Antioxidant activity and peroxidase inhibition of Amazonian plants extracts traditionally used as anti-inflammatory.

BACKGROUND: The Amazon is the largest rainforest in the world and is home to a rich biodiversity of medicinal plants. Several of these plants are used by the local population for the treatment of diseases, many of those with probable anti-inflammatory effect. The aim of the present investigation was to evaluate the in vitro antioxidant and anti-peroxidases potential of the ethanol extracts of five plants from the Brazilian Amazon (Byrsonima japurensis, Calycophyllum spruceanum, Maytenus guyanensis, Passiflora nitida and Ptychopetalum olacoides). METHODS: DPPH, ABTS, superoxide anion radical, singlet oxygen and the ß-carotene bleaching methods were employed for characterization of free radical scavenging activity. Also, total polyphenols were determined. Antioxidant activities were evaluated using murine fibroblast NIH3T3 cell. Inhibition of HRP and MPO were evaluated using amplex red® as susbtract. RESULTS: The stem bark extracts of C. spruceanum and M. guyanensis provided the highest free radical scavenging activities. C. spruceanum exhibited IC50 = 7.5 ± 0.9, 5.0 ± 0.1, 18.2 ± 3.0 and 92.4 ± 24.8 µg/mL for DPPH(•), ABTS(+•), O2 (-•) and (1)O2 assays, respectively. P. olacoides and C. spruceanum extracts also inhibited free radicals formation in the cell-based assay. At a concentration of 100 µg/mL, the extracts of C. spruceanum, B. japurensis inhibited horseradish peroxidase by 62 and 50 %, respectively. C. spruceanum, M. guyanensis, B. japurensis also inhibited myeloperoxidase in 72, 67 and 56 %, respectively. CONCLUSIONS: This work supports the folk use these species that inhibited peroxidases and exhibited significant free radical scavenging and antioxidant activities what can be related to treatment of inflammation.

Secondary metabolites from Rubiaceae species.

This study describes some characteristics of the Rubiaceae family pertaining to the occurrence and distribution of secondary metabolites in the main genera of this family. It reports the review of phytochemical studies addressing all species of Rubiaceae, published between 1990 and 2014. Iridoids, anthraquinones, triterpenes, indole alkaloids as well as other varying alkaloid subclasses, have shown to be the most common. These compounds have been mostly isolated from the genera Uncaria, Psychotria, Hedyotis, Ophiorrhiza and Morinda. The occurrence and distribution of iridoids, alkaloids and anthraquinones point out their chemotaxonomic correlation among tribes and subfamilies. From an evolutionary point of view, Rubioideae is the most ancient subfamily, followed by Ixoroideae and finally Cinchonoideae. The chemical biosynthetic pathway, which is not so specific in Rubioideae, can explain this and large amounts of both iridoids and indole alkaloids are produced. In Ixoroideae, the most active biosysthetic pathway is the one that produces iridoids; while in Cinchonoideae, it produces indole alkaloids together with other alkaloids. The chemical biosynthetic pathway now supports this botanical conclusion.

Technical-scientific production and knowledge networks about medicinal plants and herbal medicines in the Amazon.

Introduction: This paper explores the role of Brazilian research institutions in the global and national context of study of medicinal plants. Most of these plants have ethnopharmacological use and herbal medicines related to the Amazon. It highlights Brazil's position in scientific production and the importance of Amazonian resources in developing phytomedicines. The study aims to provide an overview of the technical-scientific production of medicinal plants and herbal medicines related to the Amazon, focusing on scientific impact, collaboration, Technology Readiness Level (TRL) of scientific production, and innovation system maturity. Methods: The study employs a comprehensive methodological approach, including data collection from Scopus covering the period from 2002 to 2022. The data was cleaned and analyzed using bibliometric and network analysis techniques. Advanced natural language processing techniques, such as Latent Dirichlet Allocation and Jaccard distance measure, were used for TRL classification. Results: The findings reveal a predominant contribution from Brazilian institutions and authors, with 1,850 publications analyzed. Key areas identified include Pharmacology, Toxicology, Pharmaceuticals, Medicine, and Biochemistry. The study also uncovers various collaborative networks and technological maturity levels, with a significant focus on early-stage development phases. Discussion: The research concludes that Brazilian institutions, particularly those in the Amazon region, play a significant role in the scientific exploration and development of medicinal plants and herbal medicines. Despite this, countries like the USA were proportionally more productive in clinical trial research. The study underscores the potential of Brazil's rich biodiversity and traditional knowledge in the pharmaceutical industry, particularly for neglected diseases. It suggests the need for stronger research systems and international collaboration to leverage these resources for global health benefits.

