Cardioprotective Effects of 20(S)-Ginsenoside Rh2 against Doxorubicin-Induced Cardiotoxicity In Vitro and In Vivo

Role of Oxidative Stress and Inflammation in Doxorubicin-Induced Cardiotoxicity: A Brief Account

Cardiotoxicity is the main side effect of several chemotherapeutic drugs. Doxorubicin (Doxo) is one of the most used anthracyclines in the treatment of many tumors, but the development of acute and chronic cardiotoxicity limits its clinical usefulness. Different studies focused only on the effects of long-term Doxo administration, but recent data show that cardiomyocyte damage is an early event induced by Doxo after a single administration that can be followed by progressive functional decline, leading to overt heart failure. The knowledge of molecular mechanisms involved in the early stage of Doxo-induced cardiotoxicity is of paramount importance to treating and/or preventing it. This review aims to illustrate several mechanisms thought to underlie Doxo-induced cardiotoxicity, such as oxidative and nitrosative stress, inflammation, and mitochondrial dysfunction. Moreover, here we report data from both in vitro and in vivo studies indicating new therapeutic strategies to prevent Doxo-induced cardiotoxicity.

Natural Products for Preventing and Managing Anthracycline-Induced Cardiotoxicity: A Comprehensive Review

Doxorubicin (DOX) is an anthracycline anticancer agent that is highly effective in the treatment of solid tumors. Given the multiplicity of mechanisms involved in doxorubicin-induced cardiotoxicity, it is difficult to identify a precise molecular target for toxicity. The findings of a literature review suggest that natural products may offer cardioprotective benefits against doxorubicin-induced cardiotoxicity, both in vitro and in vivo. However, further confirmatory studies are required to substantiate this claim. It is of the utmost importance to direct greater attention towards the intricate signaling networks that are of paramount importance for the survival and dysfunction of cardiomyocytes. Notwithstanding encouraging progress made in preclinical studies of natural products for the prevention of DOX-induced cardiotoxicity, these have not yet been translated for clinical use. One of the most significant obstacles hindering the development of cardioprotective adjuvants based on natural products is the lack of adequate bioavailability in humans. This review presents an overview of current knowledge on doxorubicin DOX-induced cardiotoxicity, with a focus on the potential benefits of natural compounds and herbal preparations in preventing this adverse effect. As literature search engines, the browsers in the Scopus, PubMed, Web of Science databases and the ClinicalTrials.gov register were used.

Protective effects of Panax ginseng as a medical food against chemical toxic agents: molecular and cellular mechanisms

Humans are exposed to different types of toxic agents, which may directly induce organ malfunction or indirectly alter gene expression, leading to carcinogenic and teratogenic effects, and eventually death. Ginseng (Panax ginseng) is the most valuable of all medicinal herbs. Nevertheless, specific data on the antidotal mechanisms of this golden herb are currently unavailable. Based on the findings of in vitro, in vivo, and clinical studies, this review focused on the probable protective mechanisms of ginseng and its major components, such as protopanaxadiols, protopanaxatriols, and pentacyclic ginsenosides against various chemical toxic agents. Relevant articles from 2000 to 2023 were gathered from PubMed/Medline, Scopus, and Google Scholar. This literature review shows that P. ginseng and its main components have protective and antidotal effects against the deteriorative effects of pesticides, pharmaceutical agents, including acetaminophen, doxorubicin, isoproterenol, cyclosporine A, tacrolimus, and gentamicin, ethanol, and some chemical agents. These improvements occur through multi-functional mechanisms. They exhibit antioxidant activity, induce anti-inflammatory action, and block intrinsic and extrinsic apoptotic pathways. However, relevant clinical trials are necessary to validate the mentioned effects and translate the knowledge from basic science to human benefit, fulfilling the fundamental goal of all toxicologists.

20(S)-ginsenoside Rh2 inhibits angiotensin-2 mediated cardiac remodeling and inflammation associated with suppression of the JNK/AP-1 pathway

BACKGROUND

Enhanced levels of angiotensin-2 (Ang-II) causes hypertensive heart failure (HHF) through non-hemodynamical and hemodynamical alterations. 20(S)-ginsenoside Rh2 (20(S)-Rh2) is a natural ginseng compound with numerous cardiovascular benefits. This investigation elucidates the influence of 20(S)-Rh2 on Ang-II-induced heart failure and cardiac alterations.

METHODS

Ang-II was administered in C57BL/6 mice for 4 weeks to induce HHF. In the last 2 weeks of treatment, 20(S)-Rh2 was orally administered in mice to assess the potential 20(S)-Rh2 mechanism. Subsequently, RNA sequencing was carried out.

RESULTS

It was indicated that 20(S)-Rh2 suppresses myocardial fibrosis, hypertrophy, and inflammation, thereby inhibiting cardiac disruption in Ang-II-challenged mice without affecting blood pressure. According to the RNA sequencing data, this cardio-protective effect was linked with the (JNK)/AP 1 pathway. 20(S)-Rh2 alleviated heart tissue and cardiomyocytes inflammation by inhibiting the Ang-II-mediated JNK/AP-1 pathway. Within cardiomyocytes, JNK or AP-1 absence abolished the anti-inflammatory effects of 20(S)-Rh2.

CONCLUSION

This study investigation indicated that 20(S)-Rh2 prevents cardiovascular dysfunction induced by Ang-II induced by decreasing JNK-regulated inflammatory responses, providing evidence for its use as an efficient regimen for HHF.

