Amazonian Medicinal Plant Research Articles

Antimicrobial activity of amazonian medicinal plants

ObjectivesThe aqueous extracts of currently utilized Amazonian medicinal plants were assayed in vitro searching for antimicrobial activity against human and animal pathogenic microorganisms.MethodsMedium resuspended lyophilized aqueous extracts of different organs of Amazonian medicinal plants were assayed by in vitro screening for antimicrobial activity. ATCC and standardized microorganisms obtained from Oswaldo Cruz Foundation/Brazil were individually and homogeneously grown in agar plate, and holes previously perforated in the gel were filled with diluted plant aqueous extracts. Inhibition halos were evaluated and controlled by the use of the fluoroquinolone ciprofloxacin.ResultsThe Amazonian medicinal plants, Hymenelobium petraeum showed inhibitory activity over Staphylococcus aureus, Enterococcus faecalis, Salmonella enterica serovar Typhi, Acinetobacter baumannii and Candida albicans, while Vatairea guianensis and Symphonia globulifera presented inhibitory activity exclusively for Staphylococcus aureus. Also, Ptychopetalum olacoides and Pentaclethra macroloba inhibited the growth of Klebsiella ozaenae and Acinetobacter baumannii.ConclusionThe aqueous botanic extracts that showed activity against microroganisms of ATTC and Osvaldo Cruz strains had at least 40% of antimicrobial activity when compared to halo inhibition produced by the commercial antibiotic ciprofloxacin utilized as a control. Of all plants extracts assayed, the Hymenelobium petraeum had the best performance, sometimes exhibiting higher activity than ciprofloxacin. It is not well-defined by the physicians the exact indication of the majority of medicinal plants in the Amazon area in Brazil. Natives utilize the plants according to their symptoms, based on the traditional knowledge transmitted orally from generation to generation, among Amerindians, Afrodescendents and ethnic mixed populations. A significant number of Amazonian medicinal plants are totally unknown related to their medicinal properties including mechanism of action and therapeutic effects, as very few information is reported in the scientific literature. A tiny amount of data is presented, as the preliminary antimicrobial properties of the medicinal plants here accessed, under the urgent necessity of new antibiotics in the market and in face of the increased resistance of infectious microorganisms to antimicrobials.

Amazonian Brazilian medicinal plants described by C.F.P. von Martius in the 19th century

Ethnopharmacological relevanceInformation regarding the use of beneficial, native Brazilian plants was compiled by European naturalists during the 19th century. The German botanist C.F.P. von Martius was one of the most prominent naturalists and described the use of several Brazilian plants. Aim of the studyTo present data on Amazonian medicinal plants documented by von Martius in his books. Materials and methodsData on Amazonian medicinal plants were obtained from three books published by von Martius. Traditional information about these plants was translated from Latin and the cited plant species reorganised according to current taxonomic criteria. Correlated pharmacological studies were obtained from different scientific databases. ResultsA total of 92 native medicinal species from the Amazon were recorded in von Martius' books. These accounts described 117 different medical uses for these plants. Several parts of the plants were used, including many exudates. The principal use of the species recorded was the treatment of dermatological problems, followed by gastro-intestinal, urinary and respiratory disorders. Few species were recorded as purgatives and febrifuges, a result that differs from the observations of other naturalists. The efficacy of the recorded traditional uses has been confirmed for the few species that have been subjected to laboratory studies. ConclusionThe data recorded by the German naturalist von Martius represent a rich, unexplored source of information about the traditional uses of Brazilian plants.

Aerobic and Facultative Microorganisms Isolated from Corroded Metallic Structures in a Hydroeletric Power Unit in the Amazon Region of Brazil

Aerobic and facultative bacteria belonging to the Enterobacteriaceae, Pseudomonadaceae, Bacillaceae, Corynebacteriaceae and Streptococcaceae families have been isolated from corroded metallic structures of a hydroelectric power unit in the Amazon region of Brazil. In addition to anamorphic dematiaceous and moniliaceous fungi, members of the archeobacteria kingdom were also detected in the same samples. Scanning electron micrographs of metal bars cultivated with consortia of the isolated microorganisms depicted suggestive images of biofilm formation and corroded metallic structures questioning the possible role of these microorganisms in the corrosion activity. We also found Amazonian medicinal plants exhibiting inhibitory activity against some of the isolated microorganisms. Our new findings need additional studies to confirm the participation of some isolated microorganisms in the process of metallic degradation despite our main question if are there particular microorganisms involved in the corrosion process? or if physicochemical conditions would favor the development of a particular microbiota and consequently the corrosion process would result from its metabolism? Therefore we hypothesize that any microorganism could be potentially involved in the genesis of corrosion process. This is the first report in the literature dealing with microbiologically induced corrosion in the Amazon region which is especially characterized by its high humidity and elevated temperature all year round.

