Scutellarin exerts its anti-hypertrophic effects via suppressing the Ca2+-mediated calcineurin and CaMKII signaling pathways.

Scutellarin is a flavonoid extracted from a traditional Chinese herb, Erigeron breviscapus Hand Mazz, which has been broadly used in treating various cardiovascular diseases. In this study, we investigated its effect on cardiac hypertrophy and the underlying mechanism. Both in vitro and in vivo cardiac hypertrophy models were employed to explore the anti-hypertrophic action of scutellarin. We found that scutellarin significantly suppressed the hypertrophic growth of neonatal cardiac myocytes exposed to phenylephrine (PE) and mouse heart subjected to pressure overload induced by aortic banding, accompanied with the decreased expression of hypertrophic markers beta-myosin heavy chain and atrial natriuretic peptide. We then measured the change of free intracellular calcium using laser scanning confocal microscope. We found that scutellarin alleviated the increment of free intracellular calcium during cardiac hypertrophy either induced by PE or aortic banding. The expression of calcium downstream effectors calcineurin and phosphorylated calmodulin kinase II (CaMKII) were significantly suppressed by scutellarin. Our study indicated that scutellarin exerts its anti-hypertrophic activity via suppressing the Ca(2+)-mediated calcineurin and CaMKII pathways, which supports the observation that clinical application of scutellarin is beneficial for cardiovascular disease patients.

Synergistic inhibitory effect of sulforaphane and 5-fluorouracil in high and low metastasis cell lines of salivary gland adenoid cystic carcinoma.

The present study aimed to evaluate the growth-inhibitory effect of sulforaphane (SFN) and a traditional chemotherapy agent, 5-fluorouracil (5-Fu), against the proliferation of salivary gland adenoid cystic carcinoma high metastatic cell line (ACC-M) and low metastasis cell line (ACC-2). Furthermore, the expression of nuclear factor kappa B (NF-kappaB) which induces resistance to anticancer chemotherapeutic agents was also detected. The combination effect of SFN and 5-Fu was quantitatively determined using the method of median effect principle and the combination index. The nuclear NF-kappaB p65 expression after treatment with the SFN-5-Fu combination was also evaluated by western blot analysis. The ACC-M and ACC-2 cells exhibited relative resistant to 5-Fu. Treatment ACCs cells with SFN and 5-Fu in combination, led to synergistic inhibition on cell growth and a decreased expression in nuclear NF-kappaB p65 protein. This synergistic inhibitory effect was more significant in ACC-M cells, which is associated with the greatly decreased expression of NF-kappaB p65 (almost 5-fold) after the combination treatment. Our results demonstrate synergism between SFN and 5-Fu at higher doses against the ACC-M and ACC-2 cells, which was associated with the decreased expression of nuclear NF-kappaB p65 protein.

[Effect of sophocarpine on HERG K+ channels].

Human ether-a-go-go-related gene (HERG) encodes the rapid component of the cardiac delayed rectifier K+ current, which has an important effect on both proarrhythmia and antiarrhythmia. To investigate the effect of sophocarpine (SC) on HERG channel stably expressing in human embryonic kidney-293 (HEK293) cells, whole-cell patch-clamp technique was used to record HERG current and kinetic curves. As the result, it was found that SC inhibited HERG current in a concentration-dependent manner (10, 30, 100, and 300 micromol x L(-1)). At 0 mV, 10, 30, 100, and 300 micromol x L(-1) SC respectively inhibited IHERG by Istep ( 10.7 +/- 2.8)% , (11.3 +/- 5.5)% , (47.0 +/- 2.3)% and (53.7 +/- 2.5)% , and Itail (1.1 +/- 3.0)%, (17.1 +/- 3.3)%, (32.7 +/- 1.9)% (P < 0.05, n = 12) and (56.0 +/- 2.4)% (P < 0.05, n = 13). The time constants of inactivation, recovery from inactivation and onset of inactivation were accelerated. SC did not change other channel kinetics (activation and deactivation). It is concluded that SC inhibited the transfected HERG channels by influencing the inactivation state, which is the probable anti-arrhythmic mechanism.

[Effect of Daming capsule on expression of connexin43 isoforms in hyperlipemic rat's cardiac muscle].

OBJECTIVE: To find the molecular mechanism of decreasing blood fat effect of Darning capsule on hyperlipemic rat, we study the expression of connexin43 in the myocardium before and after using the capsule. METHOD: Forty Wistar rats were randomly divided into 5 group: control group, hyperlipemia model group, Daming capsule group of high dose, middle dose and low dose (200, 100, 50 mg kg(-1) d(-1)). Each group had 8 rats. Hyperlipemic rat model was made firstly, the blood was obtained via vena caudalis and the indexes of TC, TG, LDL, HDL and NEFA in the serum were measured. The myocardial total RNA was extracted by Trizol method. To compare the expression of connexin43 in the following groups: hyperlipemia, normal and drug, we used the technique of RT-PCR, immunostaining and microconfoul. RESULT: The concentrations of TC, TG, LDL and NEFA in hyperlipemic serum were increased (P <0. 05), while that of HDL was decreased (P <0. 05). After treating with Daming capsule, the concentration of the preceding four indexes were decreased and the concentrations of HDL was increased up to nearly normal level. No significant difference was found in the ECG of the three groups. As compared with the normal group, the mRNA expressions of connexin43 in hyperlipemia group was weakened (P <0.05), while that of the drug group was enhanced(P <0.05). The same result in immunostaining was observed. CONCLUSION: Hyperlipemic rat model was successfully established and Daming capsule has the effect of lowering blood lipid. Furthermore, the molecular mechanism of Darning capsule is related with the change of Cx43 closely.

[Effects of matrine, oxymatrine and resveratrol on HERG channel expression].

Because HERG potassium channel has important effects on both proarrhythmia and antiarrhythmia, we use immunofluorescence and Western blotting methods to detect the expression of HERG channel of HERG-HEK cells in different concentrations of matrine, oxymatrine and resveratrol. The findings showed that both matrine (1 micromol x L(-1) ) and oxymatrine ( 1micromol x L (-1) ) increased HERG channel expression ( n = 5, P < 0. 05 ) , while matrine (100 micromol x L(-1) ) decreased HERG channel expression ( n = 5, P < 0. 05), resveratrol didn't affect HERG channel expression. In conclusion, different concentrations of matrine and oxymatrine affect HERG channel expression, while there is no relationship between resveratrol and HERG channel expression. It provides a theoretical support for the safety and mechanism of anti-arrhythmic drugs.