N-Cinnamoylpyrrole-derived alkaloids from the genus Piper as promising agents for ischemic stroke by targeting eEF1A1.

BACKGROUND: Ischemic stroke (IS) is a serious cerebrovascular disease characterized by significantly elevated mortality and disability rates, and the treatments available for this disease are limited. Neuroinflammation and oxidative stress are deemed the major causes of cerebral ischemic injury. N-Cinnamoylpyrrole alkaloids form a small group of natural products from the genus Piper and have not been extensively analyzed pharmacologically. Thus, identifying the effect and mechanism of N-cinnamoylpyrrole-derived alkaloids on IS is worthwhile. PURPOSE: The present research aimed to explore the antineuroinflammatory and antioxidative stress effects of N-cinnamoylpyrrole-derived alkaloids isolated from the genus Piper and to explain the effects and mechanism on IS. METHODS: N-cinnamoylpyrrole-derived alkaloids were isolated from Piper boehmeriaefolium var. tonkinense and Piper sarmentosum and identified by various chromatographic methods. Lipopolysaccharide (LPS)-induced BV-2 microglia and a mouse model intracerebroventricularly injected with LPS were used to evaluate the antineuroinflammatory and antioxidative stress effects. Oxygen‒glucose deprivation/reperfusion (OGD/R) and transient middle cerebral artery occlusion (tMCAO) models were used to evaluate the effect of PB-1 on IS. To elucidate the fundamental mechanism, the functional target of PB-1 was identified by affinity-based protein profiling (ABPP) strategy and verified by cellular thermal shift assay (CETSA), drug affinity responsive target stability (DARTS), and circular dichroism (CD) analyses. The effect of PB-1 on the NF-κB and NRF2 signaling pathways was subsequently evaluated via western blotting and immunofluorescence staining. RESULTS: The results showed that N-cinnamoylpyrrole-derived alkaloids significantly affected neuroinflammation and oxidative stress. The representative compound, PB-1 not only inhibited neuroinflammation and oxidative stress induced by LPS or OGD/R insult, but also alleviated cerebral ischemic injury induced by tMCAO. Further molecular mechanism research found that PB-1 promoted antineuroinflammatory and antioxidative stress activities via the NF-κB and NRF2 signaling pathways by targeting eEF1A1. CONCLUSION: Our research initially unveiled that the therapeutic impact of PB-1 on cerebral ischemic injury might rely on its ability to target eEF1A1, leading to antineuroinflammatory and antioxidative stress effects. The novel discovery highlights eEF1A1 as a potential target for IS treatment and shows that PB-1, as a lead compound that targets eEF1A1, may be a promising therapeutic agent for IS.

Chemical Composition of Piper nigrum L. Cultivar Guajarina Essential Oils and Their Biological Activity.

The essential oils and aroma derived from the leaves (L), stems (St), and spikes (s) of Piper nigrum L. cv. Guajarina were extracted; the essential oils were extracted using hydrodistillation (HD), and steam distillation (SD), and the aroma was obtained by simultaneous distillation and extraction (SDE). Chemical constituents were identified and quantified using GC/MS and GC-FID. Preliminary biological activity was assessed by determining the toxicity against Artemia salina Leach larvae, calculating mortality rates, and determining lethal concentration values (LC50). The predominant compounds in essential oil samples included α-pinene (0-5.6%), ß-pinene (0-22.7%), limonene (0-19.3%), 35 linalool (0-5.3%), δ-elemene (0-10.1%), ß-caryophyllene (0.5-21.9%), γ-elemene (7.5-33.9%), and curzerene (6.9-31.7%). Multivariate analysis, employing principal component analysis (PCA) and hierarchical cluster analysis (HCA), revealed three groups among the identified classes and two groups among individual compounds. The highest antioxidant activity was found for essential oils derived from the leaves (167.9 41 mg TE mL-1). Larvicidal potential against A. salina was observed in essential oils obtained from the leaves (LC50 6.40 µg mL-1) and spikes (LC50 6.44 µg mL-1). The in silico studies demonstrated that the main compounds can interact with acetylcholinesterase, thus showing the potential molecular interaction responsible for the toxicity of the essential oil in A. salina.

Tissue-specific variations of piperine in ten populations of Piper longum L.: bioactivities and toxicological profile.

