Alkaloids from Piper sarmentosum and Piper nigrum

Harnessing the anticancer potential of Piper nigrum: a synergistic approach to chemotherapy enhancement and reduced side effects

Cancer therapy continues to face critical challenges, including drug resistance, recurrence, and severe side effects, which often compromise patient outcomes and quality of life. Exploring novel, cost-effective approaches, this review highlights the potential of Piper nigrum (black pepper) extract (PNE) as a complementary anticancer agent. Piper nigrum, a widely available spice with a rich history in traditional medicine, contains bioactive compounds such as piperine, which have demonstrated significant anticancer activities including cell cycle arrest, apoptosis induction, and inhibition of tumor growth and metastasis. The review evaluates the recent findings from in vitro, in vivo, and clinical studies, emphasizing PNE's capacity to enhance the efficacy of conventional chemotherapeutic agents while mitigating their side effects. Key mechanisms underlying these effects include oxidative stress modulation, suppression of pro-metastatic factors, and synergistic interactions with established drugs like doxorubicin and paclitaxel. These interactions suggest that PNE could play a pivotal role in overcoming chemoresistance and improving therapeutic outcomes. Furthermore, this review highlights the potential benefits of PNE in resource-limited settings, where the cost of cancer treatments often restricts access. However, challenges such as compositional variability, limited bioavailability, and the need for standardization and clinical validation need to be addressed to advance the integration of PNE into basic oncology. By providing a comprehensive analysis of the anticancer mechanisms of PNE and its potential as a cost-effective adjuvant therapy, this review provides new insight into the exploitation of Piper nigrum to improve cancer treatment efficacy while reducing side effects. Future research directions are discussed to address current limitations and facilitate clinical translation.

Structural diversity, evolutionary origin, and metabolic engineering of plant specialized benzylisoquinoline alkaloids

Covering: up to June 2024Benzylisoquinoline alkaloids (BIAs) represent a diverse class of plant specialized metabolites derived from L-tyrosine, exhibiting significant pharmacological properties such as anti-microbial, anti-spasmodic, anti-cancer, cardiovascular protection, and analgesic effects. The industrial production of valuable BIAs relies on extraction from plants; however, challenges concerning their low concentration and efficiency hinder drug development. Hence, alternative approaches, including biosynthesis and chemoenzymatic synthesis, have been explored. Model species like Papaver somniferum and Coptis japonica have played a key role in unraveling the biosynthetic pathways of BIAs; however, many aspects, particularly modified steps like oxidation and methylation, remain unclear. Critical enzymes, e.g., CYP450s and methyltransferases, play a substantial role in BIA backbone formation and modification, which is essential for understanding the origin and adaptive evolution of these plant specialized metabolites. This review comprehensively analyzes the structural diversity of reported BIAs and their distribution in plant lineages. In addition, the progress in understanding biosynthesis, evolution, and catalytic mechanisms underlying BIA biosynthesis is summarized. Finally, we discuss the progress and challenges in metabolic engineering, providing valuable insights into BIA drug development and the sustainable utilization of BIA-producing plants.

Alkaloids and Styryl Lactones from Goniothalamus tortilipetalus and Their Biological Activities

Phytochemical investigations of the twig and leaf extracts of Goniothalamus tortilipetalus resulted in the isolation and identification of two new alkaloids, goniotortiline (1) and goniotortilactam (2), three new styryl lactone derivatives, goniotortilactone (3) and goniotortilols A (4) and B (5), and 25 known compounds. Their structures were elucidated by spectroscopic methods and HRESITOFMS data. Compounds 5, 13, 15, 16, 22, and 30 inhibited nitric oxide (NO) production with IC50 values ranging from 8.7 ± 0.1 to 17 ± 1 μM, revealing stronger effects than the standard drug, dexamethasone (IC50 16.9 ± 2.2 μM), and compound 30 possessed the most potent NO production inhibition. Compounds 12 and 29 demonstrated notable efficacy in enhancing glucose consumption with IC50 values of 77 ± 4 and 66 ± 4 μM, respectively, while their glucose uptakes were 1.7- and 2-fold, respectively.

Undescribed Lignanamide and Flavone C-Glucoside Isolated from the Aerial Parts of Piper Samentosum with NO Production Inhibitory Activity in LPS Activated RAW 264.7 Cells

In this study, two undescribed compounds (1 and 2), together with eight known compounds (3-10) were isolated from the aerial parts of Piper samentosum by various chromatography methods. Their chemical structures were determined to be 7'''-oxolyciumamide N (1), vitexin 2''-O-β-D-(6'''-feruloyl)-glucopyranoside (2), 1,2-dihydro-6,8-dimethoxy-7-hydroxy-1-(3,4-dihydroxyphenyl)-N1,N2-bis-[2-(-hydroxyphenyl)ethyl]-2,3-napthalene dicarboamide (3), vitexin 6''-O-β-D-glucopyranoside (4), vitexin 2''-O-α-L-rhamnopyranoside (5), methyl 2-hydroxybenzoate-2-O-β-D-apiofuranosyl-(1→2)-O-β-D-glucopyranoside (6), ficuside G (7), methyl 2-O-β-D-glucopyranosylbenzoate (8), methyl 2,5-dihydroxybenzoate-5-O-β-D-glucopyranoside (9), and 3,7-dimethyloct-1-ene-3,6,7-triol 6-O-β-D-glucopyranoside (10) by spectroscopic data analysis including HR-ESI-MS, 1D-, and 2D-NMR spectra. Compounds 1-5 inhibited nitric oxide production in LPS-stimulated RAW264.7 macrophages with the IC50 values of 27.62, 74.03, 38.54, 70.39, and 44.95 μM, respectively. The NMR data of 9 were firstly reported herein.

