Background: In ancient times, plants were recognized for their medicinal properties. Later, the arrival of synthetic drugs pushed it to the backstage. However, from being merely used for food, plants are now been widely explored for their therapeutic value. The current study explores the potential of skin and flesh extracts from a hard-necked Rocambole variety of purple garlic in preventing cardiomyocyte hypertrophy and cell death.Methods: Norepinephrine (NE) was used to induce hypertrophy in adult rat cardiomyocytes pretreated with garlic skin and flesh extracts. Cell death was measured as ratio of rod to round shaped cardiomyocytes. Fluorescent probes were used to measure apoptosis and oxidative stress in cardiomyocytes treated with and without extracts and NE. Pharmacological blockade of nitric oxide (NO) and hydrogen sulfide (H2S) were used to elucidate the mechanism of action of garlic extracts. Garlic extract samples were also tested for alliin and allicin concentrations.Results: Exposure of cardiomyocytes to NE induced an increase in cell size and cell death; this increase was significantly prevented upon treatment with garlic skin and flesh extracts. Norepinephrine increased apoptosis and oxidative stress in cardiomyocytes which was prevented upon pretreatment with skin and flesh extracts; NO, and H2S blockers significantly inhibited this beneficial effect. Allicin and alliin concentration were significantly higher in garlic flesh extract when compared to the skin extract.Conclusion: These results suggest that both skin and flesh garlic extracts are effective in preventing NE induced cardiomyocyte hypertrophy and cell death. Reduction in oxidative stress may also play an important role in the anti-hypertrophic and anti-apoptotic properties of garlic extracts. These beneficial effects may in part be mediated by NO and H2S.
The development and progression of heart failure (HF) due to myocardial infarction (MI) is a major concern even with current optimal therapy. Resveratrol is a plant polyphenol with cardioprotective properties. Sacubitril/valsartan is known to be beneficial in chronic HF patients. In this study, we investigated the comparative and combinatorial benefits of resveratrol with sacubitril/valsartan alongside an active comparator valsartan in MI-induced male Sprague Dawley rats. MI-induced and sham-operated animals received vehicle, resveratrol, sacubitril/valsartan, valsartan alone or sacubitril/valsartan + resveratrol for 8 weeks. Echocardiography was performed at the endpoint to assess cardiac structure and function. Cardiac oxidative stress, inflammation, fibrosis, brain natriuretic peptide (BNP), creatinine and neutrophil gelatinase associated lipocalin were measured. Treatment with resveratrol, sacubitril/valsartan, valsartan and sacubitril/valsartan + resveratrol significantly prevented left ventricular (LV) dilatation and improved LV ejection fraction in MI-induced rats. All treatments also significantly reduced myocardial tissue oxidative stress, inflammation and fibrosis, as well as BNP. Treatment with the combination of sacubitril/valsartan and resveratrol did not show additive effects. In conclusion, resveratrol, sacubitril/valsartan, and valsartan significantly prevented cardiac remodeling and dysfunction in MI-induced rats. The reduction in cardiac remodeling and dysfunction in MI-induced rats was mediated by a reduction in cardiac oxidative stress, inflammation and fibrosis.
The cardioprotective effects of ginseng root extracts have been reported. However, nothing is known about the myocardial actions of the phenolic compounds enriched in ginseng berry. Therefore, this study was undertaken to investigate the effects of American ginseng berry extract (GBE) in an experimental model of myocardial infarction (MI). Coronary artery ligation was performed on Sprague–Dawley male rats to induce MI after which animals were randomized into groups receiving either distilled water or GBE intragastrically for 8 weeks. Echocardiography and assays for malondialdehyde (MDA) and TNF-α were conducted. Flow cytometry was used to test the effects of GBE on T cell phenotypes and cytokine production. Although GBE did not improve the cardiac functional parameters, it significantly attenuated oxidative stress in post-MI rat hearts. GBE treatment also resulted in lower than control levels of TNF-α in post-MI rat hearts indicating a strong neutralizing effect of GBE on this cytokine. However, there was no effect of GBE on the proportion of different T cell subsets or ex-vivo cytokine production. Taken together, the present study demonstrates GBE reduces oxidative stress, however no effect on cardiac structure and function in post-MI rats. Moreover, reduction of TNF-α levels below baseline raises concern regarding its use as prophylactic or preventive adjunct therapy in cardiovascular disease.
