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Responsible for nearly 1.5 million deaths every year, the infectious disease tuberculosis remains one of the most serious challenges to global health. The emergence of multidrug-resistant tuberculosis and, more recently, extensively drug-resistant tuberculosis poses a significant threat in our effort to control this epidemic. New drugs are urgently needed to combat the growing threat of antimicrobial resistance. To achieve this goal, we screened approximately 500 species of medicinal plant methanol extracts and their solvent partitioned fractions for potential inhibitors of Mycobacterium tuberculosis growth. Using microdilution screening, the ethyl acetate solvent partitioned fraction from the heartwood of Caesalpinia sappan exhibited strong antitubercular activity. We isolated the active compound and identified it as 3-deoxysappanchalcone. The extracted 3-deoxysappanchalcone possessed activity against both drug-susceptible and drug-resistant strains of M. tuberculosis at MIC50 s of 3.125-12.5 μg/mL in culture broth and MIC50 s of 6.25-12.5 μg/mL inside macrophages and pneumocytes. 3-Deoxysappanchalcone was also found to act in partial synergy with streptomycin/ethambutol against M. tuberculosis H37Rv. 3-Deoxysappanchalcone had no cytotoxicity against the A549 cell line up to a concentration of 100 μg/mL (selectivity index > 8-32). Further studies are warranted to establish the in vivo effect and therapeutic potential of 3-deoxysappanchalcone. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

We investigated the photoprotective activity of phloroglucinol on ultraviolet B ( UVB)-induced deleterious effects in hairless mice in vivo. To assess the photoprotective effect of phloroglucinol, phloroglucinol-treated HR-1 hairless male mice were exposed to UVB irradiation. The inhibitory activity of phloroglucinol on wrinkle formation was determined by analysis of skin replicas, epidermal thickness based on histological examination and collagen damage. Matrix metalloproteinase-1 ( MMP-1), matrix metalloproteinase-9 ( MMP-9) and tissue inhibitor of metalloproteinase ( TIMP) mRNA levels were measured by real-time PCR. UVB induced transcription of proinflammatory cytokines, including interleukin-1 beta ( IL-1 β, IL-6) and IL-8 ( IL-8). The protective effects of phloroglucinol on UVB-induced skin photoaging were examined by measuring protein levels of MMPs and mitogen-activated protein ( MAP) kinases. The results of these experiments suggest that phloroglucinol has a significant beneficial effect on the barrier function of the skin. In hairless mice, signs of photoaging and photodamage, including coarse wrinkle formation, epidermal thickness and elastic fiber degeneration, were reduced in severity by phloroglucinol application. The phloroglucinol-treated group showed remarkably decreased mRNA levels of MMP-1, MMP-9 and inflammatory cytokines in comparison with those of the UVB-induced group. Oral administration of phloroglucinol attenuated phosphorylation of MAP kinases, including extracellular signal-regulated kinase, c-Jun N-terminal kinase and p38. [ABSTRACT FROM AUTHOR]

This study investigated the inhibitory effects of costunolide isolated from the leaves of Laurus nobilis L. (Lauraceae) on basophil-mediated allergic reactions and interleukin (IL)-5-mediated B cell growth. The effects of costunolide on β-hexosaminidase (a key parameter of degranulation) release and IL-4 expression in rat basophilic leukemia (RBL-2H3) cells were determined by measuring β-hexosaminidase activity and by semi-quantitative RT-PCR, respectively. The effects of costunolide on Y16 pro-B cell viability and growth were determined by 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide (MTT) assay. Costunolide was found significantly to inhibit β-hexosaminidase activity ( p < 0.01) and IL-4 transcription in RBL-2H3 cells in a dose-dependent manner. Its 50% inhibitory concentration (IC50) was 34 µ m, while that of the positive control, ketotifen, was 24 µ m (IL-4 mRNA transcription). Moreover, costunolide dose-dependently suppressed pro-B cell growth in IL-5-stimulated Y16 cells. These results provide evidence that costunolide stabilizes mast cells by inhibiting IgE-mediated degranulation and inhibits IL-5-stimulated B cell growth. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]