The JAK2/STAT3 pathway is involved in the anti-melanoma effects of brevilin A.

AIMS: Melanoma is lethal. Constitutively active signal transducer and activator of transcription 3 (STAT3) has been proposed as a pathogenic factor and a therapeutic target of melanoma. Brevilin A, a sesquiterpene lactone isolated from Centipeda minima (L.) A. Br. et Aschers., has been shown to exert antineoplastic effects and inhibit the STAT3 pathway in nasopharyngeal, lung, prostate and breast cancer cells. This study aimed to determine whether brevilin A has anti-melanoma effects, and whether STAT3 signaling is involved in the effects. MAIN METHODS: A mouse A375 xenograft model, as well as A375 and A2058 cell models were employed to assess the in vivo and in vitro anti-melanoma effects of brevilin A. A375 cells stably expressing STAT3C, a constitutively active STAT3 mutant, were used to determine the role of STAT3 signaling in brevilin A's anti-melanoma effects. KEY FINDINGS: Intraperitoneal injection of brevilin A dose-dependently inhibited melanoma growth in mice and suppressed STAT3 phosphorylation in the tumors. In cultured cells, brevilin A reduced cell viability, induced apoptosis, suppressed migration and invasion, decreased protein levels of phospho-JAK2 (Y1007/1008) and phospho-STAT3 (Tyr705), and restrained STAT3 nuclear localization. STAT3 over-activation diminished brevilin A's effects on cell viability and migration. Collectively, brevilin A exerts anti-melanoma effects and these effects are at least in part attributed to the inhibition of the JAK2/STAT3 pathway. SIGNIFICANCE: Our findings provide a pharmacological basis for developing brevilin A as a new phytotherapeutic agent against melanoma.

Molecular analysis of Leonurus species in China based on ITS and matK sequences.

The genus Leonurus has long been recognized as a natural group, but its interspecific relationship has not yet been studied in the light of sequence data. The ITS regions and matK sequences of all subgenera of Leonurus in China were amplified, sequenced and investigated. Phylogenies generated by maximum parsimony and neighbor-joining methods and division of the genus into two major clades. The phylogenetic results indicated that L. chaituroides has the very close phylogenetic relationship with Subg. Cardiochilium and supported the notion that L. macranthus acts as the bridge between Subg. cardiochilium and Subg. Leonurus. According to the analysis of information given by ITS and matK sequences, we suggest that ITS sequences would be more suitable to serve as markers for authentication of Herba Leonuri than matK does.

ITS sequence analysis used for molecular identification of the Bupleurum species from northwestern China.

Radix Bupleuri (Chaihu), a famous Traditional Chinese Medicine, is derived from the dried roots of Bupleurum chinense DC. and B. scorzonerifolium Willd. But nowadays, other nine species and varieties from genus Bupleurum are also used as Radix Bupleuri in northwestern China. The authentic identification of dried roots of B. chinense and B. scorzonerifolium, however, is difficult to just base on the appearance and morphology. A molecular genetic method was developed to help discriminate the original species of Radix Bupleuri. The ITS sequences ( approximately 600 bp) were amplified by the PCR technique from genomic DNA isolated from all the collected samples. According to analyzing the information given by ITS sequences, the conclusion can be made that ITS sequence could serve as markers for authentication of Radix Bupleuri.

[Nuclear ribosomal DNA internal transcribed spacer 1 sequences of 4 Leonurus species].

OBJECTIVE: To analyze the nuclear ribosome DNA (nrDNA) internal transcribed spacer (ITS) sequences of 4 Leonurus species, and the possibility of using them for molecular authentication of the crude drugs from the genus. METHODS: The nrDNA ITS sequence (including ITS1, 5.8S rDNA, ITS2, and partial 18S rDNA and 26S rDNA) of L. japonicus and its 3 adulterant species were amplified and sequenced, and CLUSTRAL X and MEGA software was employed for analysis. RESULTS: The variation of ITS1 and ITS2 between L. japonicus and its adulterant species ranged between 7.2% and 18.8% and between 14.2% and 27%, respectively. The phylogenic tree derived from the dendrograms based on the ITS sequence data contained some discrepancy from the traditional classification. CONCLUSION: The nrDNA ITS sequences can be used potentially as efficient markers for identification of L. japonicus and its adulterants, and further study is needed for studying the phylogeny of Leonurus.