Antibacterial constituents from the berries of Piper nigrum

Expression profiling of immune genes associated with black pepper (Piper nigrum) powder supplementation in the diets of broiler chickens

The present study was conducted on three hundred commercial broiler chicks with the aim to evaluate the effect of black pepper supplementation on expression of TLR gene where the negative control (T1) group was given basal diet without antibiotic and in the control group (T2) basal diet with antibiotic was fed, third (T3), fourth (T4), fifth (T5) and sixth (T6) groups were supplemented with black pepper powder (BPP) at levels 0.25, 0.5, 0.75 and 1%, respectively in diet. After 42 days, a significant reduction (p < 0.05) in ileal E. coli count and a higher value of Lactobacilli was recorded in the various black pepper powder supplemented groups, and they differed significantly (p < 0.05) from negative control. The mRNA expression levels of Toll-like receptors (TLR 2 and TLR 4) had shown significant (p < 0.05) changes in experimental groups. The TLR 2 and TLR 4 genes revealed differential expression in all black pepper supplemented groups in comparison to negative control and control group, while TLR 7 did not show any significant change. Thus, supplementation of black pepper powder can be exploited as an immunomodulator to enhance adaptive immune response of broiler chicks after validation on large number of samples.

Comparative effects of medium-chain fatty acids or phytobiotics-based feed additives on performance, caecum microbiota, volatile fatty acid production and intestinal morphology of broilers

Antibiotic growth promoters have been utilized in broiler nutrition to alleviate the negative effects of the pathogenic microbes to promote performance. However, after the prohibition of antibiotics because of the increasing disclosure related to public health issues, various products have been developed as alternatives. This study was carried out to determine the effects of medium-chain fatty acids (MCFAs) or phytobiotics (essential oils [EOs] and alkaloids [ALKs]), blended feed additives on the growth performance, jejunum histomorphology, and cecal microbiota of broiler chickens. A total of 765 male Ross 308 chicks were randomly distributed into 5 experimental groups, each having 9 replicates with 17 chicks. The experimental procedures were as follows: a control group without supplementation (T1); control group+ MCFAs and EOs blend (T2); control group+ different EOs blend (T3); control group+ ALK sanguinarine (T4); and control group+ EOs and ALK piperine mixture (T5). The results showed that, broilers fed with MCFAs blended with EOs had significantly greater body weight gain during overall period in comparision to the control and T3 groups. Further, only MCFAs blended with EOs group significantly improved jejnum morphology in comparison with the control group (p ≤ 0.05). Besides, the MCFAs blended with EOs group significantly elevated propionate, acetate and butyrate concentration, and decreased the concentration of branch chain fatty acids in caecum (p ≤ 0.05). The results indicated that, the combination of MCFAs and EOs seems to have improvement effects and could be preferred as an efficient feed additive in broiler production.

Nutrient digestibility, gut microflora, carcass yield, and meat microbiology of broilers fed diets supplemented Ethiopian pepper (Xylopia aethiopica), cloves (Syzygium aromaticum), and their composite