Systematic analysis of the material basis and mechanism of total saponins of mountain cultivated ginseng against doxorubicin-induced cardiotoxicity based on integrating network pharmacology and in vivo substance profiling

INTRODUCTION

Doxorubicin-induced cardiotoxicity (DIC) is a serious obstacle to oncologic treatment. Mountain cultivated ginseng (MCG) exhibits stronger pharmacological effects than cultivated ginseng (CG) mainly due to the differences in ginsenosides. However, the material basis and the underlying mechanism of the protective effects of total saponins of MCG (TSMCG) against DIC are unclear.

OBJECTIVES

We aimed to elucidate the material basis and the pharmacodynamic effects of TSMCG on DIC as well as the underlying mechanisms.

METHODS

To comprehensively analyze the effective substances, the chemical components of TSMCG and their prototypes or metabolites in vivo were characterized through UHPLC/Q-TOF-MS. Then, an absorbed component-target-disease network was established to explore the mechanisms underlying the protective effects of TSMCG against DIC. H9c2 cells were employed for pharmacodynamic assays. The mechanism was verified by Western blot and molecular docking simulations.

RESULTS

A total of 56 main ginsenosides were identified in TSMCG, including 27 ginsenosides of PPD type, 15 ginsenosides of PPT type, two ginsenosides of OA types, and 12 ginsenosides of other types. Moreover, 55 ginsenoside prototypes or metabolites in vivo were tentatively characterized. Ginsenoside Ra1 , a differential compound between MCG and CG, could be metabolized by oxidation and deglycosylation. Network pharmacology showed that AKT1, p53, and STAT3 are core targets of 62 intersecting genes. Molecular docking results indicated that most of the ginsenosides have favorable affinity with these core targets. After doxorubicin exposure, TSMCG could increase cell viability and inhibit apoptosis in a dose-dependent manner.

CONCLUSION

Our work reveals a novel comprehensive strategy to study the material basis of the protective effects of TSMCG against DIC and the underlying mechanisms through integrating in vivo substance identification, metabolic profiling, network pharmacology, pharmacodynamic evaluation, and mechanism verification.

Mitochondrial dysfunction at the crossroad of cardiovascular diseases and cancer

A large body of evidence indicates the existence of a complex pathophysiological relationship between cardiovascular diseases and cancer. Mitochondria are crucial organelles whose optimal activity is determined by quality control systems, which regulate critical cellular events, ranging from intermediary metabolism and calcium signaling to mitochondrial dynamics, cell death and mitophagy. Emerging data indicate that impaired mitochondrial quality control drives myocardial dysfunction occurring in several heart diseases, including cardiac hypertrophy, myocardial infarction, ischaemia/reperfusion damage and metabolic cardiomyopathies. On the other hand, diverse human cancers also dysregulate mitochondrial quality control to promote their initiation and progression, suggesting that modulating mitochondrial homeostasis may represent a promising therapeutic strategy both in cardiology and oncology. In this review, first we briefly introduce the physiological mechanisms underlying the mitochondrial quality control system, and then summarize the current understanding about the impact of dysregulated mitochondrial functions in cardiovascular diseases and cancer. We also discuss key mitochondrial mechanisms underlying the increased risk of cardiovascular complications secondary to the main current anticancer strategies, highlighting the potential of strategies aimed at alleviating mitochondrial impairment-related cardiac dysfunction and tumorigenesis. It is hoped that this summary can provide novel insights into precision medicine approaches to reduce cardiovascular and cancer morbidities and mortalities.

Targeting the NRF2/KEAP1 pathway in cervical and endometrial cancers

Cervical and endometrial cancers are among the most dangerous gynaecological malignancies, with high fatality and recurrence rates due to frequent diagnosis at an advanced stage and chemoresistance onset. The NRF2/KEAP1 signalling pathway plays an important role in protecting cells against oxidative damage due to increased reactive oxygen species (ROS) levels. NRF2, activated by ROS, induces the expression of antioxidant enzymes such as heme oxygenase, catalase, glutathione peroxidase and superoxide dismutase which neutralize ROS, protecting cells against oxidative stress damage. However, activation of NRF2/KEAP1 signalling in cancer cells results in chemoresistance, inactivating drug-mediated oxidative stress and protecting cancer cells from drug-induced cell death. We review the literature on the role of the NRF2/KEAP1 pathway in cervical and endometrial cancers, with a focus on the expression of its components and downstream genes. We also examine the role of the NRF2/KEAP1 pathway in chemotherapy resistance and how this pathway can be modulated by natural and synthetic modulators.

The role of ginseng derivatives against chemotherapy-induced cardiotoxicity: A systematic review of non-clinical studies

Aims

Although chemotherapy agents are used to treating cancers, they have serious side effects, like their harmful effects on the cardiovascular system, limiting the clinical use of these chemotherapy agents. This study aimed to systematically investigate the potential role of ginseng derivatives in the prevention of chemotherapy-induced cardiac toxicity.

Methods

This systematic review was performed according to PRISMA guidelines strategy in databases till August 2022. First, identify studies related to using search terms in titles and abstracts. After studying and screening 209 articles, 16 articles were selected in this study according to our inclusion and exclusion criteria.

Results

According to the findings of this study, ginseng derivatives showed significant changes in biochemical, histological, and heart weight loss, as well as a reduction in mortality, which occurred in the groups treated with chemotherapy agents compared to the control groups. Co-administration of ginseng derivatives with chemotherapy agents inhibited or reversed these changes to near-moderate levels. The protective effects of ginseng derivatives can be due to their anti-inflammatory, anti-oxidant, and anti-apoptotic action.