Antimicrobial and Antioxidant Activities of Endophytic Fungi Associated with Arrabidaea chica (Bignoniaceae).

The endophytic fungal community of the Amazonian medicinal plant Arrabidaea chica (Bignoniaceae) was evaluated based on the hypothesis that microbial communities associated with plant species in the Amazon region may produce metabolites with interesting bioactive properties. Therefore, the antimicrobial and antioxidant activities of the fungal extracts were investigated. A total of 107 endophytic fungi were grown in liquid medium and the metabolites were extracted with ethyl acetate. In the screening of fungal extracts for antimicrobial activity, the fungus identified as Botryosphaeria mamane CF2-13 was the most promising, with activity against E. coli, S. epidermidis, P. mirabilis, B. subtilis, S. marcescens, K. pneumoniae, S. enterica, A. brasiliensis, C. albicans, C. tropicalis and, especially, against S. aureus and C. parapsilosis (MIC = 0.312 mg/mL). Screening for antioxidant potential using the DPPH elimination assay showed that the Colletotrichum sp. CG1-7 endophyte extract exhibited potential activity with an EC50 of 11 µg/mL, which is equivalent to quercetin (8 µg/mL). The FRAP method confirmed the antioxidant potential of the fungal extracts. The presence of phenolic compounds and flavonoids in the active extracts was confirmed using TLC. These results indicate that two of the fungi isolated from A. chica exhibit significant antimicrobial and antioxidant potential.

Antimicrobial Activity of Aspergillus sp. from the Amazon Biome: Isolation of Kojic Acid.

The antimicrobial potential of Aspergillus sp., isolated from the Amazon biome, which is stored at the Amazon Fungi Collection-CFAM at ILMD/FIOCRUZ, was evaluated. The fungal culture was cultivated in yeast extract agar and sucrose (YES) for cold extraction of the biocompounds in ethyl acetate at 28 °C for 7 days in a BOD type incubator. The obtained extract was evaluated for its antimicrobial activity against Candida albicans and Gram-positive and negative bacteria by the "cup plate" method and the determination of the minimum inhibitory concentration (MIC) by the broth microdilution method. The extract was subjected to thin layer chromatography (TLC) and fractionated by open and semipreparative column chromatography. The fractions of interest had their chemical constituents elucidated by nuclear magnetic resonance and mass spectrometry. The elucidated molecule was evaluated for cytotoxicity against the human fibroblast strain (MRC5). The extract presented inhibitory activity against both Gram-positive and negative bacteria, with the range of inhibition halos from 5.3 to 14 mm in diameter and an MIC ranging from 500 to 15.6 µg/mL. Seventy-one fractions were collected and TLC analysis suggested the presence of substances with double bond groups: coumarins, flavonoids, phenolic, alkaloids, and terpenes. NMR and MS analyses demonstrated that the isolated molecule was kojic acid. The results of the cytotoxicity test showed that MRC5 cells presented viability at concentrations from 500 to 7.81 µg/mL. The kojic acid molecule of Aspergillus sp., with antibacterial activity and moderate toxicity at the concentrations tested, is a promising prototype of an alternative active principle of an antimicrobial drug.

Piper peltatum: biomass and 4-nerolidylcatechol production.

Piper peltatum L. is used for the treatment of inflammation, malaria, and other ailments. 4-Nerolidylcatechol (4-NC) is a valuable natural product that has important anti-inflammatory, antimalarial, and antioxidant properties. 4-NC is a component of P. peltatum and P. umbellatum extracts, which are used in cosmetics. The aim of this work was to evaluate the production of plant biomass and the production of 4-NC in roots of cultivated P. peltatum over a full life cycle. Seedlings were produced in a greenhouse and then transplanted. The weight of dry plant parts (leaves, stems, roots, and inflorescences); numbers of stems, leaves, and inflorescences; and the leaf-to-stem ratio were evaluated at intervals of 60 days after transplanting (DAT). Extracts were prepared using 1:1 ethanol-chloroform and an ultrasound bath. Roots, leaves, and inflorescences contained 4-NC according to TLC photodensitometry analysis. Quantification of 4-NC in root extracts was performed using HPLC-DAD analysis. Per-hectare production of 4-NC by roots was estimated based on quantitative HPLC analysis and biomass data. Optimal per-hectare yields of 4-NC were obtained by harvesting roots between 350 and 400 DAT. In this period, the average yield was 27 kg 4-NC per hectare. Importantly, at the time of maximal overall production of root biomass (470 DAT), there was a decrease in the production of 4-NC (23.8 kg/ha), probably due to the onset of senescence.