The effect of dietary supplementation of Ethiopian pepper (Xylopia aethiopica) and clove (Syzygium aromaticum) and their composite on nutrient digestibility, gut microflora, carcass yield, and meat microbiology were investigated in a 52-day boiler feeding trial. Three hundred and sixty unsexed Ross broilers were used for the study. Four experimental diets were formulated for the starter (0-28 days) and finisher (29-56 days) phases: diet 1 was the control without phytogenic supplementation, diet 2 (supplemented with 1% Ethiopian pepper (EP)), diet 3 (supplemented with 1% clove (CL)), and diet 4 (supplemented with 1% mix of equal quantity (0.5% each) of Ethiopian pepper and clove (EPCL)). Each treatment was replicated 6 times with 15 birds per replicate. Nutrient digestibility was determined on days 28 and 56, gut microflora was determined for the small intestine and caecum on day 56, carcass yield, organ weights, and meat microbiology were also determined on day 56. Data obtained were subjected to a one-way analysis of variance using SAS 2000 and significant means were separated using Tukey's test in the same software. At day 28, broilers fed the diet supplemented EPCL had the highest (P < 0.05) dry matter digestibility (DMD, 86.81%) crude protein digestibility (CPD, 71.28%), and ash digestibility (64.24%). Broilers fed EP supplemented diet had reduced (P < 0.05) DMD (70.50%). Increased (P < 0.05) ether extract digestibility (EED) was observed for broilers fed the diet supplemented CL (75.27%) and EPCL (76.43%). Ash digestibility (AD) was lowest (P < 0.05) for broilers fed control diet (50.30%). At day 56, broilers fed the diet supplemented CL and those fed the EPCL supplemented diet had higher (P < 0.05) CPD (78.07%, 79.35%) and EED (70.20%, 71.42%) than other treatments. Ash digestibility was higher (P < 0.05) for broilers fed diet supplemented EPCL (74.60%) than other treatments. Intestinal clostridium count reduced (P < 0.05) and lactobacillus count increased (P < 0.05) in the intestine and caecum of broilers fed the diet supplemented CL and those fed EPCL supplemented diet. Intestinal coliform and salmonella count reduced (P < 0.05) for broilers fed the diet supplemented EP and those fed the EPCL supplemented diet. Dietary supplementation of EPCL resulted in the highest (P < 0.05) body weight (BW, 2551.38 g), dressing percentage (DP, 81.68%), and percentage of breast muscle (20.01%). Supplementation of EP, CL, and EPCL in the diet of broilers resulted in higher (P < 0.05) spleen weight while dietary supplementation of EP and EPCL resulted in higher (P < 0.05) thymus weight. Clostridium count was reduced (P < 0.05) in the meat of broilers fed the diet supplemented CL and EPCL and the lowest (P < 0.05) salmonella count was observed in the meat of broilers fed the diet supplemented with EPCL. In conclusion, the current study reveals that dietary supplementation with EP and CL composite improves nutrient digestibility, gut microflora, and dressing percentage with reduced meat microbial load of broilers.

Antibacterial and Antifungal Alkaloids from Asian Angiosperms: Distribution, Mechanisms of Action, Structure-Activity, and Clinical Potentials

The emergence of multidrug-resistant bacteria and fungi requires the development of antibiotics and antifungal agents. This review identified natural products isolated from Asian angiosperms with antibacterial and/or antifungal activities and analyzed their distribution, molecular weights, solubility, and modes of action. All data in this review were compiled from Google Scholar, PubMed, Science Direct, Web of Science, ChemSpider, PubChem, and a library search from 1979 to 2022. One hundred and forty-one antibacterial and/or antifungal alkaloids were identified during this period, mainly from basal angiosperms. The most active alkaloids are mainly planar, amphiphilic, with a molecular mass between 200 and 400 g/mol, and a polar surface area of about 50 Ų, and target DNA and/or topoisomerase as well as the cytoplasmic membrane. 8-Acetylnorchelerythrine, cryptolepine, 8-hydroxydihydrochelerythrine, 6-methoxydihydrosanguinarine, 2′-nortiliacorinine, pendulamine A and B, rhetsisine, sampangine, tiliacorine, tryptanthrin, tylophorinine, vallesamine, and viroallosecurinine yielded MIC ≤ 1 µg/mL and are candidates for the development of lead molecules.