Stilbenoids are bioactive polyphenols, and resveratrol (trans-3,5,40-trihydroxystilbene) is a representative stilbenoid that reportedly exerts cardioprotective actions. As resveratrol exhibits low oral bioavailability, we turned our attention to other stilbenoid compounds with a history of medicinal use and/or improved bioavailability. We determined the effects of gnetol (trans-3,5,20,60-tetrahydroxystilbene) and pterostilbene (trans-3,5-dimethoxy-40-hydroxystilbene) on cardiac hypertrophy. In vitro, gnetol and pterostilbene prevented endothelin-1-induced indicators of cardiomyocyte hypertrophy including cell enlargement and protein synthesis. Gnetol and pterostilbene stimulated AMP-activated protein kinase (AMPK), and inhibition of AMPK, using compound C or shRNA knockdown,abolished these anti-hypertrophiceffects. In contrast,resveratrol, gnetol, nor pterostilbene reduced blood pressure or hypertrophy in the spontaneously hypertensive heart failure (SHHF) rat. In fact, AMPK levels were similar between Sprague-Dawley and SHHF rats whether treated by stilbenoids or not. These data suggest that the anti-hypertrophic actions of resveratrol (and other stilbenoids?) do not extend to the SHHF rat, which models heart failure superimposed on hypertension. Notably, SHHF rat hearts exhibited prolonged isovolumic relaxationtime(an indicator of diastolicdys function),and this was improved by stilbenoid treatment.In conclusion, stilbenoid-based treatment as a viable strategy to prevent pathological cardiac hypertrophy,a major risk factor for heart failure,may be context-dependent and requires furtherstudy.
In this study, we tested the potential cardioprotective effects of the phytoalexin resveratrol (Rsv) on primary adult rat cardiac fibroblasts (CF), myofibroblasts (MF) and cardiomyocytes. Adult rat CF and cardiomyocytes were isolated from male 10-week old Sprague–Dawley rats, cultured for either 24 h (cardiomyocytes) or 48 h (CF) before treatments. To isolate MF, CF were trypsinized after 48 h in culture, seeded in fresh plates and cultured for 24 h prior to treatment. All three cells were then treated for a further 24 h with a range of Rsv doses. In CF and MF, cell proliferation, viability, apoptosis assays were performed with or without Rsv treatment for 24 h. In cardiomyocytes, cell viability and apoptosis assay were performed 24 h after treatment. In separate experiments, CF was pre-incubated with estrogen, tamoxifen and fulvestrant for 30 min prior to Rsv treatment. Rsv treatment decreased proliferation of both fibroblasts and myofibroblasts. Rsv treatment also increased the proportion of dead CF and MF in a dose dependent manner. However, treatment with Rsv did not induce cell death in adult cardiomyocytes. There was an increase in the percentage of cells with condensed nuclei with Rsv treatment in both CF and MF, but not in cardiomyocytes. Treatment with estrogen, tamoxifen and fulvestrant alone or in combination with Rsv did not have any additional effects on CF survival. Our results demonstrate that treatment with Rsv can inhibit cell proliferation and induce cell death in rat CF and MF, while not affecting cardiomyocyte survival. We also demonstrated that the induction of cell death in CF with Rsv treatment was independent of estrogen receptor alpha (ERα) signaling.
Non-alcoholic fatty liver disease (NAFLD), a significant cause of chronic liver disease, presents a considerable public health concern. Despite this, there is currently no treatment available. This study aimed to investigate dietary flaxseed in the JCR:LA-corpulent rat strain model of NAFLD. Both obese male and female rats were studied along with their lean counterparts after 12 weeks of ingestion of a control diet, or control diet with flaxseed, or high fat, high sucrose (HFHS), or HFHS plus flaxseed. Obese rats showed higher liver weight and increased levels of cholesterol, triglyceride, and saturated fatty acid, which were further elevated in rats on the HFHS diet. The HFHS diet induced a significant two-fold elevation in the plasma levels of both aspartate aminotransferase and alanine aminotransferase in the obese male and female rats. Including flaxseed in the HFHS diet significantly lowered liver weight, depressed the plasma levels of both enzymes in the obese male rats, and reduced hepatic cholesterol and triglyceride content as well as improving the fatty acid profile. In summary, including flaxseed in the diet of male and female obese rats led to an improved lipid composition in the liver and significantly reduced biomarkers of tissue injury despite consuming a HFHS chow.