Evaluation of benzocaine-based anesthetic gel in anuran skins extracts: A case study using the frog Lithodytes lineatus (Anura: Leptodactylidae).

Extracts made from the skin of dead Lithodytes lineatus frog individuals with the application of the benzocaine-based anesthetic gel, introduced into the oral cavity, were analyzed by 1H Nuclear Magnetic Resonance to investigate whether the application of this product (oral) can make studies that use extracts from the skins of these animals unfeasible. For comparison, we used skins of another species of anuran following the same death protocol. No trace of the benzocaine substance was found in the 1H-NMR spectra of the skin extracts from any of the tested anuran species. Still, using the hierarchical clustering model, it was possible to observe the formation of well-defined groups between the skin extracts of anurans and the anesthetic used to kill these animals. Our results suggest that the lethal dose of benzocaine in gel used inside the mouth of frogs may have no influence on potential results regarding the chemical composition or even bioassays using extracts made from the skin of these animals killed under this protocol since there was no detection of this substance for the analyzed samples.

Neutralization of the edema-forming and myotoxic activities of the venom of Potamotrygon motoro Müller and Henle, 1841 (Chondrichthyes - Potamotrygoninae) by antivenoms and circulating immunoglobulins.

Freshwater stingrays are cartilaginous fish with stingers at the base of their tail. The stinger is covered with an epithelium containing mucous and venom glands. Human envenomation usually occurs when a person steps on a stingray hiding in the sand and the fish sinks its stinger into the victim, causing an extremely painful wound which generally leads to tissue necrosis. Medical treatment is based on the use of painkillers, anti-inflammatory drugs and antibiotics, as there is to date no specific antidote for envenomation by freshwater stingrays. The aim of this study was therefore to investigate whether sera containing anti-P. motoro antibodies can neutralize the edema-forming and myotoxic activities of Potamotrygon motoro venom. To this end, two protocols were used: seroneutralization and vaccination of mice. The seroneutralization protocol involved intramuscular injection of the P. motoro venom in the mice gastrocnemius followed by administration of hyperimmune mouse serum anti P. motoro dorsal extract and stinger extract via the ophthalmic venous plexus. The vaccination protocol involved immunizing the mice with dorsal or stinger extract adsorbed to aluminum hydroxide followed by intramuscular challenge with the P. motoro venom. The gastrocnemii of all the animals were removed for histopathological and stereological analyses, and blood was collected via the ophthalmic venous plexus to measure IL-2, IL-4, IL-6, IL-10, IL-17A, IFN-γ, TNF, C-reactive protein and total creatine kinase. Protocols did not neutralize the edema-forming or local myotoxic induced by P. motoro venom under the experimental conditions tested. But systemic rhabdomyolysis was only completely neutralized in animals vaccinated with the stinger extract. Cytokine analysis revealed that under the experimental conditions used here, seroneutralization induced release of Th1, Th2, Th17 and Treg cytokines whereas vaccination induced a Th1 response.

Evaluation of the anti-snakebite, antimicrobial and antioxidant potential of Philodendron megalophyllum Schott (Araceae), traditionally used in accidents caused by snakes in the western region of Pará, Brazil.