P. longum L., one of the most significant species of the genus Piperaceae, is most frequently employed in Indian-Ayurvedic and other traditional medicinal-systems for treating a variety of illnesses. The alkaloid piperine, is the key phytoconstituent of the plant, primarily responsible for its' pharmacological-impacts. The aim of the study is to analyse the intra-specific variation in piperine content among different chemotypes (PL1 to PL 30) and identify high piperine yielding chemotype (elite-chemotype) collected from 10 different geographical regions of West Bengal by validated HPTLC chromatography method. The study also focused on the pharmacological-screening to better understand the antioxidant activity of the methanol extracts of P. longum by DPPH and ABTS radical-scavenging activity and genotoxic activity by Allium cepa root tip assay. It was found that the P. longum fruit chemotypes contain high amount piperine (highest 16.362 mg/g in chemotype PL9) than the stem and leaf chemotypes. Both DPPH and ABTS antioxidant assays revealed that P. longum showed moderate radical-scavenging activity and the highest activity was found in PL9 (fruit) chemotype with IC50 values of 124.2 ± 0.97 and 104 ± 0.78 µg/ml respectively. The A. cepa root tip assay showed no such significant genotoxic-effect and change in mitotic-index. The quick, reproducible, and validated HPTLC approach offers a useful tool for determining quantitative variations of piperine among P. longum chemotypes from different geographical-regions and also according to the different tissues and choose elite genotypes with high piperine production for continued propagation and commercialization for the pharmaceutical sector. Additionally, the plant's in-vitro antioxidant property and lack of genotoxicity directly supports its' widespread and long history of use as a medicinal and culinary plant.

Expanded Application of Piper nigrum: Guided Isolation of Alkaloids with Inhibitory Activities of AChE/BuChE and Aß Aggregation.

Piper nigrum is a popular crop that can be used as seasoning or as an additive but its active ingredients also have an effect on the nervous system. Nineteen new amide alkaloids (1a/1b, 2-5, 6a/6b, 7, 8a/8b, 9, 10a/10b, 11a-11b, 12-14) were isolated from P. nigrum, guided by inhibitory activity of AChE and LC-MS/MS based on GNPS. The configurations were determined by extensive spectral analysis, Bulkiness rule, and NMR calculations. The inhibitory activities of AChE/BuChE and Aß aggregation were tested, and the results showed compounds 2, 7, and 12 had significant inhibitory activities. These components were identified in the crude fraction and their relative quantities were tested, which suggested that compound 2 was the index component in the active site from P. nigrum.

Chemical Profile and Biological Activities Of Piper mikanianum (Kunth) Steud Essential Oil for Development and Improvement of Oral Rinse.

INTRODUCTION: Studies prove that the use of medicinal plants is a custom carried out by man since ancient times, the evolution of the pharmaceutical industry makes more people consume more natural products. Currently, we can observe that mouthwashes containing natural compounds have shown a growth in demand in the markets and in the professional community. OBJECTIVE: The present study aims to carry out the chemical characterization and microbiological potential of Piper mikanianum (Kunth) Steud essential oil (EOPm), providing data that allows the development of a low-cost mouthwash formulation aimed at vulnerable communities. METHODS: The evaluation of the antibacterial activity and modulator of bacterial resistance was performed by the microdilution method to determine the minimum inhibitory concentration (MIC). The chemical components were characterized by gas chromatography coupled to mass spectrometry, identified 28 constituents, in which Safrole Phenylpropanoid is the major compound, representing 72.6 % of the total composition, followed by α-pinene (10.7 %), Limonene (2 %), ß-caryophyllene (2 %), E-nerolidol (1.9 %), spathulenol (1.3 %) and camphene (1.1 %). RESULTS: The EOPm showed a MIC minimum inhibitory concentration≥1024 µg/mL for all bacterial strains used in the tests. When the EOPm modulating activity combined with chlorhexidine, mouthwash, ampicillin, gentamicin and penicillin G was evaluated against bacterial resistance, the oil showed significant synergistic activity, reducing the MIC of the products tested in combination, in percentage between 20.6 % to 98 .4 %. CONCLUSIONS: We recommend the expansion of tests with greater variation of EOPm concentration combinations and the products used in this study, as well as toxicity evaluation and in vivo tests, seeking the development of a possible low-cost mouthwash formulation accessible to the most vulnerable population.

