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The ethanol extract and methanol fraction of Pityrogramma calomelanos (L.) link were evaluated for antibacterial, antifungal and modulatory activities against strains of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, C. krusei and C. tropicalis. The antimicrobial activity of the natural products was evaluated by the microdilution method associated or not with aminoglycosides and antifungals. The ethanol extract and methanol fraction of P. calomelanos showed good activity against S. aureus when associated with aminoglycosides and with benzoilmetronidazol against species of the genus Candida. These results indicate that P. calomelanos should be studied as a possible source of natural products to combat bacteria and fungi either directly or by modulating the mechanisms of resistance of these microorganisms, enhancing the antimicrobial activity of these drugs and combating microbial resistance.

In this study the physicochemical characterization of the pulp and almond fixed oil was carried out; their antibacterial activity and aminoglycoside antibiotic modifying action against standard and multiresistant Gram-positive and -negative bacteria were investigated using the broth microdilution assay. Physical properties such as moisture, pH, acidity, peroxide index, relative density and refractive index indicate stability and chemical quality of the oils. In the GC/MS chemical composition analysis, a high unsaturated fatty acid content and the presence of oleic and palmitic acids were observed in the oils. In the antibacterial assay, more significant results were obtained for Escherichia coli, while other standard and multi-resistant strains presented MIC values ≥ 1024 μg/mL. Furthermore, the fixed oils in association with antibiotics were able to significantly improve antibacterial activity against S. aureus with a reduction in MICs. [ABSTRACT FROM AUTHOR]

Essential oils are new natural medicines, which have been studied extensively in recent years. In this paper, the chemical composition of the essential oil from Alpinia zerumbet leaves and its ability to modulate the activity of aminoglycoside antibiotics is reported. The essential oil was extracted by hydrodistillation and analyzed by gas chromatography (GC) and GC–mass spectrometry (GC/MS). The antibacterial activity of the essential oil alone or in association with aminoglycosides was determined by a microdilution test against twelve strains (standards and multi-resistant clinical isolates obtained from sputum and wounds), seven Gram negative and five Gram positive. The major components identified by GC/MS were 4-terpineol (32.9 ± 4.0%), 1,8-cineole (21.4 ± 1.2%), γ-terpinolene (10.0 ± 1.8%) and sabinene (7.1 ± 4.6%), with a strong predominance of monoterpenes. The results indicated that the multi-resistant clinical isolates Staphylococcus aureus 358 and Escherichia coli 27 were more sensitive to the essential oil, exhibiting minimum inhibitory concentrations (MICs) of 32 and 128 μg/mL, respectively. The essential oil was capable of enhancing the antimicrobial activity of aminoglycosides against all strains tested, except for S. aureus 358. Very significant reductions in the MICs of the antibiotics were found, with a 94% decrease in MIC of neomycin against Klebsiella pneumoniae ATCC 10031. The results obtained indicate that the A. zerumbet essential oil has a significant synergistic antibiotic effect when combined with aminoglycosides, demonstrating that its constituents may act as potentiators of the antibiotic activity of aminoglycosides. [ABSTRACT FROM AUTHOR]

Recently, several plants have been evaluated not only for antimicrobial activity but also for resistance-modifying action. In this work, the chemical composition and antibacterial and antibiotic-modulatory activities of the essential oils from Lantana camara L. and Lantana montevidensis Briq. were analyzed. The essential oils extracted from the leaves by hydrodistillation and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) were characterized by a high percentage of sesquiterpene hydrocarbons. Among the 34 constituents identified, bicyclogermacrene (19.4%), isocaryophyllene (16.7%), valencene (12.9%) and germacrene D (12.3%) were the main constituents of the oil from L. camara, while in the oil from L. montevidensis, β-caryophyllene (31.5%), germacrene D (27.5%) and bicyclogermacrene (13.9%) predominated. The essential oils were examined for antibiotic activities alone and in combination with aminoglycosides by a microdilution assay utilizing five bacterial strains. They exhibited significant antibacterial activities, mainly against Proteus vulgaris (MIC 64 μg/mL, L. camara; MlC 128 μg/mL, L. montevidensis). Both oils also showed a synergistic effect on the activity of aminoglycoside antibiotics. Thus, the essential oils of L. camara and L. montevidensis could be used as a source of plant-derived natural products with resistance-modifying antibacterial activity. [ABSTRACT FROM AUTHOR]

