Ginsenoside Rg1 Reduces Cardiotoxicity While Increases Cardiotonic Effect of Aconitine in vitro.

OBJECTIVE: To explore the synergic mechanism of ginsenoside Rg1 (Rg1) and aconitine (AC) by acting on normal neonatal rat cardiomyocytes (NRCMs) and pentobarbital sodium (PS)-induced damaged NRCMs. METHODS: The toxic, non-toxic, and effective doses of AC and the most suitable compatibility concentration of Rg1 for both normal and damaged NRCMs exposed for 1 h were filtered out by 3- (4,5)-dimethylthiahiazo (-z-y1)-3,5-diphenytetrazoliumromide, respectively. Then, normal NRCMs or impaired NRCMs were treated with chosen concentrations of AC alone or in combination with Rg1 for 1 h, and the cellular activity, cellular ultrastructure, apoptosis, leakage of acid phosphatase (ACP) and lactate dehydrogenase (LDH), intracellular sodium ions [Na+], potassium ions [K+] and calcium ions [Ca2+] levels, and Nav1.5, Kv4.2, and RyR2 genes expressions in each group were examined. RESULTS: For normal NRCMs, 3000 µ mol/L AC significantly inhibited cell viability (P<0.01), promoted cell apoptosis, and damaged cell structures (P<0.05), while other doses of AC lower than 3000 µ mol/L and the combinations of AC and Rg1 had little toxicity on NRCMs. Compared with AC acting on NRCMs alone, the co-treatment of 3000 and 10 µ mol/L AC with 1 µ mol/L Rg1 significantly decreased the level of intracellular Ca2+ (P<0.01 or P<0.05), and the co-treatment of 3000 µ mol/L AC with 1 µ mol/L Rg1 significantly decreased the level of intracellular Ca2+ via regulating Nav1.5, RyR2 expression (P<0.01). For damaged NRCMs, 1500 µ mol/L AC aggravated cell damage (P<0.01), and 0.1 and 0.001 µ mol/L AC showed moderate protective effect. Compared with AC used alone, the co-treatment of Rg1 with AC reduced the cell damage, 0.1 µ mol/L AC with 1 µ mol/L Rg1 significantly inhibited the level of intracellular Na+ (P<0.05), 1500 µ mol/L AC with 1 µ mol/L Rg1 significantly inhibited the level of intracellular K+ (P<0.01) via regulating Nav1.5, Kv4.2, RyR2 expressions in impaired NRCMs. CONCLUSION: Rg1 inhibited the cardiotoxicity and enhanced the cardiotonic effect of AC via regulating the ion channels pathway of [Na+], [K+], and [Ca2+].

Rhein activated Fas-induced apoptosis pathway causing cardiotoxicity in vitro and in vivo.

Rhein, one of the main active components of rhubarb (Dahuang) and Polygonum multiflorum (Heshouwu), has a wide range of effective pharmacological effects. Recently, increasing studies have focused on its potential hepatorenal toxicity, but the cardiotoxicity is unknown. In this study, we found that the IC50 of rhein to H9c2 cells at 24 h and 48 h were 94.5 and 45.9µmol/L, respectively, with positive correlation of dose-toxicity and time-toxicity. After the treatment of rhein (106, 124 and 132µmol/L), the number of H9c2 cells decreased significantly, and the morphology of H9c2 cells showed atrophy, round shape and wall detachment. Moreover, the proportion of apoptotic cells in H9c2 cells treated with rhein was significantly increased in a dose-dependent manner. And rhein induced S phase arrest of H9c2 cells and inhibited cell proliferation. Rhein up-regulated ROS, LDH levels and low MMP but down-regulated SOD content in H9c2 cells. Additionally, the results showed that the cardiac function LVEF and LVFS of rhein high-medium-low dose groups (350, 175, 87.5 mg/kg) were significantly reduced. And the contents of Ca2+, cTnT, CK and LDH in serum of KM mice were significantly up-regulated by rhein. Furthermore, western blot results suggested that rhein the above effects via promoting Fas-induced apoptosis pathway in vitro and in vivo. In general, rhein may cause cardiotoxicity via Fas-induced apoptosis pathway in vivo and in vitro, which provides reference for the safe use of medicinal plant containing rhein and its preparations.

Update on Pharmacological Activities, Security, and Pharmacokinetics of Rhein.

Rhein, belonging to anthraquinone compounds, is one of the main active components of rhubarb and Polygonum multiflorum. Rhein has a variety of pharmacological effects, such as cardiocerebral protective effect, hepatoprotective effect, nephroprotective effect, anti-inflammation effect, antitumor effect, antidiabetic effect, and others. The mechanism is interrelated and complex, referring to NF-κB, PI3K/Akt/MAPK, p53, mitochondrial-mediated signaling pathway, oxidative stress signaling pathway, and so on. However, to some extent, its clinical application is limited by its poor water solubility and low bioavailability. Even more, rhein has potential liver and kidney toxicity. Therefore, in this paper, the pharmacological effects of rhein and its mechanism, pharmacokinetics, and safety studies were reviewed, in order to provide reference for the development and application of rhein.

Erianin inhibits human lung cancer cell growth via PI3K/Akt/mTOR pathway in vitro and in vivo.

Erianin is a small-molecule compound that is isolated from Dendrobium chrysotoxum Lindl. In recent years, it has been found to have evident antitumor activity in various cancers, such as bladder cancer, cervical cancer, and nasopharyngeal carcinoma. In this study, we assessed the effect of erianin on lung cancer in terms of cell growth inhibition and the related mechanism. First, erianin at a concentration of less than 1 nmol/L exhibited cytotoxicity in H1975, A549, LLC lung cancer cells, did not cause marked growth inhibition in normal lung and kidney cells, induced obvious apoptosis and G2/M phase arrest of cells, and inhibited the migration and invasion of lung cancer cells in vitro. Second, in a mouse xenograft model of lewis lung cancer (LLC), oral administration of erianin (50, 35, and 10 mg kg-1  day-1 for 12 days) substantially inhibited nodule growth, reduced the fluorescence counts of lewis cells and the percentage vascularity of tumor tissues, increased the number of apoptotic tumor cells, the thymus indices, up-regulated the levels of interleukin (IL)-2 and tumor necrosis factor-α (TNF-α), decreased IL-10 levels and the spleen index, and enhanced immune function. Lastly, the possible targets of erianin were determined by molecular docking and verified via western blot assay. The results indicated that erianin may achieve the above effects via inhibiting the phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway in vitro and vivo. Taken together, the results showed that erianin had obvious antitumor effects via inhibiting the PI3K/Akt/mTOR pathway in vitro and vivo and may have potential clinical value for the treatment of lung cancer.