Network pharmacology-based anti-colorectal cancer activity of piperlonguminine in the ethanolic root extract of Piper longum L.

Colorectal cancer (CRC) has the second highest incidence and fatality rates of any malignancy, at 10.2 and 9.2%, respectively. Plants and plants-based products for thousands of years have been utilized to treat cancer along with other associated health issues. Alkaloids are a valuable class of chemical compounds with great potential as new medicine possibilities. Piper longum Linn contains various types of alkaloids. In this research, the ethanolic root extract of P. longum (EREPL) is the subject of study based on network pharmacology. Two alkaloids were chosen from the gas chromatography mass spectrometry (GC-MS) analysis. However, only piperlonguminine received preference because it adhered to Lipinski's rule and depicted no toxicity. Web tools which are available online, like, Swiss ADME, pkCSMand ProTox-II were used to evaluate the pharmacokinetics and physiochemical properties of piperlonguminine. The database that SwissTargetPrediction and TCMSP maintain contains the targets for piperlonguminine. Using DisGeNET, GeneCards and Open Targets Platform databases, we were able to identify targets of CRC. The top four hub genes identified by Cytoscape are SRC, MTOR, EZH2, and MAPK3. The participation of hub genes in colorectal cancer-related pathways was examined using the Kyoto Encyclopaedia of Genes and Genomes (KEGG) database. The colorectal cancer pathway, the ErbB signaling pathway and the mTOR signaling pathway emerged to be important. Our findings show that the hub genes are involved in the aforementioned pathways for tumor growth, which calls for their downregulation. Additionally, piperlonguminine has the potential to become a successful medicine in the future for the treatment of CRC.

Quality Control and Authentication of Black Betel Leaf Extract (Piper acre Blume) from East Kalimantan as an Antimicrobial Agent Using a Combination of High-Performance Liquid Chromatography and Chemometric Fourier Transform Infrared.

Black betel leaf from East Kalimantan contains various secondary metabolites such as alkaloid saponins, flavonoids, and tannins. A compound, piperenamide A, which has antimicrobial activity, is also found in black betel leaf. This study aims to identify and authenticate the compound piperenamide A found in black betel leaf extract in other types of betel plant using HPLC and FTIR-chemometrics. The extraction method used was maceration with 70% ethanol solvent. Determination of piperenamide A content in black betel leaf extract was via HPLC column C18, with a maximum wavelength of 259 nm and a mobile phase of water:acetonitrile at a flow rate of 1 mL/minute. From the results, piperenamide A was only found in black betel (Piper acre) and not in Piper betel and Piper crocatum. Piperenamide A levels obtained were 4.03, 6.84, 5.35, 13.85, and 2.15%, respectively, in the samples studied. The combination of FTIR spectra with chemometric methods such as PCA and PLS-DA was used to distinguish the three types of betel. Discriminant analysis can classify black betel (Piper acre), Piper betel, and Piper crocatum according to its type. These methods can be used for identification and authentication of black betel.

Alkaloids from Piper longum Exhibit Anti-inflammatory Activity and Synergistic Effects with Chemotherapeutic Agents against Cervical Cancer Cells.

Piper longum L. is widely cultivated for food, medicine, and other purposes in tropical and subtropical regions. Sixteen compounds including nine new amide alkaloids were isolated from the roots of P. longum. The structures of these compounds were determined by spectroscopic data. All compounds showed better anti-inflammatory activities (IC50 = 1.90 ± 0.68-40.22 ± 0.45 µM) compared to indomethacin (IC50 = 52.88 ± 3.56 µM). Among the isolated compounds, five dimeric amide alkaloids exhibited synergistic effects with three chemotherapeutic drugs (paclitaxel, adriamycin, or vincristine) against cervical cancer cells. Moreover, these dimeric amide alkaloids also enhanced the efficacy of paclitaxel in paclitaxel-resistant cervical cancer cells. The combination treatment of one of these dimeric amide alkaloids and paclitaxel promoted cancer cell apoptosis, which is related to the Src/ERK/STAT3 signaling pathway.

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.

A review on multi-therapeutic potential of (-)-cubebin: experimental evidences.