Conclusion

This systematic review shows evidence that concomitant administration of ginseng derivatives improves chemotherapy-induced cardiac toxicity. However, for better conclusions about the practical mechanisms of ginseng derivatives in reducing the cardiac toxic effects of chemotherapy agents and evaluating the efficacy and safety of the compound simultaneously, it is necessary to design comprehensive studies.

Facile approach for surfactant-free synthesis of Au@ginsenoside Rh2 nanoparticles and researches on anticancer activity

Background

Inorganic nanocomposites especially Au nanostructures have exhibited outstanding physicochemical properties in biomedical fields. For further clinical applications on theranostics, especially drug delivery, numerous explorations of green and facile synthesis methods combining with pharmacoactive natural components have been investigated to construct safe and multifunctional bioactive Au nanoparticles (NPs). Ginsenoside Rh2 is protopanaxadiol type compound isolated from plants of genus Panax, with excellent anticancer effect and antioxidant activity. In this research, we prepared the novel Au nanoparticles using ginsenoside Rh2 as both reducing and stabilizing agents.

Results

The synthesized Au@ginsenoside Rh2 NPs were proved to exhibit desirable inhibitory effect on different cancer cell lines, which benefited from the inherent anticancer effect of the ginsenoside Rh2. Investigations in vitro indicated that Au@ginsenoside Rh2 NPs inhibited cell proliferation, cell migration and invasion, induced cell cycle arrest, enhanced the reactive oxygen species (ROS) generation, and regulated the protein expressions of caspase-3, 8, 9 to trigger cell apoptosis as well.

Conclusions

Because of the absence of toxic chemical surfactants, the eco-friendly synthesis method of Au NPs modified by natural phytochemicals avoided tedious separation and modification processes. On the other hand, Au@ginsenoside Rh2 NPs also improved water solubility and bioavailability of the hydrophobic drug ginsenoside Rh2. It broadened minds for preparation and application of traditional Chinese medicines (TCMs) modified metal nanoparticles and deserved further study.

Progress on the efficacy and mechanism of action of panax ginseng monomer saponins treat toxicity

As a traditional Chinese herbal medicine, Panax ginseng C. A. Meyer (PG) has preventive and therapeutic effects on various diseases. Ginsenosides are main active ingredients of PG and have good pharmacological effects. Due to the diversity of chemical structures and physicochemical properties of ginsenosides, Currently, related studies on PG monomer saponins are mainly focused on the cardiovascular system, nervous system, antidiabetic, and antitumor. There are few types of research on the toxin treatment, predominantly exogenous toxicity. PG and its monomer ginsenosides are undoubtedly a practical option for treating exogenous toxicity for drug-induced or metal-induced side effects such as nephrotoxicity, hepatotoxicity, cardiotoxicity, metal toxicity and other exogenous toxicity caused by drugs or metals. The mechanism focuses on antioxidant, anti-inflammatory, and anti-apoptotic, as well as modulation of signaling pathways. It summarized the therapeutic effects of ginseng monomer saponins on exogenous toxicity and demonstrated that ginsenosides could be used as potential drugs to treat exogenous toxicity and reduce drug toxicities.

Saponins and their derivatives: Potential candidates to alleviate anthracycline-induced cardiotoxicity and multidrug resistance

Anthracyclines (ANTs) continue to play an irreplaceable role in oncology treatment. However, the clinical application of ANTs has been limited. In the first place, ANTs can cause dose-dependent cardiotoxicity such as arrhythmia, cardiomyopathy, and congestive heart failure. In the second place, the development of multidrug resistance (MDR) leads to their chemotherapeutic failure. Oncology cardiologists are urgently searching for agents that can both protect the heart and reverse MDR without compromising the antitumor effects of ANTs. Based on in vivo and in vitro data, we found that natural compounds, including saponins, may be active agents for other both natural and chemical compounds in the inhibition of anthracycline-induced cardiotoxicity (AIC) and the reversal of MDR. In this review, we summarize the work of previous researchers, describe the mechanisms of AIC and MDR, and focus on revealing the pharmacological effects and potential molecular targets of saponins and their derivatives in the inhibition of AIC and the reversal of MDR, aiming to encourage future research and clinical trials.

In-silico efficacy of potential phytomolecules from Ayurvedic herbs as an adjuvant therapy in management of COVID-19

The recent COVID-19 outbreak caused by SARS-CoV-2 virus has sparked a new spectrum of investigations, research and studies in multifarious directions. Efforts are being made around the world for discovery of effective vaccines/drugs against COVID-19. In this context, Ayurveda, an alternative traditional system of medicine in India may work as an adjuvant therapy in compromised patients. We selected 40 herbal leads on the basis of their traditional applications. The phytomolecules from these leads were further screened through in-silico molecular docking against two main targets of SARS-CoV-2 i.e. the spike protein (S; structural protein) and the main protease (MPRO; non-structural protein). Out of the selected 40, 12 phytomolecules were able to block or stabilize the major functional sites of the main protease and spike protein. Among these, Ginsenoside, Glycyrrhizic acid, Hespiridin and Tribulosin exhibited high binding energy with both main protease and spike protein. Etoposide showed good binding energy only with Spike protein and Teniposide had high binding energy only with main protease. The above phytocompounds showed promising binding efficiency with target proteins indicating their possible applications against SARS-CoV-2. However, these findings need to be validated through in vitro and in vivo experiments with above mentioned potential molecules as candidate drugs for the management of COVID-19. In addition, there is an opportunity for the development of formulations through different permutations and combinations of these phytomolecules to harness their synergistic potential.