Studies of a Novel Cysteine Sulfoxide Lyase fromPetiveria alliacea: The First Heteromeric Alliinase

A novel alliinase (EC 4.4.1.4) was detected and purified from the roots of the Amazonian medicinal plant Petiveria alliacea. The isolated enzyme is a heteropentameric glycoprotein composed of two alpha-subunits (68.1 kD each), one beta-subunit (56.0 kD), one gamma-subunit (24.8 kD), and one delta-subunit (13.9 kD). The two alpha-subunits are connected by a disulfide bridge, and both alpha- and beta-subunits are glycosylated. The enzyme has an isoelectric point of 4.78 and pH and temperature optima of 8.0 and approximately 52 degrees C, respectively. Its activation energy with its natural substrate S-benzyl-l-cysteine sulfoxide is 64.6 kJ mol(-1). Kinetic studies showed that both K(m) and V(max) vary as a function of substrate structure, with the most preferred substrates being the naturally occurring P. alliacea compounds S-benzyl-l-cysteine sulfoxide and S-2-hydroxyethyl-l-cysteine sulfoxide. The alliinase reacts with these substrates to produce S-benzyl phenylmethanethiosulfinate and S-(2-hydroxyethyl) 2-hydroxyethanethiosulfinate, respectively.

Discovery and Characterization of a Novel Lachrymatory Factor Synthase inPetiveria alliaceaand Its Influence on Alliinase-Mediated Formation of Biologically Active Organosulfur Compounds

A novel lachrymatory factor synthase (LFS) was isolated and purified from the roots of the Amazonian medicinal plant Petiveria alliacea. The enzyme is a heterotetrameric glycoprotein comprised of two alpha-subunits (68.8 kD each), one gamma-subunit (22.5 kD), and one delta-subunit (11.9 kD). The two alpha-subunits are glycosylated and connected by a disulfide bridge. The LFS has an isoelectric point of 5.2. It catalyzes the formation of a sulfine lachrymator, (Z)-phenylmethanethial S-oxide, only in the presence of P. alliacea alliinase and its natural substrate, S-benzyl-l-cysteine sulfoxide (petiveriin). Depending on its concentration relative to that of P. alliacea alliinase, the LFS sequesters, to varying degrees, the sulfenic acid intermediate formed by alliinase-mediated breakdown of petiveriin. At LFS:alliinase of 5:1, LFS sequesters all of the sulfenic acid formed by alliinase action on petiveriin, and converts it entirely to (Z)-phenylmethanethial S-oxide. However, starting at LFS:alliinase of 5:2, the LFS is unable to sequester all of the sulfenic acid produced by the alliinase, with the result that sulfenic acid that escapes the action of the LFS condenses with loss of water to form S-benzyl phenylmethanethiosulfinate (petivericin). The results show that the LFS and alliinase function in tandem, with the alliinase furnishing the sulfenic acid substrate on which the LFS acts. The results also show that the LFS modulates the formation of biologically active thiosulfinates that are downstream of the alliinase in a manner dependent upon the relative concentrations of the LFS and the alliinase. These observations suggest that manipulation of LFS-to-alliinase ratios in plants displaying this system may provide a means by which to rationally modify organosulfur small molecule profiles to obtain desired flavor and/or odor signatures, or increase the presence of desirable biologically active small molecules.

Biological activity of neosergeolide and isobrucein B (and two semi-synthetic derivatives) isolated from the Amazonian medicinal plant Picrolemma sprucei (Simaroubaceae)

In the present study, in vitro techniques were used to investigate a range of biological activities of known natural quassinoids isobrucein B (1) and neosergeolide (2), known semi-synthetic derivative 1,12-diacetylisobrucein B (3), and a new semi-synthetic derivative, 12-acetylneosergeolide (4). These compounds were evaluated for general toxicity toward the brine shrimp species Artemia franciscana, cytotoxicity toward human tumour cells, larvicidal activity toward the dengue fever mosquito vector Aedes aegypti, haemolytic activity in mouse erythrocytes and antimalarial activity against the human malaria parasite Plasmodium falciparum. Compounds 1 and 2 exhibited the greatest cytotoxicity against all the tumor cells tested (IC50 = 5-27 microg/L) and against multidrug-resistant P. falciparum K1 strain (IC50 = 1.0-4.0 g/L) and 3 was only cytotoxic toward the leukaemia HL-60 strain (IC50 = 11.8 microg/L). Quassinoids 1 and 2 (LC50 = 3.2-4.4 mg/L) displayed greater lethality than derivative 4 (LC50 = 75.0 mg/L) toward A. aegypti larvae, while derivative 3 was inactive. These results suggest a novel application for these natural quassinoids as larvicides. The toxicity toward A. franciscana could be correlated with the activity in several biological models, a finding that is in agreement with the literature. Importantly, none of the studied compounds exhibited in vitro haemolytic activity, suggesting specificity of the observed cytotoxic effects. This study reveals the biological potential of quassinoids 1 and 2 and to a lesser extent their semi-synthetic derivatives for their in vitro antimalarial and cytotoxic activities.

