran sodium sulfate (DSS)-induced colitis in mice. Oral pretreatment of Viphyllin at the 50 mg and 100 mg/kg doses significantly reversed the clinical symptoms of colitis in mice. Viphyllin markedly inhibited NLRP3 inflammasome activation and improved barrier function in colon tissue. Viphyllin further mitigated the DSS-induced anxiety-like behavior in mice. Interestingly, Viphyllin improved brain antioxidant status and promoted neuronal cell survival in colitis model mice. In conclusion, our findings strongly support the health claims of Viphyllin as a functional ingredient to deal with IBD and related neuronal symptoms. PRACTICAL APPLICATIONS: Prevalence of inflammatory bowel diseases is not uncommon in the modern lifestyle. Gut health is associated with neurological disorders that contribute substantially to the deterioration of quality of life and socioeconomic development. In this research work, the protective action of a black pepper seed extract standardized to 30% ß-caryophyllene (Viphyllin) is evaluated against Dextran sodium sulfate-induced experimental colitis model. Here we have demonstrated the beneficial role of Viphyllin in mitigating intestinal inflammation as a function of NLRP3 inflammasome inhibition. Further, the extract improves intestinal barrier function. In an important aspect of the study, we have provided the data on the effect of Viphyllin on neurological symptoms and brain health in colitis model mice.

In silico assisted identification of peppery aroma compound 'rotundone' backbone genes from black pepper.

Rotundone, an oxygenated sesquiterpene compound, responsible for the peppery aroma. The importance of the rotundone in the flavor industry warrants search for the precursor genes in plants. We report in this study, the first on the identification of rotundone backbone genes viz., α-guaiene synthase & α-guaiene oxidase in black pepper. We identified the precursor genes of rotundone using berry transcriptome profiling. The metabolite profiling using head space mass spectrometry showed the presence of the direct precursor compounds for rotundone biosynthesis in black pepper berries. The identification of the genes & compounds of the guaiene skeleton is expected to help in bioprospecting of black pepper varieties & also in recombinant production of the aroma compound.Communicated by Ramaswamy H. Sarma [Formula: see text]Identification of rotundone backbone genes & precursor compounds from Piper nigrum.

Essential Oils from Spices Inhibit Cholinesterase Activity and Improve Behavioral Disorder in AlCl3 Induced Dementia.

The chemical compositions of essential oils (EOs) prepared from six spices including cinnamon, amomum tsao-ko, cardamom, amomum, black pepper and white pepper were analyzed by gas chromatography-mass spectrometry (GC/MS), which led to identify almost 200 volatile compounds. All EOs of spices showed cholinesterase inhibitory activity. Among them, pepper EO showed most potent acetylcholinesterase (AChE) inhibitory activity with IC50 values of 8.54 µg/mL (black pepper EO) and 5.02 µg/mL (white pepper EO). Molecular docking and in vitro validation suggested that 3-carene, α-pinene and ß-pinene with IC50 value of 1.73, 2.66, and 14.75 µg/mL, respectively, might be active constituents of spices oil in inhibiting AChE. Furthermore, amomum tsao-ko EO and amomum EO can improve behavioral disorder in dementia zebrafish induced by aluminum trichloride (AlCl3 ).

Non-Targeted Metabolite Profiling Reveals Host Metabolomic Reprogramming during the Interaction of Black Pepper with Phytophthora capsici.