Lignans are a large category of polyphenolic compounds that have low molecular weight and are widely distributed in the plant kingdom. They have been recognized for their potential antioxidizing and antiproliferative action. One of the most important lignans is cubebin which is abundantly isolated from the leaves and seeds of Piper cubeba and Piper nigrum. Cubebin possesses numerous biological actions such as antileukemic, trypanocidal, antimycobacterial, analgesic, anti-inflammatory, histamine antagonist, antifungal, and antispasmodic. This review discusses the in vitro and in vivo pharmacological studies on cubebin related to biochemistry and pharmacological applications and it ensures that it widely shows therapeutic potential. We expect that these therapeutic actions will set a new track in the formation of novel biological agents by the derivatization of cubebin. This review will assuredly fascinate countless researchers to begin further experimentation that might lead to novel agents for the treatment and prevention of diseases.

Characterization and Bioactive Potential of Secondary Metabolites Isolated from Piper sarmentosum Roxb.

Piper sarmentosum Roxb. (Piperaceae) is a traditional medicinal plant in South-East Asian countries. The chemical investigation of leaves from this species resulted in the isolation of three previously not described compounds, namely 4″-(3-hydroxy-3-methylglutaroyl)-2″-ß-D-glucopyranosyl vitexin (1), kadukoside (2), and 6-O-trans-p-coumaroyl-D-glucono-1,4-lactone (3), together with 31 known compounds. Of these known compounds, 21 compounds were isolated for the first time from P. sarmentosum. The structures were established by 1D and 2D NMR techniques and HR-ESI-MS analyses. The compounds were evaluated for their anthelmintic (Caenorhabditis elegans), antifungal (Botrytis cinerea, Septoria tritici and Phytophthora infestans), antibacterial (Aliivibrio fischeri) and cytotoxic (PC-3 and HT-29 human cancer cells lines) activities. Methyl-3-(4-methoxyphenyl)propionate (8), isoasarone (12), and trans-asarone (15) demonstrated anthelmintic activity with IC50 values between 0.9 and 2.04 mM. Kadukoside (2) was most active against S. tritici with IC50 at 5.0 µM and also induced 94% inhibition of P. infestans growth at 125 µM. Trans-asarone (15), piperolactam A (23), and dehydroformouregine (24) displayed a dose-dependent effect against B. cinerea from 1.5 to 125 µM up to more than 80% inhibition. Paprazine (19), cepharadione A (21) and piperolactam A (23) inhibited bacterial growth by more than 85% at 100 µM. Only mild cytotoxic effects were observed.

Neuroprotective potential of lignan-rich fraction of Piper cubeba L. by improving antioxidant capacity in the rat's brain.

Piper cubeba contains various types of lignans. These compounds have been found to have potential pharmacological activities, one being a neuroprotector through an antioxidant mechanism, especially in the brain. This study examined the antioxidant activity of the lignan-rich fraction of P. cubeba (LF) in rat brains. The rats were given LF (200 and 400 mg/kg), Vitamin C (200 mg/kg), and a carrier as the control group for one-week p.o. The following day, rat brains were collected for antioxidant tests, including examining lipid peroxide inhibition, superoxide dismutase and catalase activity, and determination of nitric oxide (NO) concentration. The phytochemical compounds were analyzed with thin-layer chromatography (TLC), ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS), and gas chromatography-mass spectrometry (GC-MS). Test results show that the LF of both doses of 200 and 400 mg/kg could significantly increase antioxidant activity in the brain by inhibiting lipid peroxidation. LF could also increase catalase, despite the decrease in superoxide dismutase activity. Reduction in NO only occurred in the LF-200 group, while LF-400 showed insignificant results compared to the control group. In conclusion, LF showed potential as an antioxidant in the brain and could be beneficial for treating neurological diseases.

Lignans from the genus Piper L. and their pharmacological activities: An updated review.

The genus Piper, a member of the Piperaceae family, comprises >2000 species, of which many are well known to possess considerable economic and medicinal values. Lignans are essential ingredients and are rich in Piper plants. Although many phytochemical studies have reported many lignans identified from Piper plants, comprehensive research has not reviewed these compounds. Hence, the present review reports on natural lignans from the genus Piper and their pharmacological activities. At least 275 lignans have been discovered from the Piper genus until October 2022, including traditional lignans, neolignans, oxyneolignans, norlignans, secolignans, and polyneolignans, especially some neolignans and norlignans with novel and complex scaffolds. In addition, these lignans have been reported to show various pharmacological activities, such as antimicrobial, anti-inflammatory, neuroprotective, antioxidative, anti-platelet aggregation, cytotoxic, anti-parasitic, CYP3A4 inhibitory activities, and so on. The current work presents an up-to-date critical review and a systematic summary of publications on lignans from the genus Piper to lay the groundwork and show better insights for further investigations.

