Chemical composition and anti-proliferative activity of essential oils from some medicinal plants from Cachicadán, Región La Libertad, Perú.

This study evaluated the chemical composition and anti-proliferative activity of essential oils (EOs) obtained by hydrodistillation from seven medicinal plants from Cachicadán, La Libertad Región, Perú. Limonene (0.64 to 44.43%) and linalool (0.36 to 2.12%) were identified in all EOs by gas chromatography coupled to mass spectrometry analysis. The major components (relative intensity ≥ 10%) were cis-dihydro carvone, carvone, and cis-piperitone epoxide for Minthostachys mollis leaves; ß-pinene, limonene, and ledol for Lepechinia heteromorpha leaves; limonene, neral, and geranial for Aloysia citriodora, both leaves and flowers; α-pinene, and limonene for Myrcianthes myrsinoides leaves; and α-pinene, ß-myrcene, and (E)-ß-Ocimene for Dalea carthagenensis leaves. Constituted by (Z)-ß-ocimene, dihydrotagetone, (Z)-tagetone, and car-3-en-2-one, EO of Tagetes minuta leaves induced an irreversible cytostatic effect against MCF-7 human breast tumor cells. Further in vivo studies must be carried out to establish the safe and efficient dose of T. minuta EO as adjuvant treatment in oncological therapies.

Antiplasmodial Activity of Hydroalcoholic Extract from Jucá (Libidibia ferrea) Pods.

Malaria is an infectious and parasitic disease caused by protozoa of the genus Plasmodium, which affects millions of people in tropical and subtropical areas. Recently, there have been multiple reports of drug resistance in Plasmodium populations, leading to the search for potential new active compounds against the parasite. Thus, we aimed to evaluate the in vitro antiplasmodial activity and cytotoxicity of the hydroalcoholic extract of Jucá (Libidibia ferrea) in serial concentrations. Jucá was used in the form of a freeze-dried hydroalcoholic extract. For the cytotoxicity assay, the(3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) method with the WI-26VA4 human cell line was used. For the antiplasmodial activity, Plasmodium falciparum synchronized cultures were treated with serial concentrations (0.2 to 50 µg/mL) of the Jucá extract. In terms of the chemical composition of the Jucá extract, gas chromatography coupled to mass spectrometry measurements revealed the main compounds as ellagic acid, valoneic acid dilactone, gallotannin, and gallic acid. The Jucá hydroalcoholic extract did not show cytotoxic activity per MTT, with an IC50 value greater than 100 µg/mL. Regarding the antiplasmodial activity, the Jucá extract presented an IC50 of 11.10 µg/mL with a selective index of nine. Because of its antiplasmodial activity at the tested concentrations and low toxicity, the Jucá extract is presented as a candidate for herbal medicine in the treatment of malaria. To the best of our knowledge, this is the first report of antiplasmodial activity in Jucá.

Identification of Coumarins and Antimicrobial Potential of Ethanolic Extracts of Dipteryx odorata and Dipteryx punctata.

Dipteryx odorata and Dipteryx punctata are species native to the Amazonian, traded by extractivists to obtain coumarin. We aimed to analyze the presence of coumarin in the ethanolic extracts of leaves, branches and fruits of D. odorata and D. punctata and to evaluate the antimicrobial activity of these extracts against phytopathogenic fungi and bacteria of clinical interest. Chemical analyses were performed by thin layer chromatography (TLC) and by gas chromatography coupled to mass spectrometry (GC-MS). For the antifungal assays, the fungi used were Cercospora longissima, Colletotrichum gloeosporioides, two isolates of Fusarium spp. and Sclerotium rolfsii, and the antibacterial assay was performed using the minimum inhibitory concentration (MIC) test with Burkholderia cepacia, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus bacteria. In D. odorata seed extracts and in D. punctata husks, endocarps, and seeds, we identified 1,2-benzopyrone. D. odorata endocarp extracts and D. punctata seeds provided the greatest decrease in mycelial growth of the evaluated phytopathogens, showing promise as an alternative control. The husk and endocarp extracts of both species had a weak effect on E. coli. This research is the first to compare the different parts of species of the genus Dipteryx and to evaluate the use of husks and endocarps of D. punctata fruits to obtain coumarin. Chemical analyses used to quantify the compounds existing in the extracts, and tests with phytopathogens in vitro and in vivo are currently being carried out.