Panax ginseng and its ginsenosides: potential candidates for the prevention and treatment of chemotherapy-induced side effects

Chemotherapy-induced side effects affect the quality of life and efficacy of treatment of cancer patients. Current approaches for treating the side effects of chemotherapy are poorly effective and may cause numerous harmful side effects. Therefore, developing new and effective drugs derived from natural non-toxic compounds for the treatment of chemotherapy-induced side effects is necessary. Experiments in vivo and in vitro indicate that Panax ginseng (PG) and its ginsenosides are undoubtedly non-toxic and effective options for the treatment of chemotherapy-induced side effects, such as nephrotoxicity, hepatotoxicity, cardiotoxicity, immunotoxicity, and hematopoietic inhibition. The mechanism focus on anti-oxidation, anti-inflammation, and anti-apoptosis, as well as the modulation of signaling pathways, such as nuclear factor erythroid-2 related factor 2 (Nrf2)/heme oxygenase-1 (HO-1), P62/keap1/Nrf2, c-jun N-terminal kinase (JNK)/P53/caspase 3, mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinases (ERK), AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR), mitogen-activated protein kinase kinase 4 (MKK4)/JNK, and phosphatidylinositol 3-kinase (PI3K)/AKT. Since a systemic review of the effect and mechanism of PG and its ginsenosides on chemotherapy-induced side effects has not yet been published, we provide a comprehensive summarization with this aim and shed light on the future research of PG.

Inhibitory effects of Panax ginseng glycoproteins in models of doxorubicin-induced cardiac toxicity in vivo and in vitro

Doxorubicin (DOX) is an effective antineoplastic drug; however, its clinical application is limited owing to the side effect of fatal heart dysfunction on its use. Panax ginseng glycoproteins have antioxidant, antiapoptotic, and anti-inflammatory properties. Thus, the aim of this study was to investigate the effects and possible action mechanisms of P. ginseng glycoproteins against DOX-induced cardiotoxicity. To this end, we used an in vitro model of DOX-treated H9C2 cells and an in vivo model of DOX-treated rats. We found that P. ginseng glycoproteins markedly increased H9C2 cell viability, decreased creatine kinase and lactate dehydrogenase levels, and improved histopathological and electrocardiogram changes in rats, protecting them from DOX-induced cardiotoxicity. Furthermore, P. ginseng glycoproteins significantly inhibited myocardial oxidative insult through adjusting the intracellular ROS, MDA, SOD, and GSH levels in vitro and in vivo. In conclusion, our data suggest that P. ginseng glycoproteins alleviated DOX-induced myocardial oxidative stress-related cardiotoxicity. This natural product could be developed as a new candidate for alleviating DOX-induced cardiotoxicity.

Protective Effect of Pyxinol, One Active Ingredient of Lichenes on Cisplatin-Induced Nephrotoxicity via Ameliorating DNA Damage Response

Background: Cisplatin is a valuable chemotherapeutic agent against malignant tumors. However, the clinical use of cisplatin is limited by its side effects such as renal injury. Pyxinol is an active constituent of Lichenes and its effects on cisplatin-induced nephrotoxicity is currently unknown. This study aims to examine the potential protective effects of pyxinol on cisplatin-induced renal injury and explore the underlying mechanisms.

Methods:In vivo rat model of cisplatin-induced nephrotoxicity was induced by intraperitoneal (i.p) administration of cisplatin. The blood urea nitrogen and creatinine levels were measured and renal histological analysis was conducted to evaluate the renal function; The TUNEL staining, western blotting and real-time PCR assays were conducted to examine related molecular changes. Finally, the in vivo anti-tumor efficacy was examined in the xenograft tumor model using nude mice.

Results: Pretreatment with pyxinol attenuated cisplatin-induced increase in blood urea nitrogen, creatinine and urinary protein excretion and the magnitude of injury in the renal tubules. Pyxinol ameliorated the activation of p53 via attenuating the DNA damage response, which then attenuated the tubular cell apoptosis. Finally, pyxinol could potentiate the in vivo anti-tumor efficacy of cisplatin against the xenograft tumor of cervical cancer cells in nude mice.

Conclusions: Combining pyxinol with cisplatin could alleviate cisplatin-induced renal injury without decreasing its therapeutic efficacy, which might represent a beneficial adjunct therapy for cisplatin-based chemotherapeutic regimens in the clinic.

Benazepril hydrochloride protects against doxorubicin cardiotoxicity by regulating the PI3K/Akt pathway

Doxorubicin (DOX) stimulates the generation of reactive oxygen species, thereby impairing mitochondrial functions. Angiotensin-converting enzyme inhibitors (ACEIs) have been identified to exhibit protective effects on cardiovascular diseases. The present study aimed to test the hypothesis that an ACEI benazepril hydrochloride (HCl) may protect against DOX-induced cardiotoxicity. The DOX injury model was established using rat embryonic cardiac myoblast cells (H9c2 cell line) treated with DOX in vitro. H9c2 cells were treated with benazepril-HCl, DOX or a mixture of DOX and benazepril-HCl to measure the activities of myocardial enzymes including lactate dehydrogenase (LDH), superoxide dismutase, catalase and glutathione peroxidase, in addition to the concentration of malondialdehyde in the culture medium. Cells without any treatment were used as a control. DOX treatment increased the levels of activity of myocardial enzymes in H9c2 cells compared with those in the untreated control cells. Additionally, co-treatment with benazepril-HCl significantly reduced the levels of apoptosis occurring due to DOX-mediated cellular damage. The mechanistic experiment revealed that pretreatment with benazepril-HCl counteracted the DOX-induced oxidative stress and suppressed the activation of apoptosis via the PI3K/Akt signaling pathway. By contrast, an Akt inhibitor (MK2206) inhibited the protective effects of benazepril-HCl against DOX-induced H9c2 cell injury, as revealed by increased LDH release in H9c2 cells. These results suggested that benazepril-HCl may potentially be administered as an adjuvant for DOX in long-term clinical use.

