Victor Navarro

Antimicrobial evaluation of some plants used in Mexican traditional medicine for the treatment of infectious diseases

Twelve methanolic plant extracts from botanical species used in traditional medicine in Morelos, México to cure infectious diseases have been subjected to a screening study to detect potential antimicrobial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. The antimicrobial activity of the products was evaluated using colonies growing in solid medium, establishing the minimal concentration required to inhibit their in vitro growth (MIC). The results showed that extracts from Eucalyptus globolus Labill, Punica granatum L., Artemisia mexicana Wild., and Bocconia arborea Watt. possess strong in vitro antimicrobial activity against the tested microorganisms.

Antimicrobial evaluation of certain plants used in Mexican traditional medicine for the treatment of respiratory diseases

Eighteen crude extracts, including six hexanic, six chloroformic and six methanolic from six different plant species used in Mexican traditional medicine for the treatment of respiratory infections, were evaluated for potential antimicrobial activity against Staphylococcus aureus, Enterococcus faecalis, Streptococcus pneumoniae, Streptococcus pyogenes, Escherichia coli, and Candida albicans. The minimal inhibitory concentration was determined for each extract using a two-fold dilution assay. The results showed that 16 crude extracts (89%) exhibited antimicrobial activity against at least one of the microorganisms tested at concentrations of 5 mg/ml or below. The extracts from Gnaphalium oxyphyllum, Gnaphalium americanum, and Crescentia alata possessed strong antimicrobial activity against the pathogens tested.

Bioactive oleanolic acid saponins and other constituents from the roots of Viguiera decurrens

The bisdesmoside oleanolic acid saponin, 3-0-(methyl-beta-D-glucuronopyranosiduronoate)-28-0-beta-D-glucopyranosyl-oleanolate along with nine known compounds (two diterpenic acids, one chromene, three triterpenes, one steroidal glycoside, and two monodesmoside oleanolic acid saponins), were obtained from Viguiera decurrens roots. The chemical structure of the bisdesmoside oleanolic saponin was determined by chemical and NMR spectral evidence. A mixture of monodesmoside saponins displayed cytotoxic activity against P388 and COLON cell lines (ED50= 2.3 and 3.6 microg/ml, respectively). Two of the known compounds showed insecticidal activity against the Mexican bean beetle larvae (Epilachna varivestis).

Two antimicrobial alkaloids from Bocconia arborea.

Two alkaloid constituents of Bocconia arborea showed considerable antimicrobial activity against gram-positive and gram-negative bacteria and Candida albicans. Bioactivity-guided fractionation with thin-layer bioautography led to the isolation of the two known benzophenanthridine alkaloids, dihydrochelerythrine and dihydrosanguinarine. The minimal inhibitory concentration was determined for each compound using a twofold serial dilution assay. The structures of these compounds were determined by 1H and 13C NMR analyses.

Healing of Chronic Arterial and Venous Leg Ulcers With Systemic Electromagnetic Fields

Abstract Background Mitogen-activated autologous peripheral blood mononuclear cells applied locally on the ulcer surface promote healing of chronic arterial and venous leg ulcers. In vitro , extremely low frequency electromagnetic fields (ELF) interact with peripheral blood mononuclear cells (PBMC) via Ca ++ channels, activating signal transduction cascades, promoting cytokine synthesis, and changing cell proliferation patterns. Methods ELF frequencies were configured to interact in vitro with the proliferation patterns of PBMC obtained from normal human volunteers. These ELF were then applied peripherally as the sole treatment to 26 patients with 42 chronic leg ulcers of predominantly arterial or venous etiology unresponsive to previous medical and/or surgical treatments in a phase I before-after design. Results At admission, age of ulcers had a skewed distribution with a median of 639 days. Wound healing or deleterious effects began in all patients during the first 2 weeks after ELF exposure, permitting their previously unresponsive ulcers to function as internal controls. After ELF exposure, 69% of all lesions were cured or healed >50% in a period 30). Lesions worsened in patients with autoimmune diseases. Conclusions Systemic effects are hypothetically explained by ELF activation of PBMC and their subsequent transportation to the ulcer site via humoral route. This therapy is effective in selected patients with chronic arterial and venous leg ulcers.

Cytotoxic and antimicrobial screening of selected terpenoids from Asteraceae species.

