Analysis of Piperaceae germplasm by HPLC and LCMS: a method for isolating and identifying unsaturated amides from Piper spp extracts

Green synthesis of Piper nigrum copper-based nanoparticles: in silico study and ADMET analysis to assess their antioxidant, antibacterial, and cytotoxic effects

Nanobiotechnology is a popular branch of science that is gaining interest among scientists and researchers as it allows for the green manufacturing of nanoparticles by employing plants as reducing agents. This method is safe, cheap, reproducible, and eco-friendly. In this study, the therapeutic property of Piper nigrum fruit was mixed with the antibacterial activity of metallic copper to produce copper nanoparticles. The synthesis of copper nanoparticles was indicated by a color change from brown to blue. Physical characterization of Piper nigrum copper nanoparticles (PN-CuNPs) was performed using UV-vis spectroscopy, FT-IR, SEM, EDX, XRD, and Zeta analyzer. PN-CuNPs exhibited potential antioxidant, antibacterial, and cytotoxic activities. PN-CuNPs have shown concentration-dependent, enhanced free radical scavenging activity, reaching maximum values of 92%, 90%, and 86% with DPPH, H2O2, and PMA tests, respectively. The antibacterial zone of inhibition of PN-CuNPs was the highest against Staphylococcus aureus (23 mm) and the lowest against Escherichia coli (10 mm). PN-CuNPs showed 80% in vitro cytotoxicity against MCF-7 breast cancer cell lines. Furthermore, more than 50 components of Piper nigrum extract were selected and subjected to in silico molecular docking using the C-Docker protocol in the binding pockets of glutathione reductase, E. coli DNA gyrase topoisomerase II, and epidermal growth factor receptor (EGFR) tyrosine to discover their druggability. Pipercyclobutanamide A (26), pipernigramide F (32), and pipernigramide G (33) scored the highest Gibbs free energy at 50.489, 51.9306, and 58.615 kcal/mol, respectively. The ADMET/TOPKAT analysis confirmed the favorable pharmacokinetics, pharmacodynamics, and toxicity profiles of the three promising compounds. The present in silico analysis helps us to understand the possible mechanisms behind the antioxidant, antibacterial, and cytotoxic activities of CuNPs and recommends them as implicit inhibitors of selected proteins.

Black Pepper (Piper nigrum) Alleviates Oxidative Stress, Exerts Potential Anti-Glycation and Anti-AChE Activity: A Multitargeting Neuroprotective Agent against Neurodegenerative Diseases

Neurodegenerative diseases (NDs) are a family of disorders that cause progressive structural and functional degeneration of neurons. Among all the organs in the body, the brain is the one that is the most affected by the production and accumulation of ROS. Various studies have shown that an increase in oxidative stress is a common pathophysiology for almost all NDs, which further affects various other pathways. The available drugs lack the wide spectrum necessary to confront these complexities altogether. Hence, a safe therapeutic approach to target multiple pathways is highly desirable. In the present study, the hexane and ethyl acetate extracts of Piper nigrum (black pepper), an important spice, were evaluated for their neuroprotective potential in hydrogen peroxide-induced oxidative stress in human neuroblastoma cells (SH-SY5Y). The extracts were also subjected to GC/MS to identify the important bioactives present. The extracts exhibited neuroprotection by significantly decreasing the oxidative stress and restoring the mitochondrial membrane potential in the cells. Additionally, the extracts displayed potent anti-glycation and significant anti-Aβ fibrilization activities. The extracts were competitive inhibitors of AChE. The multitarget neuroprotective mechanism displayed by Piper nigrum indicates it as a potential candidate in the treatment of NDs.

Comparative Quantification of the Phenolic Compounds, Piperine Content, and Total Polyphenols along with the Antioxidant Activities in the Piper trichostachyon and P. nigrum

India is the largest producer in the world of black pepper and it is the center of origin for Piper. The present study gives a comparative account of the chemical composition of the Piper nigrum and its wild putative parent the P. trichostachyon. Microextractions were performed and the quantification of six phenolic compounds (namely epicatechin, gallic acid, catechol, chlorogenic acid, caffeic acid, and catechin), piperine from leaves, petioles, and the fruits of both the species, were accomplished using the RP-UFLC system. The polyphenols (phenolic, flavonoid) and their antioxidant activities were also estimated. Among the six phenolic compounds studied, only three were detected and quantified. The polyphenol content correlating to the antioxidant activities was higher in the P. trichostachyon, whereas the piperine content was 108 times greater in the P. nigrum fruits. The Piper trichostachyon comparatively showed a higher content of polyphenols. The microextractions reduced the solvent consumption, the quantity of the plant material, and the amount of time used for the extraction. The first report on the TPC, TF, and the antioxidant activity of the P. trichostachyon has been described, and it also forms a scientific basis for its use in traditional medicine. The petioles of both species are good sources of phenolic compounds. A quantitative chemical analysis is a useful index in the identification and comparison of the species.