Phytophthora capsici is one of the most destructive pathogens causing quick wilt (foot rot) disease in black pepper (Piper nigrum L.) to which no effective resistance has been defined. To better understand the P. nigrum-P. capsici pathosystem, we employed metabolomic approaches based on flow-infusion electrospray-high-resolution mass spectrometry. Changes in the leaf metabolome were assessed in infected and systemic tissues at 24 and 48 hpi. Principal Component Analysis of the derived data indicated that the infected leaves showed a rapid metabolic response by 24 hpi whereas the systemic leaves took 48 hpi to respond to the infection. The major sources of variations between infected leaf and systemic leaf were identified, and enrichment pathway analysis indicated, major shifts in amino acid, tricarboxylic acid cycle, nucleotide and vitamin B6 metabolism upon infection. Moreover, the individual metabolites involved in defensive phytohormone signalling were identified. RT-qPCR analysis of key salicylate and jasmonate biosynthetic genes indicated a transient reduction of expression at 24 hpi but this increased subsequently. Exogenous application of jasmonate and salicylate reduced P. capsici disease symptoms, but this effect was suppressed with the co-application of abscisic acid. The results are consistent with abscisic acid reprogramming, salicylate and jasmonate defences in infected leaves to facilitate the formation of disease. The augmentation of salicylate and jasmonate defences could represent an approach through which quick wilt disease could be controlled in black pepper.

The Effect of a Traditional Preparation Containing Piper nigrum L. and Bunium persicum (Boiss.) B.Fedtsch. on Immobility Stress-Induced Memory Loss in Mice.

OBJECTIVE: Alzheimer's disease is a progressive, age-related, and neurodegenerative disease characterized by mental decline. The exact cause of Alzheimer's disease is unclear, but cholinergic dysfunction, protein accumulation, and oxidative stress are among the most important hypotheses. The main purpose of our study was to investigate the effects of aqueous and hydroalcoholic extract combination of these two medicinal plants, black pepper and cumin (as a related formulation in traditional Persian medicine), on memory and learning of an immobilized stress animal model. METHODS: In this study, hydroalcoholic and aqueous extracts of cumin and black pepper fruits were prepared. Six groups of mice were treated orally for 2 weeks: control group, immobility stress, and stress-induced immobility mice received different doses of the hydroalcoholic extract (100 and 200 mg/kg) and aqueous extract (100 and 200 mg/kg). The shuttle box, novel object detection, and rotarod test were used to evaluate memory and learning. The activities of acetylcholinesterase, catalase (CAT), and superoxide dismutase (SOD) and the level of reduced glutathione (GSH) and malondialdehyde (MDA) were measured in the brain tissue. RESULTS: Immobility stress significantly reduced learning and motor coordination. Furthermore, MDA levels and acetylcholinesterase activity were significantly increased, while CAT and SOD activities were significantly reduced in the brain of immobility-induced stress mice. Other findings indicated that hydroalcoholic and aqueous extracts (100 and 200 mg/kg) of cumin and black pepper fruits have an improving effect on animal motor coordination and learning ability, GSH content, and CAT, SOD, and acetylcholinesterase enzyme function in comparison with stress groups (p < 0.05). CONCLUSION: The hydroalcoholic and aqueous extracts of cumin and black pepper fruits have protective effects against stress-induced memory deficit and oxidative stress and may have beneficial therapeutic effect in the treatment of neurodegenerative diseases.

Black pepper prevents anemia of inflammation by inhibiting hepcidin over-expression through BMP6-SMAD1/ IL6-STAT3 signaling pathway.

Hepcidin, a circulatory hepatic peptide hormone, is associated with systemic iron homeostasis. Inflammation leads to an increase in hepcidin expression, which dysregulates body iron level. The related disorder, anemia of inflammation, is the second most prevalent anemia-related disorder worldwide. In the present study, we conducted in vitro and in vivo studies to evaluate the effect of black pepper (BP) and its major bioactive alkaloid, piperine, on anemia of inflammation. The initial in vitro study using human hepatocyte cell line, HepG2, confirmed that among different black pepper extracts: methanol (BPME), ethanol (BPEE) and aqueous (BPAE), BPME to be most effective in downregulating transcription of hepcidin gene. Further, BPME and piperine significantly downregulated hepcidin protein expression at 200 µg/ml and 100 µM concentrations, respectively. In the next phase, BPME and piperine were found to significantly attenuate BMP-6 and IL-6 induced hepcidin overexpression by downregulating the increased level of pSMAD1 and pSTAT3 proteins, respectively. For in vivo study, we first subcutaneously injected male BALB/c mice with oil of turpentine, thrice within a period of two weeks, in order to enhance the expression of hepcidin. After that, the intraperitoneal administration of BPME and piperine at 70 and 25 mg/kg body weight, respectively, on alternate days for a period of another two weeks resulted in downregulation of hepcidin overexpression in diseased mice, as confirmed by RT-PCR and immunoblot analysis. The histopathology of liver tissue confirmed increased iron bioavailability in BPME and piperine treated animals. The molecular docking-based interaction studies demonstrated the binding potential of piperine with SMAD1 and STAT3 proteins. The binding patterns supported the proposed inhibition of hepcidin activating proteins. All together, these findings suggest black pepper as a therapeutic candidate for the treatment of anemia of inflammation.