Rapid Analysis of Compounds from Piperis Herba and Piperis Kadsurae Caulis and Their Differences Using High-Resolution Liquid-Mass Spectrometry and Molecular Network Binding Antioxidant Activity

There is a serious mixing of Piperis Herba and Piperis Kadsurae Caulis in various parts of China due to the similar traits of lianas, and there is a lack of systematic research on the compound and activity evaluation of the two. Likewise, the differences in compounds brought about by the distribution of origin also need to be investigated. In this study, high-resolution liquid-mass spectrometry (UPLC-Q-Zeno-TOF-MS/MS) was used to analyze samples of Piperis Herba from five origins and Piperis Kadsurae Caulis from five origins, with three batches collected from each origin. The compounds were identified based on precise molecular weights, secondary fragments, and an online database combined with node-to-node associations of the molecular network. The t-test was used to screen and analyze the differential compounds between the two. Finally, the preliminary evaluation of antioxidant activity of the two herbs was carried out using DPPH and ABTS free radical scavenging assays. The results showed that a total of 72 compounds were identified and deduced in the two Chinese medicines. These compounds included 54 amide alkaloids and 18 other compounds, such as flavonoid glycosides. The amide alkaloids among them were then classified, and the cleavage pathways in positive ion mode were summarized. Based on the p-value of the t-test, 32 differential compounds were screened out, and it was found that the compounds of Piperis Herba were richer and possessed a broader spectrum of antioxidant activity, thus realizing a multilevel distinction between Piperis Herba and Piperis Kadsurae Caulis. This study provides a preliminary reference for promoting standardization and comprehensive quality research of the resources of Piperis Herba using Piperis Kadsurae Caulis as a reference.

Piperine: Chemistry and Biology

Piperine is a plant-derived promising piperamide candidate isolated from the black pepper (Piper nigrum L.). In the last few years, this natural botanical product and its derivatives have aroused much attention for their comprehensive biological activities, including not only medical but also agricultural bioactivities. In order to achieve sustainable development and improve survival conditions, looking for environmentally friendly pesticides with low toxicity and residue is an extremely urgent challenge. Fortunately, plant-derived pesticides are rising like a shining star, guiding us in the direction of development in pesticidal research. In the present review, the recent progress in the biological activities, mechanisms of action, and structural modifications of piperine and its derivatives from 2020 to 2023 are summarized. The structure-activity relationships were analyzed in order to pave the way for future development and utilization of piperine and its derivatives as potent drugs and pesticides for improving the local economic development.

Enhancing Paclitaxel Efficacy with Piperine-Paclitaxel Albumin Nanoparticles in Multidrug-Resistant Triple-Negative Breast Cancer by Inhibiting P-Glycoprotein

Triple-negative breast cancer (TNBC) is a highly aggressive disease with rapid progression and poor prognosis due to multidrug resistance (MDR). Piperine (PIP) shows promise as a P-gp inhibitor, capable of sensitizing chemotherapeutic drugs and exhibiting antitumor properties. This study explores the inhibitory mechanism of PIP on P-glycoprotein (P-gp) and its capacity to enhance the sensitivity of paclitaxel (PTX). We subsequently evaluated the efficacy and safety of albumin nanoparticles that co-encapsulate PTX and PIP (PP@AN). The results demonstrated that PIP enhanced the accumulation of PTX intracellularly, as determined with HPLC/MS/MS analysis. PIP was also found to increase cell sensitivity to PTX. Furthermore, we explored the inhibitory mechanism of PIP on P-gp, utilizing molecular docking simulations, RT-qPCR, and Western blot analysis. PIP appears to compete with the active paclitaxel binding site on P-gp, affecting ATPase activity and downregulating the MDR1 gene and P-gp expression. In summary, PIP could inhibit P-gp and act as a sensitizer in the treatment of TNBC with PTX. Moreover, stable and uniform PP@AN was successfully formulated, resulting in a significant increase in drug accumulation within cells as well as the downregulation of P-gp in tumors at the optimal ratio (PTX:PIP = 1:2). This led to an improvement in the antitumor effect in vivo while also reducing hepatotoxicity and hemototoxicity following chemotherapy. This study comprehensively investigated PIP's inhibitory effect and mechanism on P-gp. We present a new approach for co-delivering PIP and PTX using albumin nanoparticles, which reduced toxicity and improved therapeutic efficacy both in vivo and in vitro.

Chemical Constituents and Biological Activities of Piper as Anticancer Agents: A Review

Cancer has become the primary cause of death worldwide, and anticancer drugs are used to combat this disease. Synthesis of anticancer drugs has limited success due to adverse side effects has made compounds from natural products with minimal toxicity gain much popularity. Piper species are known to have a biological effect on human health. The biological activity is due to Piper species rich with active secondary metabolites that can combat most diseases, including cancer. This review will discuss the phytochemistry of Piper species and their anticancer activity. The identification and characterization of ten active metabolites isolated from Piper species were discussed in detail and their anticancer mechanism. These metabolites were mainly found could inhibit anticancer through caspase and P38/JNK pathways. The findings discussed in this review support the therapeutic potential of Piper species against cancer due to their rich source of active metabolites with demonstrated anticancer activity.