The terminal enzymatic step in piperine biosynthesis is co-localized with the product piperine in specialized cells of black pepper (Piper nigrum L.)

Piperine (1-piperoyl piperidine) is responsible for the pungent perception of dried black pepper (Piper nigrum) fruits and essentially contributes to the aromatic properties of this spice in combination with a blend of terpenoids. The final step in piperine biosynthesis involves piperine synthase (PS), which catalyzes the reaction of piperoyl CoA and piperidine to the biologically active and pungent amide. Nevertheless, experimental data on the cellular localization of piperine and the complete biosynthetic pathway are missing. Not only co-localization of enzymes and products, but also potential transport of piperamides to the sink organs is a possible alternative. This work, which includes purification of the native enzyme, immunolocalization, laser microdissection, fluorescence microscopy, and electron microscopy combined with liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS), provides experimental evidence that piperine and PS are co-localized in specialized cells of the black pepper fruit perisperm. PS accumulates during early stages of fruit development and its level declines before the fruits are fully mature. The product piperine is co-localized to PS and can be monitored at the cellular level by its strong bluish fluorescence. Rising piperine levels during fruit maturation are consistent with the increasing numbers of fluorescent cells within the perisperm. Signal intensities of individual laser-dissected cells when monitored by LC-ESI-MS/MS indicate molar concentrations of this alkaloid. Significant levels of piperine and additional piperamides were also detected in cells distributed in the cortex of black pepper roots. In summary, the data provide comprehensive experimental evidence of and insights into cell-specific biosynthesis and storage of piperidine alkaloids, specific and characteristic for the Piperaceae. By a combination of fluorescence microscopy and LC-MS/MS analysis we localized the major piperidine alkaloids to specific cells of the fruit perisperm and the root cortex. Immunolocalization of native piperine and piperamide synthases shows that enzymes are co-localized with high concentrations of products in these idioblasts.

The use of black pepper (Piper guineense) as an ecofriendly antimicrobial agent to fight foodborne microorganisms

Consumers demand clean-label food products, necessitating the search for new, natural antimicrobials to meet this demand while ensuring food safety. This review aimed at investigating the antimicrobial properties of black pepper (Piper guineense) against foodborne microorganisms. The existence of foodborne illness, food spoilage, food waste, the resulting negative economic impact of these issues, and consumer interests have all pushed the food industry to find alternative, safe, and natural antimicrobials to be used in foods and beverages. Consumers have also influenced the demand for novel antimicrobials due to the perceived association of current synthetic preservatives with diseases and adverse effects on children. They also have a desire for clean-label products. These combined concerns have prompted researchers at investigating plant extracts as potential sources for antimicrobials. Plants possess many antimicrobial properties; therefore, evaluating these plant extracts as a natural source of antimicrobials can lead to a preventative control method in reducing foodborne illness and food spoilage, inclusively meeting consumer needs. In most regions, P. guineense is commonly utilized due to its potent and effective medicinal properties against foodborne microorganisms.

Natural Bioactive Cinnamoyltyramine Alkylamides and Co-Metabolites

Natural products are a vital source for agriculture, medicine, cosmetic and other fields. Among them alkylamides are a broad and expanding group found in at least 33 plant families. Frequently, they possess a simple carbon skeleton architecture but show broad structural variability and important properties such as immunomodulatory, antimicrobial, antiviral, larvicidal, insecticidal and antioxidant properties, amongst others. Despite to these several and promising biological activities, up to today, only two reviews have been published on natural alkylamides. One focuses on their potential pharmacology application and their distribution in the plant kingdom and the other one on the bioactive alkylamides specifically found in Annona spp. The present review is focused on the plant bioactive cinnamoyltyramine alkylamides, which are subject of several works reported in the literature. Furthermore, the co-metabolites isolated from the same natural sources and their biological activities are also reported.

Antidepressant, anxiolytic, antipyretic, and thrombolytic profiling of methanol extract of the aerial part of Piper nigrum: In vivo, in vitro, and in silico approaches

Piper nigrum L. also called black pepper is popular for its numerous uses. The present research is designed to investigate the pharmacological potential of methanol extract of Piper nigrum (MEPN). The antidepressant investigation was performed by using both in vivo forced swimming test (FST) and tail suspension test (TST) methods while the anxiolytic research by hole-board test (HBT) method. Again, the antipyretic analysis was conducted through yeast-induced pyrexia method, whereas clot lysis activity was employed by the thrombolytic method. Furthermore, in silico studies followed by molecular docking analysis of several secondary metabolites, pass prediction, and ADME/T were evaluated with AutoDock Vina, Discovery Studio 2020, UCSF Chimera software PASS online, and ADME/T online tools. The plant extract demonstrated dose-dependent potentiality in antidepressant, anxiolytic, antipyretic, and thrombolytic activities. Induction of MEPN produced a significant (p < .5, p < .001) increase of mobility in FST and TST, and increased the head dipping and decreased the latency of time (p < .01, p < .001) in HBT. MEPN 400 (mg/kg; b.w.; p.o.) lowered the rectal temperature of yeast-induced pyrexia substantially (p < .001). Besides, MEPN produced promising (p < .001) clot lysis activity. In the computational approach, among all the proteins, a docking score was found ranging from -1.0 to -7.90 kcal/mol. Besides, all the compounds were found safe in ADME/T study. The results of our scientific research validate the suitability of this plant as an alternative source of novel therapeutics.