Antioxidant, hepatoprotective and antifungal activities of black pepper (Piper nigrum L.) essential oil.

The essential oil extracted from the black Piper nigrum L. (BPEO) was analyzed for antioxidant, hepatoprotective and antifungal activities. BPEO is rich in total phenolics, total flavonoids and proanthocyanidins, and showed good free radicals and lipid peroxidation scavenging capacities. In a CCl4-induced liver injury mice model, the BPEO treated groups showed increases in the catalase (CAT), glutathione (GSH) and total superoxide dismutase (T-SOD) activities present in the liver and kidney, and reverses the CCl4-elevated total bilirubin (TBIL), glutamate pyruvate transaminase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AKP) and malondialdehyde (MDA) level, which were confirmed in further analyses of kidney tissue sections. BPEO can effectively inhibit the growth of Aspergillus flavus spoilage fungus in maize. Further analyses indicated that BPEO disrupt the permeability barrier of the cell membrane and lead to mitochondrial dysfunction in A. flavus. Therefore, the current study proved BPEO's potential as hepatoprotective products and natural food preservatives.

Secondary Metabolic Profile as a Tool for Distinction and Characterization of Cultivars of Black Pepper (Piper nigrum L.) Cultivated in Pará State, Brazil.

This study evaluated the chemical compositions of the leaves and fruits of eight black pepper cultivars cultivated in Pará State (Amazon, Brazil). Hydrodistillation and gas chromatography-mass spectrometry were employed to extract and analyze the volatile compounds, respectively. Sesquiterpene hydrocarbons were predominant (58.5-90.9%) in the cultivars "Cingapura", "Equador", "Guajarina", "Iaçará", and "Kottanadan", and "Bragantina", "Clonada", and "Uthirankota" displayed oxygenated sesquiterpenoids (50.6-75.0%). The multivariate statistical analysis applied using volatile composition grouped the samples into four groups: γ-Elemene, curzerene, and δ-elemene ("Equador"/"Guajarina", I); δ-elemene ("Iaçará"/"Kottanadan"/"Cingapura", II); elemol ("Clonada"/"Uthirankota", III) and α-muurolol, bicyclogermacrene, and cubebol ("Bragantina", IV). The major compounds in all fruit samples were monoterpene hydrocarbons such as α-pinene, ß-pinene, and limonene. Among the cultivar leaves, phenolics content (44.75-140.53 mg GAE·g-1 FW), the enzymatic activity of phenylalanine-ammonia lyase (20.19-57.22 µU·mL-1), and carotenoids (0.21-2.31 µg·mL-1) displayed significant variations. Due to black pepper's susceptibility to Fusarium infection, a molecular docking analysis was carried out on Fusarium protein targets using each cultivar's volatile components. F. oxysporum endoglucanase was identified as the preferential protein target of the compounds. These results can be used to identify chemical markers related to the susceptibility degree of black pepper cultivars to plant diseases prevalent in Pará State.

Degree of crosslinking in ß-cyclodextrin-based nanosponges and their effect on piperine encapsulation.