Effect of dietary supplementation with phytogenic blend on growth performance, apparent ileal digestibility of nutrients, intestinal morphology, and cecal microflora of broiler chickens

The effects of dietary supplementation with phytogenic blend (PB) of Aerva lanata, Piper betle, Cynodon dactylon, and Piper nigrum on growth performance, ileal nutrient digestibility, intestinal morphology, and cecal microflora were determined in a 42-day broiler feeding trial. A total of 192 broilers were assigned to 4 dietary treatments (6 replicates and 8 birds/replicate): basal diet, basal diet supplemented with antibiotic (chlortetracycline), 1% and 2% PB, respectively. The body weight gain (BWG) of starter chicks increased linearly (P = 0.023) as dietary supplementation levels of PB increased. At grower phase, broilers fed diet supplemented with 1% PB had similar BWG with the antibiotic group, but other treatments had reduced (P = 0.0001) BWG. Dietary supplementation with 1% PB resulted in the highest (P < 0.0001) BWG during the study. Feed intake was not affected by the treatments during the starter, finisher, and overall rearing periods. Broilers fed diet supplemented with 1% PB had the best (P < 0.0001) feed conversion ratio during the study. Overall, broilers fed only basal diet had the highest (P = 0.0450) mortality. Ileal organic matter (OM) digestibility increased linearly (P = 0.044) with broilers fed diet supplemented with PB, but reduced with antibiotic group. Dietary supplementation with 1% PB had the highest (P = 0.0402) ileal digestibility of tryptophan. In the duodenum, broilers fed diet supplemented with PB had longer (P = 0.0006) villi heights than the birds fed only basal diet, but similar with antibiotic group. Broilers fed diet supplemented with PB had longer (P = 0.0064) villi height in the jejunum than the antibiotic group. Bifidobacterium concentration of the cecum content showed a slight increase (P = 0.053) with increasing supplementation levels of PB. In conclusion, the current study shows that dietary supplementation with PB improves growth performance, intestinal morphology, and apparent ileal digestibility of OM and tryptophan in a dose-dependent manner with the best response at 1% inclusion level.

Experimental Approaches and Computational Modeling of Rat Serum Albumin and Its Interaction with Piperine

The bioactive piperine (1-piperoyl piperidine) compound found in some pepper species (Piper nigrum linn and Piper sarmentosum Roxb) has been shown to have therapeutic properties and to be useful for well-being. The tests used to validate these properties were performed in vitro or with small rats. However, in all these assays, the molecular approach was absent. Although the first therapeutic trials relied on the use of rats, no proposal was mentioned either experimentally or computationally at the molecular level regarding the interaction between piperine and rat serum albumin (RSA). In the present study, several spectroscopic techniques were employed to characterize rat serum albumin and, aided by computational techniques, the protein modeling was proposed. From the spectroscopic results, it was possible to estimate the binding constant (3.9 × 10⁴ M^-1 at 288 K) using the Stern-Volmer model and the number of ligands (three) associated with the protein applying interaction density function model. The Gibbs free energy, an important thermodynamic parameter, was determined (-25 kJ/mol), indicating that the interaction was spontaneous. This important set of experimental results served to parameterize the computational simulations. The results of molecular docking and molecular dynamics matched appropriately made it possible to have detailed microenvironments of RSA accessed by piperine.

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.

A Survey of the Chemical Compounds of Piper spp. (Piperaceae) and Their Biological Activities

The genus Piper is one of the largest genera in the Piperaceae, with most species widely distributed globally, covering all continents. To date, many Piper species have been scientifically investigated for their chemical diversities and interesting broad spectrum of bioactivities, including central nervous system (CNS), pesticidal, antifungal and antibacterial effects. This review systematically summarizes the scaffolds of the alkaloids reported, the major chemicals isolated from Piper spp., and their biological activities. Besides the alkaloids, some neolignans with rearranged skeletons show structural diversities, while the chalcones, flavonoids and kava-pyrones have some potential activities. Herein, the sesquiterpenes and phenolic compounds from Piper species and their bioactivities are also surveyed.