Anti-Inflammatory Potential of the Oleoresin from the Amazonian Tree Copaifera reticulata with an Unusual Chemical Composition in Rats.

Copaifera reticulata Ducke is a popularly known species known as copaíba that is widely spread throughout the Amazon region. The tree yields an oleoresin which is extensively used in local traditional medicine mainly as an anti-inflammatory and antinociceptive agent. The aim of the present study was to assess the anti-inflammatory potential of this oleoresin obtained from a national forest in the central Amazon which presented an unusual chemical composition. The chemical composition of volatile compounds of oleoresin was analyzed by gas chromatography-mass spectrometry. The acute toxicity assay was performed with a single dose of 2000 mg/kg. The anti-inflammatory potential was evaluated by carrageenan-induced paw edema and air pouch assays using four different C. reticulata oleoresin concentrations (10, 100, and 400 mg/kg). The exudate was evaluated for nitrite concentration through the colorimetric method and for TNF-α, IL-1ß, and PGE2 by ELISA. C. reticulata oleoresin collected in the Amazonian summer contained six major sesquiterpene compounds (ß-bisabolene, cis-eudesma-6,11-diene, trans-α-bergamotene, ß-selinene, α-selinene, and ß-elemene) and was nontoxic at a dose of 2000 mg/kg, showing low acute toxicity. Different from oleoresin obtained from other sites of the Brazilian Amazon, the major volatile compound found was ß-Bisabolene with 25.15%. This ß-Bisabolene-rich oleoresin reduced the formation of paw edema induced by carrageenan and reduced the global number of cells in the air pouch assay, as well as exudate volume and nitrite, TNF-α, IL-1ß, and prostaglandin E2 levels (p < 0.05). C. reticulata oleoresin with a high ß-Bisabolene concentration showed anti-inflammatory activity, reducing vascular permeability and consequently edema formation, and thus reducing cell migration and the production of inflammatory cytokine, confirming its traditional use by local Amazonian communities.

Chemical Composition and Antiproliferative Activity of the Ethanolic Extract of Cyperus articulatus L. (Cyperaceae).

Cyperus articulatus L. (Priprioca) is a plant of the Cyperaceae family traditionally used in traditional medicine in the Amazon region. Studies of the essential oil of this species have identified many terpene compounds. However, little is known about the possible uses of solid waste generated by the extraction of essential oils. This study aimed to investigate the chemical composition of volatile compounds and to evaluate the antiproliferative activity of the ethanolic extract of solid residues generated by the extraction of the essential oil of C. articulatus L. rizhomes in experimental models in vitro using peritoneal macrophages of mice and human tumor cell lines. The analysis of the chemical composition of volatile compounds indicated the presence of sesquiterpenes and particularly sequiterpenic ketones as main constituents. The results showed that the treatment with ethanolic extract of C. articulatus L. reduced the activity of the enzyme arginase and proliferation of cancer cells (p < 0.0001). The extract also showed no cytotoxicity in macrophages in concentrations between 12.5; 25 and 50 mg/mL (p < 0.0001). The results indicated that the extract of C. articulatus L. exerts antiproliferative activity (p < 0.0001) with low toxicity on healthy cells in experimental models in vitro.

In Vitro Calli Production Resulted in Different Profiles of Plant-Derived Medicinal Compounds in Phyllanthus amarus.

The efficient production of plant-derived medicinal compounds (PDMCs) from in vitro plants requires improvements in knowledge about control of plant or organ development and factors affecting the biosynthesis pathway of specific PDMCs under in vitro conditions, leading to a realistic large-scale tool for in vitro secondary metabolite production. Thus, this study aimed to develop an in vitro technique, through the induction and proliferation of calli, for production of plant fresh weight, and to compare the PDMC profile obtained from the plants versus in vitro calli of Phyllanthus amarus. It was successfully possible to obtain and proliferate two types of calli, one with a beige color and a friable appearance, obtained in the dark using Murashige and Skoog (MS) medium plus 2,4-dichlorophenoxyacetic acid (2,4-D), and a second type with a green color, rigid consistency, and nonfriable appearance obtained under light conditions and MS medium plus 6-benzyladenine (6-BA). In vitro micropropagated plants that gave rise to calli were also acclimatized in a greenhouse and cultivated until obtaining the mass for PDMC analysis and used as a control. While the micropropagated-derived plants concentrated the lignans niranthin, nirtetralin, and phyllanthin, the Phyllanthus amarus calli proliferated in vitro concentrated a completely different biochemical profile and synthesis of compounds, such as betulone, squalene, stigmasterol, and ß-sitosterol, in addition to others not identified by GC-MS database. These results demonstrate the possibility of applying the calli in vitro from Phyllanthus amarus for production of important PDMCs unlike those obtained in cultures of differentiated tissues from field plants.