Piperine (PIP) is an alkaloid which is potent as a therapeutic agent. However, its applications are restricted by its poor water solubility. Nanosponges (NS) derived from polymers are versatile carriers for poor water-soluble substances. The aim of this work was to synthesize ß-cyclodextrin NS, by microwave-assisted fusion, for the encapsulation of PIP. Different formulations of NS were synthesized by varying the molar ratio of ß-cyclodextrin:diphenyl carbonate (ß-CD:DPC; 1:2, 1:6 and 1:10). NS specimens derived from 1:2, 1:6 and 1:10 ß-CD:DPC molar ratios exhibited degree of substitution values of 0.345, 0.629 and 0.878, respectively. The crystallinity of NS was enhanced by increasing diphenyl carbonate concentration. A high degree of crosslinking in the NS increased the loading efficiency due to increased surface area available for bioactive inclusion. This study demonstrated the feasibility of synthesizing NS derived from ß-cyclodextrin of high crystallinity for the encapsulation of PIP at high loading capacity.

A piperic acid CoA ligase produces a putative precursor of piperine, the pungent principle from black pepper fruits.

Black pepper (Piper nigrum L.) is known for its high content of piperine, a cinnamoyl amide derivative regarded as largely responsible for the pungent taste of this widely used spice. Despite its long history and worldwide use, the biosynthesis of piperine and related amides has been enigmatic up to now. In this report we describe a specific piperic acid CoA ligase from immature green fruits of P. nigrum. The corresponding enzyme was cloned and functionally expressed in E. coli. The recombinant enzyme displays a high specificity for piperic acid and does not accept the structurally related feruperic acid characterized by a similar C-2 extension of the general C6-C3 phenylpropanoid structure. The enzyme is also inactive with the standard set of hydroxycinnamic acids tested including caffeic acid, 4-coumaric acid, ferulic acid, and sinapic acid. Substrate specificity is corroborated by in silico modelling that suggests a perfect fit for the substrate piperic acid to the active site of the piperic acid CoA ligase. The CoA ligase gene shows its highest expression levels in immature green fruits, is also expressed in leaves and flowers, but not in roots. Virus-induced gene silencing provided some preliminary indications that the production of piperoyl-CoA is required for the biosynthesis of piperine in black pepper fruits.

Enantioselective Separation and Dissipation of Prothioconazole and Its Major Metabolite Prothioconazole-desthio Enantiomers in Tomato, Cucumber, and Pepper.

In this study, a simple and effective chiral analytical method was developed to monitor prothioconazole and prothioconazole-desthio at the enantiomeric level using supercritical fluid chromatography-tandem triple quadrupole mass spectrometry. The baseline enantioseparation for prothioconazole and prothioconazole-desthio was achieved within 2 min on a Chiralcel OD-3 column with CO2/0.2% acetic acid-5 mmol/L ammonium acetate 2-propanol (85:15, v/v) as the mobile phase at a flow rate of 1.5 mL/min and column temperature of 25 °C. The limit of quantitation for each enantiomer was 5 µg/kg, with a baseline resolution of >3.0. The results of enantioselective dissipation showed that R-(-)-prothioconazole was preferentially degraded in tomato, cucumber, and pepper under greenhouse conditions. S-(-)-prothioconazole-desthio was preferentially degraded in tomato and cucumber; however, R-(+)-prothioconazole-desthio was preferentially degraded in pepper. Results of this study may help to facilitate more accurate risk assessment of prothioconazole and its major metabolite in agricultural products.

The CaAP2/ERF064 Regulates Dual Functions in Pepper: Plant Cell Death and Resistance to Phytophthora capsici.

