Arsenic Trioxide Combining Leflunomide Activates Nrf2-ARE-HO-1 Signaling Pathway and Protects Heart Xenografts.

OBJECTIVE: To investigate the molecular mechanisms underlying the effects of arsenic trioxide (As2O3) in combination with leflunomide on the hamster-to-rat heart xenotransplant. METHODS: Transplantation of LVG hamster hearts to Lewis rats was performed by anastomosis of vessels in the neck using end-to-end anastomosis with a non-suture cuff technique. Four groups of recipient rats (n=6 in each) were treated with normal saline (control), As2O3 [5 mg/(kg·day) intraperitoneally], leflunomide [5 mg/(kg·d) orally], or leflunomide [5 mg/(kg·d)+As2O3 [5 mg/(kg·d)] in combination. Donor hearts and/or rat spleens were harvested and analyzed 4 days after transplantation. Quantitative reverse-transcription polymerase chain reaction and Western blot analysis were performed to detect the expression of the nuclear factor erythroid-derived factor 2-related factor (Nrf2) and its target gene heme oxygenase-1 (HO-1), Treg cell marker fork-head Box P3 (FOXP3), apoptosis-associated proteins Bcl-2, Bax, and cleaved caspase-3. Immunohistochemical staining was used to detect the levels of inflammatory natural killer cell and macrophage infiltration, intercellular cell adhesion molecule-1 (ICAM-1) and complement C3. RESULTS: Expression of Nrf2-ARE-HO-1 signaling pathway was upregulated in heart xenografts in rats treated with As2O3 plus leflunomide compared with control rats or rats treated with either drug alone (P<0.01), and this was accompanied by an increased Treg cells in the recipient rat spleen (P<0.01). In contrast, the expressions of Bax, cleaved caspase-3, ICAM-1, and complement C3, and infiltration of inflammatory cells in the xenografts were inhibited by As2O3 plus leflunomide treatment (P<0.01). CONCLUSION: Combination treatment with As2O3 and leflunomide protected hamster heart-xenografts in recipient rats.

Characterization and quantification of eight water-soluble constituents in tubers of Pinellia ternata and in tea granules from the Chinese multiherb remedy Xiaochaihu-tang.

In traditional Chinese medicine, multiple herbs are usually used in combination to generate the joint actions of a multiherb remedy. The recent development of LC-hyphenated techniques enables efficient and rapid profiling of the chemical constituent in extracts from multiherb remedies. Xiaochaihu-tang is a seven-herb remedy that has attracted a great deal of attention for reported ability to treat liver dysfunction. Dried tubers of Pinellia ternata (banxia in Chinese) is one of the ingredients, but its chemical contribution to Xiaochaihu-tang remains poorly understood. In the study presented here, LC-UV-MS, LC-MS-MS, and LC-NMR were used in a complementary manner to determine the nature and content of eight water-soluble constituents of banxia and their presence in various tea granules from Xiaochaihu-tang. Among the eight chemicals identified in banxia, cytidine, adenosine, tryptophan, uridine, and adenine are reported for the first time, while tyrosine, guanosine, and phenylalanine were previously described. These chemicals are also present in all of the samples of Xiaochaihu-tang granules, and the amounts of the chemicals ingested due to a daily dose of the multiherb remedies range from 0.008 to 6.3mg.