Fruits Of Piper Longum Research Articles

Quantitative determination of chemical constituents of Piper spp. using UPLC–ESI–MS/MS

Species of the genus Piper are important medicinal plants of high commercial and economic importance have been used extensively as an individual plant part in various systems of medicine. To provide chemical information for differential use, quantitative determination and comparative analysis were carried out in different plant parts (fruits & leaves) of ten Piper species. To determine the contents and distribution of thirteen compounds a new method has been established using ultra performance liquid chromatography coupled with triple quadrupole electrospray tandem mass spectrometry in multiple reaction monitoring (MRM) mode with continuous polarity switching. A good linear regression relationship for each analyte was obtained (r, 0.9986–0.9999), intraday precision (%RSD, 0.63–3.37), interday precision (%RSD, 0.91–4.09), stability (RSD, 1.59–3.14) and recovery (%RSD, 0.78–2.78). The method sensitivity expressed in terms of limit of detection (LOD), which is ≤1.34ng/mL for all analytes. The analysis results showed that piperamides are the signature class of compounds, which were found highest in fruits of Piper longum (21,500μg/g), while phenolics were in close proportion and highest in fruits of Piper mullesa (1129μg/g) and leaves of P. longum (1094μg/g). Similarly, terpenoid content was detected highest in fruits of Piper umbellatum (8600μg/g). Principal component analysis was carried out to compare and evaluate the quality of ten Piper species based on the contents of the thirteen investigated compounds. The present comparative study is of great importance for the rational application and quality control of different Piper species.

Facile and surfactant-free synthesis of Pd nanoparticles by the extract of the fruits of Piper longum and their catalytic performance for the Sonogashira coupling reaction in water under ligand- and copper-free conditions

This work reports a facile synthesis of palladium nanoparticles (Pd NPs) by the extract of the fruits of Piper longum without any stabilizer or surfactant.

Green synthesis of a natrolite zeolite/palladium nanocomposite and its application as a reusable catalyst for the reduction of organic dyes in a very short time

A natrolite zeolite/palladium (natrolite zeolite/Pd) nanocomposite has been successfully synthesized applying a simple in situ reduction method using an aqueous extract of fruits of Piper longum as a reducing and stabilizing agent.

A novel high-performance liquid chromatography-electron spray ionization-mass spectrometry method for simultaneous determination of guggulsterones, piperine and gallic acid in Triphala guggulu.

“Triphalaguggulu” is an important Ayurvedic formulation comprising of Guggulu, that is, Commiphora wightii (Arn.) Bhandari as a base wherein powdered fruits of triphala, that is, Phyllanthus emblica L., Terminalia bellirica (Gaertn.) Roxb and Terminalia chebula Retz, along with powdered fruit of Piper longum L. are compounded. This polyherbal preparation has been strongly recommended in chronic inflammation, piles, and fistula. However, due to the complexity of compound formulation standardization of commercial products is challenging. In the present communication marker-based standardization of “Triphalaguggulu” preparation using gallic acid (for triphala), piperine (for P. longum L.) and guggulsterones (for guggulu) is reported. These compounds of diverse chemistry were successfully separated on a Waters HR-C18 column by isocratic elution with methanol and water (80:20 v/v) as mobile phase at the flow rate of 1.0 mL/min coupled with photodiode array detector. These optimal chromatographic conditions were used for simultaneous quantification of gallic acid, guggulsterones (E and Z) and piperine in commercial samples by high-performance liquid chromatography-electron spray ionization-mass spectrometry and method was validated as per ICH guidelines.

Long lasting preventive effects of piperlongumine and a Piper longum extract against stress triggered pathologies in mice