Phytophthora blight is one of the most destructive diseases of pepper (Capsicum annuum L.) globally. The APETALA2/Ethylene Responsive Factors (AP2/ERF) genes play a crucial role in plant response to biotic stresses but, to date, have not been studied in the context of Phytophthora resistance in pepper. Here, we documented potential roles for the pepper CaAP2/ERF064 gene in inducing cell death and conferring resistance to Phytophthora capsici (P. capsici) infection. Results revealed that the N-terminal, AP2 domain, and C-terminal of CaAP2/ERF064 protein is responsible for triggering cell death in Nicotiana benthamiana (N. benthamiana). Moreover, the transcription of CaAP2/ERF064 in plant is synergistically regulated by the Methyl-Jasmonate (MeJA) and ethephon (ET) signaling pathway. CaAP2/ERF064 was found to regulate the expression of CaBPR1, which is a pathogenesis-related (PR) gene of pepper. Furthermore, the silencing of CaAP2/ERF064 compromised the pepper plant resistance to P.capsici by reducing the transcript level of defense-related genes CaBPR1, CaPO2, and CaSAR82, while the ectopic expression of CaAP2/ERF064 in N. benthamiana plant elevated the expression level of NbPR1b and enhanced resistance to P.capsici. These results suggest that CaAP2/ERF064 could positively regulate the defense response against P. capsici by modulating the transcription of PR genes in the plant.

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.

Comprehensive evaluation of untargeted metabolomics data processing software in feature detection, quantification and discriminating marker selection.

Data analysis represents a key challenge for untargeted metabolomics studies and it commonly requires extensive processing of more than thousands of metabolite peaks included in raw high-resolution MS data. Although a number of software packages have been developed to facilitate untargeted data processing, they have not been comprehensively scrutinized in the capability of feature detection, quantification and marker selection using a well-defined benchmark sample set. In this study, we acquired a benchmark dataset from standard mixtures consisting of 1100 compounds with specified concentration ratios including 130 compounds with significant variation of concentrations. Five software evaluated here (MS-Dial, MZmine 2, XCMS, MarkerView, and Compound Discoverer) showed similar performance in detection of true features derived from compounds in the mixtures. However, significant differences between untargeted metabolomics software were observed in relative quantification of true features in the benchmark dataset. MZmine 2 outperformed the other software in terms of quantification accuracy and it reported the most true discriminating markers together with the fewest false markers. Furthermore, we assessed selection of discriminating markers by different software using both the benchmark dataset and a real-case metabolomics dataset to propose combined usage of two software for increasing confidence of biomarker identification. Our findings from comprehensive evaluation of untargeted metabolomics software would help guide future improvements of these widely used bioinformatics tools and enable users to properly interpret their metabolomics results.

Black pepper-based beverage induced appetite-suppressing effects without altering postprandial glycaemia, gut and thyroid hormones or gastrointestinal well-being: a randomized crossover study in healthy subjects.

Pleiotropic effects of spices on health, particularly on glucose metabolism and energy regulation, deserve further clinical investigation into their efficacy. The aim of the current study was to evaluate whether consumption of a black pepper-based beverage (BPB) preload containing 20 mg gallic acid equivalent (GAE) would exert any effect on postprandial glycaemia, appetite sensations, gut hormones, thyroid function, and gastrointestinal well-being after a white wheat bread (WWB) challenge meal containing 50 g available carbohydrates (CHO) compared to a control beverage. Sixteen healthy subjects (10 men; 6 women; 26 ± 0.9 years; BMI 22.93 ± 0.53 kg m-2) completed a randomized, crossover intervention study. The BPB's bioactive compounds were characterized using ultra high-performance liquid chromatography coupled to a quadrupole time-of-flight mass spectrometer with an electrospray ionization source (UHPLC-DAD-ESI-QTOF-MS). Nine compounds tentatively identified in BPB include: dihydroxybenzoic acid hexoside-pentoside, decaffeoyl-acteoside, cynaroside A, apigenin 6,8-di-C-hexoside, luteolin 6-C-hexoside-8-C-rhamnoside, apigenin 8-C-hexoside-C-deoxyhexoside, kaempferol 3-rhamnoside-4'-xyloside, apigenin 7-neohesperidoside, and apigenin-8-C-arabinopyranoside-2''-rhamnoside. Blood glucose and serum insulin responses, insulin sensitivity and ß-cell function were not affected during the acute intervention with BPB. Neither were effects on gastrointestinal well-being observed after BPB. However, BPB modulated overall acute appetite by lowering 'hunger', 'desire to eat', and 'prospective consumption', and increasing 'satiety' and 'fullness'. In contrast, there were no changes in gut (peptide tyrosine-tyrosine [PYY] and glucagon-like peptide-1 [GLP-1]) and thyroid (triiodothyronine [T3] and thyroxine [T4]) hormones after BPB compared to the control beverage. In conclusion, inclusion of BPB prior to the WWB challenge meal might be beneficial for appetite modulation, but we did not find supporting evidence in glycaemia, gut and thyroid hormones. Further studies are needed to elucidate the mechanisms of appetite-reducing pungent spices, such as 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.