ETHNOPHARMACOLOGICAL RELEVANCE: In the region of Western Pará, Amazonia, Brazil, Philodendron megalophyllum is widely used for the treatment of envenomations caused by bites from venomous snakes. The traditional use of plants is usually done through oral administration of an infusion (decoction) soon after the bite occurs. The efficiency of aqueous extracts of P. megalophyllum was demonstrated for blocking the activity of the venom of Bothrops sp., but only for a pre-incubation protocol (venom:extract), which fails to simulate the real form of use of this species. In this context, the objective of this research was to evaluate the anti-snakebite potential of the aqueous extract of P. megalophyllum to inhibit for the biological activity induced by Bothrops atrox venom (BaV) using traditional treatment methods. MATERIAL AND METHODS: Initially, an aqueous extract using the stem of P. megalophyllum (AEPm) was prepared following the standard procedure used by the residents of the rural area along the Tapajós River (Eixo Forte region) in Santarém, PA, Brazil. The phytochemical profile of AEPm was conducted using thin layer chromatography (TLC) and phenolic compounds were quantified through colorimetric trials. The cytotoxicity of AEPm was evaluated using the MRC-5 human fibroblast line, and the antioxidant potential was measured using DPPH methods and cell culture. AEPm antimicrobial action was evaluated by the 96-well plate microdilution and the minimum inhibitory concentration (MIC) methods using 18 types of microorganisms including bacteria that are present in the oral cavity of snakes. AEPm blocking potential was tested against BaV activity in vitro (fibrinolytic) and in vivo (defibrinating and hemorrhagic). In order to test for an interaction between BaV and AEPm SDS-PAGE electrophoresis was conducted. RESULTS: The presence of coumarins, fatty acids, and hydrolysable tannins were detected in the AEPm. The colorimetric trials showed that AEPm had a high concentration of condensed tannins (20.1 ± 1.2%). The potential of AEPm for blocking of hemorrhagic and fibrinolytic activity of BaV showed a maximum reduction of 86.1% and 96.5%, respectively, for the pre-incubation protocol (1:10, venom:extract). However, when the extract was administered orally there was no significant blocking of these activities. The interaction of BaV and AEPm showed a modification of the profile of proteic bands when compared to the pattern of bands obtained from the BaV alone. The AEPm was not considered toxic, demonstrated antioxidant activity, and was capable of reducing the growth of 10 of the 18 studied microorganisms. CONCLUSION: Although the stem of P. megalophyllum is indicated by traditional medicine techniques as effective against snakebites, the extract, when tested orally was not able to significantly inhibit (p ˃ 0.05) hemorrhage and defibrinating activity induced by the B. atrox venom. On the other hand, the extract yielded a promising result with respect to antioxidant and antimicrobial potential, and after further studies it could be used as a complementary treatment for localized action and secondary infections that frequently occur with snakebites from the genus of Bothrops sp.

Guarana (Paullinia cupana) Extract Protects Caenorhabditis elegans Models for Alzheimer Disease and Huntington Disease through Activation of Antioxidant and Protein Degradation Pathways.

Guarana (Paullinia cupana) is largely consumed in Brazil in high energy drinks and dietary supplements because of its stimulant activity on the central nervous system. Although previous studies have indicated that guarana has some protective effects in Parkinson's (PD), Alzheimer's (AD), and Huntington's (HD) disease models, the underlying mechanisms are unknown. Here, we investigated the protective effects of guarana hydroalcoholic extract (GHE) in Caenorhabditis elegans models of HD and AD. GHE reduced polyglutamine (polyQ) protein aggregation in the muscle and also reduced polyQ-mediated neuronal death in ASH sensory neurons and delayed ß-amyloid-induced paralysis in a caffeine-independent manner. Moreover, GHE's protective effects were not mediated by caloric restriction, antimicrobial effects, or development and reproduction impairment. Inactivation of the transcription factors SKN-1 and DAF-16 by RNAi partially blocked the protective effects of GHE treatment in the AD model. We show that the protective effect of GHE is associated with antioxidant activity and modulation of proteostasis, since it increased the lifespan and proteasome activity, reduced intracellular ROS and the accumulation of autophagosomes, and increased the expression of SOD-3 and HSP-16.2. Our findings suggest that GHE has therapeutic potential in combating age-related diseases associated with protein misfolding and accumulation.

Connarus favosus Planch.: An inhibitor of the hemorrhagic activity of Bothrops atrox venom and a potential antioxidant and antibacterial agent.