Endophytic fungi from Passiflora incarnata: an antioxidant compound source.

Endophytes are considered one of the most important microbial resources for obtaining biomolecules of therapeutic use. Passiflora incarnata, widely employed by the pharmaceutical industry, shows therapeutic effects on anxiety, nervousness, constipation, dyspepsia and insomnia based on their antioxidant compounds. In this study, from 315 endophytic fungi isolated from P. incarnata leaves, 60 were selected to determinate presence of chemical constituents related with antioxidant activity, based on their production of soluble pigments. The promising fungi were evaluated specifically on their potential to produce phenolic compounds, flavonoids and for antioxidant activity. Five isolates significantly produced flavonoids and phenolic compounds in the ethyl acetate and n-Butanol extracts, also saponins and high antioxidant activity against the DPPH (2.2-diphenyl-1-picrylhydrazyl) free radical. A strain of Aspergillus nidulans var. dentatus (former Emericella dentata) was able to produce tannins as well; its butanolic extract was very similar than the BHT (butylated hydroxytoluene) (94.3% × 94.32%) and Rutin (95.8%) reference substances in the DPPH radical scavenging. Similarly, a Chaetomium strain exhibited 93.6% and 94.7% of antioxidant activity in their ethyl acetate and butanolic fractions, respectively. The chromatographic analysis of the ethyl acetate fraction from the Aspergillus strain revealed the production of orcinol (3.19%). Four-methoxymethylphenol (4.79%), sorbicillin (33.59%) and ergosterol (23.08%) was produced by Trichoderma longibrachiatum and isopropenyl-1,4-dimethyl-1,2,3,3a,4,5,6,7-octahydroazulene were found in two Fusarium oxysporum strains. The phytochemical screening showed that all analyzed fungi were able to produce a kind of secondary metabolite (phenols, flavonoids, tannins and/or saponins). The study shows a great underexplored potential for industrial application of P. incarnata endophytes.

Effects of Artemisia annua alcohol extract on physiological and innate immunity of Nile tilapia (Oreochromis niloticus) to improve health status.

Plants are a potential source of active molecules and are environmentally safer and cheaper than synthetic antibiotics. Bioactive compounds of Artemisia annua have shown pharmacological activities and are used globally as a supplement. The present study tested whether dietary supplementation with alcohol extract of the plant A. annua (ae-Aa; patent BR10201902707) improves the health status of juvenile Nile tilapia and increases resistance to diseases when fish are challenged with the bacteria Aeromonas hydrophila. The experimental design was completely randomized with four experimental groups (0.0, 0.1, 0.25, and 0.5% ae-Aa in the diets) with five repetitions (12 fish per repetition/experimental unit). We assessed serum glucose and cortisol levels in plasma, leukocyte respiratory activity, total plasma protein, serum lysozyme levels, as well as the number of circulating red blood cells and fish leukocytes at the end of the 30 days of feeding (phase I) and 24h after exposure to bacteria (phase II). The levels of lipid peroxidation, catalase activity and glutathione S-transferase of fish were also analyzed. The supplementation of 0.5% of ae-Aa was sufficient to increase the respiratory burst of leukocyte and lysozyme activity, total plasma protein, blood thrombocytes, neutrophils and monocytes after bacterial challenge (P < 0.05), and minimized stress response with decreases in plasmatic glucose and cortisol, and reduction in lipid peroxidation levels (P < 0.05). Results of the present study suggest that ae-Aa as a dietary supplement has benefits, including supplementation with 0.5% A. annua extract for 30 days to minimize the stress response and modulate innate immunity in Nile tilapia, providing fish with greater resistance and disease protection.

Leishmanicidal activity of Piper marginatum Jacq. from Santarém-PA against Leishmania amazonensis.