Synthesis, Cytotoxicity, and Anti-Trypanosoma cruzi Activity of New Chalcones

Synthesis of a cytotoxic dihydrochalcone, first isolated from a traditional Amazonian medicinal plant Iryanthera juruensis Warb (Myristicaceae), followed by a comprehensive SAR analysis of saturated and unsaturated chalcone synthetic intermediates, led to the identification of analogues with selective and significant in vitro anti- Trypanosoma cruzi activity. Further SAR studies were undertaken with the synthesis of 21 new chalcones containing two allyloxy moieties that resulted in the discovery of 2',4'-diallyloxy-6'-methoxy chalcones with improved selectivity against this parasite at concentrations below 25 microM, four of which exhibited a selectivity index greater than 12.

Isolation of Cytotoxic Metabolites from Targeted Peruvian Amazonian Medicinal Plants

The antiproliferative bioassay-guided fractionation of five Peruvian plants, Doliocarpus dentatus, Picramnia sellowii, Strychnos mitscherlichii, Iryanthera juruensis, and Croton alnifolius, led to the isolation and identification of their different major cytotoxic constituents, betulinic acid (1), nataloe-emodin (2), bisnordihydrotoxyferine (4), 2',4'-dihydroxy-6'-methoxy-3,4-methylenedioxydihydrochalcone (5), and 2',4'-dihydroxy-4,6'-dimethoxydihydrochalcone (6) and 12-O-tetradecanoylphorbol-13-acetate (7), respectively. Eight human tumor cell lines and two nontumorigenic cell lines were used in this investigation. Their in vitro activity against Mycobacterium tuberculosis is also reported.

Chondroprotective effects of a proanthocyanidin rich Amazonian genonutrient reflects direct inhibition of matrix metalloproteinases and upregulation of IGF-1 production by human chondrocytes

BackgroundThe Amazonian medicinal plant Sangre de grado (Croton palanostigma) has traditional applications for the treatment of wound healing and inflammation. We sought to characterize two extracts (progrado and zangrado) in terms of safety and oligomeric proanthocyanidin chain length. Additionally progrado was evaluated for antioxidant activity and possible chondroprotective actions.MethodsAcute oral safety and toxicity was tested in rats according under OECD protocol number 420. The profile of proanthocyanidin oligomers was determined by HPLC and progrado's antioxidant activity quantified by the ORAC, NORAC and HORAC assays. Human cartilage explants, obtained from surgical specimens, were used to assess chondroproteciton with activity related to direct inhibitory effects on human matrix metalloproteinase (MMP, gelatinolytic) activity using synovial fluid and chondrocytes activated with IL-1β (10 ng/ml). Additionally, progrado (2–10 μg/ml) was tested for its ability to maintain optimal IGF-1 transcription and translation in cartilage explants and cultured chondrocytes.ResultsBoth progrado and zangrado at doses up to 2000 mg/kg (po) displayed no evidence of toxicity. Oligomeric proanthocyanidin content was high for both progrado (158 mg/kg) and zangrado (124 mg/kg), with zangrado almost entirely composed of short oligomers (<6 mer), whereas the majority of oligomers in progrado exceeded 10 mers. Progrado was a remarkably potent antioxidant in the standardized tests ORAC, NORAC and HORAC. Progrado was exceptionally effective in reducing both basal and IL-1β induced glycosaminoglycan release from human cartilage explants at concentrations that also directly blocked the gelatinolytic activity of MMP-2 and MMP-9. Progrado prevented IL-1β induced suppression of IGF-1 production from human cartilage explants as well as stimulating basal IGF-1 production (P < 0.05). Comparable changes in IGF-1 gene expression were noted in cultured human chondrocytes.ConclusionProgrado has a promising safety profile, significant chondroprotective and antioxidant actions, directly inhibits MMP activity and promotes the production of the cartilage repair factor, IGF-1. This suggests that progrado may offer therapeutic benefits in joint health, wound healing and inflammation.