Metabolic Signatures of 10 Processed and Non-processed Meat Products after In Vitro Digestion

The intake of processed meat has been associated with several adverse health outcomes such as type II diabetes and cancer; however, the mechanisms are not fully understood. A better knowledge of the metabolite profiles of different processed and non-processed meat products from this heterogeneous food group could help in elucidating the mechanisms associated with these health effects. Thirty-three different commercial samples of ten processed and non-processed meat products were digested in triplicate with a standardized static in vitro digestion method in order to mimic profiles of small molecules formed in the gut upon digestion. A metabolomics approach based on high-resolution mass spectrometry was used to identify metabolite profiles specific to the various meat products. Processed meat products showed metabolite profiles clearly distinct from those of non-processed meat. Several discriminant features related to either specific ingredients or processing methods were identified. Those were, in particular, syringol compounds deposited in meat during smoking, biogenic amines formed during meat fermentation and piperine and related compounds characteristic of pepper used as an ingredient. These metabolites, characteristic of specific processed meat products, might be used as potential biomarkers of intake for these foods. They may also help in understanding the mechanisms linking processed meat intake and adverse health outcomes such as cancer.

The Effects of Houttuynia cordata Thunb and Piper ribesioides Wall Extracts on Breast Carcinoma Cell Proliferation, Migration, Invasion and Apoptosis

Houttuynia cordata Thunb. (HCT) and Piper ribesioides Wall. (PR) are common herbs that are widely distributed throughout East Asia and possess various biological properties including anti-cancer effects. However, in breast cancer, their mechanisms responsible for anti-carcinogenic effects have not been clarified yet. In this study, the inhibitory effects of HCT and PR ethanolic extracts on breast cancer cell proliferation, migration, invasion and apoptosis were examined. In MCF-7 and MDA-MB-231 cells, HCT and PR extracts at low concentrations can inhibit colony formation and induce G1 cell cycle arrest by downregulating cyclinD1 and CDK4 expression. Additionally, HCT and PR extracts also decreased the migration and invasion of both breast cancer cell lines through inhibition of MMP-2 and MMP-9 secretion. Moreover, the induction of apoptosis was observed in breast cancer cells treated with high concentrations of HCT and PR extracts. Not only stimulated caspases activity, but HCT and PR extracts also upregulated the expression of caspases and pro-apoptotic Bcl-2 family proteins in breast cancer cells. Altogether, these findings provide the rationale to further investigate the potential actions of HCT and PR extracts against breast cancer in vivo.

Antimicrobial and Synergistic Effects of Commercial Piperine and Piperlongumine in Combination with Conventional Antimicrobials

Microbial resistance to currently available antibiotics is a public health problem in the fight against infectious diseases. Most antibiotics are characterized by numerous side effects that may be harmful to normal body cells. To improve the efficacy of these antibiotics and to find an alternative way to minimize the adverse effects associated with most conventional antibiotics, piperine and piperlongumine were screened in combination with conventional rifampicin, tetracycline, and itraconazole to evaluate their synergistic, additive, or antagonistic interactions against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. The fractional inhibitory concentration index was used to estimate the synergistic effects of various combination ratios of the piperamides and antibiotics against the bacterial and fungal strains. Both piperine and piperlongumine showed synergistic effects against S. aureus when combined at various ratios with rifampicin. Synergistic interaction was also observed with piperine in combination with tetracycline against S. aureus, while antagonistic interaction was recorded for piperlongumine and tetracycline against S. aureus. All the piperamide/antibacterial combinations tested against P. aeruginosa showed antagonistic effects, with the exception of piperine and rifampicin, which recorded synergistic interaction at a ratio of 9:1 rifampicin/piperine. No synergistic interaction was observed when the commercial compounds were combined with itraconazole and tested against C. albicans. The results showed that piperine and piperlongumine are capable of improving the effectiveness of rifampicin and tetracycline. Dosage combinations of these bioactive compounds with the antibiotics used may be a better option for the treatment of bacterial infections that aims to minimize the adverse effects associated with the use of these conventional antibacterial drugs.

An ethnobotanical survey and antifungal activity of Piper guineense used for the treatment of fungal infections in West-African traditional medicine

ETHNOBOTANICAL RELEVANCE

Piper guineense occurs commonly in West Africa where it is used for fungal infections instead of the costly and not always accessible conventional antifungals. Fungal, yeast-based diseases are common in West-Africa especially among those living with HIV/AIDS, and thus this study was performed in Imo state, South-Eastern Nigeria, where P. guineense is predominantly used for the treatment of fungal diseases, such as skin rashes, oral thrush and vaginosis.

