Effect of Lippia alba (Mill.) N.E. Brown Essential Oil on the Human Umbilical Artery.

Lippia alba is popularly known as lemon balm, with its essential oil (EO) cited for displaying antimicrobial, sedative, and vasorelaxant effects. Yet, its action on isolated human vessels has not been described in the literature. Thus, we evaluated the vasorelaxant effect of essential oil of L. alba (EOLa) on human umbilical arteries (HUA) isolated in organ baths. HUA rings were isolated, subjected to contractions induced by potassium chloride (KCl), serotonin (5-HT), or histamine (HIST) to record the isometric tension, and then treated with EOLa (30-1000 µg/mL). The EOLa showed a more prominent inhibitory effect on the pharmacomechanical coupling contraction via HIST with an EC50 value of 277.1 ± 8.5 µg/mL and maximum relaxant effect at 600 µg/mL. The addition of tetraethylammonium (TEA) or 4-aminopyridine (4-AP) in HUA preparations did not inhibit EOLa total relaxant effect at 1000 µg/mL. In the presence of gliblenclamide (GLI), the oil relaxed the HUA rings by 90.8% at maximum concentration. The EOLa was also investigated for its effects on voltage-operated calcium channels (VOCCs), where the HUA preincubation with this oil at 1000 µg/mL inhibited BaCl2 (0.1-30 mM)-induced contractions. This study demonstrates for the first time that EOla has a vasorelaxant effect on HUA and its particular blockade of VOCCs.

Effect of the Lippia alba (Mill.) N.E. Brown essential oil and its main constituents, citral and limonene, on the tracheal smooth muscle of rats.

The Lippia alba (Mill.) N.E. Brown (Verbenaceae) species, has effects sedative, analgesic and spasmolytic properties. This study had as its main objective to evaluate the essential oil of L. alba (EOLa) effect and that of its main constituents, citral and limonene, over tracheal smooth muscle from Wistar rats. EOLa, citral and limonene promoted relaxation of tracheal smooth muscle in contractions induced by potassium (60 mM K+), presenting an EC50 of 148 ±â€¯7 µg/mL for the EOLa, 136 ±â€¯7 µg/mL for citral and 581 ±â€¯7 µg/mL for limonene. In contractions induced by Acetylcholine (Ach; 10 µM) the EC50 for the EOLa and citral were of 731 ±â€¯5 µg/mL and 795 ±â€¯9 µg/mL, respectively. In preparations pre-incubated with 1000 µg/mL of the EOLa and citral, both agents were found to block the influx of BaCl2 by VOCCs. This study demonstrated that the EOLa and its main component citral present antispasmodic effect over tracheal smooth muscle of rats.

Potentiation of antibiotic activity by Passiflora cincinnata Mast. front of strains Staphylococcus aureus and Escherichia coli.

The development of new drugs from plants is an interesting alternative approach to overcoming microbial resistance. Passiflora cincinnata shows resistance to diseases and pests and a higher concentration of chemical components that may be useful in the pharmaceutical industry. We investigated the potential antimicrobial and antibiotic-modifying activity of hydroalcoholic extracts of leaves, stems, bark, pulp and seeds of P. cincinnata. The extracts were prepared by homogenization of material in 50% ethanol. Minimum inhibitory concentration (MIC) was determined by the broth dilution method, and the bacterial strains tested were Staphylococcus aureus and Escherichia coli. Antibiotic-modifying activity was evaluated against the strains S. aureus 03 and E. coli 08, using a subinhibitory concentration of extract. The antibiotics tested were: amikacin, gentamicin, ampicillin, potassium benzylpenicillin and oxacillin. The extracts did not show antimicrobial activity of clinical relevance, where the MIC was equal to or greater than 1024 µg/mL. S. aureus showed 13 events, while E. coli showed only 4 events. Among these events, 14 involved synergistic activity, potentiating the effect of the antibiotics, and only 3 events demonstrated antagonistic activity toward ampicillin. Hydroalcoholic extracts are potential antimicrobial agents when combined with conventional drugs little utilized in in vivo treatment.

The use of herbs against neglected diseases: Evaluation of in vitro leishmanicidal and trypanocidal activity of Stryphnodendron rotundifolium Mart.