Development of a convenience and safety chilled sous vide fish dish: Diversification of aquacultural products

The dynamic expansion of the ready-to-eat seabream sector in its adaptation to new lifestyles has led to the search for new presentation formats in seabream ( Sparus aurata). Green sauce (olive oil, wine vinegar, garlic, fresh parsley, black pepper, basil and salt) and 60 ℃ of cooking temperature were chosen by the panellists for the sous vide cooking process. Seabream fillet and sauce were packaged in polypropylene trays, cooked, chilled and stored at 2 ℃. Microbiological (total viable counts, Enterobacteriaceae, lactic acid bacteria, anaerobic psychrotrophic, moulds and yeasts, Salmonella and Listeria monocytogenes), chemical (pH and TBARs) and sensory parameters were determined at 0, 7, 17, 34, 48 and 62 days. In the conditions used, the microbiological counts remained stable, and Salmonella and Listeria monocytogenes were absent. The acidic sauce had a positive effect on the pH of the product, and low TBARs were obtained throughout storage. The processing conditions used in the present study allowed a chilled ready-to-eat seabream product of consistently high quality up to 62 days of storage to be obtained, representing an expansion of the products offered by the aquacultural industry.

Anti-septic effects of pellitorine in HMGB1-induced inflammatory responses in vitro and in vivo

High mobility group box 1 (HMGB1) acts as a late mediator of vascular inflammatory conditions. Pellitorine (PT), an active amide compound from Asarum sieboldii, is known to possess antibacterial and anticancer properties. In this study, we investigated the anti-septic effects of PT against pro-inflammatory responses in human umbilical vein endothelial cells (HUVECs) induced by HMGB1 and the associated signaling pathways. According to our findings, treatment with PT resulted in inhibited release of HMGB1, down-regulation of HMGB1-dependent inflammatory responses in HUVECs, and inhibited HMGB1-mediated hyperpermeability and leukocyte migration in mice. In addition, treatment with PT resulted in reduced cecal ligation and puncture (CLP)-induced release of HMGB1 and sepsis-related mortality. PT suppressed the production of tumor necrosis factor-α and interleukin 6 and the activation of nuclear factor-κB and extracellular regulated kinases 1/2 by HMGB1. Collectively, these results indicate the potential of PT as a candidate therapeutic agent for treatment of various severe vascular inflammatory diseases via inhibition of the HMGB1 signaling pathway.

Anti-biofilm, anti-hemolysis, and anti-virulence activities of black pepper, cananga, myrrh oils, and nerolidol against Staphylococcus aureus

The long-term usage of antibiotics has resulted in the evolution of multidrug-resistant bacteria. Unlike antibiotics, anti-virulence approaches target bacterial virulence without affecting cell viability, which may be less prone to develop drug resistance. Staphylococcus aureus is a major human pathogen that produces diverse virulence factors, such as α-toxin, which is hemolytic. Also, biofilm formation of S. aureus is one of the mechanisms of its drug resistance. In this study, anti-biofilm screening of 83 essential oils showed that black pepper, cananga, and myrrh oils and their common constituent cis-nerolidol at 0.01 % markedly inhibited S. aureus biofilm formation. Furthermore, the three essential oils and cis-nerolidol at below 0.005 % almost abolished the hemolytic activity of S. aureus. Transcriptional analyses showed that black pepper oil down-regulated the expressions of the α-toxin gene (hla), the nuclease genes, and the regulatory genes. In addition, black pepper, cananga, and myrrh oils and cis-nerolidol attenuated S. aureus virulence in the nematode Caenorhabditis elegans. This study is one of the most extensive on anti-virulence screening using diverse essential oils and provides comprehensive data on the subject. This finding implies other beneficial effects of essential oils and suggests that black pepper, cananga, and myrrh oils have potential use as anti-virulence strategies against persistent S. aureus infections.