AIM OF STUDY

The scarce number of previous studies on the documentation of the traditional uses of P. guineense extracts for the treatment of fungal infections in Nigeria prompted this survey. The investigation focused on how traditional healers recognize and diagnose fungal infections, how P. guineense is collected, on the various parts used for the treatments, methods of preparations, administrations and treatments. In addition, an in vitro antifungal screening of P. guineense fruit and leaf extracts of various polarities, and piperine and piperlongumine, representing the main constituents in these extracts, were performed.

METHODS

A house to house ethnobotanical survey was conducted using questionnaires. Twenty traditional medical practitioners (TMP) and herb sellers from ten villages were interviewed. Four human pathogenic strains of yeast and Cryptococcus neoformans, a yeast-like basidiomycete causing meningitis in immunocompromised individuals, were used for the antifungal screening.

RESULTS

The traditional medical practitioners (TMP) and herb sellers explained that the leaves and fruits are the most commonly used plant parts for the treatments. The oral intake of the extracts in locally produced bamboo alcohol (Kai-kai) is the most common method of administration. In accordance with these recorded traditional uses, we found that extracts of P. guineense were growth inhibitory against the fungal strains with MIC values ranging from 39 to 2500 µg/mL. The lowest MIC value of 39 µg/mL was recorded for a methanol fruit extract against Candida albicans, C. glabrata and C. tropicalis. In addition, ethanol and hexane fruit extracts were effective against the growth of C. albicans and C. glabrata, respectively, with a MIC of 78 µg/mL. Piperlongumine and piperine were active against C. albicans with MIC values of 39 and 78 µg/mL respectively.

CONCLUSION

P. guineense fruit and leaf extracts, as well as their piperamide alkaloid constituents piperine and piperlongumine, have interesting antifungal properties and could have potential as new antifungal scaffolds. Our results warrant further in-depth investigations to isolate and characterize piperamide alkaloids and other compounds responsible for the antifungal activity in the extracts.

Alkaloid-Rich Crude Extracts, Fractions and Piperamide Alkaloids of Piper guineense Possess Promising Antibacterial Effects

Piper guineense is a food and medicinal plant commonly used to treat infectious diseases in West-African traditional medicine. In a bid to identify new antibacterial compounds due to bacterial resistance to antibiotics, twelve extracts of P. guineense fruits and leaves, obtained by sequential extraction, as well as the piperine and piperlongumine commercial compounds were evaluated for antibacterial activity against human pathogenic bacteria. HPLC-DAD and UHPLC/Q-TOF MS analysis were conducted to characterize and identify the compounds present in the extracts with promising antibacterial activity. The extracts, with the exception of the hot water decoctions and macerations, contained piperamide alkaloids as their main constituents. Piperine, dihydropiperine, piperylin, dihydropiperylin or piperlonguminine, dihydropiperlonguminine, wisanine, dihydrowisanine and derivatives of piperine and piperidine were identified in a hexane extract of the leaf. In addition, some new piperamide alkaloids were identified, such as a piperine and a piperidine alkaloid derivative and two unknown piperamide alkaloids. To the best of our knowledge, there are no piperamides reported in the literature with similar UVλ absorption maxima and masses. A piperamide alkaloid-rich hexane leaf extract recorded the lowest MIC of 19 µg/mL against Sarcina sp. and gave promising growth inhibitory effects against S. aureus and E. aerogenes as well, inhibiting the growth of both bacteria with a MIC of 78 µg/mL. Moreover, this is the first report of the antibacterial activity of P. guineense extracts against Sarcina sp. and E. aerogenes. Marked growth inhibition was also obtained for chloroform extracts of the leaves and fruits against P. aeruginosa with a MIC value of 78 µg/mL. Piperine and piperlongumine were active against E. aerogenes, S. aureus, E. coli, S. enterica, P. mirabilis and B. cereus with MIC values ranging from 39–1250 µg/mL. Notably, the water extracts, which were almost devoid of piperamide alkaloids, were not active against the bacterial strains. Our results demonstrate that P. guineense contains antibacterial alkaloids that could be relevant for the discovery of new natural antibiotics.