ETHNOPHARMACOLOGICAL RELEVANCE: The plant species Connarus favosus is used in folk medicine in the west of Pará state, Brazil, to treat snakebites. AIM OF THE STUDY: To investigate the potential of the aqueous extract of Connarus favosus (AECf) to inhibit hemorrhagic and phospholipase A2 activities induced by Bothrops atrox venom (BaV) and to determine the antioxidant and antimicrobial potentials of the extract. MATERIALS AND METHODS: AECf was analyzed phytochemically for phenolics (condensed tannins and hydrolyzable tannins) by colorimetry. Antioxidant activity was evaluated by quantitative assays using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Fe(3+)/phenanthroline. Antimicrobial activity was evaluated by the minimal inhibitory concentration test, and cytotoxicity was evaluated using human fibroblast cells (MRC-5). Inhibition of BaV-induced hemorrhagic activity was assessed after oral administration of the extract using pre-treatment, post-treatment and combined (BA plus AECf) treatment protocols. Inhibition of indirect hemolysis caused by phospholipase A2 (PLA2) was investigated in vitro. Interaction between AECf and BaV was investigated by SDS-PAGE electrophoresis, Western blot (Wb) and zymography. RESULTS: The phytochemical profile of AECf revealed ten secondary metabolite classes, and colorimetry showed high total phenolic and total (condensed and hydrolyzable) tannin content. AECf exhibited high antioxidant and antimicrobial potentials. The IC50 for the cytotoxic effect was 51.91 (46.86-57.50)µg/mL. Inhibition of BaV-induced hemorrhagic activity was significant in all the protocols, and inhibition of PLA2 activity was significant with the two highest concentrations. The BaV/AECf mixture produced the same bands as BaV by itself in SDS-PAGE and Wb although the bands were much fainter. Zymography confirmed the proteolytic activity of BaV, but when the venom was pre-incubated with AECf this activity was blocked. CONCLUSION: AECf was effective in reducing BaV-induced hemorrhagic activity when administered by the same route as that used in folk medicine and exhibited antioxidant and antimicrobial potentials.

Evaluation of the anti-snakebite, antimicrobial and antioxidant potential of Philodendron megalophyllum Schott (Araceae), traditionally used in accidents caused by snakes in the western region of Pará, Brazil

Ethnopharmacological relevance In the region of Western Pará, Amazonia, Brazil, Philodendron megalophyllum is widely used for the treatment of envenomations caused by bites from venomous snakes. The traditional use of plants is usually done through oral administration of an infusion (decoction) soon after the bite occurs. The efficiency of aqueous extracts of P. megalophyllum was demonstrated for blocking the activity of the venom of Bothrops sp., but only for a pre-incubation protocol (venom:extract), which fails to simulate the real form of use of this species. In this context, the objective of this research was to evaluate the anti-snakebite potential of the aqueous extract of P. megalophyllum to inhibit for the biological activity induced by Bothrops atrox venom (BaV) using traditional treatment methods. Material and methods Initially, an aqueous extract using the stem of P. megalophyllum (AEPm) was prepared following the standard procedure used by the residents of the rural area along the Tapajós River (Eixo Forte region) in Santarém, PA, Brazil. The phytochemical profile of AEPm was conducted using thin layer chromatography (TLC) and phenolic compounds were quantified through colorimetric trials. The cytotoxicity of AEPm was evaluated using the MRC-5 human fibroblast line, and the antioxidant potential was measured using DPPH methods and cell culture. AEPm antimicrobial action was evaluated by the 96-well plate microdilution and the minimum inhibitory concentration (MIC) methods using 18 types of microorganisms including bacteria that are present in the oral cavity of snakes. AEPm blocking potential was tested against BaV activity in vitro (fibrinolytic) and in vivo (defibrinating and hemorrhagic). In order to test for an interaction between BaV and AEPm SDS-PAGE electrophoresis was conducted. Results The presence of coumarins, fatty acids, and hydrolysable tannins were detected in the AEPm. The colorimetric trials showed that AEPm had a high concentration of condensed tannins (20.1 ± 1.2%). The potential of AEPm for blocking of hemorrhagic and fibrinolytic activity of BaV showed a maximum reduction of 86.1% and 96.5%, respectively, for the pre-incubation protocol (1:10, venom:extract). However, when the extract was administered orally there was no significant blocking of these activities. The interaction of BaV and AEPm showed a modification of the profile of proteic bands when compared to the pattern of bands obtained from the BaV alone. The AEPm was not considered toxic, demonstrated antioxidant activity, and was capable of reducing the growth of 10 of the 18 studied microorganisms. Conclusion Although the stem of P. megalophyllum is indicated by traditional medicine techniques as effective against snakebites, the extract, when tested orally was not able to significantly inhibit (p > 0.05) hemorrhage and defibrinating activity induced by the B. atrox venom. On the other hand, the extract yielded a promising result with respect to antioxidant and antimicrobial potential, and after further studies it could be used as a complementary treatment for localized action and secondary infections that frequently occur with snakebites from the genus of Bothrops sp

Antioxidant Activity and Polyphenol Content of Some Brazilian Medicinal Plants Exploiting the Formation of the Fe(II)/2,2'-bipyridine Complexes.

