Antifungal Activity of Mexican Propolis on Clinical Isolates of Candida Species.

Infections caused by micro-organisms of the genus Candida are becoming a growing health problem worldwide. These fungi are opportunistic commensals that can produce infections-clinically known as candidiasis-in immunocompromised individuals. The indiscriminate use of different anti-fungal treatments has triggered the resistance of Candida species to currently used therapies. In this sense, propolis has been shown to have potent antimicrobial properties and thus can be used as an approach for the inhibition of Candida species. Therefore, this work aims to evaluate the anti-Candida effects of a propolis extract obtained from the north of Mexico on clinical isolates of Candida species. Candida species were specifically identified from oral lesions, and both the qualitative and quantitative anti-Candida effects of the Mexican propolis were evaluated, as well as its inhibitory effect on C. albicans isolate's germ tube growth and chemical composition. Three Candida species were identified, and our results indicated that the inhibition halos of the propolis ranged from 7.6 to 21.43 mm, while that of the MFC and FC50 ranged from 0.312 to 1.25 and 0.014 to 0.244 mg/mL, respectively. Moreover, the propolis was found to inhibit germ tube formation (IC50 ranging from 0.030 to 1.291 mg/mL). Chemical composition analysis indicated the presence of flavonoids, including pinocembrin, baicalein, pinobanksin chalcone, rhamnetin, and biochanin A, in the Mexican propolis extract. In summary, our work shows that Mexican propolis presents significant anti-Candida effects related to its chemical composition, and also inhibits germ tube growth. Other Candida species virulence factors should be investigated in future research in order to determine the mechanisms associated with antifungal effects against them.

Hibiscus Acid from Hibiscus sabdariffa L. Inhibits Flagellar Motility and Cell Invasion in Salmonella enterica.

Extracts of Hibiscus sabdariffa L. (commonly called Rosselle or "Jamaica flower" in Mexico) have been shown to have antibiotic and antivirulence properties in several bacteria. Here, an organic extract of H. sabdariffa L. is shown to inhibit motility in Salmonella enterica serovars Typhi and Typhimurium. The compound responsible for this effect was purified and found to be the hibiscus acid. When tested, this compound also inhibited motility and reduced the secretion of both flagellin and type III secretion effectors. Purified hibiscus acid was not toxic in tissue-cultured eukaryotic cells, and it was able to reduce the invasion of Salmonella Typhimurium in epithelial cells. Initial steps to understand its mode of action showed it might affect membrane proton balance.

Cutin from Solanum Myriacanthum Dunal and Solanum Aculeatissimum Jacq. as a Potential Raw Material for Biopolymers.

Plant cuticles have attracted attention because they can be used to produce hydrophobic films as models for novel biopolymers. Usually, cuticles are obtained from agroresidual waste. To find new renewable natural sources to design green and commercially available bioplastics, fruits of S. aculeatissimum and S. myriacanthum were analyzed. These fruits are not used for human or animal consumption, mainly because the fruit is composed of seeds. Fruit peels were object of enzymatic and chemical methods to get thick cutins in good yields (approximately 77% from dry weight), and they were studied by solid-state resonance techniques (CPMAS 13C NMR), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), atomic force microscopy (AFM) and direct injection electrospray ionization mass spectrometry (DIESI-MS) analytical methods. The main component of S. aculeatissimum cutin is 10,16-dihydroxypalmitic acid (10,16-DHPA, 69.84%), while S. myriacanthum cutin besides of 10,16-DHPA (44.02%); another two C18 monomers: 9,10,18-trihydroxy-octadecanoic acid (24.03%) and 18-hydroxy-9S,10R-epoxy-octadecanoic acid (9.36%) are present. The hydrolyzed cutins were used to produce films demonstrating that both cutins could be a potential raw material for different biopolymers.

Facile Synthesis of a Series of Non-Symmetric Thioethers Including a Benzothiazole Moiety and Their Use as Efficient In Vitro anti-Trypanosoma cruzi Agents.

A series of 2-benzylsulfanyl benzothiazole (BTA) derivatives were synthesized and fully characterized and in vitro tested against two strains of T. cruzi (NINOA and INC-5), exhibiting good activities at low concentrations.

Broad-spectrum antimicrobial activity by Burkholderia cenocepacia TAtl-371, a strain isolated from the tomato rhizosphere.