Carbon nanomaterials for cardiovascular theranostics: Promises and challenges

Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Heart attack and stroke cause irreversible tissue damage. The currently available treatment options are limited to "damage-control" rather than tissue repair. The recent advances in nanomaterials have offered novel approaches to restore tissue function after injury. In particular, carbon nanomaterials (CNMs) have shown significant promise to bridge the gap in clinical translation of biomaterial based therapies. This family of carbon allotropes (including graphenes, carbon nanotubes and fullerenes) have unique physiochemical properties, including exceptional mechanical strength, electrical conductivity, chemical behaviour, thermal stability and optical properties. These intrinsic properties make CNMs ideal materials for use in cardiovascular theranostics. This review is focused on recent efforts in the diagnosis and treatment of heart diseases using graphenes and carbon nanotubes. The first section introduces currently available derivatives of graphenes and carbon nanotubes and discusses some of the key characteristics of these materials. The second section covers their application in drug delivery, biosensors, tissue engineering and immunomodulation with a focus on cardiovascular applications. The final section discusses current shortcomings and limitations of CNMs in cardiovascular applications and reviews ongoing efforts to address these concerns and to bring CNMs from bench to bedside.

Doxorubicin-induced cardiotoxicity: An update on the molecular mechanism and novel therapeutic strategies for effective management

Doxorubicin (Dox) is a secondary metabolite of the mutated strain of Streptomyces peucetius var. Caesius and belongs to the anthracyclines family. The anti-cancer activity of Dox is mainly exerted through the DNA intercalation and inhibiting topoisomerase II enzyme in fast-proliferating tumors. However, Dox causes cumulative and dose-dependent cardiotoxicity, which results in increased risks of mortality among cancer patients and thus limiting its wide clinical applications. There are several mechanisms has been proposed for doxorubicin-induced cardiotoxicity and oxidative stress, free radical generation and apoptosis are most widely reported. Apart from this, other mechanisms are also involved in Dox-induced cardiotoxicity such as impaired mitochondrial function, a perturbation in iron regulatory protein, disruption of Ca²⁺ homeostasis, autophagy, the release of nitric oxide and inflammatory mediators and altered gene and protein expression that involved apoptosis. Dox also causes downregulation of DNA methyltransferase 1 (DNMT1) enzyme activity which leads to a reduction in the DNA methylation process. This hypomethylation causes dysregulation in the mitochondrial genes like peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1-alpha (PGC-1α), nuclear respiratory factor 1 (NRF-1) and mitochondrial transcription factor A (TFAM) unit in the heart. Apart from DNA methylation, Dox treatment also alters the micro RNAs levels and histone deacetylase (HDAC) activity. Therefore, in the current review, we have provided a detailed update on the current understanding of the pathological mechanisms behind the well-known Dox-induced cardiotoxicity. Further, we have provided some of the most plausible pharmacological strategies which have been tested against Dox-induced cardiotoxicity.

Enhanced production of ginsenoside Rh2(S) from PPD-type major ginsenosides using BglSk cloned from Saccharibacillus kuerlensis together with two glycosidase in series

Background

Ginsenoside Rh2(S) is a promising compound for the prevention of various kinds of cancers, inflammation, and diabetes. However, due to its low concentration (<0.02%), researchers are still trying to find an efficient glycoside hydrolase for the scaled-up production of Rh2(S).

Method

Three glycoside hydrolases (BglBX10, Abf22-3, and BglSk) were cloned in Escherichia coli BL21 (DE3) and the expressed recombinant enzyme was used for the scaled-up production of Rh2(S) through the conversion of PPD-type (protopanaxadiol) major ginsenosides (Rb1, Rc, and Rd, except Rb2) extracted from Korean red ginseng. Specific and specialized bioconversion pathways were designed that evolved the initial bioconversion of PPD-mix → Rg3(S) → Rh2(S). The reaction was started with 50 mg/mL of PPD-mix, 20 mg/mL of BglBX10, Abf22-3, and BglSk in series, respectively. The process was completed in a 10 L jar fermenter with a 5 L working volume at 37 °C for 48 hrs.

Results

The designed bioconversion pathways show that Abf22-3 and BglBX10 were responsible for the conversion of Rb1, Rc and Rd → Rg3(S), and then Rg3(S) was completely transformed to Rh2(S) by BglSk. As a result, 15.1 g of ginsenoside Rh2(S) with 98.0 ± 0.2% purity was obtained after strict purification using the Prep-HPLC system with a 100 φ diameter column. Additionally, BglSk was also investigated for its production activity with seven different kinds of PPD-mix type ginsenosides.

Conclusion

Our pilot data demonstrate that BglSk is a suitable enzyme for the gram unit production of ginsenoside Rh2(S) at the industrial level.