Evaluation of Anti-Candida Potential of Piper nigrum Extract in Inhibiting Growth, Yeast-Hyphal Transition, Virulent Enzymes, and Biofilm Formation

Due to the increased incidence of fungal infections and the emergence of antifungal resistance mainly by Candida species, the need for safe and effective novel therapies is imperative. Consequently, plants and herbs are a powerful source to combat infections. Here, we evaluated the anti-Candida potential of an ethanolic extract from Piper nigrum. The phytochemical analysis of P. nigrum revealed bioactive compounds such as alkaloids, terpenoids, and tannis. Our results showed that P. nigrum extract suppressed the virulence factors of C. albicans strains, including hyphae formation in both liquid and solid media, reduced secretion of phospholipases/proteinases, and affected biofilm formation. Furthermore, the P. nigrum extract showed no hemolytic effect in vitro and exhibited reduced cytotoxicity on Vero cells and G. mellonella larvae at concentrations that inhibited hyphae and biofilm in C. albicans. Moreover, the extract demonstrated antifungal activity against C. auris strains. In conclusion, the P. nigrum extract affected the growth and morphogenesis of Candida (even in resistant strains), demonstrating that this plant has an anti-candida activity and represents a promising resource for discovering novel antifungal compounds.

Identification of potential inhibitors of SARS-CoV-2 main protease and spike receptor from 10 important spices through structure-based virtual screening and molecular dynamic study

The outbreak of novel coronavirus disease (COVID-19) caused by SARS-CoV-2 poses a serious threat to human health and world economic activity. There is no specific drug for the treatment of COVID-19 patients at this moment. Traditionally, people have been using spices like ginger, fenugreek and onion, etc. for the remedy of a common cold. This work identifies the potential inhibitors of the main protease (Mpro) and spike (S) receptor of SARS-CoV-2 from 10 readily available spices. These two proteins, S and Mpro, play an important role during the virus entry into the host cell, and replication and transcription processes of the virus, respectively. To identify potential molecules an in-house databank containing 1040 compounds was built-up from the selected spices. Structure-based virtual screening of this databank was performed with two important SARS-CoV-2 proteins using Glide. Top hits resulted from virtual screening (VS) were subjected to molecular docking using AutoDock 4.2 and AutoDock Vina to eliminate false positives. The top six hits against Mpro and top five hits against spike receptor subjected to 130 ns molecular dynamic simulation using GROMACS. Finally, the compound 1-, 2-, 3- and 5-Mpro complexes, and compound 17-, 18-, 19-, 20- and 21- spike receptor complexes showed stability throughout the simulation time. The ADME values also supported the drug-like nature of the selected hits. These nine compounds are available in onion, garlic, ginger, peppermint, chili and fenugreek. All the spices are edible and might be used as home remedies against COVID-19 after proper biological evaluation.

Neolignans and polyoxygenated seco-cyclohexenes from the stems and leaves of Piper suipigua Buch.-Ham. ex D. Don

Five new compounds including, a neolignan, eupomatenoid-19 (1) and four polyoxygenated seco-cyclohexenes, artahongkongenes G-J (2-5), together with fifteen known compounds (6-20) were isolated from the stems and leaves of Piper suipigua Buch.-Ham. ex D. Don. Their structures were determined by spectroscopic evidence (IR, UV, ¹H NMR, ¹³C NMR and 2 D NMR) as well as MS. The absolute configurations of polyoxygenated seco-cyclohexenes 2-8 were identified by NOESY data and by comparison of their experimental and calculated ECD spectral data. Neolignans, eupomatenoid-19 (1) and eupomatenoid-7 (10), displayed cytotoxicity against several cancer cell lines. In addition, eupomatenoid-7 (10) showed antibacterial activity against Bacillus cereus, Bacillus subtilis and Staphylococcus aureus.

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.

Ontogenetic Changes in the Chemical Profiles of Piper Species

The chemical composition of seedlings and adult plants of several Piper species were analyzed by ¹H NMR spectroscopy combined with principal component analysis (PCA) and HPLC-DAD, HPLC-HRESIMS and GC-MS data. The chromatographic profile of crude extracts from leaves of Piper species showed remarkable differences between seedlings and adult plants. Adult leaves of P. regnellii accumulate dihydrobenzofuran neolignans, P. solmsianum contain tetrahydrofuran lignans, and prenylated benzoic acids are found in adult leaves of P. hemmendorffii and P. caldense. Seedlings produced an entirely different collection of compounds. Piper gaudichaudianum and P. solmsianum seedlings contain the phenylpropanoid dillapiole. Piper regnellii and P. hemmendorffii produce another phenylpropanoid, apiol, while isoasarone is found in P. caldense. Piper richadiaefolium and P. permucronatum contain dibenzylbutyrolactones lignans or flavonoids in adult leaves. Seedlings of P. richardiaefolium produce multiple amides, while P. permucronatum seedlings contain a new long chain ester. Piper tuberculatum, P. reticulatum and P. amalago produce amides, and their chemistry changes less during ontogeny. The chemical variation we documented opens questions about changes in herbivore pressure across ontogeny.