Effects of Piper sarmentosum on Bone Health and Fracture Healing: A Scoping Review.

BACKGROUND: Piper sarmentosum (PS) is a traditional herb used by Southeast Asian communities to treat various illnesses. Recent pharmacological studies have discovered that PS possesses antioxidant and anti-inflammatory activities. Since oxidative stress and inflammation are two important processes driving the pathogenesis of bone loss, PS may have potential therapeutic effects against osteoporosis. OBJECTIVE: This review systematically summarised the therapeutic effects of PS on preventing osteoporosis and promoting fracture healing. METHODS: A systematic literature search was performed in November 2021 using 4 electronic databases and the search string "Piper sarmentosum" AND (bone OR osteoporosis OR osteoblasts OR osteoclasts OR osteocytes). RESULTS: Nine unique articles were identified from the literature. The efficacy of PS has been studied in animal models of osteoporosis induced by ovariectomy and glucocorticoids, as well as bone fracture models. PS prevented deterioration of bone histomorphometric indices, improved fracture healing and restored the biomechanical properties of healed bone in ovariectomised rats. PS also prevented osteoblast/osteocyte apoptosis, increased bone formation and mineralisation and subsequently improved trabecular bone microstructures and strength of rats with osteoporosis induced by glucocorticoids. Apart from its antioxidant and anti-inflammatory activity, PS also suppressed circulating and skeletal expression of corticosterone and skeletal expression of 11ß hydroxysteroid dehydrogenase type 1 but increased the enzyme activity in the glucocorticoid osteoporosis model. This review also identified several research gaps about the skeletal effects of PS and suggested future studies to bridge these gaps. CONCLUSION: PS may be of therapeutic benefit to bone health. However, further research is required to validate this claim.

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.

Impact of dietary leaf extracts of Black pepper Piper nigrum L on the growth, hematological and immunological parameters of Labeo rohita (Hamilton, 1822) cultured in glass aquaria / Impacto de extratos de folhas da dieta de pimenta-do-reino Piper nigrum L sobre o crescimento, parâmetros hematológicos e imunológicos de Labeo rohita (Hamilton, 1822) cultivado em aquários de vidro

A study was conducted to evaluate the effect of Piper nigrum (black pepper) leaf extract on on the growth performance, proximate composition, hematological parameters, and immune response of Labeo rohita fingerlings with an average weight of 22.14 ± 0.98g. After acclimation for two weeks, fish (n=25) were randomly selected and placed in four glass aquaria (T0, T1, T2 and T3) at constant water temperature (30.0 ± 1.0 °C), pH (7.50 ± 0.5) and total hardness (200 ± 2.0 mgL,-¹) for a period of 12 weeks, with three replicates each. Fish were fed with P. nigrum leaf extract supplemented feed @ 0.0%, 1.0%, 2.0% and 3.0% in T0, T1, T2 and T3, respectively. At the end of experiment, five fish were randomly selected from each aquaria for proximate composition, gut and skin microbial load, hematological parameters. Total proteins, albumins, and globulins were also recorded to evaluate immunological memory. The result revealed that fish in T2 showed better growth performance with an average weight gain of 56.11 ± 0.51 g. Thus, it had been concluded that Piper nigrum, a medicinal plant, can also be used to enhance the growth performance and immune response of Labeo rohita as attractive alternatives against antibiotics and vaccines and has shown no negative side effects on fish health as well as on its environment.