Aim:To compare doxycycline (DOX) such as oral efficacies of piperlongumine (PL) and a Piper longum fruits extract (PLE) as stress resistance inducers.Materials and Methods:Efficacies of oral pretreatments with 5 mg/kg PL or PLE or of 50 mg/kg DOX for 10 consecutive days against stress resistance were compared. Mice in treated groups were subjected to a stress induced hyperthermia on the 1st, 5th, 7th, and 10thday. Treated mice were then subjected to tail suspension test on the 11thday. Alteration in body weights, core temperatures, and gastric ulcers triggered by occasional exposures to foot shocks were determined.Results:DOX like long-lasting protective effects of PL and PLE against gradual alterations in body weights, basal temperatures and transient hyperthermic responses triggered by foot shocks during the post-treatment days were observed. Altered responses of stressed mice in tail suspension test observed 1 day after the last foot-shock exposures and gastric ulcers and other pathologies quantified 1 day after the test were also suppressed in PL or PLE or DOX pretreated groups.Conclusion:PL and crude PLE are DOX like long-acting desensitizers of stress triggered co-morbidities. Reported observations add further experimental evidences justifying traditionally known medicinal uses of P. longum and other plants of the Piperaceae family, and reveal that PL is also another very long acting and orally active inducer of stress resistance. Efforts to confirm stress preventive potentials of low dose plant-derived products enriched in PL or piperine like amide alkaloids in volunteers and patients can be warranted.

Piperlongumine attenuates collagen-induced arthritis via expansion of myeloid-derived suppressor cells and inhibition of the activation of fibroblast-like synoviocytes.

Piperlonguminine (PL), a key compound from the Piper longum fruit, is known to exhibit anti‑tumor and anti‑inflammatory activities. However, little is known about its effects on collagen‑induced arthritis (CIA). Fibroblast‑like synoviocytes (FLS) have a pivotal role in the development of rheumatoid arthritis (RA). Myeloid‑derived suppressor cells (MDSCs) are able to suppress T cell responses and have important roles in the regulation of autoimmune arthritis. The current study investigated whether PL alters the progression of RA. It was determined that PL reduces the arthritis score and histopathologic lesions in a mouse model of CIA. PL also reduces the expression levels of serum anti‑collagen II antibodies (anti‑CⅡ), tumor necrosis factor‑α (TNF‑α), interleukin (IL)‑1β, IL‑23 and IL‑17 in CIA mice. In draining lymph nodes (DLNs), MDSCs were significantly expanded, however, the number of Th17 cells was markedly decreased by PL treatment. Additionally, PL reduced secretion of IL‑1β, IL‑23 and IL‑17 by TNF‑α‑stimulated human RA FLS. PL significantly inhibited the migration and invasion of TNF‑α‑stimulated human RA FLS. These results indicate that PL may be a candidate therapeutic agent for the treatment of RA, via the expansion of MDSCs and the inhibition of the Th17 response and activation of FLS.

Piperlongumine-induced phosphatidylserine translocation in the erythrocyte membrane.

Background: Piperlongumine, a component of Piper longum fruit, is considered as a treatment for malignancy. It is effective by inducing apoptosis. Mechanisms involved in the apoptotic action of piperlongumine include oxidative stress and activation of p38 kinase. In analogy to apoptosis of nucleated cells, erythrocytes may undergo eryptosis, the suicidal death of erythrocytes characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine-exposure at the erythrocyte surface. Signaling involved in eryptosis include increase of cytosolic Ca2+-activity ([Ca2+]i), formation of ceramide, oxidative stress and activation of p38 kinase. Methods: Cell volume was estimated from forward scatter, phosphatidylserine-exposure from annexin V binding, [Ca2+]i from Fluo3 fluorescence, reactive oxygen species from 2',7'-dichlorodihydrofluorescein-diacetate fluorescence, and ceramide abundance from binding of fluorescent antibodies in flow cytometry. Results: A 48 h exposure to piperlongumine (30 µM) was followed by significant decrease of forward scatter and increase of annexin-V-binding. Piperlongumine did not significantly modify [Ca2+]i and the effect was not dependent on presence of extracellular Ca2+. Piperlongumine significantly increased ROS formation and ceramide abundance. Conclusions: Piperlongumine triggers cell membrane scrambling, an effect independent from entry of extracellular Ca2+ but at least partially due to ROS and ceramide formation.

