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Diterpenoids from the Vietnamese medicinal plant Croton tonkinensis are rich in ent-kaurane, kaurane and the grayanane class and are valuable intermediate plant metabolites with different bioactivities. In this study, we report the antituberculosis activity of these diterpenoids against both susceptible and resistant strains of M. tuberculosis for the first time. All of the ent-kaurane, kaurane and grayanane diterpenoids showed high to moderate activity against Mycobacterium. The highest antituberculosis activity was observed for ent-1β,7α,14β-triacetoxykaur-16-en-15-one ( cpp604), with MIC values of 0.78, 1.56 and 3.12-12.5 µg/ml against H37Ra, H37Rv and all other resistant strains of Mycobacterium tuberculosis examined. In addition, other ent-kaurane-type diterpenoids also showed very high activities against mycobacterium, including cpp609 (1.56 µg/ml), cpp610 (1.56 µg/ml), cpp601 (3.12-6.25 µg/ml), cpp602 (3.12-6.25 µg/ml), cpp607 (3.12-6.25 µg/ml) and cpp608 (3.12-6.25 µg/ml). From the structure-activity relationship, functional groups R3 and R5 of the ent-kaurane skeleton were found to modulate the antimycobacterial activity. [ABSTRACT FROM AUTHOR]

Sappanchalcone, a bioactive flavonoid isolated from the heartwood of Caesalpinia sappan L. possesses anti-inflammatory effects. We studied the efficacy of sappanchalcone in attenuating collagen-induced arthritis (CIA) in a mouse model of rheumatoid arthritis. Sappanchalcone was purified to homogeneity from the chloroform fraction of the methanolic extract of C. sappan, and identified using mass spectrometry and H-nuclear magnetic resonance spectroscopy. CIA-induced male DBA/1J mice were divided into control, sappanchalcone-treated, and methotrexate-treated groups ( n = 10 per group). Paw swelling, arthritis severity, radiographic and histomorphometric changes were assessed to measure the protective role of sappanchalcone against chronic disease progression. Sappanchalcone administration significantly reduced clinical arthritis and inflammatory edema in paws. Bone mineral density and trabecular structure were maintained in CIA mice administered sappanchalcone. The levels of pro-inflammatory cytokines (TNF-α, IL-6, and 1L-1β) were significantly lower in the serum of sappanchalcone-treated mice as compared with the control group. Our results suggest that sappanchalcone could be used as an anti-inflammatory and bone-protective agent during the treatment of rheumatoid arthritis. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the physiological effects of different selenium (Se) levels on the growth of white-rot fungus, Pleurotus eryngii, with special reference to the regulation of ligninolytic enzymes such as laccase and versatile peroxidase. The fungus was grown in medium supplemented with 1, 10, 100, 1,000 and 10,000 μM of sodium selenite. Mycelial growth was stronger at lower Se levels, but declined significantly at higher concentrations of 1,000 and 10,000 μM, highlighting its association in mediating toxic responses. Inhibition of fungal growth was accompanied with dense and entangled hyphae taking the shape of irregular short strips. Additionally, hyphal swellings and septation were noticed which lead to a reduction in the advancement of the mycelium. Along with the inhibition of fungal biomass, the reducing sugar and protein concentrations increased to about 30.2 and 3.5 mg/ml respectively in the growth medium. Additionally, the laccase gene expression showed a twofold upregulation at higher levels of Se, although the activity of the enzyme was compromised with an inverse relationship with increased gene transcripts. The versatile peroxidase transcript showed a complete downregulation at 10,000 μM after an upregulation at lower levels of Se. We also confirmed the direct relationship of different Se levels on laccase activity of Rhus vernicifera that showed similar behavior to the fungal laccase. The results of the present study suggest that Se supplementation regulates mRNA levels of laccase and versatile peroxidase depending on exposure and may play a role in the toxicity associated with Se. [ABSTRACT FROM AUTHOR]

A correction to the article " Effects of different selenium levels on growth and regulation of laccase and versatile peroxidase in white-rot fungus, Pleurotus eryngii" in the April 23, 2014 is presented.