New Tyramine- and Aporphine-Type Alkamides with NO Release Inhibitory Activities from Piper puberulum

Three new tyramine-type alkamides (1-3), three new natural products (4-6), five new N-acylated/formylated aporphine alkamides with different ratios of rotational isomers (7-11), and 20 known alkamides (12-31) were isolated from an EtOH extract of the stems and leaves of Piper puberulum. The absolute configurations of compounds 7, 8, and 10 were determined by single-crystal X-ray diffraction analysis. In the biological activity assay, compounds 3, 5, and 10-23 displayed inhibitory effects against lipopolysaccharide-induced NO release in BV-2 microglial cells, exhibiting IC₅₀ values of 0.93-45 μM.

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.

Separation of alkaloids and their analogs in HPLC using rosin-based polymer microspheres as stationary phases

Rosin-based polymer microspheres (RPMs) as stationary phases in HPLC, and an RPM chromatographic column show good performance.

Piper sarmentosum Roxb.: A review on its botany, traditional uses, phytochemistry, and pharmacological activities

ETHNOPHARMACOLOGICAL RELEVANCE

Piper sarmentosum Roxb. (Piperaceae) is a traditional medicinal plant widely distributed in India, Malaysia, Thailand, and the southeastern coastal areas of China including Fujian, Guangdong, and Guizhou. It has been used for centuries for the treatment of wind-cold cough, fever, rheumatism arthralgia, diarrhea dysentery, postpartum foot swelling, stomachache, toothache, diabetes, and traumatic injury.

AIMS OF THE REVIEW

To critically anayze the literature for the botany, traditional uses, phytochemistry, pharmacology, toxicity, and clinical trials of P. sarmentosum in order to provide a scientific consensus for further research and discovery of potential candidate drugs.

MATERIALS AND METHODS

The contents of this review were sourced from electronic databases including PubMed, SciFinder, Web of Science, Science Direct, Elsevier, Google Scholar, Chinese Knowledge On frastructure (CNKI), Wanfang, Chinese Scientific and Technological Periodical Database (VIP), Chinese Biomedical Database (CBM), Cochrane Controlled register of Clinical Trials, Clinical Trials. gov, and Chinese Clinical Trial Registry. Chinese medicine books published over the years were used to elucidate the traditional uses of P. sarmentosum and additional information was also collected from Yao Zhi website (https://db.yaozh.com/).

RESULTS

Phytochemical analyses of the chemical constituents of P. sarmentosum include essential oil, alkaloids, flavonoids, lignans, and steroids. The literature supports the ethnomedicinal uses of P. sarmentosum for the treatment of cold, gastritis, and rheumatoid joint pain, and further confirms its relatively new pharmacological activities, including anti-inflammatory, antineoplastic, and antipyretic activities. Other biological roles such as anti-osteoporosis, antibacterial, antidepressant, anti-atherosclerotic, and hypoglycemic activities have also been reported. However, the methodologies employed in individual studies are limited.

CONCLUSIONS

There is convincing evidence from both in vitro and in vivo studies supporting the traditional use of P. sarmentosum and it is imperative that natural bioactive compounds are examined further. More efforts should be focused on the pharmacodynamic constituents of P. sarmentosum to provide practical basis for quality control, and additional studies are needed to understand the mechanism of their action. Further studies on the comprehensive evaluation of medicinal quality and understandings of serum chemistry, multi-target network pharmacology, and molecular docking technology of P. sarmentosum are of great importance and should be considered.

Overview of the Anticancer Potential of the "King of Spices" Piper nigrum and Its Main Constituent Piperine

The main limits of current anticancer therapy are relapses, chemoresistance, and toxic effects resulting from its poor selectivity towards cancer cells that severely impair a patient's quality of life. Therefore, the discovery of new anticancer drugs remains an urgent challenge. Natural products represent an excellent opportunity due to their ability to target heterogenous populations of cancer cells and regulate several key pathways involved in cancer development, and their favorable toxicological profile. Piper nigrum is one of the most popular spices in the world, with growing fame as a source of bioactive molecules with pharmacological properties. The present review aims to provide a comprehensive overview of the anticancer potential of Piper nigrum and its major active constituents-not limited to the well-known piperine-whose undeniable anticancer properties have been reported for different cancer cell lines and animal models. Moreover, the chemosensitizing effects of Piper nigrum in association with traditional anticancer drugs are depicted and its toxicological profile is outlined. Despite the promising results, human studies are missing, which are crucial for supporting the efficacy and safety of Piper nigrum and its single components in cancer patients.

Prebiotic Potential of Culinary Spices Used to Support Digestion and Bioabsorption

Although the impact of medicinal and culinary herbs on health and disease has been studied to varying extents, scarcely little is known about the impact of these herbs on gut microbiota and how such effects might contribute to their health benefits. We applied in vitro anaerobic cultivation of human fecal microbiota followed by 16S rRNA sequencing to study the modulatory effects of 4 culinary spices: Curcuma longa (turmeric), Zingiber officinale (ginger), Piper longum (pipli or long pepper), and Piper nigrum (black pepper). All herbs analyzed possessed substantial power to modulate fecal bacterial communities to include potential prebiotic and beneficial repressive effects. We additionally analyzed the sugar composition of each herb by mass spectrometry and conducted genome reconstruction of 11 relevant sugar utilization pathways, glycosyl hydrolase gene representation, and both butyrate and propionate biosynthesis potential to facilitate our ability to functionally interpret microbiota profiles. Results indicated that sugar composition is not predictive of the taxa responding to each herb; however, glycosyl hydrolase gene representation is strongly modulated by each herb, suggesting that polysaccharide substrates present in herbs provide selective potential on gut communities. Additionally, we conclude that catabolism of herbs by gut communities primarily involves sugar fermentation at the expense of amino acid metabolism. Among the herbs analyzed, only turmeric induced changes in community composition that are predicted to increase butyrate-producing taxa. Our data suggests that substrates present in culinary spices may drive beneficial alterations in gut communities thereby altering their collective metabolism to contribute to the salubrious effects on digestive efficiency and health. These results support the potential value of further investigations in human subjects to delineate whether the metabolism of these herbs contributes to documented and yet to be discovered health benefits.