Optimization of Thin-layer Chromatography and High-Performance Liquid Chromatographic Method for Piper guineense Extracts

In this study, a thin-layer chromatography (TLC) and a high performance liquid chromatographic (HPLC) methods were developed for the chemical profiling, qualitative and quantitative analysis of P. guineense extracts. To obtain a chromatogram with satisfactory resolution and favorable retention time, DryLab software was used to simulate and optimize a HPLC method for the analysis of P. guineense extracts. The aim was to achieve the best possible overall resolution while keeping the analysis time and solvent consumption to a minimum. With the optimized method, a total of 16 main components in the extract were separated with favorable resolution. Optimal TLC conditions were also developed using solvents of various solvent strength (ST) and solvent selectivity (PS) values. The mobile phase composition was systematically tested using various proportions of solvents differing in ST and PS values under the same experimental conditions. During the optimization, emphasis was set on achieving the best possible overall separation of the main components of the extracts (for example piperine). In addition, the effects of the developing chamber was tested using three types of unsaturated chamber conditions: horizontal chamber in sandwich configuration, horizontal chamber in non-sandwich configuration and twin-trough vertical chamber. During the study, a TLC method was developed, and the best mobile-phase composition giving favorable resolution of the bands was toluene: ethyl acetate (PS 6-4 corresponding to 60:40 % v/v). The developing chamber conditions did not affect the TLC separation efficacy in the analysis of P. guineense extracts. The HPLC method was applied to determine the percentage content of piperine in P. guineense. The piperine content was 0.43 % w/w, linearity (0.997), interday precision (% relative standard deviation (RSD), 1.6), intraday precision (% RSD, 2.7 – 5.9), recovery (98.4%), limit of detection (0.001 μg /mL) and limit of quantification (0.003 μg /mL).

A Dynamic Survival Detection and Analysis System for Mosquito Larvae Viability in Drug Assays

Bioinformatics studies have emerged in the domain of larval behavior analysis in recent years. A dynamic survival detection and analysis system for automatically monitoring a large amount of mosquito larvae in bioassays with multiwell plates by acquiring and processing videos is proposed in this article. In our system, equipment is designed for acquiring the video of the mosquito larvae in several multiwell plates simultaneously by a camera, and a video analysis module is developed for detecting the survival states of larvae in each well in real time. Also, a novel model and a new image registration algorithm are proposed to accurately obtain the survival state by analyzing the larval motion activities and the weights of larvae in each well. In our experiments, several spinosad bioassays against 2-instar Aedes aegypti with 96-well plates are used to evaluate the proposed system, and the accuracy of the larval survival state in our system is more than 85%. Moreover, this investigation has indicated that the developed system not only can be used in the mosquito larval bioassays but also can be suitable to detect and analyze the behaviors of large amount of other larvae.

Piperine and Its Various Physicochemical and Biological Aspects: A Review

Piper nigrumL. is examined as the king of species worldwide by virtue of its principle piperine. In Ayurveda, since from the ancient times, it is known as “Yogvahi”. It is one of the important alkaloids of Pepper fruits (Family Piperaceae) and has been found to have numerous medicinal properties such as antioxidant, antiplatelet, anti-inflammatory, antihypertensive, hepatoprotective, antithyroid, antitumor, antiasthmatic activity and also have significant role as fertility enhancer. The present review discusses the biosynthetic pathway, extraction process, chemistry and various analytical methods of piperine. It also describes the structural modification of piperine and its various effects on biological system. The utility of piperine as a bioenhancer for certain antibacterial- antibiotics and a potent inhibitor of drug metabolism are also discussed. Thus, review provides knowledgeable erudition on the piperine which paves way for further work.

Piper nigrum ethanolic extract rich in piperamides causes ROS overproduction, oxidative damage in DNA leading to cell cycle arrest and apoptosis in cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Ayurvedic and Chinese traditional medicine and tribal people use herbal preparations containing Piper nigrum fruits for the treatment of many health disorders like inflammation, fever, asthma and cancer. In Brazil, traditional maroon culture associates the spice Piper nigrum to health recovery and inflammation attenuation.

AIMS OF THE STUDY

The aim of the current work was to evaluate the relationship between reactive oxygen species (ROS) overproduction, DNA fragmentation, cell cycle arrest and apoptosis induced by Piper nigrum ethanolic extract and its antitumor activity.

METHODS

The plant was macerated in ethanol. Extract constitution was assessed by TLC, UV-vis and ESI-IT-MS/MS spectrometry. The cytotoxicity, proliferation and intracellular ROS generation was evaluated in MCF-7 cells. DNA damage effects were evaluated through intercalation into CT-DNA, plasmid DNA cleavage and oxidative damage in CT-DNA. Tumor growth inhibition, survival time increase, apoptosis, cell cycle arrest and oxidative stress were assessed in Ehrlich ascites carcinoma-bearing mice.

RESULTS

Extraction yielded 64mg/g (36% piperine and 4.2% piperyline). Treatments caused DNA damage and reduced cell viability (EC50=27.1±2.0 and 80.5±6.6µg/ml in MCF-7 and HT-29 cells, respectively), inhibiting cell proliferation by 57% and increased ROS generation in MCF-7 cells (65%). Ehrlich carcinoma was inhibited by the extract, which caused reduction of tumor growth (60%), elevated survival time (76%), cell cycle arrest and induced apoptosis. The treatment with extract increased Bax and p53 and inhibited Bcl-xL and cyclin A expression. It also induced an oxidative stress in vivo verified as enhanced lipid peroxidation and carbonyl proteins content and increased activities of glutathione reductase, superoxide dismutase and catalase. GSH concentration was decreased in tumor tissue from mice.