In-vivo and In-vitro Activities of Medicinal Plants on Ecto, Endo and Haemoparasitic Infections: A Review

Crude methanol, pet. ether, ethyl acetate, n-hexane, dichloromethane and aqueous extracts of various species of medicinal plants have shown significant in-vivo and in-vitro pharmacological activities against ecto, endo and haemoparasites. The scientific evaluations of the use of the plants as antiparasitic agents were based on the claims of folklore drawn from traditional healers from various communities across the world. The pharmacological activities of these plants were associated with the presence of various bioactive compounds such as alkaloids, flavonoids, saponins, glycosides, allicinine, harmala, harmaline, harman, tetrahydroharman, ursolic acid, terapines, tannins, phenolic compounds, embelin and brucine. These compounds were either found in the leaves, seeds, bulbs, flowers, stem, root barks or entire plant. In the in-vivo studies, plant extracts were tested using animal models such as mice, sheep, goats, cattle and dogs. The in-vivo anthelmintic activities of the plants were assessed by faecal egg out puts and post-mortem worm counts which in most instances achieved 70-90% priori levels with some of the plants. For haemoparasitic infections, parasitaemia clearance levels were used, while larvae and adult deaths were used to measure the activity of the plants against ectoparasites. For in-vitro activities, inhibitory concentration IC50 values using the brine lethality test, micro dilution, flow cytometery and larval packet test were used to assess the efficacy of the plant extracts on the parasites in various cell cultures. Significant in-vitro activity of 99.8% at 3.1mg/ml was achieved with the ethanolic extract of Azadirachta indica. Many of the plants were found to be more potent and possessed similar mechanism of action as their novel synthetic drugs. Such breakthroughs have led to the development of less toxic, cheaper and readily available drugs. Worthy of note is the use of the fruit of the Thai plant Piper longum (PIPERACEAE) as part of a drug formulation used in India for the treatment of clinical giardiosis in human patients.

Effect on oxidative stress, glucose uptake level and lipid droplet content by Apigenin 7, 4'-dimethyl ether isolated from Piper longum L.

Piper longum L. (Family: Piperaceae), is a widely used herb in several Ayurvedic formulations prescribed for various diseases. Potential of the plant material as an antidiabetic and cardio protective agent has not been evaluated so far. In the study, we designed experiments to evaluate antioxidant, glucose uptake potential and lipid content regulating potential of extracts and compound from P. longum fruits. Solvent extracts from Piper longum fruits using hexane, ethyl acetate, methanol, 70% methanol-water were taken and apigenin 7, 4'-dimethyl ether (ADE) was isolated from ethyl acetate extract. Antioxidant activity, glucose uptake potential and adipocyte differentiation assay was performed with extract and pure compound. Antioxidant activity in terms of TRP (196.03μg/mg GAE), DPPH assay (IC50-173.09μg/mL), hydroxyl radical scavenging assay (IC50-20.42μg/mL), inhibiting LDL oxidation (IC50-51.99 μg/mL) and to enhance SOD activity (25.3%) was higher in ethyl acetate extract (EAP). Phenolic and flavonoid content was measured and showed a positive correlation with antioxidant activity. Presence of apigenin 7, 4'-dimethyl ether (ADE) and piperine (Pip) in EAP was determined by HPTLC analysis and was isolated. ADE inhibited α-glucosidase and α-amylase enzymes and enhanced 2-NBDG uptake in L6 cells. Hypolipidemic effect of ADE on mouse pre-adipocyte (3T3L1) cell lines also showed a dose dependent reduction on lipid droplet content and effective concentration range was determined as 1-2.5μg/mL. The results suggested that Piper longum fruits can provide a natural source of antioxidants with antidiabetic and anti obesity potential.

Piperlongumine alleviates lupus nephritis in MRL-Fas(lpr) mice by regulating the frequency of Th17 and regulatory T cells

Recent data have shown that piperlongumine (PL), an important component of Piper longum fruits, is known to possess anti-inflammatory and vascular-protective activities. This study aimed to examine the therapeutic effects and underlying mechanisms of PL on lupus-prone MRL-Fas(lpr) mice. Female MRL-Fas(lpr) mice were intraperitoneally treated with PL (2.4mgkg−1d−1) for 10 weeks, and the proteinuria level was biweekly monitored. After the mice were euthanized, serum biochemical parameters and renal damage were determined. Splenocytes of MRL-Fas(lpr) mice were isolated for in vitro study. Treatment of the mice with PL significantly attenuated the progression of proteinuria and glomerulonephritis. The improvement was accompanied by decreased serum levels of nephritogenic anti-dsDNA antibodies, IL-6, IL-17, IL-23 and TNF-α. Treatment of the mice with PL suppressed the frequency of Th17 cells and increased the regulatory T cells (Tregs). In vitro, the levels of IL-6, IL-17, IL-23 and TNF-α were significantly decreased in the cultures of splenocytes from PL-treated mice compared with those from vehicle-treated mice. In addition, PL treatment impeded activation of the JAK/STAT3 signaling in splenocytes. Of great important, the survival of MRL-Fas(lpr) mice were improved by PL treatment. In summary, PL effectively ameliorates lupus syndrome in MRL-Fas(lpr) mice by suppressing the pathogenic Th17 cells and increasing the Tregs as well as inhibiting activation of the JAK/STAT3 signaling pathway. This study sheds new light on the immune-modulatory role of PL.