Vascular barrier protective effects of pellitorine in LPS-induced inflammation in vitro and in vivo

Pellitorine (PT), an active amide compound, is well known to possess insecticidal, antibacterial and anticancer properties. In this study, we first investigated the possible barrier protective effects of pellitorine against pro-inflammatory responses induced by lipopolysaccharide (LPS) and the associated signaling pathways in vitro and in vivo. The barrier protective activities of PT were determined by measuring permeability, monocyte adhesion and migration, and activation of pro-inflammatory proteins in LPS-activated human umbilical vein endothelial cells (HUVECs) and in mice. We found that PT inhibited LPS-induced barrier disruption, expression of cell adhesion molecules (CAMs) and adhesion/transendothelial migration of monocytes to human endothelial cells. PT also suppressed LPS-induced hyperpermeability and leukocyte migration in vivo. Further studies revealed that PT suppressed the production of tumor necrosis factor-α (TNF-α) or Interleukin (IL)-6 and activation of nuclear factor-κB (NF-κB) or extracellular regulated kinases (ERK) 1/2 by LPS. Moreover, treatment with PT resulted in reduced LPS-induced lethal endotoxemia. These results suggest that PT protects vascular barrier integrity by inhibiting hyperpermeability, expression of CAMs, and adhesion and migration of leukocytes, thereby endorsing its usefulness as a therapy for vascular inflammatory diseases.

Antithrombotic activities of pellitorine in vitro and in vivo

Pellitorine (PLT), an active amide compound, is well known to possess insecticidal, antibacterial and anticancer properties. However, the anti-coagulant functions of PLT are not studied yet. Here, the anticoagulant activities of PLT were examined by monitoring activated partial thromboplastin time (aPTT), prothrombin time (PT), and the activities of cell-based thrombin and activated factor X (FXa). Furthermore, the effects of PLT on the expressions of plasminogen activator inhibitor type 1 (PAI-1) and tissue-type plasminogen activator (t-PA) were tested in tumor necrosis factor (TNF)-α activated human umbilical vein endothelial cells (HUVECs). Treatment with PLT resulted in prolonged aPTT and PT and inhibition of the activities of thrombin and FXa, and PLT inhibited production of thrombin and FXa in HUVECs. And PLT inhibited thrombin-catalyzed fibrin polymerization and platelet aggregation. In accordance with these anticoagulant activities, PLT elicited anticoagulant effects in mouse. In addition, treatment with PLT resulted in the inhibition of TNF-α-induced production of PAI-1 and in the significant reduction of the PAI-1 to t-PA ratio. Collectively, PLT possesses antithrombotic activities and offers bases for development of a novel anticoagulant.

Black pepper essential oil to enhance intravenous catheter insertion in patients with poor vein visibility: a controlled study

OBJECTIVES

To evaluate the effect of topically applied black pepper essential oil on easing intravenous catheter insertion (IVC) in patients with no palpable or visible veins compared to a control group (standard nursing practice).

DESIGN

Randomized, controlled study.

SUBJECTS

One hundred twenty hospitalized patients, who were referred to a hospital vascular team because of difficulty in accessing veins for IVC insertion.

INTERVENTIONS

Topical application of 20% essential oil of black pepper in aloe vera gel or standard nursing care (hot packs with or without vigorous tactile stimulation).

OUTCOME MEASURES

Pre- and post-test vein visibility and/or palpability and number of attempts at IVC insertion.

RESULTS

A higher percentage of patients achieved optimal scoring (vein score=2) or improved scoring (vein score of 1 or 2) to black pepper intervention than standard nursing care. The black pepper group also reduced the number of patients whose veins were still not visible or palpable after the intervention to nearly half that of the control group (p<0.05). The number of IVC attempts following black pepper was also half that of the control group.

CONCLUSION

Topical application of black pepper is a viable and effective way to enhance vein visibility and palpability prior to intravenous insertion in patients with limited vein accessibility; it also improves ease of IVC insertion.