The Role of Reactive Oxygen Species in Tumor Treatment and its Impact on Bone Marrow Hematopoiesis

Reactive oxygen species (ROS), an important molecule inducing oxidative stress in organisms, play a key role in tumorigenesis, tumor progression and recurrence. Recent findings on ROS have shown that ROS can be used to treat cancer as they accelerate the death of tumor cells. At present, pro-oxidant drugs that are intended to increase ROS levels of the tumor cells have been widely used in the clinic. However, ROS are a double-edged sword in the treatment of tumors. High levels of ROS induce not only the death of tumor cells but also oxidative damage to normal cells, especially bone marrow hemopoietic cells, which leads to bone marrow suppression and (or) other side effects, weak efficacy of tumor treatment and even threatening patients' life. How to enhance the killing effect of ROS on tumor cells while avoiding oxidative damage to the normal cells has become an urgent issue. This study is a review of the latest progress in the role of ROS-mediated programmed death in tumor treatment and prevention and treatment of oxidative damage in bone marrow induced by ROS.

Novel ginsenoside derivative 20(S)-Rh2E2 suppresses tumor growth and metastasis in vivo and in vitro via intervention of cancer cell energy metabolism

Increased energy metabolism is responsible for supporting the abnormally upregulated proliferation and biosynthesis of cancer cells. The key cellular energy sensor AMP-activated protein kinase (AMPK) and the glycolytic enzyme alpha-enolase (α-enolase) have been identified as the targets for active components of ginseng. Accordingly, ginseng or ginsenosides have been demonstrated with their potential values for the treatment and/or prevention of cancer via the regulation of energy balance. Notably, our previous study demonstrated that the R-form derivative of 20(R)-Rh2, 20(R)-Rh2E2 exhibits specific and potent anti-tumor effect via suppression of cancer energy metabolism. However, the uncertain pharmacological effect of S-form derivative, 20(S)-Rh2E2, the by-product during the synthesis of 20(R)-Rh2E2 from parental compound 20(R/S)-Rh2 (with both R- and S-form), retarded the industrialized production, research and development of this novel effective candidate drug. In this study, 20(S)-Rh2E2 was structurally modified from pure 20(S)-Rh2, and this novel compound was directly compared with 20(R)-Rh2E2 for their in vitro and in vivo antitumor efficacy. Results showed that 20(S)-Rh2E2 effectively inhibited tumor growth and metastasis in a lung xenograft mouse model. Most importantly, animal administrated with 20(S)-Rh2E2 up to 320 mg/kg/day survived with no significant body weight lost or observable toxicity upon 7-day treatment. In addition, we revealed that 20(S)-Rh2E2 specifically suppressed cancer cell energy metabolism via the downregulation of metabolic enzyme α-enolase, leading to the reduction of lactate, acetyl-coenzyme (acetyl CoA) and adenosine triphosphate (ATP) production in Lewis lung cancer cells (LLC-1), but not normal cells. These findings are consistent to the results obtained from previous studies using a similar isomer 20(R)-Rh2E2. Collectively, current results suggested that 20(R/S)-Rh2E2 isomers could be the new and safe anti-metabolic agents by acting as the tumor metabolic suppressors, which could be generated from 20(R/S)-Rh2 in industrialized scale with low cost.

Increase in Protective Effect of Panax vietnamensis by Heat Processing on Cisplatin-Induced Kidney Cell Toxicity

Cisplatin is a platinum-based anticancer agent used for treating a wide range of solid cancers. One of the side effects of this drug is its severe nephrotoxicity, limiting the safe dose of cisplatin. Therefore, many natural products have been studied and applied to attenuate the toxicity of this compound. In this study, we found that steamed Vietnamese ginseng (Panax vietnamensis) could significantly reduce the kidney damage of cisplatin in an in vitro model using porcine proximal tubular LLC-PK1 kidney cells. From processed ginseng under optimized conditions (120 °C, 12 h), we isolated seven compounds (20(R,S)-ginsenoside Rh2, 20(R,S)-ginsenoside Rg3, ginsenoside Rk1, ginsenoside-Rg5, and ocotillol genin) that showed kidney-protective potential against cisplatin toxicity. By comparing the 50% recovery concentration (RC₅₀), the R form of ginsenoside, Rh2 and Rg3, had RC₅₀ values of 6.67 ± 0.42 µM and 8.39 ± 0.3 µM, respectively, while the S forms of ginsenoside, Rh2 and Rg3, and Rk1, had weaker protective effects, with RC₅₀ ranging from 46.15 to 88.4 µM. G-Rg5 and ocotillol, the typical saponin of Vietnamese ginseng, had the highest RC₅₀ (180.83 ± 33.27; 226.19 ± 66.16, respectively). Our results suggest that processed Vietnamese gingseng (PVG), as well as those compounds, has the potential to improve kidney damage due to cisplatin toxicity.

Ginsenoside Rb3 exerts protective properties against cigarette smoke extract-induced cell injury by inhibiting the p38 MAPK/NF-κB and TGF-β1/VEGF pathways in fibroblasts and epithelial cells

Cigarette smoke causes many adverse effects such as inflammation, oxidative stress, and excessive accumulation of the extracellular matrix (ECM). Ginsenoside Rb3 has anti-inflammatory and anti-oxidative effects, which may contribute to delaying the injury caused by cigarette smoke. In this study, we used cigarette smoke extract (CSE) to establish cell injury models in WI-38 human fetal lung fibroblasts and 16HBE human bronchial epithelial cells. Our results showed that Rb3 protected against CSE-induced cytotoxicity in both cell lines. In addition, it significantly inhibited the secretion of inflammatory factors, such as interleukin-8 and tumor necrosis factor alpha, by inhibiting the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB). Moreover, Rb3 pre-treatment led to an increase in the levels of glutathione (GSH) and activities of superoxide dismutase, glutathione peroxidase (GSH-Px), and catalase to reduce the oxidative stress induced by CSE. Additionally, Rb3 decreased the levels of ECM proteins including collagen I (Col I), Col III, and elastin after CSE treatment by inhibiting the expression of transforming growth factor beta 1 (TGF-β1)-induced vascular endothelial growth factor (VEGF). Our findings suggest that Rb3 prevented CSE-induced inflammation and oxidative stress as well as the excessive accumulation of ECM in WI-38 and 16HBE cells to protect against cell injury by inhibiting the p38 MAPK/NF-κB and TGF-β1/VEGF pathways. The results of this study may be valuable for the development of Rb3 to combat the damage caused by cigarette smoke.