Efficacy and safety of freeze-dried cat's claw in osteoarthritis of the knee: mechanisms of action of the species Uncaria guianensis

The purpose of this investigation was to evaluate the ability of cat's claw, an Amazonian medicinal plant, to treat osteoarthritis of the knee, collect safety and tolerance information and compare the antioxidant, and anti-inflammatory actions of Uncaria guianensis and Uncaria tomentosa in vitro. Forty-five patients with osteoarthritis of the knee were recruited, 30 were treated with freeze-dried U guianensis, and 15 with placebo. Hematological parameters were assessed on entry and exit of the four-week trial. Pain, medical and subject assessment scores and adverse effects were collected at weeks 1, 2 and 4. The antioxidant and anti-inflammatory activity of the cat's claw species was determined by the alpha,alpha-diphenyl-beta-picrylhydrazyl (DPPH) free radical scavenging method. Inhibition of TNFalpha and prostaglandin E2 (PGE2) production was determined in RAW 264.7 cells by ELISA. Cat's claw had no deleterious effects on blood or liver function or other significant side-effects compared to placebo. Pain associated with activity, medical and patient assessment scores were all significantly reduced, with benefits occurring within the first week of therapy. Knee pain at rest or at night, and knee circumference were not significantly reduced by cat's claw during this brief trial. In vitro tests indicated that U guianensis and U. tomentosa were equivalent at quenching DPPH radicals (EC50, 13.6-21.7 microg/ml) as well as inhibiting TNFalpha production. However, the latter action was registered at much lower concentrations (EC50, 10.2-10.9 ng/ml). Cat's claw (10 microg/ml) had no effect on basal PGE2 production, but reduced LPS-induced PGE2 release (P < 0.05), but at higher concentrations than that required for TNFalpha inhibition. Cat's claw is an effective treatment for osteoarthritis. The species, U guianensis and U tomentosa are equiactive. They are effective antioxidants, but their anti-inflammatory properties may result from their ability to inhibit TNFalpha and to a lesser extent PGE2 production.

A xanthone from Clusia insignis

Abstract A new xanthone, clusone, isolated from the fresh flowers of an Amazonian medicinal plant, Clusia insignis, has been characterized as 1,3,4,5,6-pentamethoxy 9H-xanthen-9-one by means of spectroscopic evidence.

Colony Stimulating Factor-Inducing Activity of IsoflavoneC-Glucosides from the Bark ofDalbergia monetaria

To obtain immunomodulating substances from Amazonian medicinal plants, hot water extracts from 21 samples available commercially were tested in terms of mitogenic and colony-stimulating factor (CSF)-inducing activities. Among them, Dalbergia monetaria exhibited the highest CSF-inducing activity. Orobol 8-C-glucoside (OCG-8) and orobol 6-C-glucoside (OCG-6) were isolated from the bark of D. monetaria as major constituents. The CSF-inducing activity of OCG-8 was higher than that of OCG-6 and a dose-dependent manner at a range of 0.1-10 mg/mouse. Serum CSF production induced by an intraperitoneal (i.p.) injection with 1 mg OCG-8 reached a peak at 4-6 h later, suggesting that OCG-8 would act on hematopoietic system.

Effects ofPtychopetalum olacoides extract on mouse behaviour in forced swimming and open field tests

Ptychopetalum olacoides (Olacaceae) is a popular Amazonian medicinal plant in Brazil claimed to be aphrodisiac and to cure male impotence. In the present study, we have evaluated the hydroalcohol extract prepared from stem bark on the behaviour in mice using forced swimming-induced immobility and open field as test models. The plant extract was found to possess both motor depressant and stimulant properties depending on the test model used. While it diminished locomotor activity in the open field test, it caused a reduction of immobility time in the forced swimming test. Also, these effects were found to be similar to those produced by clonidine, an α 2 -adrenoceptor agonist and were abolished by yohimbine, an α 2 -adrenergic antagonist. The findings obtained suggest a clonidine-like effect of P. olacoides bark extract.

Piscicidal properties of piperovatine from Piper piscatorum (Piperaceae)

Extraction of the roots of the Amazonian medicinal plant, Piper piscatorum Trelease and Yuncker, with MeOH and subsequent bioassay guided fractionation using the guppy, Girardina guppii, yielded the active amide, N-isobutyl-6-( p-methoxyphenyl) 2 E, 4 E-hexadieneamide (piperovatine) and a second inactive amide, N-isobutyl-( E)-7-(3,4-methylenedioxyphenyl)hept-2-enamide (pipercallosidine). The former displayed an LC 50 of 115 ng/ml in toxicity tests and proved to be the constituent responsible for the dual ethnobotanical uses of this plant: that of fish stupefacient (barbasco) and oral local anesthetic.

Isolation of leishmanicidal triterpenes and lignans from the Amazonian lianaDoliocarpus dentatus (dilleniaceae)

The in vitro antileishmanial activity of triterpenes and lignans of an Amazonian medicinal plant, Doliocarpus dentatus (Aublet) Standley, is reported for the first time against amastigotes of Leishmania amazonensis. Terpenes, for example, betulinic acid, betulin and betulinaldehyde were isolated by bioassay-linked extraction. The lignans were characterized as (+) pinoresinol, (+) medioresinol and (−) lirioresinol B.