1.25 Dihydroxyvitamin D3 Attenuates Hypertrophy Markers in Cardiomyoblast H9c2 Cells: Evaluation of Sirtuin3 mRNA and Protein Level.

Background: The cellular and molecular mechanisms of cardioprotective effects of Vitamin D are poorly understood. Given the essential role of sirtuin-3 (SIRT3) as an endogenous negative regulator of cardiac hypertrophy, this study was designed to investigate the effect of 1, 25-dihydroxyvitamin D3 (calcitriol) on hypertrophy markers and SIRT3 mRNA and protein levels following angiotensin II induced - hypertrophy in cardiomyoblast H9c2 cells. Methods: Rat cardiomyoblast H9c2 cells were treated for 48 hr with angiotensin II alone (Ang group) or in combination with 1, 10 and 100 nM of calcitriol (C + Ang groups). Intact cells served as control (Ctl). The cell area was measured using methylene blue staining. Atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and SIRT3 transcription levels were measured by real time RT-PCR. SIRT3 protein expression was evaluated using western blot technique. Results: The results showed that in Ang group cell size was increase by 128.4 ± 15% (P < 0.001 vs. Ctl) whereas in C100 + Ang group it was increased by 21.3 ± 6% (P < 0.001 vs. Ang group). Calcitriol pretreatment decreased ANP mRNA level significantly (P < 0.05) in comparison with Ang group (Ang: 75.5 ± 15%, C100 + Ang: 19.2 ± 9%). There were no significant differences between Ang group and cells pretreated with 1 and 10 nM of calcitriol. SIRT3 at mRNA and protein levels did not change significantly among the experimental groups. Conclusions: In conclusion, pretreatment with calcitriol (100 nM) prevents Ang II-induced hypertrophy in cardiomyoblast H9c2 cells. This probably occurs through other pathways except SIRT3 upregulation.

Carvacrol Ameliorates Pathological Cardiac Hypertrophy in Both In-vivo and In-vitro Models.

Hypertension-induced left ventricular hypertrophy is the most important risk factor for heart failure. This study aimed at investigating the effects of monoterpenoid phenol, carvacrol, on myocardial hypertrophy using both in-vivo and in-vitro models. Male Wistar rats were divided into the control (Ctl), un-treated hypertrophy (H), and carvacrol-treated hypertrophy groups (25, 50 and 75 mg/kg/day, Car+H). In the hypertrophy groups animals underwent abdominal aorta banding. Blood pressure (BP) was recorded via carotid artery cannulation. TUNEL assay and Masson's trichrome staining were used to assess apoptosis and fibrosis, respectively. The 2-2-diphenyl 1-picril-hydrasil )DPPH( radical scavenging activity and malondialdehyde (MDA) level were estimated by biochemical tests. In in-vitro study H9c2 cardiomyoblasts were treated with angiotensin II (Ang II) to promote hypertrophy. Cell size was measured using crystal violet staining. Gene expression was evaluated by real-time RT-PCR technique. In the carvacrol-treated rats BP, heart rate, and heart weight to the body weight ratio were significantly decreased. In-vitro study showed that H9c2 cell size was significantly reduced compared to Ang II-treated cells. Both in-vivo and in-vitro studies demonstrated that carvacrol decreased atrial natriuretic peptide )ANP( mRNA level significantly (vs. H groups). The number of apoptotic cells increased in H group, while it was decreased in the Car50+H and Car75+H. In Car+H groups, in comparison with H group, the serum concentration of MDA was decreased and DPPH was increased significantly. Our findings demonstrated that carvacrol decreases hypertrophy markers in in-vivo and in-vitro models of hypertrophy.

The effect of resveratrol on angiotensin II levels and the rate of transcription of its receptors in the rat cardiac hypertrophy model.

This study investigated the effect of resveratrol on serum and cardiac levels of angiotensin II and transcription of its main receptors following pressure overload induced-hypertrophy. Rats were divided into untreated (Hyp) and resveratrol treated hypertrophied groups (H + R). Intact animals served as the control (Ctl). Cardiac hypertrophy was induced by abdominal aortic banding. Blood pressure (BP) was recorded via left carotid artery cannula. Fibrosis was confirmed by Masson trichrome staining. Angiotensin II level was measured using an ELIZA test. Gene expression was assessed by a real time PCR (RT-PCR) technique. We observed that in the H + R group BP and heart weight/body weight were decreased significantly (p < 0.001, p < 0.05, respectively vs Hyp). The cardiac levels of angiotensin II and AT1a mRNA were increased in the Hyp group (p < 0.01 vs Ctl). In the H + R group the AT1a mRNA level was decreased significantly (p < 0.05 vs Hyp). It could be concluded that resveratrol protects the heart against hypertrophy progression in part by affecting cardiac AT1a transcription.