A systematic review on black pepper (Piper nigrum L.): from folk uses to pharmacological applications

Considered as the "King of spices", black pepper (Piper nigrum L.) is a widely used spice which adds flavor of its own to dishes, and also enhances the taste of other ingredients. Piper nigrum has also been extensively explored for its biological properties and its bioactive phyto-compounds. There is, however, no updated compilation of these available data to provide a complete profile of the medicinal aspects of P. nigrum. This study endeavors to systematically review scientific data on the traditional uses, phytochemical composition, and pharmacological properties of P. nigrum. Information was obtained using a combination of keywords via recognized electronic databases (e.g., Science Direct and Google Scholar). Google search was also used. Books and online materials were also considered, and the literature search was restricted to the English language. The country with the highest number of traditional reports of P. nigrum for both human and veterinary medicine was India, mostly for menstrual and ear-nose-throat disorders in human and gastrointestinal disorders in livestock. The seeds and fruits were mostly used, and the preferred mode of preparation was in powdered form, pills or tablets, and paste. Piper nigrum and its bioactive compounds were also found to possess important pharmacological properties. Antimicrobial activity was recorded against a wide range of pathogens via inhibition of biofilm, bacterial efflux pumps, bacterial swarming, and swimming motilities. Studies also reported its antioxidant effects against a series of reactive oxygen and nitrogen species including the scavenging of superoxide anion, hydrogen peroxide, nitric oxide, DPPH, ABTS, and reducing effect against ferric and molybdenum (VI). Improvement of antioxidant enzymes in vivo has also been reported. Piper nigrum also exhibited anticancer effect against a number of cell lines from breast, colon, cervical, and prostate through different mechanisms including cytotoxicity, apoptosis, autophagy, and interference with signaling pathways. Its antidiabetic property has also been confirmed in vivo as well as hypolipidemic activity as evidenced by decrease in the level of cholesterol, triglycerides, and low-density lipoprotein and increase in high-density lipoprotein. Piper nigrum also has anti-inflammatory, analgesic, anticonvulsant, and neuroprotective effects. The major bioactive compound identified in P. nigrum is piperine although other compounds are also present including piperic acid, piperlonguminine, pellitorine, piperolein B, piperamide, piperettine, and (-)-kusunokinin, which also showed biological potency. Most pharmacological studies were conducted in vitro (n = 60) while only 21 in vivo and 1 clinical trial were performed. Hence, more in vivo experiments using a pharmacokinetic and pharmacokinetic approach would be beneficial. As a conclusive remark, P. nigrum should not only be regarded as "King of spices" but can also be considered as part of the kingdom of medicinal agents, comprising a panoply of bioactive compounds with potential nutraceutical and pharmaceutical applications.

In Vitro Evaluation of Cytotoxic Activities of Marketed Herbal Products in Ghana

There are numerous herbal products on the Ghanaian market that are purported to cure various ailments, including cancer. However, scientific investigations on efficacy and toxicity of most of these products are not done. The aim of the study was to assess the anticancer potentials of herbal products on the Ghanaian market. Antiproliferative effects of Kantinka BA (K-BA), Kantinka Herbaltics (K-HER), Centre of Awareness (COA), a stomach (STO) and multicancer (MUT) product were evaluated in vitro using liver (Hep G2), breast (MCF-7), prostate (PC-3 and LNCaP), and blood (Jurkat) cancer cell lines. Cytotoxicity of the medicinal products was assessed using tetrazolium-based colorimetric assay, and total phenolic content and antioxidant activity of the products were determined using Folin-Ciocalteau and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays, respectively. Phytochemical screening resulted in the detection of terpenoids and flavonoids in most of the products, and alkaloids were detected in only MUT. Tannins were absent from all the products. The highest and lowest concentrations of phenolics were recorded for MUT and K-BA, respectively. The highest and lowest antioxidant activities were measured for MUT and K-HER, respectively. Only 2 products (STO and MUT) were cytotoxic to Hep G2 cells; with MUT being the only product that was cytotoxic to MCF-7 cells. All but K-BA were cytotoxic to PC-3 cells, while all products except K-HER were cytotoxic to LNCaP and Jurkat cells. The study thus confirms that the herbal products have selective cytotoxic activities against the tested cancer cell lines. However, comprehensive toxicity studies must be conducted to establish their safety.