Synthesis and biological evaluation of new piplartine analogues as potent aldose reductase inhibitors (ARIs)

As a continuation of our efforts directed towards the development of anti-diabetic agents from natural sources, piplartine was isolated from Piper chaba, and was found to inhibit recombinant human ALR2 with an IC(50) of 160 μM. To improve the efficacy, a series of analogues have been synthesized by modification of the styryl/aromatic and heterocyclic ring functionalities of this natural product lead. All the derivatives were tested for their ALR2 inhibitory activity, and results indicated that adducts 3c, 3e and 2j prepared by the Michael addition of piplartine with indole derivatives displayed potent ARI activity, while the other compounds displayed varying degrees of inhibition. The active compounds were also capable of preventing sorbitol accumulation in human red blood cells.

A survey of folk remedies for gastrointestinal tract diseases from Thailand's three southern border provinces

ETHNOPHARMACOLOGICAL RELEVANCE

Gastrointestinal tract diseases commonly occur in Thailand. However, surveying for finding out traditional drugs has never been done.

AIM OF STUDY

To quantify and categorize the folk medicinal remedies that are used for healing the gastrointestinal tract by the traditional healers living in Thailand's three southern border provinces.

MATERIALS AND METHODS

The Pattani, Yala and Narathiwat provinces were selected. Semi-structured interviews of nine healers were conducted to collect information that included the remedy names, herbal ingredients, plant parts used, preparation, properties and treatment methods. The data were then further analyzed.

RESULT

The results revealed that 39 multi-species remedies and 36 single-species remedies were used to treat gastrointestinal disorders. A total of 103 plant species and 5 other materia medica were used as therapeutics. Most of the plants used were of the Zingiberaceae, Fabaceae and Euphorbiaceae families. Furthermore, it was found that although most of the healers used different remedies for a particular disease, some of the ingredients might have been similar. For example, Caesalpinia bonduc (L.) Roxb. was an ingredient used for parasitic disease remedies, and Senna alata (L.) Roxb. was used for constipation remedies.

CONCLUSION

A review of the literature revealed 57 plant species and 2 other materia medica that have already been tested for their biological activities, whereas 46 plant species and 3 materia medica have never been tested. Consequently, research should be performed to confirm the pharmacological properties of folk remedies.

First Total Synthesis of Two New Amide Alkaloids from Piper boehmeriaefolium

3-(3,4,5-Trimethoxyphenyl)propanoylpyrrole and 3-(3,5-dimethoxy-4-hydroxyphenyl)propanoylpyrrole, two new amide alkaloids, were prepared from 3,4,5-trimethoxybenzaldehyde via 3,4,5-trimethoxycinnamic acid and the corresponding dihydroacid. This route is simple and the reaction conditions are mild.

Simultaneous determination of ten active components in 12 Chinese Piper species by HPLC

Piper is a genus that is recently valued for the treatment of central nervous system diseases. The major constituents, amides and lignans, are responsible for the antinociceptive and antidepressant activities. This study developed a RP-HPLC-UV method for the simultaneous determination of eight amides and two lignans in twelve different species of Piper. HPLC separation was accomplished on a C18 analytical column (5 μm, 250 mm × 4.6 mm, i.d.) with a gradient mobile phase consisting of acetonitrile and water at a flow rate of 1.0 ml/min. All the calibration curves showed good linear correlation coefficients (r > 0.9997) over the test ranges. The relative standard deviation of the current method was less than 2.90% for intra- and inter-day assays and the average recoveries were between 98.25% and 103.08%. The HPLC method established is appropriate for quality control purposes and allows for the differentiation of Piper species.