A complex micellar system co-delivering curcumin with doxorubicin against cardiotoxicity and tumor growth

Background

Dose-dependent irreversible cardiac toxicity of doxorubicin (DOX) becomes a major obstacle for the clinical use. Nowadays much attention is being paid to combination therapy with DOX and antioxidant agents, which would improve the clinical efficacy by protecting from cardiotoxicity along with the maintained performance as an antitumor drug. With the assistance of nanoscience and polymer engineering, herein a complex polymeric micellar system was developed for co-loading DOX and a premium natural antioxidant curcumin (CUR), and we investigated whether this new formulation for DOX delivery could achieve such a goal.

Methods

The dually loaded micelles co-encapsulating DOX and CUR (CPMDC) were prepared through thin-film rehydration by using the amphiphilic diblock copolymer monomethoxy poly(ethylene glycol) (mPEG)–poly(ε-caprolactone) (PCL)–N-t-butoxycarbonyl-phenylalanine (BP) synthesized by end-group modification of mPEG–PCL with BP. Quantitative analysis was conducted by HPLC methods for drugs in micelles or biosamples. Molecular dynamics simulation was performed using HyperChem software to illustrate interactions among copolymer and active pharmaceutical ingredients. The safety and antitumor efficacy were evaluated by in vitro viability of H9C2 cells, and tumor growth inhibition in tumor-bearing mice respectively. The protection effects against DOX-induced cardiotoxicity were investigated according to several physiological, histopathological and biochemical markers concerning systemic and cardiac toxicity.

Results

CPMDC were obtained with favorable physicochemical properties meeting the clinical demand, including uniform particle size, fairly high encapsulation efficiency and drug loadings, as well as good drug release profiles and colloidal stability. The result from molecular dynamics simulation indicated a great impact of the interactions among copolymer and small molecules on the ratiometrical co-encapsulation of both drugs. MTT assay of in vitro H9C2 cells viability demonstrated good safety of the CPMDC formulation, which also showed definite signs of decrease in xenograft tumor growth. The studies on pharmacokinetics and tissue distribution further revealed that DOX delivered by CPMDC could result in prolonged systemic circulation and increased DOX accumulation in tumor but decreased level of the toxic metabolite doxorubicinol in heart tissue compared to free DOX alone or the cocktail combination.

Conclusion

The findings from present study substantiated that such a complex micellar system codelivering DOX with CUR does produce the effect of killing two birds with one stone via distinctive nanocarrier-modified drug-drug interactions.

Ginsenoside Drug Nanocomposites Prepared by the Aerosol Solvent Extraction System for Enhancing Drug Solubility and Stability

Ginsenosides are the pharmacologically active constituents of ginseng. So far, more than 30 ginsenosides have been identified and widely used in pharmaceutical formulations. However, the therapeutic applications of ginsenosides are hampered by their poor solubility and low bioavailability. In this study, we selected two of the most important ginsenosides-Re and Rh₂ as model drugs to prepare ginsenoside drug nanocomposites (NanoGS) using the simple aerosol solvent extraction system (ASES) technique to address the poor solubility and bioavailability of these compounds. Compared with raw ginsenosides, NanoGS exhibited significantly enhanced dissolution rate owing to their low crystallinity and high surface area. Furthermore, in vitro cellular investigations showed that NanoGS-Rh₂ exhibited outstanding anticancer activity against MCF-7 cancer cells. Therefore, this study is expected to provide a promising strategy that could optimize and broaden the applications of ginsenosides, as well as other water-insoluble drugs in pharmaceutical formulations.

L-Theanine Protects H9C2 Cells from Hydrogen Peroxide-Induced Apoptosis by Enhancing Antioxidant Capability

BACKGROUND L-theanine is a non-protein amino acid in green tea, and its hepatoprotection and neuroprotection have been verified. However, whether L-theanine can prevent cardiomyocytes from apoptosis is unclear yet. This study evaluated the protective effects of L-theanine on H2O2-induced heart injury in vitro. MATERIAL AND METHODS The certified H9C2 cells were pretreated with L-theanine (0 mM, 4 mM, 8 mM, and 16 mM) for 24 h, followed by 160 µM H2O2 solution for 4 h. The cell viability and antioxidant indices were assayed. Quantitative evaluation of apoptosis was performed by flow cytometric analysis. Nuclear morphology of the cells was monitored by 4',6-diamidino-2-phenylindole staining. Expression of Caspase-3, poly ADP-ribose polymerase (PARP), c-Jun N-terminal kinase (JNK), and mitogen-activated protein kinase p38 was assayed by Western blot. RESULTS Compared to the H2O2 treatment, all doses of L-theanine treatments increased the cell viability, glutathione level, and the activities of glutathione peroxidase and superoxide dismutase (P<0.001). The contents of reactive oxygen species, nitric oxide, and oxidized glutathione were decreased by L-theanine treatments (P<0.001). Meanwhile, L-theanine treatments decreased the apoptosis ratio of H2O2-induced H9C2 cells (P<0.001). Pro-Caspase-3 expression was upregulated and cleavaged-PARP expression was inhibited by L-theanine (P<0.001). However, the phosphorylation of JNK and p38 was not affected by L-theanine treatments (P>0.05). CONCLUSIONS These data indicate that L-theanine pretreatment prevents H2O2-induced apoptosis in H9C2 cells, probably via antioxidant capacity improvement. Therefore, it might be a promising potential drug candidate for prophylaxis of ischemia/reperfusion-induced heart diseases.