CONCLUSION

The ethanolic extract has cytotoxic and antiproliferative effect on MCF-7 cells and antitumor effect in vivo probably due to ROS overproduction that induced oxidative stress affecting key proteins involved in cell cycle arrest at G1/S and triggering apoptosis. Finally, the overall data from this study are well in line with the traditional claims for the antitumor effect of Piper nigrum fruits.

Anxiolytic and antidepressant profile of the methanolic extract of Piper nigrum fruits in beta-amyloid (1-42) rat model of Alzheimer's disease

Background

Piper nigrum L. (Piperaceae) is employed in traditional medicine of many countries as analgesic, antiinflammatory, anticonvulsant, antioxidant, antidepressant and cognitive-enhancing agent. This study was undertaken in order to evaluate the possible anxiolytic, antidepressant and antioxidant properties of the methanolic extract of Piper nigrum fruits in beta-amyloid (1–42) rat model of Alzheimer’s disease.

Methods

The anxiolytic- and antidepressant-like effects of the methanolic extract were studied by means of in vivo (elevated plus-maze and forced swimming tests) approaches. Also, the antioxidant activity in the amygdala was assessed using superoxide dismutase, glutathione peroxidase and catalase specific activities, the total content of the reduced glutathione, protein carbonyl and malondialdehyde levels. Statistical analyses were performed using one-way analysis of variance (ANOVA). Significant differences were determined by Tukey’s post hoc test. F values for which p < 0.05 were regarded as statistically significant. Pearson’s correlation coefficient and regression analysis were used in order to evaluate the connection between behavioral measures, the antioxidant defence and lipid peroxidation.

Results

The beta-amyloid (1–42)-treated rats exhibited the following: decrease of the exploratory activity, the percentage of the time spent and the number of entries in the open arm within elevated plus-maze test and decrease of swimming time and increase of immobility time within forced swimming test. Administration of the methanolic extract significantly exhibited anxiolytic- and antidepressant-like effects and also antioxidant potential.

Conclusions

Taken together, our results suggest that the methanolic extract ameliorates beta-amyloid (1–42)-induced anxiety and depression by attenuation of the oxidative stress in the rat amygdala.

Characterization of phytochemicals and evaluation of anti-cancer potential of Blumea eriantha DC

The aim of the present study was to evaluate the in vitro anti-cancer and anti-oxidant potential of methanol extract of Blumea eriantha as well as its phytochemical characterization. The in vitro cytotoxic and antiproliferative activities of B. eriantha methanolic extract of leaves were evaluated using MTT assay on HeLa and B16F10 cell lines, and wound scratch and colony formation assays on B16F10 cell lines. The expressions of p53 and Bcl-2 genes were also determined by reverse transcriptase-polymerase chain reaction to establish apoptosis. Isolation and identification of chemical constituents were carried out by various chromatographic and spectroscopic analytical techniques including HPTLC and LC-MS. The methanol extract of the leaves of B. eriantha showed potent in vitro antioxidant and anticancer properties. Moreover, the extract showed significant loss of wound healing, thus suggesting that it could prevent a possible metastasis. Hence, B. eriantha could be explored as a potential anticancer plant with antimetastatic properties.

Methanolic extract of Piper nigrum fruits improves memory impairment by decreasing brain oxidative stress in amyloid beta(1-42) rat model of Alzheimer's disease

The present study analyzed the possible memory-enhancing and antioxidant proprieties of the methanolic extract of Piper nigrum L. fruits (50 and 100 mg/kg, orally, for 21 days) in amyloid beta(1-42) rat model of Alzheimer's disease. The memory-enhancing effects of the plant extract were studied by means of in vivo (Y-maze and radial arm-maze tasks) approaches. Also, the antioxidant activity in the hippocampus was assessed using superoxide dismutase-, catalase-, glutathione peroxidase-specific activities and the total content of reduced glutathione, malondialdehyde, and protein carbonyl levels. The amyloid beta(1-42)-treated rats exhibited the following: decrease of spontaneous alternations percentage within Y-maze task and increase of working memory and reference memory errors within radial arm-maze task. Administration of the plant extract significantly improved memory performance and exhibited antioxidant potential. Our results suggest that the plant extract ameliorates amyloid beta(1-42)-induced spatial memory impairment by attenuation of the oxidative stress in the rat hippocampus.

Compound Specific Extraction of Camptothecin from Nothapodytes nimmoniana and Piperine from Piper nigrum Using Accelerated Solvent Extractor

Effects of varying temperatures with constant pressure of solvent on extraction efficiency of two chemically different alkaloids were studied. Camptothecin (CPT) from stem of Nothapodytes nimmoniana (Grah.) Mabb. and piperine from the fruits of Piper nigrum L. were extracted using Accelerated Solvent Extractor (ASE). Three cycles of extraction for a particular sample cell at a given temperature assured complete extraction. CPT and piperine were determined and quantified by using a simple and efficient UFLC-PDA (245 and 343 nm) method. Temperature increased efficiency of extraction to yield higher amount of CPT, whereas temperature had diminutive effect on yield of piperine. Maximum yield for CPT was achieved at 80°C and for piperine at 40°C. Thus, the study determines compound specific extraction of CPT from N. nimmoniana and piperine from P. nigrum using ASE method. The present study indicates the use of this method for simple, fast, and accurate extraction of the compound of interest.