Crude leaf extracts of Piperaceae species downmodulate inflammatory responses by human monocytes

In this study, we aimed to evaluate the immunomodulatory effects of crude leaf extracts from Piper gaudichaudianum Kunth, P. arboreum Aub., P. umbellata L., P. fuligineum Kunth, and Peperomia obtusifolia A. Dietr. on an in vitro model of inflammatory response. The crude extracts were previously obtained by maceration of the leaves. The half-maximal inhibitory concentration was determined by the MTT assay using human peripheral blood mononuclear cells. Human monocytes were simultaneously challenged with each crude extract and lipopolysaccharide (LPS), the major component of the outer membrane of Gram-negative bacteria, to induce a strong inflammatory response. After 24 h of incubation, cell-free supernatants were used for evaluating the mediators involved in inflammation: H₂O₂, TNF-α, IL-8, IL-6, IL-1β, IL-10, IL-12, FGF-b, and TGF-β1. We also compared the results with the effects of ketoprofen, a well-known anti-inflammatory drug. The P. gaudichaudianum crude extract downmodulated the production of H₂O₂, IL-1β, IL-6, IL-8, and TGF-β1 by LPS-stimulated monocytes; P. arboreum, IL-1β, IL-6, IL-8, and TNF-α; P. umbellata and P. fuligineum, H₂O₂, IL-1β, IL-6, IL-8, IL-10, and TNF-α; and P. obtusifolia, H₂O₂, IL-6, IL-8, IL-10, and TNF-α. In general, the crude leaf extracts amplified the anti-inflammatory response when compared with ketoprofen, particularly reducing the production of IL-8, a mediator involved in neutrophil recruitment during tissue damage. Thus, the crude leaf extracts of P. gaudichaudianum, P. arboreum, P. umbellata, P. fuligineum, and Peperomia obtusifolia elicited an anti-inflammatory response against LPS-challenged monocytes. These findings show the anti-inflammatory properties of these crude leaf extracts and offer new perspectives for their use in the treatment of inflammatory diseases.

Anti-inflammatory, anti-cholinergic and cytotoxic effects of Sida rhombifolia

CONTEXT

Sida (Malvaceae) has been used as a traditional remedy for the treatment of diarrhoea, malarial, gastrointestinal dysentery, fevers, asthma and inflammation.

OBJECTIVES

This study evaluates the anti-inflammatory, cytotoxic and anti-cholinergic activities of Sida rhombifolia Linn. whole plant for the first time.

MATERIALS AND METHODS

S. rhombifolia whole plant was extracted by n-hexane, ethyl acetate and methanol using Soxhlet apparatus. The plant extracts were evaluated for their antioxidant (DPPH, FIC and FRAP), anti-inflammatory (NO and protein denaturation inhibitions), cytotoxic (MTT) and anti-cholinesterase (AChE) properties in a range of concentrations to obtain IC₅₀ values. GC-MS analysis was carried out on the n-hexane extract.

RESULTS AND DISCUSSION

The ethyl acetate extract exhibited the most significant antioxidant activities by scavenging DPPH radicals and ferrous ions with EC₅₀ of 380.5 and 263.4 μg/mL, respectively. In contrast, the n-hexane extract showed the strongest anti-inflammatory activity with IC₅₀ of 52.16 and 146.03 μg/mL for NO and protein denaturation inhibition assays, respectively. The same extract also revealed the strongest effects in anti-cholinesterase and cytotoxic tests at the concentration of 100 μg/mL, AChE enzyme inhibition was 58.55% and human cancer cells, SNU-1 and Hep G2 inhibition was 68.52% and 47.82%, respectively. The phytochemicals present in the n-hexane extract are palmitic acid, linoleic acid and γ-sitosterol.

CONCLUSIONS

The present study revealed that the n-hexane extract possessed relatively high pharmacological activities in anti-inflammation, cytotoxicity and anti-cholinesterase assays. Thus, further work on the detail mechanism of the bioactive phytochemicals which contribute to the biological properties are strongly recommended.

Sensory active piperine analogues from Macropiper excelsum and their effects on intestinal nutrient uptake in Caco-2 cells

The phytochemical profile of Macropiper excelsum (G.Forst.) Miq. subsp. excelsum (Piperaceae), a shrub which is widespread in New Zealand, was investigated by LC-MS-guided isolation and characterization via HR-ESI-TOF-MS and NMR spectroscopy. The isolated compounds were sensorily evaluated to identify their contribution to the overall taste of the crude extract with sweet, bitter, herbal and trigeminal impressions. Besides the known non-volatile Macropiper compounds, the lignans (+)-diayangambin and (+)-excelsin, four further excelsin isomers, (+)-diasesartemin, (+)-sesartemin, (+)-episesartemin A and B were newly characterized. Moreover, piperine and a number of piperine analogues as well as trans-pellitorine and two homologues, kalecide and (2E,4E)-tetradecadienoic acid N-isobutyl amide were identified in M. excelsum, some of them for the first time. Methyl(2E,4E)-7-(1,3-benzodioxol-5-yl)hepta-2,4-dienoate was identified and characterized for the first time in nature. Sensory analysis of the pure amides indicated that they contributed to the known chemesthetic effects of Macropiper leaves and fruits. Since the pungent piperine has been shown to affect glucose and fatty acid metabolism in vivo in previous studies, piperine itself and four of the isolated compounds, piperdardine, chingchengenamide A, dihydropiperlonguminine, and methyl(2E,4E)-7-(1,3-benzodioxol-5-yl)hepta-2,4-dienoate, were investigated regarding their effects on glucose and fatty acid uptake by enterocyte-like Caco-2 cells, in concentrations ranging from 0.1 to 100 μM. Piperdardine showed the most pronounced effect, with glucose uptake increased by 83 ± 18% at 100 μM compared to non-treated control cells. An amide group seems to be advantageous for glucose uptake stimulation, but not necessarily for fatty acid uptake-stimulating effects of piperine-related compounds.