Context: Chagas disease, caused by Trypanosoma cruzi, is a public health problem. Currently, chemotherapy is the only available treatment for this disease, and the drugs used, nifurtimox and benzonidazol, present high toxicity levels. An alternative for replacing these drugs are natural extracts from Momordica charantia L. (Cucurbitaceae) used in traditional medicine because of their antimicrobial and biological activities. Objective: In this study, we evaluated the extract of M. charantia for its antiepimastigote, antifungal, and cytotoxic activities. Materials and methods: An ethanol extract of leaves from M. charantia was prepared. To research in vitro antiepimastigote activity, T. cruzi CL-B5 clone was used. Epimastigotes were inoculated at a concentration of 1×105 cells/mL in 200 µl tryptose--liver infusion. For the cytotoxicity assay, J774 macrophages were used. The antifungal activity was evaluated by microdilution using strains of Candida albicans, Candida tropicalis, and Candida krusei. Results: The effective concentration capable of killing 50% of parasites (IC50) was 46.06 µg/mL. The minimum inhibitory concentration (MIC) was ≤ 1024 µg/mL. Metronidazole showed a potentiation of its antifungal effect when combined with an extract of M. charantia. Conclusions: Our results indicate that M. charantia could be a source of plant-derived natural products with antiepimastigote and antifungal-modifying activity with moderate toxicity. [ABSTRACT FROM AUTHOR]

Context: Bacterial infectious agents represent a risk to populations, where they are responsible for the high morbidity and mortality. In combating these pathogens, our main line of defense is the use of antibiotics. However, the indiscriminate use of these drugs select resistant strains to these same drugs. Objective: In this study the ethanol extract of Hyptis martiusii Benth. (EEHM) (Lamiaceae) was tested for its antimicrobial activity against aminoglycoside multi-resistant Staphylococcus aureus (MRSA). Materials and methods: In this study, the ethanol extract of H. martiusii was prepared and tested with chlorpromazine for its antimicrobial activity using the microdilution method. Chlorpromazine and the ethanol extract were used alone and also in combination with aminoglycosides against a MRSA strain resistant to these antibiotics to determine the participation of efflux systems in resistance mechanisms. The FIC index was calculated and evaluated by the checkerboard method. Results: A potentiating effect between this extract and aminoglycosides was demonstrated. Similarly, a potentiating effect of chlorpromazine with kanamycin was detected, indicating the involvement of an efflux system in the resistance to this aminoglycoside. The checkerboard method with combinations of aminoglycosides and EEHM demonstrated additive effect with kanamycin and gentamicin. It is therefore suggested that extracts from H. martiusii could be used as a source of plant-derived natural products with resistance- modifying activity. Conclusion: This is the first report about the modifying antibiotic activity of Hyptis martiusii, constituting a new approach against bacterial resistance to antibiotics as aminoglycosides. [ABSTRACT FROM AUTHOR]

Abstract: Aim of the study: Tupinambis merianae is one of the animals that is most frequently used for medicinal purposes in Brazil as its body fat has many therapeutic indications in local folk medicine. This work presents the chemical compositions of the body fat of Tupinambis merianae and evaluates the antibacterial activity of the body fat as well as the ecological implications of its use in traditional medicine. Materials and methods: Oil (OTM) was extracted from body fat located in the ventral region of Tupinambis merianae using hexane as a solvent. Fatty acids were determined indirectly using their corresponding methyl esters. The antibacterial activity of OTM was tested against standard as well as multi-resistant lines of Escherichia coli and Staphylococcus aureus, either alone or in combination with antibiotics and UV-A light. Results: Body fat of Tupinambis merianae presents 57% and 43% of unsaturated and saturated fatty acids respectively. Our results indicated that OTM did not demonstrate relevant antibacterial activity against any of the lines of Escherichia coli or Staphylococcus aureus, nor when combined with antibiotics or with UV-A light. Conclusions: In light of these results, we recommend (i) development of management plans for a sustainable and rational use of Tupinambis merianae reducing the possible pressure on this species; and (ii) more studies be focused on the use of OTM and other natural products derived from animals that are used to treat other illnesses. [Copyright &y& Elsevier]

Abstract: Ethnopharmacological relevance: Croton campestris A. St.-Hill., popularly known as “velame do campo”, is a species native from savannah area of Northeast Brazil, which is used by traditional communities in folk medicine for a variety of health problems, especially detoxification, inflammation and gastritis. The present study investigates the possible gastric antiulcer activity of Croton campestris root extract (CCRE) and mechanisms of action underlying this effect. Materials and methods: Gastric lesions were induced in mice by ethanol, acidified ethanol and indomethacin. CCRE was previously administered orally in doses ranging from 50 to 750mg/kg. Stomach lesions were measured. The involvement of Nitric Oxide (NO), prostaglandins (PGEs), ATP-dependent K+ channel and adrenergic receptor was investigated through specific inhibitors. Results: CCRE produced significant antiulcer activity against absolute ethanol, acidified ethanol and indomethacin induced gastric lesions. The pretreatment with L-NAME (10mg/kg, p.o.), an inhibitor of nitric oxide synthesis and indomethacin (10mg/kg, s.c.), an inhibitor of prostaglandin production, reversed the antiulcer action of CCRE. Conclusion: Taking together, these results suggest that the antiulcer activity of CCRE is dependent of NO and prostaglandin pathways possibly due to its ability to stimulate the synthesis of NO, and activation of endogenous prostaglandin production. Therefore, the use of CCRE in traditional Brazilian medicine against gastric disorders has a scientific basis. [Copyright &y& Elsevier]