Occurrence of piperidine alkaloids in Piper species collected in different areas

A simple and convenient method was established for simultaneous quantitative determination of piperine and piperlonguminine in dried fruits of Piper longum and allied plants. The average content of piperine in P. longum (18.26 mg/g, range 12.05-33.23 mg/g) was about one half that of P. nigrum (40.09 mg/g, range 29.57-54.23 mg/g), but the content of piperlonguminine in P. longum was in the range of 0.42-1.82 mg/g, and the average content of piperlonguminne (0.91 mg/g) was about seven times higher than that in P. nigrum (0.13 mg/g). A sample of P. longum from Vietnam and a sample of P. retrofractum collected in Ishigaki, Japan, showed high contents of piperine and piperlonguminine. On the other hand, a sample of P. betle collected in Taiwan showed low content of piperine, and piperlonguminine was not detected.

Development and validation of a micellar electrokinetic chromatography method for quantitative determination of butenolides in Piper malacophyllum (C. Presl) C. DC

INTRODUCTION

A large number of natural and synthetic compounds having butenolides as a core unit have been described and many of them display a wide range of biological activities. Butenolides from P. malacophyllum have presented potential antifungal activities but no specific, fast, and precise method has been developed for their determination.

OBJECTIVE

To develop a methodology based on micellar electrokinetic chromatography to determine butenolides in Piper species.

METHODOLOGY

The extracts were analysed in an uncoated fused-silica capillaries and for the micellar system 20 mmol/L SDS, 20% (v/v) acetonitrile (ACN) and 10 mmol/L STB aqueous buffer at pH 9.2 were used. The method was validated for precision, linearity, limit of detection (LOD) and limit of quantitation (LOQ) and the standard deviations were determined from the standard errors estimated by the regression line.

RESULTS

A micellar electrokinetic chromatography (MEKC) method for determination of butenolides in extracts gave full resolution for 1 and 2. The analytical curve in the range 10.0-50.0 µg/mL (r(2) = 0.999) provided LOD and LOQ for 1 and 2 of 2.1/6.3 and 1.1/3.5 µg/mL, respectively. The RSD for migration times were 0.12 and 1.0% for peak area ratios with 100.0 ± 1.4% of recovery.

CONCLUSIONS

A novel high-performance MEKC method developed for the analysis of butenolides 1 and 2 in leaf extracts of P. malacophyllum allowed their quantitative determined within an analysis time shorter than 5 min and the results indicated CE to be a feasible analytical technique for the quantitative determination of butenolides in Piper extracts.

Pellitorine, a potential anti-cancer lead compound against HL6 and MCT-7 cell lines and microbial transformation of piperine from Piper Nigrum

Pellitorine (1), which was isolated from the roots of Piper nigrum, showed strong cytotoxic activities against HL60 and MCT-7 cell lines. Microbial transformation of piperine (2) gave a new compound 5-[3,4-(methylenedioxy)phenyl]-pent-2-ene piperidine (3). Two other alkaloids were also found from Piper nigrum. They are (E)-1-[3’,4’-(methylenedioxy)cinnamoyl]piperidine (4) and 2,4-tetradecadienoic acid isobutyl amide (5). These compounds were isolated using chromatographic methods and their structures were elucidated using MS, IR and NMR techniques.

Alkaloids from Piper sarmentosum and Piper nigrum

Detailed chemical studies on the roots of Piper sarmentosum and Piper nigrum have resulted in several alkaloids. The roots of P. sarmentosum gave a new aromatic compound, 1-nitrosoimino-2,4,5-trimethoxybenzene (1). Piper nigrum roots gave pellitorine (2), (E)-1-[3',4'-(methylenedioxy)cinnamoyl]piperidine (3), 2,4-tetradecadienoic acid isobutyl amide (4), piperine (5), sylvamide (6), cepharadione A (7), piperolactam D (8) and paprazine (9). Structural elucidation of these compounds was achieved through NMR and MS techniques. Cytotoxic activity screening of the plant extracts indicated some activity.