A new benzophenanthridine alkaloid and other bioactive constituents from the stem bark of Zanthoxylum heitzii

Heitziquinone (7), a new benzophenanthridine alkaloid, together with five known compounds; isoarnottianamide (5), rhoifoline B (6), isobauerenol (8), 6-hydroxypellitorine (9) and sylvamide (10), were isolated as minor compounds from the hexane extract of stem bark from Zanthoxylum heitzii. Four previously reported compounds (1-4) were found, as well. Compounds 5 and 7 were both found to exist as 4:1 mixtures of two atropisomers. The structures were elucidated by 1D and 2D NMR spectroscopy and by mass spectrometry. Compounds 5-10 were identified for the first time in this species, and they are all rare natural compounds. Pellitorine (4), one of the main compounds from the hexane bark extract, was found to be responsible for the brine shrimp larvae toxicity (LC50 37 μM, 8 μg/ml) of the crude extract (LC50 24 μg/ml). Low cytotoxicity against a macrophage cell line was observed.

Anticancer principles from medicinal piper ( hú jiāo) plants

The ethnomedical uses of Piper (胡椒 Hú Jiāo) plants as anticancer agents, in vitro cytotoxic activity of both extracts and compounds from Piper plants, and in vivo antitumor activity and mechanism of action of selected compounds are reviewed in the present paper. The genus Piper (Piperaceae) contains approximately 2000 species, of which 10 species have been used in traditional medicines to treat cancer or cancer-like symptoms. Studies have shown that 35 extracts from 24 Piper species and 32 compounds from Piper plants possess cytotoxic activity. Amide alkaloids account for 53% of the major active principles. Among them, piplartine (piperlongumine) shows the most promise, being toxic to dozens of cancer cell lines and having excellent in vivo activity. It is worthwhile to conduct further anticancer studies both in vitro and in vivo on Piper plants and their active principles.

Piperine attenuates cardiovascular, liver and metabolic changes in high carbohydrate, high fat-fed rats

Black pepper is used worldwide to enhance food flavor. We investigated dietary supplementation with piperine, the active principle of black pepper, to high carbohydrate, high fat (HCHF) diet-fed rats as a model of human metabolic syndrome. Rats were fed with either HCHF diet (carbohydrate, 52%; fat, 24%; 25% fructose in drinking water) or cornstarch (CS) diet for a total of 16 weeks. Diets of the treatment groups (CS + piperine and HCHF + piperine) were supplemented with piperine for the last 8 weeks of this protocol. After 16 weeks, rats fed with HCHF diet developed hypertension, elevated oxidative stress and inflammation-induced cardiac changes (infiltration of inflammatory cells in heart, increase in count and degranulation of mast cells in heart, cardiac fibrosis and increase in ventricular stiffness), reduced responsiveness of aortic rings, impaired glucose tolerance, abdominal obesity together with liver fibrosis, fat deposition and increased plasma liver enzymes. Supplementation with piperine (375 mg/kg food; approximately 30 mg/kg/day) in HCHF-fed rats normalized blood pressure, improved glucose tolerance and reactivity of aortic rings, reduced plasma parameters of oxidative stress and inflammation, attenuated cardiac and hepatic inflammatory cell infiltration and fibrosis and improved liver function. These changes clearly suggest that piperine reduces symptoms of human metabolic syndrome in HCHF-fed rats by reducing inflammation and oxidative stress.

Alkaloids analysis using off-line two-dimensional supercritical fluid chromatography × ultra-high performance liquid chromatography

2-D SFC × UHPLC method with high orthogonality for analysis of the amide alkaloids fraction of P. longum L.

Neolignans and phenylpropanoids from the roots of Piper taiwanense and their antiplatelet and antitubercular activities

Bioassay-guided fractionation of roots from Piper taiwanense led to isolation of three neolignans, diallylcatechol (1) and neotaiwanensols A, B (2, 3), two diphenylpropanoid ethers, taiwandimerols A, B (4, 5), with one phenylpropanoid, 2,3-diacetoxy-1-methoxy-5-allylbenzene (6), previously unknown in nature, together with 18 known compounds (7-24). Their structures were elucidated by spectroscopic evidence. Among the isolates, hydroxychavicol acetate (7), and 4-allylcatechol (8) showed potent inhibitory activities against platelet aggregation induced by collagen, with IC50 values of 2.1, and 5.3 μM, respectively. Hydroxychavicol acetate (7), 4-allylcatechol (8), and trans-caffeicaldehyde (9) showed antitubercular activities against Mycobacterium tuberculosis H37Rv, with MIC values of 30.3, 27.6, and 25.5 μg/mL, respectively.

Hypolipidemic effects of a new piperine derivative GB-N from Piper longum in high-fat diet-fed rats

CONTEXT

Long pepper, Piper longum Linn. (Piperaceae), is widely used in traditional Mongolian medicine for treating hyperlipidemia and coronary heart disease.

OBJECTIVE

To investigate the hypolipidemic effects of a new piperine derivative GB-N isolated from long pepper in high-fat diet-fed rats.

METHODS

The levels of serum total cholesterol, triacylglycerols (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were determined by enzymatic colorimetric method. The levels of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA), CYP7A1, lecithin cholesterol acyltransferase (LCAT) and LDL receptor (LDLR) mRNA and protein expression were detected by real-time polymerase chain reaction and western blot analysis.