Aqueous plant extracts contain polyphenols that reduce Fe3+ to Fe2+, which in the presence of excess 2,2'-bipyridine (bipy) yield the Fe(bipy)3(2+) complex (λmax = 521 nm). This reaction was used to quantify the total polyphenol content (TPC) of nineteen Brazilian medicinal species using pyrogallic acid (PA) as a standard. A calibration curve of absorbance values at 521 nm values vs. PA was linear from 0.378 to 3.03 mg L(-1) (r = 0.998; n = 8) with a limit of detection 0.16 mg L(-1). The TPC quantification using the proposed reaction was compared with values obtained with the Folin-Ciocalteu reagent, yielding good agreement (r = 0.965). For the same species the TPC obtained with the proposed method also resulted in good correlation (r = 0.773) with the antioxidant capacity values quantified using the 2,2-diphenyl-lI-picrylhydrazyl method. It was also found that Fe(bipy)3(2+) complexes can be used to calculate the reducing capability of polyphenols. The polyphenol structure, and the number and position of the hydroxyl group attached to the benzene ring modify this reductive capacity.

Evaluation of the anti-snakebite, antimicrobial and antioxidant potential of Philodendron megalophyllum Schott (Araceae), traditionally used in accidents caused by snakes in the western region of Pará, Brazil

Ethnopharmacological relevance In the region of Western Pará, Amazonia, Brazil, Philodendron megalophyllum is widely used for the treatment of envenomations caused by bites from venomous snakes. The traditional use of plants is usually done through oral administration of an infusion (decoction) soon after the bite occurs. The efficiency of aqueous extracts of P. megalophyllum was demonstrated for blocking the activity of the venom of Bothrops sp., but only for a pre-incubation protocol (venom:extract), which fails to simulate the real form of use of this species. In this context, the objective of this research was to evaluate the anti-snakebite potential of the aqueous extract of P. megalophyllum to inhibit for the biological activity induced by Bothrops atrox venom (BaV) using traditional treatment methods. Material and methods Initially, an aqueous extract using the stem of P. megalophyllum (AEPm) was prepared following the standard procedure used by the residents of the rural area along the Tapajós River (Eixo Forte region) in Santarém, PA, Brazil. The phytochemical profile of AEPm was conducted using thin layer chromatography (TLC) and phenolic compounds were quantified through colorimetric trials. The cytotoxicity of AEPm was evaluated using the MRC-5 human fibroblast line, and the antioxidant potential was measured using DPPH methods and cell culture. AEPm antimicrobial action was evaluated by the 96-well plate microdilution and the minimum inhibitory concentration (MIC) methods using 18 types of microorganisms including bacteria that are present in the oral cavity of snakes. AEPm blocking potential was tested against BaV activity in vitro (fibrinolytic) and in vivo (defibrinating and hemorrhagic). In order to test for an interaction between BaV and AEPm SDS-PAGE electrophoresis was conducted. Results The presence of coumarins, fatty acids, and hydrolysable tannins were detected in the AEPm. The colorimetric trials showed that AEPm had a high concentration of condensed tannins (20.1 ± 1.2%). The potential of AEPm for blocking of hemorrhagic and fibrinolytic activity of BaV showed a maximum reduction of 86.1% and 96.5%, respectively, for the pre-incubation protocol (1:10, venom:extract). However, when the extract was administered orally there was no significant blocking of these activities. The interaction of BaV and AEPm showed a modification of the profile of proteic bands when compared to the pattern of bands obtained from the BaV alone. The AEPm was not considered toxic, demonstrated antioxidant activity, and was capable of reducing the growth of 10 of the 18 studied microorganisms. Conclusion Although the stem of P. megalophyllum is indicated by traditional medicine techniques as effective against snakebites, the extract, when tested orally was not able to significantly inhibit (p > 0.05) hemorrhage and defibrinating activity induced by the B. atrox venom. On the other hand, the extract yielded a promising result with respect to antioxidant and antimicrobial potential, and after further studies it could be used as a complementary treatment for localized action and secondary infections that frequently occur with snakebites from the genus of Bothrops sp

Sesquiterpene lactone from Wunderlichia crulsiana inhibits the respiratory burst of leukocytes triggered by distinct biochemical pathways.