Twelve pure compounds originally obtained through a systematic chemotaxonomical study with Mexican plants of the Asteraceae, were subjected to a cytotoxic and in vitro antimicrobial screening. Three different cell lines in culture (KB, KB-VI and P388) were used in the cytotoxicity assay, while antimicrobial activity was tested against Gram-positive and Gram-negative bacteria, as well as Candida albicans. Of the twelve terpenoids tested, only taraxasterol showed antimicrobial activity against Staphylococcus aureus. The significant cytotoxic activity exhibited by five sesquiterpene lactones, and the moderate cytotoxicity of an eudesmane, is discussed.

Two new benzofuranes from Eupatorium aschenbornianum and their antimicrobial activity.

Through a bioassay-guided fractionation, from the aerial parts of the medicinal plant Eupatorium aschenbornianum were isolated two new benzofurane compounds, 5-acetyl-3beta-angeloyloxy-2beta-(1-hydroxyisopropyl)-2,3-dihydrobenzofurane ( 1) and 5-acetyl-3beta-angeloyloxy-2beta-(1-hydroxyisopropyl)-6-methoxy-2,3-dihydrobenzofurane ( 2) in addition to 4-hydroxy-3,5-diprenylacetophenone, espeletone ( 3), encecalinol ( 4), beta-sitosterol and stigmasterol. The antimicrobial evaluation of these natural products showed that 1 [MIC = 200 microg/mL against T. mentagrophytes and 100 microg/mL against T. rubrum], 2 [MIC = 50 microg/mL towards both] and 3 [MIC = 100 microg/mL against both] were active against dermatophytes, while 4 was active against all of microorganisms assayed [MIC = 12.5 microg/mL ( T. mentagrophytes), 12.5 microg/mL ( T. rubrum), 100 microg/mL ( C. albicans) and 200 microg/mL ( A. niger)].

Solanum chrysotrichum (Schldl.) a plant used in Mexico for the treatment of skin mycosis.

An ethnobotanical field study carried out in 200 rural communities determined that the leaves of Solanum chrysotrichum Schldl. are used in Mexican traditional medicine for the treatment of skin mycosis, being particularly recommended to cure Tinae pedis. Clinical trials were performed using a cream containing 5% of a methanolic leaf extract of this plant. Results showed that 45% of the patients were completely cured after 4 weeks of topical treatment. The rest of the cases improved notably in comparison with the control group of patients using the habitual miconazole treatment. The same plant extract inhibited the growth in vitro of the dermatophytes Trychophyton mentagrophytes, T. rubrum and Microsporum gypseum at MICs under 15 mg/ml.

Antibacterial, Antifungal, and Cytotoxic Activities of Distictis buccinatoria.

Abstract The current study was undertaken to evaluate the in vitro. antimicrobial and cytotoxic activity of six crude extracts obtained from the leaves and flowers of Distictis buccinatoria. (DC.) A.H. Gentry (Bignoniaceae). Antimicrobial activity was tested against the Gram-positive bacteria Staphylococcus aureus., Streptococcus pyogenes., and Streptococcus faecalis.; the Gram-negative bacteria Escherichia coli., Klebsiella pneumoniae., and Salmonella typhi.; and the fungi Candida albicans., Trichophyton mentagrophytes., Trichophyton rubrum., and Aspergillus niger.. The cytotoxic activity of each extract was determined using two human tumor cell lines in culture, nasopharyngeal carcinoma (KB) and colon carcinoma (HCT-15). The results showed that extracts from D. buccinatoria. possess antimicrobial activity against the Gram-positive bacteria and against both dermatophyte fungal species. The strongest antibacterial activity observed was that of the dichloromethane extract prepared from flowers, and the best antifungal activity was demonstrated by the dichloromethane extract from the leaves. The hexane and dichloromethane extracts from the flowers exhibited cytotoxicity against KB cells. These results support the traditional folk medicinal uses of this plant.

Sulfur-Containing Aristoloxazines and Other Constituents of the Roots of Aristolochia orbicularis

Six new compounds, aristoloxazine A (1), aristoloxazine B (2), 7-methoxytaliscanine (3), humul-7-en-1,4,11-triol (4), 8-hydroxy-β-logipinene (5), and 1β-hydroxy-4(14)-eudesmene (6), corresponding to two sulfur-containing aristoloxazines (1 and 2), an aristolactam (3), and three sesquiterpenes (4-6) were isolated, along with 26 known compounds, from the roots of Aristolochia orbicularis. The structures of the new compounds were established based on their spectroscopic and spectrometric data and in the case of aristoloxazine A (1) by single-crystal X-ray crystallography. This is the first report of sulfur-containing aristoloxazines from a natural source. Furthermore, aristoloxazine A (1) was found to possess potent in vitro antimicrobial activity against all resistant Staphylococcus aureus and several fungal strains in which it was evaluated.