Extraction of piperine from Piper longum using ultrasound

Efforts were made to enhance the yield of piperine using ultrasound assisted extraction (UAE) from fruit of Piper longum. The effects of various factors such as solvent, extraction time, solid to solvent ratio, duty cycle, ultrasound frequency, ultrasound power and temperature on the yield of piperine were investigated and optimized. The maximum yield of piperine (5.8mg/g) from Piper longum powder was obtained at optimal UAE conditions such as, ethanol as extracting solvent, extraction time 18min, solid to solvent ratio 1:10, ultrasound power 125W, 80% duty cycle, ultrasound frequency 25kHz and temperature 50°C. The experimental results revealed the advantage of UAE over traditional method of batch extraction and solvent extraction. The extraction time is reduced from 8h of batch solvent extraction and 4h of Soxhlet to 18min in UAE with enhanced extraction yield of piperine. Extraction yields of piperine obtained from Soxhlet extraction and batch extraction methods were found to be 1.67mg/g and 0.98mg/g, respectively, which were much lower than UAE optimized results. Hence, ultrasound assisted extraction of natural phytoconstituents will diminish the problem of lower extractability and higher extraction time over traditional methods.

Drug-repositioning screening identified piperlongumine as a direct STAT3 inhibitor with potent activity against breast cancer.

Signal transducer and activator of transcription (STAT) 3 regulates many cardinal features of cancer including cancer cell growth, apoptosis resistance, DNA damage response, metastasis, immune escape, tumor angiogenesis, the Warburg effect, and oncogene addiction and has been validated as a drug target for cancer therapy. Several strategies have been employed to identify agents that target Stat3 in breast cancer but none has yet entered into clinical use. We used a high-throughput fluorescence microscopy search strategy to identify compounds in a drug-repositioning library (Prestwick library) that block ligand-induced nuclear translocation of Stat3 and identified piperlongumine (PL), a natural product isolated from the fruit of the pepper Piper longum. Piperlongumine inhibited Stat3 nuclear translocation, inhibited ligand-induced and constitutive Stat3 phosphorylation, and modulated expression of multiple Stat3-regulated genes. Surface plasmon resonance assay revealed that piperlongumine directly inhibited binding of Stat3 to its phosphotyrosyl (pY) peptide ligand. Phosphoprotein antibody array analysis revealed that PL does not modulate kinases known to activate Stat3 such as JAKs, Src kinase family members, or RTKs. PL inhibited anchorage-independent and anchorage-dependent growth of multiple breast cancer cell lines having increased pStat3 or total Stat3, and induced apoptosis. PL also inhibited mammosphere formation by tumor cells from patient derived xenografts (PDX). PL’s anti-tumorigenic function was causally linked to its Stat3-inhibitory effect. PL was non-toxic in mice up to a dose of 30 mg/Kg/day for 14 days and caused regression of breast cancer cell line xenografts in nude mice. Thus, PL represents a promising new agent for rapid entry into the clinic for use in treating breast cancer, as well as other cancers in which Stat3 plays a role.