RESULTS AND DISCUSSION

Compared with model rats, oral administration of GB-N at doses of 2.5-10 mg/kg to hyperlipidemic rats could significantly decrease the levels of serum TG from 1.54 mmol/L in hyperlipidemic rats to 0.94-1.02 mmol/L, with an increase in serum HDL-C levels from 0.40 mmol/L in hyperlipidemic rats to 1.21-2.26 mmol/L. Treatment with GB-N (10 mg/kg) could also significantly upregulate levels of hepatic HMG-CoA reductase, CYP7A1, LCAT and LDLR mRNA and protein expression.

CONCLUSION

GB-N had hypolipidemic activity via regulating lipid metabolism pathways in liver of hyperlipidemic rats and could be explored as a potential agent for the prevention of hyperlipidemia diseases.

A review of the literature and latest advances in research of Piper sarmentosum

CONTEXT

Piper sarmentosum Roxb. (Piperaceae) is a traditional medicinal as well as a culinary plant in South East Asian countries, whereby aerial parts of the plant are consumed as a vegetable in various forms and the whole plant or parts are used as folk remedies, alone or in combination with other herbs, to treat various ailments. The plant has extensively been investigated in a broad range of studies to provide scientific evidence for folklore claims or to find new therapeutic uses; however, heretofore, a summary of the data are not available.

OBJECTIVE

In order to describe nutritional and therapeutic potential of P. sarmentosum and summarize scientific evidence that supports traditional claims, a literature review and latest advances in research of the plant are given herein.

MATERIALS AND METHODS

The literature has been retrieved from a number of databases such as Google Scholar, PubMed, Medline, Science Direct and SciFinder. The articles related to synthetic work, ecology and agriculture have been excluded.

RESULTS AND DISCUSSION

The review has not only revealed a number of pharmacological activities supporting the traditional claims but indicates new prospects for the plant. Antiangiogenic activity and toxicity studies suggest the usage of the plant in treating diseases involving neo-vascularization. The available efficacy, safety, pharmacokinetic and stability data urge clinical studies on extracts of the plant.

CONCLUSION

The present review may be helpful to future researchers intending to investigate the plant and natural pharmaceutical industry for preparing evidence-based formulations.

Piper sarmentosum as an antioxidant on oxidative stress in human umbilical vein endothelial cells induced by hydrogen peroxide

Endothelial cell death due to increased reactive oxygen species (ROS) may contribute to the initial endothelial injury, which promotes atherosclerotic lesion formation. Piper sarmentosum (PS), a natural product, has been shown to have an antioxidant property, which is hypothesized to inhibit production of ROS and prevent cell injury. Thus, the present study was designed to determine the effects of PS on the hydrogen peroxide (H(2)O(2))-induced oxidative cell damage in cultured human umbilical vein endothelial cells (HUVECs). In this experiment, HUVECs were obtained by collagenase perfusion of the large vein in the umbilical cord and cultured in medium M200 supplemented with low serum growth supplementation (LSGS). HUVECs were treated with various concentrations of H(2)O(2) (0-1000 micromol/L) and it was observed that 180 micromol/L H(2)O(2) reduced cell viability by 50% as denoted by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Using the above concentration as the positive control, the H(2)O(2)-induced HUVECs were concomitantly treated with various concentrations (100, 150, 250 and 300 microg/ml) of three different extracts (aqueous, methanol and hexane) of PS. Malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) levels showed a significant increase (P<0.05) in HUVECs compared to the negative control. However, PS extracts showed a protective effect on HUVECs from H(2)O(2)-induced cell apoptosis with a significant reduction in MDA, SOD, CAT and GPX levels (P<0.05). Furthermore, PS had exhibited ferric reducing antioxidant power with its high phenolic content. Hence, it was concluded that PS plays a beneficial role in reducing oxidative stress in H(2)O(2)-induced HUVECs.

In vivo anti-nociceptive and anti-inflammatory activities of the aqueous extract of the leaves of Piper sarmentosum

ETHNOPHARMACOLOGICAL RELEVANCE

Piper sarmentosum (Piperaceae) is a medicinal plant traditionally used by the Malays to treat headaches, toothaches, coughs, asthma and fever.

AIM OF THE STUDY

In order to establish the pharmacological properties of the leaf of this plant, studies were performed on anti-nociceptive and anti-inflammatory activities.

MATERIALS AND METHODS

The aqueous extract of Piper sarmentosum (AEPS) was prepared in the doses of 30, 100 and 300 mg/kg. Anti-nociceptive activity of AEPS was evaluated by abdominal constriction and hot-plate tests. AEPS was also pre-challenged with 5mg/kg naloxone to determine the involvement of opioid receptors. Anti-inflammatory activity was evaluated using carrageenan-induced paw edema assay.

RESULTS

Subcutaneous administration of AEPS exhibited anti-nociceptive activity (P<0.05) in a dose-dependent manner in the abdominal constriction and hot-plate tests. Pre-treatment with naloxone completely (P<0.05) diminished the extract anti-nociceptive activity in both tests. The AEPS, at all doses used, exerted significant (P<0.05) anti-inflammatory activity in a dose-dependent manner.

CONCLUSIONS

The AEPS exhibits opioid-mediated anti-nociceptive activity at the peripheral and central levels, as well as anti-inflammatory activity, which confirmed the traditional uses of the plant in the treatment of pain- and inflammatory-related ailments.