Um estudo foi conduzido para avaliar o efeito do extrato da folha de Piper nigrum (pimenta-do-reino) sobre o desempenho de crescimento, composição centesimal, parâmetros hematológicos e resposta imune de alevinos de Labeo rohita com peso médio de 22,14 ± 0,98g. Após aclimatação por duas semanas, os peixes (n = 25) foram selecionados aleatoriamente e colocados em quatro aquários de vidro (T0, T1, T2 e T3) em temperatura constante da água (30,0 ± 1,0 °C), pH (7,50 ± 0,5) e dureza total (200 ± 2,0 mgL-¹) por um período de 12 semanas, com três repetições cada. Os peixes foram alimentados com ração suplementada com extrato de folha de P. nigrum @ 0,0%, 1,0%, 2,0% e 3,0% em T0, T1, T2 e T3, respectivamente. Ao final do experimento, cinco peixes foram selecionados aleatoriamente de cada aquário para composição centesimal, carga microbiana intestinal e cutânea e parâmetros hematológicos. Proteínas totais, albuminas e globulinas também foram registradas para avaliar a memória imunológica. O resultado revelou que os peixes em T2 apresentaram melhor desempenho de crescimento com ganho de peso médio de 56,11 ± 0,51 g. Assim, concluiu-se que Piper nigrum, uma planta medicinal, também pode ser usado para melhorar o desempenho de crescimento e resposta imunológica de Labeo rohita como alternativas atraentes contra antibióticos e vacinas e não mostrou efeitos colaterais negativos na saúde dos peixes, bem como sobre seu ambiente.

Water Extract of Piper longum Linn Ameliorates Ovariectomy-Induced Bone Loss by Inhibiting Osteoclast Differentiation.

Piper longum linn has traditionally been used for the treatment of respiratory and gastrointestinal disorders in India. Although various pharmacological effects of P. longum have been studied, its effects on bone have not been clearly elucidated. Therefore, this study examined the inhibitory effect of the water extract of P. longum Linn (WEPL) on osteoclast differentiation. WEPL directly affected the osteoclast precursors and suppressed osteoclast differentiation in vitro. In addition, the expression levels of c-Fos and nuclear factor of activated T cells 1, a critical transcription factor for osteoclastogenesis, were significantly downregulated by WEPL via the suppression of the receptor activator of nuclear factor (NF)-κB ligand-induced mitogen-activated protein kinase and NF-κB signaling pathways. Consistent with the in vitro results, oral administration of WEPL (100 and 300 mpk) to ovariectomized mice for six weeks relieved the OVX-induced bone loss. We also identified phytochemicals in WEPL that are reported to exert inhibitory effects on osteoclastogenesis and/or bone loss. Collectively, the findings of our study indicate that WEPL has an anti-osteoporotic effect on OVX-induced bone loss by diminishing osteoclast differentiation, suggesting that it may be useful to treat several bone diseases caused by excessive bone resorption.

In vitro acaricidal activity of Piper longum L. against amitraz resistant Rhipicephalus microplus (Acari: Ixodidae).

The cattle tick, Rhipicephalus microplus Canestrini (Acari: Ixodidae) is one of the most important tick species severely affecting health and causes huge losses to dairy industry. Chemical acaricides are mainly applied for tick control but development of resistance, environmental pollution and contamination of milk and meat products with residues has led to exploration alternative eco-friendly tick control strategies. The dried fruits of Piper longum L. (Indian long pepper, Thippali or Pippali) generally used as flavoring agent have also been shown to have insecticidal property. Different concentrations (0.625%-10%) of alcoholic and aqueous extracts of Piper longum L. were prepared and evaluated for acaricidal activity against amitraz resistant R. microplus adult and larval stages. Against larval stages a dose-dependent mortality response was recorded for both extracts and higher acaricidal property was exhibited by the alcoholic extract with LC50 and LC95 (95% CL) values of 0.488% (0.48-0.49) and 1.39% (1.35-1.44), respectively. Similarly, against adult engorged females, ethanolic extract showed higher acaricidal property with LC50 and LC95 (95% CL) values of 4.67% (4.61-4.74) and 12.38% (12.05-12.73), respectively. Significant (p < 0.05) reduction was recorded in reproductive index of ticks treated and but no effect on hatchability of eggs was recorded in treated groups. The present study establishes acaricidal activity of P. longum fruit extracts against both larval and adult stages of amitraz resistant population of cattle tick.

Chemical composition and anti-inflammatory activity of the essential oils of Piper gaudichaudianum and Piper mikanianum.