Vascular barrier protective effects of piperlonguminine in vitro and in vivo

The nuclear DNA binding protein known as high-mobility group box 1 (HMGB1) acts as a late mediator of severe vascular inflammatory conditions, such as sepsis and septic shock. Piperlonguminine (PL), an important component of Piper longum fruit, is known to exhibit anti-hyperlipidemic, anti-platelet, and anti-melanogenesis activities. However, little is known about its effects on HMGB1-mediated inflammatory response. We investigated the effects of PL on HMGB1-mediated inflammatory response by monitoring the effects of PL on lipopolysaccharide or cecal ligation and puncture (CLP)-mediated release of HMGB1, as well as on the modulation of HMGB1-mediated inflammatory responses. According to our data, PL caused inhibition of the release of HMGB1 and downregulation of HMGB1-dependent inflammatory responses in human endothelial cells. PL also inhibited HMGB1-mediated hyperpermeability and leukocyte migration in mice. In addition, treatment with PL reduced the CLP-induced release of HMGB1 and sepsis-related mortality. These results indicate that PL could be a candidate therapeutic agent for various severe vascular inflammatory diseases via inhibition of the HMGB1 signaling pathway.

New amide alkaloids from Piper longum fruits

Three new amide alkaloids piperlongumamides A-C (1–3), together with 12 known ones (4–15), were isolated from the fruits of Piper longum. The structures of the new isolates were determined using spectroscopic data analyses. Cytotoxic activity of these amides against HL-60 (human leukemia), A-549 (human lung cancer), MCF-7 (human breast cancer), SMMC-7721 (human liver cancer) and SW480 (human rectal cancer) cell lines were evaluated. Piperchabamide B (11) exhibited weak inhibitory activity against HL-60 (IC50 = 21.32 μM ), A-549 (IC50 = 23.82 μM ) and MCF-7 (IC50 = 16.58 μM ) cell lines. Electronic Supplementary MaterialSupplementary material is available for this article at 10.1007/s13659-013-0073-0 and is accessible for authorized users.

In vitro inhibitory effect of piperlonguminine isolated from Piper longum on human cytochrome P450 1A2

Piperlonguminine (PL), a major alkaloid isolated from Piper longum fruits, shows several biological activities including anti-tumor, anti-hyperlipidemic and anti-inflammatory effects. Although there have been studies of the biological effects of PL, the potential drug-interaction effect of PL following evaluation of inhibitory effects of cytochrome P450 (CYP) activities was not investigated. Here, to investigate the inhibitory effects of PL on the activities of CYP isoforms, CYP inhibition assays were conducted using a cocktail of probe substrates in pooled human liver microsome (HLMs) and human recombinant cDNA-expressed CYP. PL strongly inhibited CYP1A2-mediated phenacetin O-deethylation with an IC50 value of 8.8 μM, as NADPH-independent inhibition, while other CYPs were not significantly inhibited. A Lineweaver-Burk plot resulted in the inhibition mechanism of PL being divided into two different modes, reversible competitive inhibition in a low concentration range of 0-16 μM with a Ki value of 1.39 μM and uncompetitive inhibitory behavior at a high concentration range of 16-40 μM. In addition, PL only decreased CYP 1A2-catalyzed phenacetin O-deethylase activity with IC50 values of 10.0 μM in human recombinant cDNA-expressed 1A2, not 1A1. Overall, this is the first investigation of potential herb-drug interactions associated with PL conducted by identifying the competitive inhibitory effects of PL on CYP1A2 in HLMs.

Anticoagulant activities of piperlonguminine in vitro and in vivo

Piperlonguminine (PL), an important component of Piper longum fruits, is known to exhibit anti-hyperlipidemic, antiplatelet and anti-melanogenic activities. Here, the anticoagulant activities of PL were examined by monitoring activatedpartial-thromboplastin-time (aPTT), prothrombin-time (PT), and the activities of thrombin and activated factor X (FXa). The effects of PL on the expressions of plasminogen activator inhibitor type 1 (PAI-1) and tissue-type plasminogen activator (t-PA) were also tested in tumor necrosis factor-α (TNF-α) activated HUVECs. The results showed that PL prolonged aPTT and PT significantly and inhibited the activities of thrombin and FXa. PL inhibited the generation of thrombin and FXa in HUVECs. In accordance with these anticoagulant activities, PL prolonged in vivo bleeding time and inhibited TNF-α induced PAI-1 production. Furthermore, PAI-1/t-PA ratio was significantly decreased by PL. Collectively, our results suggest that PL possesses antithrombotic activities and that the current study could provide bases for the development of new anticoagulant agents. [BMB Reports 2013; 46(10): 484-489]