Leishmaniasis is an infectious disease that has high endemicity and is among the six parasitic diseases of higher occurrence in the world. The current treatments are limited due to their toxicity, treatment resistance and high cost which have increased the search for new substances of natural origin for its therapy. Based on this, an in vitro biological and chemical investigation was carried out to evaluate the potential of Piper marginatum against Leishmania amazonesis. P. marginatum leaves were collected to obtain the essential oil (EO) and the ethanolic extract (CE). The chemical profile of the CE and fractions was obtained by 1H NMR. The analysis of the EO chemical composition was performed by GC-MS. EO, CE and fractions were submitted to antileishmanial and cytotoxicity assays against macrophages. The chromatographic profiles of EO, CE and fractions showed the presence of phenolic compounds and terpenoids, having 3,4-Methylenedioxypropiophenone as a major compound. All P. marginatum samples showed low toxicity to macrophages. The CE and the methanolic, hexane and ethyl acetate fractions had low cytotoxicity when compared to Pentamidine. All tested samples inhibited growth of L. amazonensis promastigotes. The antileishmanial activity of EO, CE and fractions were evaluated in macrophages infected with L. (L.) amazonensis and treated with the concentrations 1, 10 and 100 µg/mL for 48 h. All samples were active, but EO and CE showed superior activity against amastigote forms when compared to the promastigote forms of L. amazonensis. This work describes for the first time the antileishmanial activity of the species P. marginatum and its cytotoxicity against macrophages, suggesting that it can be an alternative source of natural products in the phytotherapeutic treatment of leishmaniasis.

In vitro effects of Melaleuca alternifolia essential oil on growth and production of volatile sulphur compounds by oral bacteria

ABSTRACT Objective Halitosis can be caused by microorganisms that produce volatile sulphur compounds (VSCs), which colonize the surface of the tongue and subgingival sites. Studies have reported that the use of natural products can reduce the bacterial load and, consequently, the development of halitosis. The aim of this study was to evaluate the antimicrobial activity of the essential oil of Melaleuca alternifolia on the growth and volatile sulphur compound (VSC) production of oral bacteria compared with chlorhexidine. Material and Methods The effects of these substances were evaluated by the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) in planktonic cultures of Porphyromonas gingivalis and Porphyromonas endodontalis. In addition, gas chromatography analyses were performed to measure the concentration of VSCs from bacterial cultures and to characterize M. alternifolia oil components. Results The MIC and MBC values were as follows: M. alternifolia - P. gingivalis (MIC and MBC=0.007%), P. endodontalis (MIC and MBC=0.007%=0.5%); chlorhexidine - P. gingivalis and P. endodontalis (MIC and MBC=1.5 mg/mL). M. alternifolia significantly reduced the growth and production of hydrogen sulfide (H2S) by P. gingivalis (p<0.05, ANOVA-Dunnet) and the H2S and methyl mercaptan (CH3SH) levels of P. endodontalis (p<0.05, ANOVA-Dunnet). Chlorhexidine reduced the growth of both microorganisms without altering the production of VSC in P. endodontalis. For P. gingivalis, the production of H2S and CH3SH decreased (p<0.05, ANOVA-Dunnet). Conclusion M. alternifolia can reduce bacterial growth and VSCs production and could be used as an alternative to chlorhexidine.

In vitro effects of Melaleuca alternifolia essential oil on growth and production of volatile sulphur compounds by oral bacteria.

OBJECTIVE: Halitosis can be caused by microorganisms that produce volatile sulphur compounds (VSCs), which colonize the surface of the tongue and subgingival sites. Studies have reported that the use of natural products can reduce the bacterial load and, consequently, the development of halitosis. The aim of this study was to evaluate the antimicrobial activity of the essential oil of Melaleuca alternifolia on the growth and volatile sulphur compound (VSC) production of oral bacteria compared with chlorhexidine. MATERIAL AND METHODS: The effects of these substances were evaluated by the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) in planktonic cultures of Porphyromonas gingivalis and Porphyromonas endodontalis. In addition, gas chromatography analyses were performed to measure the concentration of VSCs from bacterial cultures and to characterize M. alternifolia oil components. RESULTS: The MIC and MBC values were as follows: M. alternifolia - P. gingivalis (MIC and MBC=0.007%), P. endodontalis (MIC and MBC=0.007%=0.5%); chlorhexidine - P. gingivalis and P. endodontalis (MIC and MBC=1.5 mg/mL). M. alternifolia significantly reduced the growth and production of hydrogen sulfide (H2S) by P. gingivalis (p<0.05, ANOVA-Dunnet) and the H2S and methyl mercaptan (CH3SH) levels of P. endodontalis (p<0.05, ANOVA-Dunnet). Chlorhexidine reduced the growth of both microorganisms without altering the production of VSC in P. endodontalis. For P. gingivalis, the production of H2S and CH3SH decreased (p<0.05, ANOVA-Dunnet). CONCLUSION: M. alternifolia can reduce bacterial growth and VSCs production and could be used as an alternative to chlorhexidine.