The evaluation of the leishmanicidal and trypanocidal activity of the hydroalcoholic extract of the bark of Stryphnodendron rotundifolium Mart. (EHCSR) was carried out to find an alternative treatment for parasitic diseases. EHCSR was prepared and used at four different concentrations (1000, 500, 250, 125 µg/mL) in in vitro assays for activity against Leishmania promastigotes using the species Leishmania brasiliensis and Leishmania infantum and for trypanocidal activity using the epimastigotes of Trypanosoma cruzi. We also tested EHCSR for cytotoxicity against adhered cultured Murine J774 fibroblasts. The tests were performed in triplicate, and the percent mortality of parasites, IC50 and percent toxicity were determined. With regard to anti-leishmania activity against L. infantum, there was a mean mortality of 45% at all concentrations, and against L. brasiliensis, a substantial effect was seen at 1000 µg/mL with 56.38% mortality, where the IC50 values were 1338.76 and 987.35 µg/mL, respectively. Trypanocidal activity was notably high at 1000 µg/mL extract with 82.31% mortality of epimastigotes. Cytotoxicity at the highest extract concentrations of 500 and 1000 µg/mL was respectively 75.12% and 94.14%, with IC50 = 190.24 µg/mL. Despite that the extract has anti-parasitic activity, its substantial cytotoxicity against fibroblasts cells makes its systemic use nonviable as a therapeutic alternative.

Composição química e estudo da atividade antibacteriana de Bowdichiavirgilioides Kunth (Sucupira) – Fabaceae – Papilonoidae / Study on the chemical composition and antibacterial activity of Bowdichia virgilioides kunth (Sucupira) - Fabaceae - Papilonoidae

Bowdichia virgilioides (Fabaceae - Papilionoidea), popularly known as Sucupira-preta, is a Brazilian native tree used in the traditional medicine against throat infections. Due this fact and due the interest to validate the traditional use, the objective of this work was evaluates the in vitro antibacterial activity of extracts and fractions of the stem and heartwood of the plant. The phytochemical profile revealed the presence of tannins and flavonoids in the stem and heartwood, and only alkaloids in the stem.The HPLC analysis revealed the presence of flavonoids and phenolic acids, natural products with several biological activities, including the modifying antibiotic activity. All microrganisms were inhibited only with MIC > 1024 microgramo/mL. However, when associated with aminoglycosides, was demonstrated a potentiation of these antibiotics when associated with almost all products assayed and against one bacterium at least.

Bowdichia virgilioides (Fabaceae - Papilionoidea), popularmente conhecida como Sucupira-preta, é uma espécie arbórea nativa do Brasil utilizadas na medicina popular para infecções de garganta. Com base nessas evidências, e com o interesse para justificar o uso popular, este trabalho teve como objetivo verificar a atividade antibacteriana in vitro de extratos brutos e fracionados de cascas e cerne da planta. Observou-se pela conclusão do levantamento fitoquímico a presença de taninos e flavonóides nas cascas e no cerne, e alcalóides apenas encontrados na casca. A análise por HPLC revelou a presença de flavonóides e ácidos fenólicos, produtos naturais, com diversas atividades biológicas, incluindo a atividade modificadora antibiótica. Todos os microorganismos foram inibidos apenas com o CIM > 1024 ug/mL. No entanto, quando associado a antibióticos aminoglicosídeos, foi demonstrada potenciação destes em quase todos os produtos testados e em pelo menos uma bactéria foi observada uma atividade moduladora significativa.

Protective effects of Croton campestris A. St-Hill in different ulcer models in rodents: evidence for the involvement of nitric oxide and prostaglandins.

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 750 mg/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 (10 mg/kg, p.o.), an inhibitor of nitric oxide synthesis and indomethacin (10 mg/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.

Antiulcerogenic Activity of the Hydroalcoholic Extract of Leaves of Croton campestris A. St.-Hill in Rodents.