Piperlonguminine Downregulates Endothelial Protein C Receptor Shedding In Vitro and In Vivo

Endothelial cell protein C receptor (EPCR) plays an important role in coagulation and inflammation. EPCR can be shed from the cell surface, and this is mediated by tumor necrosis factor-α-converting enzyme (TACE). Piperlonguminine (PL), an important component of Piper longum fruits, is known to exhibit antihyperlipidemic, antiplatelet, and antimelanogenesis activities. However, little is known about the effects of PL on EPCR shedding. Here, we investigated this issue by monitoring the effects of PL on phorbol-12-myristate 13-acetate (PMA) and on cecal ligation and puncture (CLP)-mediated EPCR shedding and underlying mechanisms. PL induced potent inhibition of PMA, and CLP induced EPCR shedding through suppression of TACE expression. And treatment with PL resulted in reduced PMA-stimulated phosphorylation of p38, extracellular regulated kinases (ERK) 1/2, and c-Jun N-terminal kinase (JNK). Given these results, PL might have potential as an anti-sEPCR shedding reagent against PMA- and CLP-mediated EPCR shedding.

Production of high titre antibody response against Russell's viper venom in mice immunized with ethanolic extract of fruits of Piper longum L. (Piperaceae) and piperine

Piper longum L. fruits have been traditionally used against snakebites in north-eastern and southern region of India. The aim of the study was to assess the production of antibody response against Russell's viper venom in mice after prophylactic immunization with ethanolic extract of fruits of Piper longum L. and piperine. The mice sera were tested for the presence of antibodies against Russell's viper venom by in vitro lethality neutralization assay and in vivo lethality neutralization assay. Polyvalent anti-snake venom serum (antivenom) manufactured by Haffkine Bio-Pharmaceutical Corporation Ltd. was used as standard. Further confirmation of presence of antibodies against the venom in sera of mice immunized with PLE and piperine was done using indirect enzyme-linked immunosorbent assay (ELISA) and double immunodiffusion test. Treatment with PLE-treated mice serum and piperine-treated mice serum was found to inhibit the lethal action of venom both in the in vitro lethality neutralization assay and in vivo lethality neutralization assay. ELISA testing indicated that there were significantly high (p<0.01) levels of cross reactions between the PLE and piperine treated mice serum and the venom antigens. In double immunodiffusion test, a white band was observed between the two wells of antigen and antibodies for both the PLE-treated and piperine-treated mice serum. Thus it can be concluded that immunization with ethanolic extract of fruits of Piper longum and piperine produced a high titre antibody response against Russell's viper venom in mice. The antibodies against PLE and piperine could be useful in antivenom therapy of Russell's viper bites. PLE and piperine may also have a potential interest in view of the development of antivenom formulations used as antidote against snake bites.

Evaluation of antioxidant, antibacterial and cytotoxic effects of green synthesized silver nanoparticles by Piper longum fruit

Silver nanoparticles synthesized through bio-green method has been reported to have biomedical applications to control pathogenic microbes as it is cost effective compared to commonly used physical and chemical methods. In present study, silver nanoparticles were synthesized using aqueous Piper longum fruit extract (PLFE) and confirmed by UV–visible spectroscopy. The nanoparticles were spherical in shape with an average particle size of 46nm as determined by scanning electronic microscopy (SEM) and dynamic light scattering (DLS) particle size analyzer respectively. FT-IR spectrum revealed the capping of the phytoconstituents, probably polyphenols from P. longum fruit extract and stabilizing the nanoparticles. Further the ferric ion reducing test, confirmed that the capping agents were condensed tannins. The aqueous P. longum fruit extract (PLFE) and the green synthesized silver nanoparticles (PLAgNPs) showed powerful antioxidant properties in in vitro antioxidant assays. The results from the antimicrobial assays suggested that green synthesized silver nanoparticles (PLAgNPs) were more potent against pathogenic bacteria than the P. longum fruit extract (PLFE) alone. The nanoparticles also showed potent cytotoxic effect against MCF-7 breast cancer cell lines with an IC 50 value of 67μg/ml/24h by the MTT assay. These results support the advantages of using bio-green method for synthesizing silver nanoparticles with antioxidant, antimicrobial and cytotoxic activities those are simple and cost effective as well.

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.