The sesquiterpene lactone tubiferin was chemically purified from the brazilian native plant Wunderlichia crulsiana and identified by NMR and GC/MS data. Its ability to inhibit the respiratory burst of peritoneal inflammatory polymorphonuclear leukocytes (PMN) stimulated upon addition of phorbol miristate acetate (PMA), opsonized zymosan (OZ), and N-formyl-methionyl-leucyl-phenylalanine (fMLP) was evaluated. The tubiferin inhibition was more pronounced when PMN were stimulated through the protein kinase C pathway (PMA) compared to the alternative complement pathway (OZ). The inhibition when PMN were triggered by a chemoattractant stimulus (fMLP) was similar to that achieved with OZ-stimulated phagocytes. Tubiferin showed dose-dependent effects on the PMN respiratory burst triggered by the three different substances, and also decreased substantially the carrageenan-induced mice paw edema.

Triterpenes and the antimycobacterial activity of Duroia macrophylla Huber (Rubiaceae).

Duroia macrophylla popularly known as "cabeça-de-urubú," "apuruí," or "puruí-grande-da-mata" occurs in the Amazon Forest. Its leaves and branches were collected twice and extracted with dichloromethane and methanol. All extracts were subjected to phytochemical investigation and terpenes and flavonoids were found in all dichloromethane and methanol extracts, respectively. Methanol extracts from both branches (1st collection) and leaves (2nd collection) presented hydrolyzed tannins, yet alkaloids were only detected in the dichloromethane and methanol extracts from branches at the 2nd collection. Phenol compounds were found in both dichloromethane extracts' collections. The action of every extract was assayed against Mycobacterium tuberculosis (RMPr, H37Rv, and INHr strains), showing that the dichloromethane extract from leaves (1st collection) has the major biological activity, with a MIC of 6.25 µg/mL for the INHr strain, 25.0 µg/mL for the RMPr strain, and ≤6.25 µg/mL for the H37Rv strain. The chromatographic fractioning of the dichloromethane extract from leaves (1st collection) yielded the isolation of two triterpenes: oleanolic and ursolic acids, which were identified by NMR analysis and reported for the first time in the Duroia genus.

Evaluation of larvicidal activity and brine shrimp toxicity of rhizome extracts of Zingiber zerumbet (L.) Smith.

INTRODUCTION: In this study, we used dichloromethane (DCM) and methanol (MeOH) extracts of the Zingiber zerumbet rhizome to evaluate brine shrimp lethality and larvicidal activity on Aedes aegypti and Anopheles nuneztovari mosquitoes. METHODS: Bioassays were performed by exposing third-instar larvae of each mosquito species to the DCM or MeOH extracts. RESULTS: Probit analysis with DCM and MeOH extracts demonstrated efficient larvicidal activity against A. aegypti and A. nuneztovari larvae. CONCLUSIONS: The DCM and MeOH extracts showed higher activity against A. nuneztovari larvae than against A. aegypti larvae, suggesting that the extracts have species-specific activity.

Larvicidal effects of endophytic and basidiomycete fungus extracts on Aedes and Anopheles larvae (Diptera, Culicidae).

INTRODUCTION: In vitro bioassays were performed to access the larvicidal activity of crude extracts from the endophytic fungus Pestalotiopsis virgulata (Melanconiales, Amphisphaeriaceae) and the saprophytic fungus Pycnoporus sanguineus (Basidiomycetes, Polyporaceae) against the mosquitoes Aedes aegypti and Anopheles nuneztovari. METHODS: The extracts were tested at concentrations of 100, 200, 300, 400 and 500ppm. Ethyl acetate mycelia (EAM) extracts and liquid culture media (LCM) from Pe. virgulata and Py. sanguineus were tested against third instar larvae of Ae. aegypti and An. nuneztovari. RESULTS: The larvicidal activity of the EAM extracts from Pe. virgulata against Ae. aegypti had an LC50=101.8ppm, and the extract from the basidiomycete fungus Py. sanguineus had an LC50=156.8ppm against the Ae. aegypti larvae. The Pe. virgulata extract had an LC50=16.3ppm against the An. nuneztovari larvae, and the Py. sanguineus extract had an LC50=87.2ppm against these larvae. CONCLUSIONS: These results highlight the larvicidal effect of EAM extracts from the endophyte Pe. virgulata against the two larval mosquitoes tested. Thus, Pe. virgulata and Py. sanguineus have the potential for the production of bioactive substances against larvae of these two tropical disease vectors, with An. nuneztovari being more susceptible to these extracts.