Analysis by HPLC and LC/MS of pungent piperamides in commercial black, white, green, and red whole and ground peppercorns

Pepper plants accumulate pungent bioactive alkaloids called piperamides. To facilitate studies in this area, high-performance liquid chromatography (HPLC) and liquid chromatography/mass spectrometry methods were developed and used to measure the following piperamides in 10 commercial whole (peppercorns) and in 10 ground, black, white, green, and red peppers: piperanine, piperdardine, piperine, piperlonguminine, and piperettine. Structural identification of individual compounds in extracts was performed by associating the HPLC peak of each compound with the corresponding mass spectrum. The piperanine content of the peppers (in mg/g piperine equivalents) ranged from 0.3 for the ground white pepper to 1.4 in black peppercorns. The corresponding range for piperdardine was from 0.0 for seven samples to 1.8 in black peppercorns; for four isomeric piperines, from 0.7 for red to 129 in green peppercorns; for piperlonguminine, from 0.0 in red peppercorns to 1.0 in black peppercorns; and for piperyline, from 0.9 in ground black pepper to 5.9 for red peppercorn. Four well-separated stereoisomeric forms of piperettine with the same molecular weight were present in 19 peppers. The sums of the piperamides ranged from 6.6 for red to 153 for green peppercorns. In contrast to large differences in absolute concentrations among the peppers, the ratios of piperines to total piperamide were quite narrow, ranging from 0.76 for black to 0.90 for white peppercorns, with an average value of 0.84 +/- 0.04 ( n = 19). Thus, on average, the total piperamide content of the peppers consists of 84% piperines and 16% other piperamides. These results demonstrate the utility of the described extraction and analytical methods used to determine the wide-ranging individual and total piperamide contents of widely consumed peppers.

Kinetics of light-induced cis-trans isomerization of four piperines and their levels in ground black peppers as determined by HPLC and LC/MS

The pungent compounds piperine and isomers thereof, secondary metabolites present in black and white pepper fruit, undergo light-induced isomerizations. To facilitate studies in this area, an HPLC method has been developed for analysis and isolation of the following four possible piperine-derived photoinduced isomers: piperine, isopiperine, chavicine, and isochavicine. The limits of detection (LOD) estimated from calibration plots were approximately 15-30 ng for each isomer. Reproducibilities of the analyses were excellent, and recoveries of spiked samples were as follows (average +/- SD; n = 3): chavicine, 98.4 +/- 2.1%; isopiperine, 96.2 +/- 3.2%; piperine, 104 +/- 3.8%; isochavicine, 98.9 +/- 3.0%. To determine the kinetics of these isomerizations, fluorescent light, sunlight, and UV radiation at 254 nm was used to induce cis-trans geometric isomerization as a function of light intensities and time of exposure determined with the aid of high-performance liquid chromatography (HPLC) and liquid chromatography with diode array UV detection-mass spectrometry (LC-DAD/MS). HPLC was also used to determine the distribution of the isomers in four commercial ground black pepper products used as spices in culinary practice. Isomerization increased with light intensities and time of exposure and leveled off at the so-called photostationary phases. The piperine levels of the four products were quite similar, ranging (in wt %) from 10.17 to 11.68. The amounts of the other three isomers ranged from 0.01 to 0.07 of the total for chavicine; from 0.15 to 0.23 for isopiperine; and from 0.37 to 0.42 for isochavicine. The results establish the utility of the HPLC method for simultaneous analysis of the four isomers both in pure form and in black pepper extracts. The dietary significance of the results is discussed.

Rapid structural determination of amides in Piper longum by high-performance liquid chromatography combined with ion trap mass spectrometry

A reversed-phase liquid chromatography/tandem multistage mass spectrometry (MS/MS) method was developed for the characterization of amides from the extracts of Piper longum. The characteristic fragmentations of the amides found in P. longum showed diagnostic structural information. Extracted ion chromatography (EIC) and constant neutral losses were used to guide the search for the amides of interest. Amides of known structures that contain four subtypes of amides were rapidly determined, and novel amides were also identified for this plant. Forty-two amides were rapidly identified, of which 22 were found in this plant for the first time and 9 were new compounds. The method is convenient and sensitive, especially for minor components in the unpurified, complex mixture; the structures of unknown constituents could be determined, in the absence of authentic sample, by comparison of the fragmentation patterns with those of homologous compounds.

Gene expression profiles of Drosophila melanogaster exposed to an insecticidal extract of Piper nigrum

Black pepper, Piper nigrum L. (Piperaceae), has insecticidal properties and could potentially be utilized as an alternative to synthetic insecticides. Piperine extracted from P. nigrum has a biphasic effect upon cytochrome P450 monooxygenase activity with an initial suppression followed by induction. In this study, an ethyl acetate extract of P. nigrum seeds was tested for insecticidal activity toward adult Musca domestica and Drosophila melanogaster. The effect of this same P. nigrum extract upon differential gene expression in D. melanogaster was investigated using cDNA microarray analysis of 7380 genes. Treatment of D. melanogaster with P. nigrum extract led to a greater than 2-fold upregulation of transcription of the cytochrome P450 phase I metabolism genes Cyp 6a8, Cyp 9b2, and Cyp 12d1 as well as the glutathione-S-transferase phase II metabolism gene Gst-S1. These data suggests a complex effect of P. nigrum upon toxin metabolism.