Antioxidant/Antibacterial Activities of a Topical Phytopharmaceutical Formulation Containing a Standardized Extract ofBaccharis incarum, an Extremophile Plant Species from Argentine Puna

Evaluating Potentials of Species Rich Taxonomic Groups in Cosmetics and Dermatology: Clustering and Dispersion of Skin Efficacy of Asteraceae and Ranunculales Plants on the Species Phylogenetic Tree

BACKGROUND

The medicinal properties of plants can be predicted by virtue of phylogenetic methods, which nevertheless have not been utilized to explore the regularity of skin-related bioactivities of ethnomedicinal plants. We aim to investigate the distribution of skin efficacy of Asteraceae and Ranunculales plants on the species-level Tree of Life.

METHODS

The clinical efficacy data of 551 ethnomedicinal species belonging to Ranunculales, as well as 579 ethnomedicinal species of Asteraceae, were systematically collected and collated; these therapeutic data fell into 15 categories, including skin disease/cosmeceutical. The large phylogenetic tree of all China angiosperm species was used to detect the phylogenetic signals of ethnomedicinal plants by calculating the D statistic, phylogenetic diversity (PD), net relatedness index (NRI), and nearest taxon index (NTI). Of all Chinese ethnomedicinal plants of Ranunculales and Asteraceae, 339 (61.5% of all ethnomedicinal species) and 382 (66.0% of all) are used for skin problems. In Ranunculales, a clustered structure was suggested by the NRI value for skin uses. In Asteraceae, the skin utility was not clustered; Artemisia, Aster, Cremanthodium, Ligularia, and Saussurea are the most used Asteraceae genera for skin issues.

RESULTS

The clustering structure was identified in Artemisia, and the skin efficacy in other genera was of overdispersion (NRI < 0). NTI values and D statistics largely agree with NRI. When compared with PD values of different therapeutic categories, the PD value of the skin category was relatively high in Cremanthodium, Ranunculales, Asteraceae, and Artemisia, suggesting the enormous efficacy space in the new taxa of these taxonomic groups.

CONCLUSION

By resolving the distribution of therapeutic effects of Ranunculales/Asteraceae taxa, the importance of phylogenetic methods in mining botanical resources with skin utilities is validated.

Disinfectant activities of extracts and metabolites from Baccharis dracunculifolia DC

The concern regarding the harm caused by biocides to human health has been increasing over the years, making the natural products an alternative to less toxic and more efficient biocides. Therefore, this paper reports the investigation of the disinfectant potential of extracts and isolated compounds from Baccharis dracunculifolia. For this purpose, extracts of aerial parts (BD-C), tricomial wash (BD-L) and roots (BD-R) of B. dracunculifolia were obtained by maceration. The extracts were submitted to different chromatographic techniques, including high-speedy countercurrent chromatography (HSCCC) furnishing nine isolated compounds. The extracts and isolated compounds were evaluated regarding their antimicrobial activity by the broth microdilution method, according to the Clinical and Laboratory Standards Institute, and regarding their sanitizing activity according to Standard Operating Procedure No. 65.3210.007 (INCQS, 2011), developed by the National Institute for Quality Control in Health (INCQS) - Oswaldo Cruz Foundation (FIOCRUZ). In the antimicrobial evaluation the BD-C extract showed minimum inhibitory concentration (MIC) values of 200 and 100 µg/mL against S. aureus and T. mentagrophytes, respectively. BD-L extract showed MIC value of 200 µg/mL against S. aureus. The isolated compounds caffeic acid (MBC 2.22 µM), ferulic acid (MBC 2.06 µM) and baccharin (MBC 0.27 µM) showed significant inhibitory activity against S. aureus. All B. dracunculifolia isolated compounds were active with exception of aromadrendin-4´-O-methyl-ether for T. mentagrophytes. Additionally, isosakuranetin was active against S. choleraesuis (MIC 1.4 µM). Regarding the sanitizing activity, the hydroalcoholic solution containing 0.2% of B. dracunculifolia extract in 40 ºGL ethanol was effective in eliminating the microbial contamination on all carrier cylinders and against all microorganisms evaluated in the recommended exposure time of 10 min. Therefore, B. dracunculifolia has potential for the development of sanitizing agents to be used in hospitals, food manufactures and homes.

Antifungal activity of phytotherapeutic preparation of Baccharis species from argentine Puna against clinically relevant fungi

ETHNOPHARMACOLOGICAL RELEVANCE

B. boliviensis and B. tola are used in traditional medicine in the Argentine Puna to treat skin and soft tissue infections and inflammatory processes in humans and animals.

AIM OF THE STUDY

To assess the potential of phytotherapeutic preparations of Baccharis species as antifungal agents against clinically relevant fungi and to determine the chemical composition of the extracts.

MATERIAL AND METHODS

Phytotherapeutic preparations of B. boliviensis and B. tola collected in Argentine Puna were evaluated as an antifungal agent against clinically relevant fungi (yeast, non-dermatophytes, and dermatophytes) isolated of patients from a local Hospital, and reference strains, using macrodilution and microdilution assays. The bioactivity was supported by UHPLC-OT-MS metabolome fingerprinting.