Environmental variables and Piper assemblage composition: a mesoscale study in the Madeira-Purus interfluve, Central Amazonia

This study aimed to determine the effects of canopy openness, litter depth, soil cation content and texture on Piper assemblage composition at a mesoscale. Piper assemblage composition and environmental variables were inventoried in 41 0.125 ha (250 × 5 m) plots placed in a terra firme forest located in the Madeira-Purus interfluve, Central Amazonia. Ordination of the 41 plots by Non-metric Multidimensional Scaling (NMDS) in one dimension captured 58% of the floristic variation and was used as the response variable in multiple regression models. Environmental variables explained 39% of the variation in Piper assemblage composition, which was significantly related to litter depth, soil texture and canopy openness, but not to the cation content. Effects of edaphic components on plant assemblage structure have been reported for different plant groups, however the strong effect of litter depth at a mesoscale had not yet been demonstrated. We suggest that litter depth variation not only influences the structure of Piper assemblages, but also of other plant groups at a mesoscale, as this environmental variable has a direct or indirect effect on species germination and establishment.

Cytotoxic amide alkaloids from Piper boehmeriaefolium

Eight new amide alkaloids (1-8) and 19 known ones were isolated from the whole plant of Piper boehmeriaefolium. Their structures were determined through spectroscopic data analyses. Cytotoxic activity of these amides against human cervical carcinoma HeLa cells was evaluated, and 1-[(9E)-10-(3,4-methylenedioxyphenyl)-9-decenoyl]pyrrolidine (9) exhibited significant inhibitory activity with an IC(50) value of 2.7 μg/mL.

Anti-listerial compounds from Asari Radix

Asari Radix, the roots of Asarum heterotropoides F. Maekawa var. manshuricum F. Maekawa or A. sieboldii F. Maekawa, has traditionally been used for the treatment of various infectious diseases. Since its MeOH extract inhibited the growth of Listeria monocytogenes in a preliminary test, the aim of this study was to isolate and identify the anti-listerial compounds from the plant. Activity-guided fractionation led to the isolation of seven compounds 1-7 from the MeOH extract, and their chemical structures were identified by comparison of the spectroscopic data with those in the literature. Compounds 1-7 exhibited inhibitory activity against all five tested strains of L. monocytogenes with diameter of inhibition zones ranging from 7 to 11 mm in the agar disc diffusion method. Compounds 1-3 and 7 demonstrated potent antimicrobial effects on the L. monocytogenes strains, with MICs between 62.5 and 125 μg/mL. This is the first report that AR possesses inhibitory activity against L. monocytogenes.

Antifungal activities of compounds isolated from Piper abutiloides Kunth

Piperaceae is a family of tropical plants known to have antifungal, antibacterial, tumour-inhibitory, antiviral, antioxidant, molluscicidal and leishmanicidal activities. In this work, extracts and fractions from aerial parts of Piper abutiloides (Piperaceae), a traditional medicinal plant, were evaluated against the fungal species Candida albicans, C. parapsilosis, C. krusei, C. glabrata, C. tropicalis, Cryptococcus neoformans and Sporothrix schenckii. The results have shown that the antifungal activity of this plant can be concentrated in the hexanic fraction after partitioning its hydroalcoholic extract between hexane and 90% aqueous methanol. The chromatographic fractionation of the bioactive part was monitored with a bioautographic assay using C. glabrata, and allowed the isolation of three antifungal compounds: pseudodillapiol, eupomatenoid-6 and conocarpan. These compounds presented different potencies against the fungi tested, with the strongest effect being observed for eupomatenoid-6 against C. glabrata, which presented a minimal inhibitory concentration value of 0.3 microg spot(-1). Conocarpan showed antifungal activity without apparent cytotoxic effect on normal human lymphocytes, as assessed by the proliferation assay with human peripheral blood mononuclear cells stimulated with phytohaemaglutinin. This work reveals for the first time the occurrence of these compounds in P. abutiloides and justifies further studies to clarify their mechanisms of action.

In vitro screening for anthelmintic and antitumour activity of ethnomedicinal plants from Thailand

AIM OF STUDY

This study screened for anthelmintic and/or antitumour bioactive compounds from Thai indigenous plants and evaluated effectiveness against three different worm species and two cancer cell lines.