Abstract: Lippia sidoides Cham. (Verbenaceae) is used in the folk medicine as topical antiseptic in skin and mucous membranes and its therapeutic effect is attributed to the thymol presence. The objective of this work was to verify the chemical composition and antibiotic modifying activity of the essential oil extracted from the leaves of L. sidoides and its major component thymol. The essential oil was obtained by hydrodistillation and analyzed by GC/MS. The synergistic activity was evaluated using gaseous contact method. The essential oil was obtained (yield of 1.06%) and the GC/MS analysis identified the main constituents: thymol (84.9%) and p-cymene (5.33%). The antibiotic modifying activity was verified using the minimal inhibitory dose method and gaseous contact. It verified the interference of essential oil and thymol against all tested aminoglycosides. There were no statistical differences between the activity of the essential oil and thymol against Pseudomonas aeruginosa, indicating this to be the responsible composition for such activity. However, the oil was shown more effective when compared to the thymol against Staphylococcus aureus. The essential oil of L. sidoides and its major component thymol influence the activity of aminoglycosides and may be used as adjuvant in antibiotic therapy against respiratory tract bacterial pathogens. [Copyright &y& Elsevier]

Abstract: Aim of the study: Caryocar coriaceum Wittm. fruit pulp fixed oil (CCFO) has been widely employed by communities from Brazil Northeastern in the treatment of skin inflammation, respiratory affections, wound healing and muscle pain. In this study, we evaluated the topical effect of CCFO against different irritant agents in vivo, in order to verify its antiedematous effect as well to unravel its tentative mechanisms of action. Materials and methods: CCFO was obtained from Caryocar coriaceum fruits using ethyl acetate as solvent. Ear edema provoked by the application of Croton oil (single and multiple applications), arachidonic acid (AA), capsaicin, phenol and histamine to Swiss mice was used to evaluate the topical anti-inflammatory effect of CCFO. Histological analysis from mice ears sensitized with Croton oil and AA single application was also performed. Results: Crude CCFO (20μL/ear) demonstrated significant topical antiedematous effect against Croton oil single (inhibition of 32.0%; P <0.05) and multiple (41.4% after 9 days, P <0.001) applications, AA (inhibition of 49.7%; P <0.01) and phenol (inhibition of 38.8%; P <0.001). In contrast, CCFO did not antagonize the edema caused by topical treatment with capsaicin and histamine when compared to control group (P >0.05). Histological analysis also revealed that CCFO was able to reduce the edema and the influx of inflammatory cells in mice ears sensitized with Croton oil and AA. Conclusions: CCFO exhibited a similar profile of topical anti-inflammatory activity to that of drugs that classically modulate the production of arachidonic acid metabolites. The study also indicates the potential application of CCFO as an important herbal medicine to be used against skin inflammatory diseases. [Copyright &y& Elsevier]

Aim of the study: Tupinambis merianae is one of the most frequently used animals in traditional medicine in Brazil as its body fat has many different therapeutic indications as a folk remedy. The present study evaluated the topical anti-inflammatory activity of Tupinambis merianae fat in treating ear edema in an animal model. Materials and methods: Oil (OTM) was extracted from body fat located in the ventral region of Tupinambis merianae using hexane as a solvent. Ear edema provoked by the application of croton oil (single and multiple application), arachidonic acid, phenol and capsaicin to Swiss mice was used to evaluate the potential anti-inflammatory value of the topical use of OTM. Topical applications of these irritants were made to the right ears of animals that were pre-treated with a acetone (control), dexamethasone, or OTM. Results: Our results indicate that Tupinambis merianae fat demonstrates significant topical anti-inflammatory activity that reduces inflammation related to ear edema caused by croton oil (single and multiple application), arachidonic acid, phenol. While the inflammation caused by capsaicin, OTM did not significantly reduce the edema. Conclusion: This represents the first evidence of anti-inflammatory activity of Tupinambis merianae fat in in vivo models, confirming its usefulness in traditional medicine as a remedy for skin diseases (dermatitis). The fatty acids present in OTM most likely inhibit the response pathway of arachidonic acid and its metabolites, thus reducing the production of pro-inflammatory mediators. [Copyright &y& Elsevier]