The Effect of Essential Oils and Bioactive Fractions on Streptococcus mutans and Candida albicans Biofilms: A Confocal Analysis.

The essential oils (EO) and bioactive fractions (BF) from Aloysia gratissima, Baccharis dracunculifolia, Coriandrum sativum, Cyperus articulatus, and Lippia sidoides were proven to have strong antimicrobial activity on planktonic microorganisms; however, little is known about their effects on the morphology or viability of oral biofilms. Previously, we determined the EO/fractions with the best antimicrobial activity against Streptococcus mutans and Candida spp. In this report, we used a confocal analysis to investigate the effect of these EO and BF on the morphology of S. mutans biofilms (thickness, biovolume, and architecture) and on the metabolic viability of C. albicans biofilms. The analysis of intact treated S. mutans biofilms showed no statistical difference for thickness in all groups compared to the control. However, a significant reduction in the biovolume of extracellular polysaccharides and bacteria was observed for A. gratissima and L. sidoides groups, indicating that these BF disrupt biofilm integrity and may have created porosity in the biofilm. This phenomenon could potentially result in a weakened structure and affect biofilm dynamics. Finally, C. sativum EO drastically affected C. albicans viability when compared to the control. These results highlight the promising antimicrobial activity of these plant species and support future translational research on the treatment of dental caries and oral candidiasis.

Action of essential oils from Brazilian native and exotic medicinal species on oral biofilms.

BACKGROUND: Essential oils (EO) obtained from twenty medicinal and aromatic plants were evaluated for their antimicrobial activity against the oral pathogens Candida albicans, Fusobacterium nucleatum, Porphyromonas gingivalis, Streptococcus sanguis and Streptococcus mitis. METHODS: The antimicrobial activity of the EO was evaluates by microdilution method determining Minimal Inhibitory Concentration. Chemical analysis of the oils compounds was performed by Gas chromatography-mass spectrometry (CG-MS). The most active EO were also investigated as to their actions on the biolfilm formation. RESULTS: The most of the essential oils (EO) presented moderate to strong antimicrobial activity against the oral pathogens (MIC--Minimal Inhibitory Concentrations values between 0.007 and 1.00 mg/mL). The essential oil from Coriandrum sativum inhibited all oral species with MIC values from 0.007 to 0.250 mg/mL, and MBC/MFC (Minimal Bactericidal/Fungicidal Concentrations) from 0.015 to 0.500 mg/mL. On the other hand the essential oil of C. articulatus inhibited 63.96% of S. sanguis biofilm formation. Through Scanning Eletronic Microscopy (SEM) images no changes were observed in cell morphology, despite a decrease in biofilm formation and changes on biofilm structure. Chemical analysis by Gas Chromatography-Mass Spectrometry (GC-MS) of the C. sativum essential oil revealed major compounds derivatives from alcohols and aldehydes, while Cyperus articulatus and Aloysia gratissima (EOs) presented mono and sesquiterpenes. CONCLUSIONS: In conclusion, the crude oil from C. articulatus exhibited the best results of antimicrobial activity e ability to control biofilm formation. The chemical analysis showed the presence of terpenes and monoterpenes such as a-pinene, a-bulnesene and copaene. The reduction of biofilms formation was confirmed from SEM images. The results of this research shows a great potential from the plants studied as new antimicrobial sources.

Antimicrobial Activity of Essential Oils against Streptococcus mutans and their Antiproliferative Effects.