MATERIALS AND METHODS

Methylene chloride and methanol extracts of 32 plant species were screened for in vitro anthelmintic activity against three species of worms, the nematode Caenorhabditis elegans, the digeneans Paramphistomum epiclitum and Schistosoma mansoni (cercariae). Cytotoxicity of the extracts was evaluated against two cancer cell lines: human amelanotic melanoma (C32) and human cervical carcinoma (HeLa) by the SRB assay. Anthelmintic and anticancer activities were evaluated by the inhibiting concentration at 50% death (IC(50)) and the selectivity index (SI) relative to human fibroblasts.

RESULTS AND CONCLUSIONS

None of the extracts were active against Paramphistomum epiclitum. Plumbagin, a pure compound from Plumbago indica, had the strongest activity against Caenorhabditis elegans. The methylene chloride extract of Piper chaba fruits had the strongest activity against schistosome cercariae. Strong cytotoxicity was shown by the methylene chloride extract of Michelia champaca bark and the methanol extract of Curcuma longa rhizome against C32 and HeLa, respectively. These extracts had higher SI (>100) than positive controls in relation to either the worms or the cell lines. The methanol extract of Bouea burmanica had a slightly lower activity towards C32 cells than did Michelia champaca but had a much higher SI (>27,000).

ETHNOPHARMACOLOGICAL RELEVANCE

The plant species screened in this research was recorded by several indigenous medicinal practitioners as antiparasitic, anticancer and/or related activities to the human major organ system.

Vibriocidal activity of certain medicinal plants used in Indian folklore medicine by tribals of Mahakoshal region of central India

OBJECTIVES

Screening of the medicinal plants and determination of minimum inhibitory concentration (MIC) against Vibrio cholerae and Vibrio parahaemolyticus.

MATERIALS AND METHODS

A simple in vitro screening assay was employed for the standard strain of Vibrio cholerae, 12 isolates of Vibrio cholerae non-O1, and Vibrio parahaemolyticus. Aqueous and organic solvent extracts of different parts of the plants were investigated by using the disk diffusion method. Extracts from 16 medicinal plants were selected on account of the reported traditional uses for the treatment of cholera and gastrointestinal diseases, and they were assayed for vibriocidal activities.

RESULTS

The different extracts differed significantly in their vibriocidal properties with respect to different solvents. The MIC values of the plant extracts against test bacteria were found to be in the range of 2.5-20 mg/ml.

CONCLUSIONS

The results indicated that Lawsonia inermis, Saraca indica, Syzygium cumini, Terminalia belerica, Allium sativum, and Datura stramonium served as broad-spectrum vibriocidal agents.

Anti-staphylococcal potential of Callistemon rigidus

The last decade witnessed the emergence of Staphylococcus aureus- a versatile human pathogen, as a deadly superbug. The enormous genetic plasticity of the organism assists it to endlessly evolve resistance mechanisms against existing anti-infectives thus necessitating the need to control the spread of resistant staphylococcal isolates in hospitals and health care settings. This in turn demands the incessant exploration of newer biological matrices in search of diverse chemical entities with novel drug targets. Since time immemorial higher plants continue to be the best source of newer compounds with high therapeutic potential. Lead fractions from same or different plants can be developed into effective antibacterial polyherbal formulations. A lead fraction from methanolic extract of leaves of Callistemon rigidus exhibited a dose dependent antistaphylococcal activity during in vitro agar well assay against a panel of twenty seven clinical multidrug resistant S. aureus isolates. Further, minimal inhibitory concentration (MIC) evaluation by in vitro 96-well microplate based assay established a MIC range of 1.25–80 μg/ml as compared to 5–320 μg/ml of positive control, Cefuroxime sodium. The MIC50 and MIC90 of the methanolic lead fraction were 5 μg/ml and 40 μg/ml respectively. The present study thus signifies the vast potential of the lead fraction from Callistemon rigidus for future development into a herbal drug/ formulation and to impede global health crisis due to multidrug resistant Staphylococcus aureus.