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A new indole alkaloid N′-formylserotonin (1), along with five known indole alkaloids N′-methylserotonin (2), 5-hydroxy-1H-indole-3-carbaldehyde (3), N-acetylserotonin (4), 6-hydroxy-1-oxo-3,4-dihydro-β-carboline (5), and bufoserotoin C (6), were isolated from the water extract of traditional Chinese medicine Chansu. Their structures were elucidated on the basis of spectral analyses. The cytotoxicities of 1-6 against human lung adenocarcinoma epithelial cells A549 were tested using the MTT method. Compound 6 exhibited stronger cytotoxic effect than 5-FU, and 1-5 showed no cytotoxic effects. Bufoserotonin C is one of the cytotoxic components in water-soluble extract of Chansu. [ABSTRACT FROM AUTHOR]

Degeneration of the central auditory system, which is characterized by reduced understanding of speech and source localization of sounds, is an important cause of age-related hearing loss (presbycusis). Accumulating evidence has demonstrated that Wnt/β-catenin signaling plays an essential role in the development of the auditory system but its potential role in presbycusis remains unclear. In this study, we used a rat model of aging, created by chronic systemic exposure to d-galactose (d-gal), and explored changes in Wnt/β-catenin signaling in the auditory cortex. A decrease in Wnt/β-catenin signaling in the auditory cortex was found in both naturally aging and d-gal-mimetic aging rats, as indicated by increased GSK3β activity and decreased β-catenin activity. Moreover, lithium chloride (Licl), an activator of Wnt signaling pathway, was administered long term to 15-month-old d-gal-treated rats. Activation of Wnt/β-catenin signaling by Licl attenuated d-gal-induced auditory cortex apoptosis and neurodegeneration. Bmi1, a transcription factor implicated in antiaging and resistance to apoptosis, can be modulated by β-catenin activity. Here, we showed that the expression of Bmi1 was reduced and the expression of its downstream genes, p16 INK 4a , p19 Arf , and p53 were increased in the auditory cortex both of naturally aging and d-gal-mimetic aging rats. In addition, Licl significantly increased Bmi1 expression and reduced p16 INK 4a , p19 Arf , and p53 expression. Our results indicated that decreased Wnt/β-catenin signaling might participate in the pathogenesis of central presbycusis through modulating the expression of Bmi1. Wnt/β-catenin signaling might be used as a potential therapeutic target against presbycusis.

Tryptophan hydroxylase I（TPH1） catalases the 5-hydroxylation reaction of L-Trp, which is the rate-limiting step in the synthesis of serotonin. Serotonin, a major component of Bufonis venenum, is involved in numerous physiological functions as an important neurotransmitter. In this study, BbgTPH1 cDNA was cloned from the parotid gland of Bufo bufo gargarizans. Genetic engineering techniques were used to construct a recombinant prokaryotic fusion expression plasmid pMAL-BbgTPH1, and the induced conditions to express the recombinant BbgTPH1 in E. coli TB1 cells were optimized. The full length of BbgTPH1 is 1 984 bp (GenBank accession No. JQ768313) with a 1 443 bp open reading frame (ORF) encoding a 480 amino acid residues. The deduced protein molecular weight is 55.2 k Da and its theoretical isoelectric point is 5.58. The sequence includes conserved domain and special signal sequence of the aromatic amino acid hydroxylase (AAAH) superfamily. Homologous alignment showed that BbgTPH1 shared a high homology with other species. Phylogenetic tree showed the closest relative to BbgTPH1 was Xenopus tropical-TPH1. The best induction conditions of recombinant BbgTPH1 were 0.5 mmol·L(-1) IPTG at 20 ℃ for 8 h. The function of BbgTPH1 was identified by in vitro enzymatic reaction and the recombinant BbgTPH1 was able to produce 5-hydroxytryptophan by catalyzing tryptophan. This study represents the first time of cloning and identification of the function of TPH1 in Bufo genus. The results of this study will be an important foundation for future studies of biosynthesis of bufotenines in the parotid gland of B. bufo gargarizans.

In the present study, we investigated the potential anti-angiogenic mechanism and anti-tumour activity of beta-eudesmol using in vitro and in vivo experimental models. Proliferation of human umbilical vein endothelial cells (HUVEC) stimulated with vascular endothelial growth factor (VEGF, 30 ng/ml) and basic fibroblast growth factor (bFGF, 30 ng/ml) was significantly inhibited by beta-eudesmol (50-100 microM). Beta-eudesmol (100 microM) also blocked the phosphorylation of cAMP response element binding protein (CREB) induced by VEGF (30 ng/ml) in HUVEC. Beta-eudesmol (10-100 microM) inhibited proliferation of HeLa, SGC-7901, and BEL-7402 tumour cells in a time- and dose-dependent manner. Moreover, beta-eudesmol treatment (2.5-5 mg/kg) significantly inhibited growth of H(22) and S(180) mouse tumour in vivo. These results indicated that beta-eudesmol inhibited angiogenesis by suppressing CREB activation in growth factor signalling pathway. This is the first study to demonstrate that beta-eudesmol is an inhibitor of tumour growth.

Aim: To study the mechanism of dracorhodin perchlorate-induced Hela cell apoptosis., Methods: Cell viability was measured by MTT method. Morphological changes were observed by phase contrast microscopy and Hoechst 33258 staining. DNA fragmentation was assayed by agarose gel electrophoresis. Protein expression was detected by Western blot analysis., Results: Dracorhodin perchlorate induced Hela cell apoptosis. The apoptosis was partially reversed by caspase-1, -3, -8, -9 and caspase family inhibitors. Treatment of Hela cells with dracorhodin perchlorate for 12 h increased the protein expression ratio of Bax/Bcl-XL; procaspase-3, -8, ICAD and PARP were cleaved to smaller molecules., Conclusion: Dracorhodin perchlorate induced Hela cell death via alteration of Bax/Bcl-XL ratio and activation of caspases.