This study aimed to evaluate the activity of essential oils (EOs) against Streptococcus mutans biofilm by chemically characterizing their fractions responsible for biological and antiproliferative activity. Twenty EO were obtained by hydrodistillation and submitted to the antimicrobial assay (minimum inhibitory (MIC) and bactericidal (MBC) concentrations) against S. mutans UA159. Thin-layer chromatography and gas chromatography/mass spectrometry were used for phytochemical analyses. EOs were selected according to predetermined criteria and fractionated using dry column; the resulting fractions were assessed by MIC and MBC, selected as active fractions, and evaluated against S. mutans biofilm. Biofilms formed were examined using scanning electron microscopy. Selected EOs and their selected active fractions were evaluated for their antiproliferative activity against keratinocytes and seven human tumor cell lines. MIC and MBC values obtained for EO and their active fractions showed strong antimicrobial activity. Chemical analyses mainly showed the presence of terpenes. The selected active fractions inhibited S. mutans biofilm formation (P < 0.05) did not affect glycolytic pH drop and were inactive against keratinocytes, normal cell line. In conclusion, EO showed activity at low concentrations, and their selected active fractions were also effective against biofilm formed by S. mutans and human tumor cell lines.

In Vitro Cytotoxic Potential of Essential Oils of Eucalyptus benthamii and Its Related Terpenes on Tumor Cell Lines.

Eucalyptus L. is traditionally used for many medicinal purposes. In particular, some Eucalyptus species have currently shown cytotoxic properties. Local Brazilian communities have used leaves of E. benthamii as a herbal remedy for various diseases, including cancer. Considering the lack of available data for supporting this cytotoxic effect, the goal of this paper was to study the in vitro cytotoxic potential of the essential oils from young and adult leaves of E. benthamii and some related terpenes (α-pinene, terpinen-4-ol, and γ-terpinene) on Jurkat, J774A.1 and HeLa cells lines. Regarding the cytotoxic activity based on MTT assay, the essential oils showed improved results than α-pinene and γ-terpinene, particularly for Jurkat and HeLa cell lines. Terpinen-4-ol revealed a cytotoxic effect against Jurkat cells similar to that observed for volatile oils. The results of LDH activity indicated that cytotoxic activity of samples against Jurkat cells probably involved cell death by apoptosis. The decrease of cell DNA content was demonstrated due to inhibition of Jurkat cells proliferation by samples as a result of cytotoxicity. In general, the essential oils from young and adult leaves of E. benthamii presented cytotoxicity against the investigated tumor cell lines which confirms their antitumor potential.

Control of Colletotrichum gloeosporioides (penz.) Sacc. In yellow passion fruit using Cymbopogon citratus essential oil

The use of antibiotics in agriculture is limited when compared to their applications in human and veterinary medicine. On the other hand, the use of antimicrobials in agriculture contributes to the drug resistance of human pathogens and has stimulated the search for new antibiotics from natural products. Essential oils have been shown to exert several biological activities including antibacterial and antifungal actions. The aim of this study was to determine the activity of 28 essential oils from medicinal plants cultivated at CPMA (Medicinal and Aromatic Plants Collection), CPQBA/UNICAMP, against Colletotrichum gloeosporioides (Penz.) Sacc., the anthracnose agent in yellow passion fruit (Passiflora edulis Sims f. flavicarpa Deg), as well as evaluating their effect in the control of post-harvest decay. The oils were obtained by water-distillation using a Clevenger-type system and their minimal inhibitory concentrations (MIC) determined by the micro-dilution method. According to the results, 15 of the 28 essential oils presented activity against Colletotrichum gloeosporioides, and the following four oils presented MIC values between 0.25 and 0.3 mg/mL: Coriandrum sativum, Cymbopogon citratus, Cymbopogon flexuosus and Lippia alba. The evaluation of Cymbopogon citratus essential oil in the control of post-harvest decay in yellow passion fruit showed that the disease index of the samples treated with the essential oil did not differ (P < 0.05) from that of the samples treated with fungicide. The present study shows the potential of Cymbopogon citratus essential oil in the control of the anthracnose agent in yellow passion fruit.

Control of Colletotrichum gloeosporioides (penz.) Sacc. In yellow passion fruit using Cymbopogon citratus essential oil.