The Burkholderia cepacia complex (Bcc) comprises a group of 24 species, many of which are opportunistic pathogens of immunocompromised patients and also are widely distributed in agricultural soils. Several Bcc strains synthesize strain-specific antagonistic compounds. In this study, the broad killing activity of B. cenocepacia TAtl-371, a Bcc strain isolated from the tomato rhizosphere, was characterized. This strain exhibits a remarkable antagonism against bacteria, yeast and fungi including other Bcc strains, multidrug-resistant human pathogens and plant pathogens. Genome analysis of strain TAtl-371 revealed several genes involved in the production of antagonistic compounds: siderophores, bacteriocins and hydrolytic enzymes. In pursuit of these activities, we observed growth inhibition of Candida glabrata and Paraburkholderia phenazinium that was dependent on the iron concentration in the medium, suggesting the involvement of siderophores. This strain also produces a previously described lectin-like bacteriocin (LlpA88) and here this was shown to inhibit only Bcc strains but no other bacteria. Moreover, a compound with an m/z 391.2845 with antagonistic activity against Tatumella terrea SHS 2008T was isolated from the TAtl-371 culture supernatant. This strain also contains a phage-tail-like bacteriocin (tailocin) and two chitinases, but the activity of these compounds was not detected. Nevertheless, the previous activities are not responsible for the whole antimicrobial spectrum of TAtl-371 seen on agar plates, suggesting the presence of other compounds yet to be found. In summary, we observed a diversified antimicrobial activity for strain TAtl-371 and believe it supports the biotechnological potential of this Bcc strain as a source of new antimicrobials.

Antimycobacterial and hypolipemiant activities of Bidens odorata (Cavanilles).

ETHNOPHARMACOLOGICAL RELEVANCE: Bidens odorata Cavanilles is a medicinal and edible plant known as "mozote blanco, aceitilla, acahual, mozoquelite" which is traditionally used in Mexico as a diuretic, hypoglycaemic, anti-inflammatory, antipyretic, antitussive, to treat gastrointestinal disorders, kidney pain, and lung or respiratory diseases. AIM OF THE STUDY: This research study was aimed at phytochemical analysis of aerial extracts of B. odorata for antimycobacterial and lipid-lowering activities. MATERIALS AND METHODS: Compounds 1 (((2R, 3R, 4S, 5S, 6R)-3,4,5-Tryhidroxy-6-(((E)-3-(4-hydroxyphenyl) acryloyl) oxy) tetrahydro-2H-pyran-2-yl) methyl-4-hydroxybenzoate) and 2 (3,5-Dihydroxybenzoic acid) were isolated from B. odorata aerial shoots and their structural elucidation was carried out using 1 and 2D NMR, infrared spectroscopy (IR) and mass spectrometry (ESI-MS). The antimycobacterial activity of various extracts and compounds 1 and 2 was determined using the Microplate Alamar Blue Assay (MABA). The evaluation of the hypolipidemic effect of the ethanolic extract and the glycosylated compound 1 was tested in a murine model of hypercholesterolemia induced by diet and by Triton WR-1339. On the other hand, the LD50 of the ethanolic extract was evaluated in ICR mice by the OECD protocol TG 423. RESULTS: Antimycobacterial assay of hexane, CH2Cl2, EtOAc, ethanolic and aqueous extracts, as well as the new glycosidic compound 1 and benzoic acid derivative 2 isolated from B. odorata showed minimal inhibitory concentrations (MIC) of 100, 12.5, 12.5, 12.5, ≥200, 3.125 and 50 µg/mL, respectively, against Mycobacterium tuberculosis H37Rv. Only hexane and CH2Cl2 extracts were observed to be active against Mycobacterium smegmatis mc2155 at a concentration of 50 and 100 µg/mL, respectively. The ethanolic extract showed lipid-lowering activity at doses of 100 and 1000 mg/kg, while glycosidic compound 1 was active at doses of 50 and 100 mg/kg. In addition, the LD50 of the ethanolic extract was >2000 mg/kg, meaning that this extract does not cause lethality or adverse effects, and no signs of organs alterations or tissue damage were observed. CONCLUSION: The hexane, CH2Cl2, EtOAc, and ethanolic extracts of B. odorata, as well as their components 1 and 2, displayed antimycobacterial activity against M. tuberculosis. Moreover, the ethanolic extract and glycosidic compound 1 showed an important lipid-lowering effect, without lethality or secondary effect. The results of this study support the documented traditional use for B. odorata.