RESULTS

The results revealed that the plant preparations were active against most of evaluated fungal strains; B. boliviensis was more active than B. tola. Dermatophyte fungi strains were the most sensitive isolates. The phytotherapeutic preparation showed Minimal Inhibitory Concentration (MIC) values between 25 and 400 μg GAE/mL and Minimum Fungicidal Concentration (MFC) values between 50 and 400 μg GAE/mL. Regarding the phytochemical analysis, total phenolic and total flavonoid contents of hydroalcoholic preparation of B. boliviensis were greater than those of the B. tola extract. Both Baccharis species showed similar chromatographic patterns, fifty-two compounds were identified based on UHPLC-OT-MS including several terpenoids, flavonoids and phenolic acids that have been identified in this two endemic South American Baccharis species for the first time. Several identified compounds present antifungal properties, the presence of these compounds support the bioactivity of the Baccharis extracts.

CONCLUSIONS

In this work the traditional use of both Baccharis species as an antimicrobial against commercial products resistant fungal strains was validate, principally against dermatophytes fungi such as T. rubrum, T. mentagrophytes, M. canis, and M. gypseum. These results indicate that the hydroalcoholic preparations could be used for the treatment of fungal infectious.

Glyceryl trinitrate blocks staphyloxanthin and biofilm formation in Staphylococcus aureus

Background

Staphylococcus aureus is an important nosocomial bacterium that is responsible for a number of infections that may be fatal. The treatment of such infections is limited by emergence of antibiotic resistance. Targeting virulence of Staphylococcus aureus may provide an alternative option to antibiotic that may bypass the emergence of resistant strains due to lack of stress on viability.

Objectives

Investigation of the ability of glyceryl trinitrate (GTN) to inhibit staphyloxanthin, biofilm and tolerance to oxidative stress.

Methods

The disk sensitivity method was used to detect the methicillin resistance of Staphylococcus aureus. The effect of sub-inhibitory concentration of GTN on biofilm formation, staphyloxanthin production and tolerance to oxidative stress was evaluated. Molecular docking study was used to investigate the ability of GTN to bind to dehydrosqualene synthase enzyme.

Results

GTN showed a significant inhibition of biofilm, staphyloxanthin and tolerance to oxidative stress. In the molecular docking study, it was found that GTN could bind to dehydrosqualene synthase enzyme by hydrogen bonding, electrostatic interaction and pi-cation interaction.

Conclusion

The present study revealed the ability of GTN to serve as a potential anti-virulence candidate for attenuation of S. aureus pathogenicity.

Network analytics approach towards identifying potential antivirulence drug targets within the Staphylococcus aureus staphyloxanthin biosynthetic network

Staphylococcus aureus is associated with several clinically significant infections among humans and infections associated with antibiotic-resistant strains are growing in frequency. Antivirulence strategies shift the target of drugs from bacterial growth to the infection process resulting to milder evolutionary pressure for the development of bacterial resistant strains. Staphyloxanthin (STX) is a yellowish-orange carotenoid pigment synthesized by S. aureus and this carotenoid functions as an important virulence factor for the bacteria. In this study, we elucidated whether network analytics can be used as a viable tool to identify significant components in the STX biosynthetic network which in-turn could serve as possible antivirulence drug targets. For confirmation, we correlated our results to known drugs that were able to inhibit STX biosynthesis. Throughout this study, we established that crtN(1) activity and 4,4'-diaponeurosporene amounts are significant components in the STX biosynthetic network and, moreover, network analytics can aid in identifying antivirulence drug targets within the STX biosynthetic network. Similarly, we found that network analytics is capable of identifying multiple potential targets simultaneously. Taken together, we propose that an effective antivirulence drug against S. aureus STX biosynthesis would involve targeting crtN(1) activity, 4,4'-diaponeurosporene levels, or both components.

Inhibition of staphyloxanthin biosynthesis in Staphylococcus aureus by rhodomyrtone, a novel antibiotic candidate

Staphyloxanthin is the eponymous feature of the human pathogen Staphylococcus aureus, and the pigment promotes resistance to reactive oxygen species and host neutrophil-based killing. To probe the possible use of rhodomyrtone isolated from Rhodomyrtus tomentosa (Aiton) Hassk. leaves to inhibit pigment production in S. aureus, experiments were carried out to compare pigment production and the susceptibility of rhodomyrtone-treated S. aureus and untreated cells to oxidants in vitro. In addition, we observed the innate immune clearance of S. aureus after incubation with rhodomyrtone using an ex vivo assay system - human whole-blood survival. The results indicated that rhodomyrtone-treated S. aureus exhibited reduced pigmentation, and that rhodomyrtone treatment led to a dose-dependent increase in the susceptibility of the pathogen to H(2)O(2) and singlet oxygen killing. Consequently, the survival ability of the treated organisms decreased in freshly isolated human whole blood due to less carotenoid pigment to act as an antioxidant scavenger. Rhodomyrtone may be acting via effects on DnaK and/or σ(B), resulting in many additional effects on bacterial virulence.