The use of antibiotics in agriculture is limited when compared to their applications in human and veterinary medicine. On the other hand, the use of antimicrobials in agriculture contributes to the drug resistance of human pathogens and has stimulated the search for new antibiotics from natural products. Essential oils have been shown to exert several biological activities including antibacterial and antifungal actions. The aim of this study was to determine the activity of 28 essential oils from medicinal plants cultivated at CPMA (Medicinal and Aromatic Plants Collection), CPQBA/UNICAMP, against Colletotrichum gloeosporioides (Penz.) Sacc., the anthracnose agent in yellow passion fruit (Passiflora edulis Sims f. flavicarpa Deg), as well as evaluating their effect in the control of post-harvest decay. The oils were obtained by water-distillation using a Clevenger-type system and their minimal inhibitory concentrations (MIC) determined by the micro-dilution method. According to the results, 15 of the 28 essential oils presented activity against Colletotrichum gloeosporioides, and the following four oils presented MIC values between 0.25 and 0.3 mg/mL: Coriandrum sativum, Cymbopogon citratus, Cymbopogon flexuosus and Lippia alba. The evaluation of Cymbopogon citratus essential oil in the control of post-harvest decay in yellow passion fruit showed that the disease index of the samples treated with the essential oil did not differ (P ≤ 0.05) from that of the samples treated with fungicide. The present study shows the potential of Cymbopogon citratus essential oil in the control of the anthracnose agent in yellow passion fruit.

Activity of essential oils from Brazilian medicinal plants on Escherichia coli.

Essential oils obtained from leaves of 29 medicinal plants commonly used in Brazil were screened against 13 different Escherichia coli serotypes. The oils were obtained by water-distillation using a Clevenger-type system and their minimal inhibitory concentration (MIC) were determined by microdilution method. Essential oil from Cymbopogon martinii exhibited a broad inhibition spectrum, presenting strong activity (MIC between 100 and 500 microg/mL) against 10 out of 13 Escherichia coli serotypes: three enterotoxigenic, two enteropathogenic, three enteroinvasive and two shiga-toxin producers. C. winterianus inhibited strongly two enterotoxigenic, one enteropathogenic, one enteroinvasive and one shiga-toxin producer serotypes. Aloysia triphylla also shows good potential to kill Escherichia coli with moderate to strong inhibition. Other essential oils showed antimicrobial properties, however with a more restricted action against the serotypes studied. Chemical analysis of Cymbopogon martinii essential oil performed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS) showed the presence of compounds with known antimicrobial activity, including geraniol, geranyl acetate and trans-cariophyllene, which tested separately, indicated geraniol as antimicrobial active compound. The significant antibacterial activity of Cymbopogon martinii oil suggests that they could serve as a source for compounds with therapeutic potential.

Anti-Candida activity of Brazilian medicinal plants.

Essential oils and ethanolic extracts from the leaves and/or roots of 35 medicinal plants commonly used in Brazil were screened for anti-Candida albicans activity. The oils were obtained by water-distillation using a Clevenger-type system. Essential oils from 13 plants showed anti-Candida activity, including Aloysia triphylla, Anthemis nobilis, Cymbopogon martini, Cymbopogon winterianus, Cyperus articulatus, Cyperus rotundus, Lippia alba, Mentha arvensis, Mikania glomerata, Mentha piperita, Mentha sp., Stachys byzantina, and Solidago chilensis. The ethanol extract was not effective at any of the concentrations tested. Chemical analyses showed the presence of compounds with known antimicrobial activity, including 1,8-cineole, geranial, germacrene-D, limonene, linalool, and menthol.

Composition and antimicrobial activity of essential oils from aromatic plants used in Brazil

Oleos essenciais foram obtidos a partir das partes aéreas de Mentha piperita, M. spicata, Thymus vulgaris, Origanum vulgare, O. applii, Aloysia triphylla, Ocimum gratissimum e O. basilicum através de arraste de vapor em sistema tipo Clevenger. Os óleos foram avaliados quanto à atividade antimicrobiana contra bactérias e contra a levedura Candida albicans pelo método de bioautografia. A concentração mínima inibitória dos óleos com atividade positiva foi em seguida determinada pelo método da microdiluição. De acordo com os resultados, a maioria dos óleos essenciais estudados foram efetivos contra Enterococcus faecium e Salmonella cholerasuis. A.triphylla e O. basilicum apresentaram inibição moderada contra Staphylococcus aureus enquanto apenas A. tryphila e M. piperita foram capazes de inibir a levedura Candida albicans. Os óleos foram analisados quimicamente por técnicas de CG e CG-EM de modo a determinar os compostos majoritários presentes.