Croton campestris A. St.-Hill., popularly known as "velame do campo," is a species native to the savannah area of Northeast Brazil, which is used by traditional communities in folk medicine for variety of health problems, especially detoxification, inflammation, and gastritis. The hydroalcoholic extract of C. campestris leaves (HELCC) was assessed for its antiulcerogenic effect in gastric lesion models and effect on intestinal motility in mice, and possible mechanisms of action were examined. HELCC showed significant gastroprotective action in all models of gastric ulcer evaluated; the results suggest that this action probably involves the nitric oxide pathway. HELCC did not show alteration of intestinal motility in mice. It was also found that C. campestris represents a promising natural source with important biological potential, justifying some of its uses in folk medicine.

Modulation of the antibiotic activity by extracts from Amburana cearensis A. C. Smith and Anadenanthera macrocarpa (Benth.) Brenan.

The aim of this study was to verify the possible interactions between ethanol extracts of Amburana cearensis A. C. Smith and Anadenanthera macrocarpa (Benth.) Brenan, combined with six antimicrobial drugs against multiresistant strains of Staphylococcus aureus and Escherichia coli isolated from humans. The antibacterial activity of the extracts was determined using the minimum inhibitory concentration (MIC). The microdilution assay was performed to verify the interactions between the natural products and the antibiotics using a subinhibitory concentration. The activity of amikacin associated with the extract of Anadenanthera macrocarpa against EC 27 was enhanced, demonstrating an MIC reduction from 128 to 4 µg/mL. Among the ß-lactams, no potentiation on its activity was observed, with exception to the antagonism of the natural products with ampicillin against S. aureus 358.

Topical antiinflammatory activity of essential oil of Lippia sidoides cham: possible mechanism of action.

This work reports the chemical composition of the essential oil of Lippia sidoides (EOLS) and evaluation of the topical effect of EOLS and thymol against different irritant agents in vivo. The essential oil was obtained by hydrodistillation, and gas chromatography/mass spectrometry analysis identified the main constituents: thymol (84.9%) and p-cymene (5.33%). The antiinflammatory activity was evaluated using the mouse models of acute ear inflammation induced by croton oil, arachidonic acid, phenol or histamine, and chronic inflammation induced by croton oil. The topical application of EOLS or thymol at a dose of 2 mg/ear significantly reduced (p < 0.001) ear edema induced with arachidonic acid by 45.1% and 47.4% and reduced ear edema induced with phenol by 33.2% (p < 0.05) and 54.7% (p < 0.01) in acute ear edema. However, a proinflammatory effect of EOLS and thymol was evidenced when it was applied for more than 1 day. There were no statistical differences in antiedematogenic activity between EOLS and thymol. In conclusion, the results indicate that thymol is the constituent responsible for the topical antiinflammatory activity of EOLS. Thus, these findings could justify the popular use of L. sidoides by alternative medicine, but chronic use has an inflammatory effect.

Antibacterial and modulatory effect of Stryphnodendron rotundifolium.

CONTEXT: Stryphnodendron rotundifolium Mart. (Leguminosae), a tree in Northeast Brazil (Chapada do Araripe), is used in popular medicine to treat different processes such as inflammation and infectious diseases, mainly caused by bacterial pathogens. OBJECTIVE: This study determined the modulatory and antimicrobial activity of the hydroethanol extract of dried stem bark, the most used form of this natural product, as a remedy by the traditional communities, against standard and clinical isolates of Escherichia coli and Staphylococcus aureus. MATERIAL AND METHODS: The antibacterial and modulatory activities of the hydroalcoholic extract from the leaves were obtained by maceration/hydrodistillation method and assayed by microdilution. RESULTS: In the microbiological assays, growth inhibition was demonstrated by this extract against the bacterial strains tested, with minimal inhibitory concentration (MIC) values of 512 µg/mL. However, when a subinhibitory concentration (MIC/8 = 64 µg/mL) was combined with conventional antimicrobial drugs (gentamicin, kanamycin, amikacin and neomycin), the extract showed a potentiating effect, reducing the MIC for all drugs assayed in a range between 312.5 and 2.4 µg/mL. CONCLUSIONS: We indicate that the extract of S. rotundifolium showed potential synergistic antibiotic activity. With the results obtained, these extracts proved to be a promising source of antibacterial and modulatory agents.

Topical anti-inflammatory effect of Caryocar coriaceum Wittm. (Caryocaraceae) fruit pulp fixed oil on mice ear edema induced by different irritant agents.

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.