Green synthesis of silver nanoparticles using Piper nigrum: tissue-specific bioaccumulation, histopathology, and oxidative stress responses in Indian major carp Labeo rohita.

The aim of the present investigation is to assess the sublethal toxicity of biologically synthesized silver nanoparticles (Ag NPs) in Indian major carp Labeo rohita. Ag NPs used in the study were synthesized by using AgNO3 with aqueous leaf extract of Piper nigrum. Median lethal concentration (LC50) of synthesized Ag NPs was determined for 96 h (25 µg/L); 2.5 µg/L (1/10th LC50) and 5 µg/L (1/5th LC50) were taken as sublethal concentrations to evaluate the toxicity for 35 days. The results of the TEM, SEM, and EDX analyses revealed that Ag NPs were considerably accumulated in the gill, liver, and kidney of fish at both concentrations (2.5 and 5 µg/L). Consequently, the activity of the antioxidant enzymes, SOD and CAT, was significantly (P < 0.05) decreased in the gill, liver, and kidney when compared to the control group during the study period. However, lipid peroxidase (LPO) activity in the gill, liver, and kidney was significantly (P < 0.05) increased, and the result concluded a possible sign of free radical-induced oxidative stress in Ag NP-exposed fish than the sham-exposed individuals. The histopathological study also confirmed the alterations such as degeneration of lamella, lifting of lamellar epithelium, hepatic necrosis, pyknotic nuclei, increased intracellular space, and shrinkage of glomerulus elicited by Ag NPs in the gill, liver, and kidney of Labeo rohita with two different concentrations. The findings of the present study revealed that green synthesis of Ag NPs from Piper nigrum at sublethal concentrations leads to accumulation of Ag, oxidative stress, and histopathological alterations in the target organs of the fish, Labeo rohita.

Secondary Metabolic Profiles of Two Cultivars of Piper nigrum (Black Pepper) Resulting from Infection by Fusarium solani f. sp. piperis.

Bragantina and Cingapura are the main black pepper (Piper nigrum L.) cultivars and the Pará state is the largest producer in Brazil with about 90% of national production, representing the third largest production in the world. The infection of Fusarium solani f. sp. piperis, the causal agent of Fusarium disease in black pepper, was monitored on the cultivars Bragantina (susceptible) and Cingapura (tolerant), during 45 days' post infection (dpi). Gas Chromatography-Mass spectrometry (GC-MS) analysis of the volatile concentrates of both cultivars showed that the Bragantina responded with the production of higher contents of α-bisabolol at 21 dpi and a decrease of elemol, mostly at 30 dpi; while Cingapura displayed an decrease of δ-elemene production, except at 15 dpi. The phenolic content determined by the Folin Ciocalteu method showed an increase in the leaves of plants inoculated at 7 dpi (Bragantina) and 7-15 dpi (Cingapura); in the roots, the infection caused a phenolic content decrease in Bragantina cultivar at 45 dpi and an increase in the Cingapura cultivar at 15, 30 and 45 dpi. High Performance Liquid Chromatography-Mass spectrometry (HPLC-MS) analysis of the root extracts showed a qualitative variation of alkamides during infection. The results indicated that there is a possible relationship between secondary metabolites and tolerance against phytopathogens.