ETHNOPHARMACOLOGICAL RELEVANCE: Inflammation is the body's normal protective response to injury and is stimulated by pathogens, toxic compounds, damaged cells or radiation, promoting healing and restoring homeostasis to the injured tissue. Leaves of Piper gaudichaudianum Kunth, known as "pariparoba" are widely used in folk medicine for the relief of toothache, while the fresh roots are used as anti-inflammatory and to treat liver disorders. For P. mikanianum (Kunth) Steud is known as "aguaxima", is widely used in the treatment of inflammation, rheumatism and ulcer, with its roots being used for stomach disorders and as a diaphoretic in intermittent fevers. AIM OF THE STUDY: Therefore, this work aims to chemically characterize the essential oil of Piper gaudichaudianum and Piper mikanianum, as well as the evaluation of neutrophil antichemotactic activity of both essential oils in order to complement the information of its traditional use, taking the leaves as plant material and, with that, corroborating its use in folk medicine for the treatment of inflammatory diseases. MATERIALS AND METHODS: The essential oil from leaves of both Piper species were obtained from crushed fresh samples, by hydrodistillation using a Clevenger type-apparatus for 4 h. The yield determination was performed as vol/wt (v/w) and in triplicate. The amount of essential oil obtained was quantified in mL. The identification and quantification of the compounds was performed using gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC-FID). The in vitro anti-inflammatory activity was evaluated using the model of modified Boyden chamber. In this test the essential oils were tested for their ability to inhibit leukocyte chemotaxis stimulated by Escherichia coli lipopolysaccharide. RESULTS: The chemical composition of the essential oils revealed the identification of 26 constituents for P. gaudichaudianum being the sesquiterpenes ß-selinene (14.0%) and viridiflorene (10.5%) the main compounds, followed by caryophyllene oxide (9.3%) and (E)-nerolidol (9.0%). For P. mikanianum essential oil, ß-myrcene (17.2%) and bicyclogermacrene (26.3%) were the major components in the monoterpenes and sesquiterpene fractions, respectively. The essential oils were also tested for their ability to inhibit neutrophil chemotaxis in vitro when stimulated by Escherichia coli lipopolysaccharide. Both essential oils showed antichemotactic effect with reduction in migration of 0-72.2% for P. gaudichaudianum and 8.6-100% for P. mikanianum to same concentrations, suggesting a response to acute inflammatory processes. CONCLUSIONS: Since up to date there is no report of this biological activities by this mechanism (antichemotactic assay) for essential oils this species. These results showed that the essential oils of P. gaudichaudianum and P. mikanianum have a great capacity to inhibit neutrophil chemotaxis in an inflammatory process, in a dose-dependent way, suggesting anti-inflammatory potential, by preventing its accumulation at the injury site with the possibility of tissue damage. Findings of these studies support the traditional use of these species in the treatment of inflammatory processes.

Involvement of a neutrophil-mast cell axis in the effects of Piper malacophyllum (C. PESL) C. DC extract and its isolated compounds in a mouse model of dysmenorrhoea.

The effects of Piper malacophyllum (C. Pesl) C. DC extracts and its isolated compounds were analysed in a mouse model of primary dysmenorrhoea (PD). Female Swiss mice (6-8 weeks old) on proestrus were intraperitoneally treated with estradiol benzoate for 3 days, to induce PD. Twenty-four hours later, animals were treated 24 h later with vehicle, plant extract, gibbilimbol B, 4,6-dimethoxy-5-E-phenylbutenolide, mixture of 4,6-dimethoxy-5-E-phenylbutenolide and 4,6-dimethoxy-5-Z-phenylbutenolide, or ibuprofen. One hour later, oxytocin was injected and the numbers of abdominal writhing were counted. Then, mice were euthanized and uteri were collected for morphometrical and histological analyses. The effects of P. malacophyllum in inflammation were investigated in mouse peritoneal neutrophils culture stimulated with LPS or fMLP (chemotaxis and mediator release). Finally, uterus contractile and relaxing responses were assessed. Similar to ibuprofen, P. malacophyllum extract and isolated compounds reduced abdominal writhing in mice with PD. Histology indicated a marked neutrophil and mast cell infiltrate in the uterus of PD animals which was attenuated by the extract. The compounds and the extract reduced neutrophil chemotaxis and inflammatory mediator release by these cells. Reduced TNF levels were also observed in uteri of PD mice treated with P. malacophyllum. The extract did not affect spontaneous uterine contractions nor those induced by carbachol or KCl. However, it caused relaxation of oxytocin-induced uterine contraction, an effect blunted by H1 receptor antagonist. Overall the results indicate that P. malacophyllum may represent interesting natural tools for reliving PD symptoms, reducing the triad of pain, inflammation and spasmodic uterus behaviour.