[Effect and mechanism of leonurine on pressure overload-induced cardiac hypertrophy in rats].

To investigate the effects of leonurine(Leo) on abdominal aortic constriction(AAC)-induced cardiac hypertrophy in rats and its mechanism. A rat model of pressure overload-induced cardiac hypertrophy was established by AAC method. After 27-d intervention with high-dose(30 mg·kg~(-1)) and low-dose(15 mg·kg~(-1)) Leo or positive control drug losartan(5 mg·kg~(-1)), the cardiac function was evaluated by hemodynamic method, followed by the recording of left ventricular systolic pressure(LVSP), left ventricular end-diastolic pressure(LVESP), as well as the maximum rate of increase and decrease in left ventricular pressure(±dp/dt_(max)). The degree of left ventricular hypertrophy was assessed based on heart weight index(HWI) and left ventricular mass index(LVWI). Myocardial tissue changes and the myocardial cell diameter(MD) were measured after hematoxylin-eosin(HE) staining. The contents of angiotensin Ⅱ(AngⅡ) and angiotensin Ⅱ type 1 receptor(AT1 R) in myocardial tissue were detected by ELISA. The level of Ca~(2+) in myocardial tissue was determined by colorimetry. The protein expression levels of phospholipase C(PLC), inositol triphosphate(IP3), AngⅡ, and AT1 R were assayed by Western blot. Real-time quantitative PCR(qRT-PCR) was employed to determine the mRNA expression levels of ß-myosin heavy chain(ß-MHC), atrial natriuretic factor(ANF), AngⅡ, and AT1 R. Compared with the model group, Leo decreased the LVSP, LVEDP, HWI, LVWI and MD values, but increased ±dp/dt_(max) of the left ventricle. Meanwhile, it improved the pathological morphology of myocardial tissue, reduced cardiac hypertrophy, edema, and inflammatory cell infiltration, decreased the protein expression levels of PLC, IP3, AngⅡ, AT1 R, as well as the mRNA expression levels of ß-MHC, ANF, AngⅡ, AT1 R, c-fos, and c-Myc in myocardial tissue. Leo inhibited AAC-induced cardiac hypertrophy possibly by influencing the RAS system.

Scubatines A-F, new cytotoxic neo-clerodane diterpenoids from Scutellaria barbata D. Don.

Phytochemical investigation of the 70% acetone extract of the whole plant of Scutellaria barbata D. Don afforded six new neo-clerodane diterpenoids, scubatines A-F (1-6), and four known analogues (7-10). Their structures were elucidated on the basis of extensive spectroscopic analyses. Cytotoxic activity against the HL-60 and A549 cell lines was assessed for all isolated compounds. Compound 9 exhibited moderate activity against HL-60 with an IC50 value of 5.6µM. Compound 6 showed weak cytotoxic activity against A549 and HL-60 with IC50 values of 10.4 and 15.3µM, respectively.

Crassins A-H, Diterpenoids from the Roots of Croton crassifolius.

Phytochemical investigation of the 70% acetone extract of Croton crassifolius roots afforded eight new diterpenoids, crassins A-H (1-8), and 19 known compounds. The structures of the new compounds were determined by spectroscopic methods, and their absolute configurations were determined by electronic circular dichroism, single-crystal X-ray diffraction analysis, comparison with literature data, and biogenetic considerations. Crassins A (1) and B (2) are new ring B-rearranged diterpenoids, whereas crassin C (3) is a new ring A-rearranged diterpenoid. Crassin H (8) exhibited selective cytotoxicity against A549 cells (IC50 5.2 µM) compared with HL-60 cells (IC50 11.8 µM). The known compound chettaphanin-II exhibited moderate activity against the A549 and HL-60 cell lines (IC50 8.4 and 10.5 µM, respectively).