Recent progress in doxorubicin-induced cardiotoxicity and protective potential of natural products

BACKGROUND

As an anthracycline antibiotic, doxorubicin (DOX) is one of the most potent and widely used chemotherapeutic agents for various types of solid tumors. Unfortunately, clinical application of this drug results in severe side effects of cardiotoxicity.

PURPOSE

We aim to review the research focused on elimination or reduction of DOX cardiotoxicity without affecting its anticancer efficacy by natural products.

METHODS

This study is based on pertinent papers that were retrieved by a selective search using relevant keywords in PubMed and ScienceDirect. The literature mainly focusing on natural products and herb extracts with therapeutic efficacies against experimental models both in vitro and in vivo was identified.

RESULTS

Current evidence revealed that multiple molecules and signaling pathways, such as oxidative stress, iron metabolism, and inflammation, are associated with DOX-induced cardiotoxicity. Based on these knowledge, various strategies were proposed, and thousands of compounds were screened. A number of natural products and herb extracts demonstrated potency in limiting DOX cardiotoxicity toward cultured cells and experimental animal models.

CONCLUSIONS

Though a panel of natural products and herb extracts demonstrate protective effects on DOX-induced cardiotoxicity in cells and animal models, their therapeutic potentials for clinical needs further investigation.

Oral administration of Ginsenoside Rg1 prevents cardiac toxicity induced by doxorubicin in mice through anti-apoptosis

Although Ginsenoside Rg1 has been reported to have protective cardiac effects, its effects on cardiac toxicity induced by doxorubicin needs to be studied. The present study investigated the effects of oral administration of Rg1 on the heart in mice treated with doxorubicin and found improved fractional shortening and ejection fraction of the heart and decreased cardiac apoptosis in mice treated with doxorubicin. The underlying mechanisms include increased phosphorylation of Akt and Erk by Rg1, increased ratio of Bcl-2 and Bax, and decreased release of cytochrome c from mitochondria, thereby protecting the heart from doxorubicin-induced apoptosis. This phenotype suggested that the oral administration of Rg1 may be a potential method preventing the cardiac toxicity caused by doxorubicin in clinical practice.

Ginsenoside Rh2 Improves Cardiac Fibrosis via PPARδ-STAT3 Signaling in Type 1-Like Diabetic Rats

Ginsenoside Rh2 (Rh2) is an active principal ingredient contained in ginseng (Panax ginseng Meyer), a medicinal herb used to enhance health worldwide. The present study is designed to investigate the effect of Rh2 on myocardial fibrosis in diabetic rats. In a streptozotocin-induced model of type-1 diabetic rats (STZ-diabetic rats), the increased fasting blood glucose levels and heart weight/body weight (HW/BW) ratio were substantially alleviated by Rh2. Moreover, Rh2 improved cardiac performance in STZ-diabetic rats. Histological results from Masson staining showed that Rh2 attenuated cardiac fibrosis in STZ-diabetic rats. The effects of Rh2 were reversed by GSK0660 at a dose sufficient to inhibit peroxisome proliferator-activated receptor δ (PPARδ) in STZ-diabetic rats. The role of PPARδ was subsequently investigated in vitro. Rh2 restored the decreased PPARδ expression level in high glucose-cultured cardiomyocytes. Moreover, increased protein levels of fibrotic signals, including signal transducer and activator of transcription 3 (STAT3), connective tissue growth factor (CCN2) and fibronectin, were reduced by Rh2 in high glucose-cultured cardiomyocytes. These effects of Rh2 were reversed by GSK0660 or siRNA specific for PPARδ Taken together, PPARδ activation may inhibit STAT3 activation to reduce CCN2 and fibronectin expression in diabetic rats with cardiac fibrosis. Moreover, Rh2 improves cardiac function and fibrosis by increasing PPARδ signaling. Therefore, Rh2 is suitable to develop as an alternative remedy for cardiac fibrosis.

Cardioprotective Potentials of Plant-Derived Small Molecules against Doxorubicin Associated Cardiotoxicity

Doxorubicin (DOX) is a potent and widely used anthracycline antibiotic for the treatment of several malignancies. Unfortunately, the clinical utility of DOX is often restricted due to the elicitation of organ toxicity. Particularly, the increased risk for the development of dilated cardiomyopathy by DOX among the cancer survivors warrants major attention from the physicians as well as researchers to develop adjuvant agents to neutralize the noxious effects of DOX on the healthy myocardium. Despite these pitfalls, the use of traditional cytotoxic drugs continues to be the mainstay treatment for several types of cancer. Recently, phytochemicals have gained attention for their anticancer, chemopreventive, and cardioprotective activities. The ideal cardioprotective agents should not compromise the clinical efficacy of DOX and should be devoid of cumulative or irreversible toxicity on the naïve tissues. Furthermore, adjuvants possessing synergistic anticancer activity and quelling of chemoresistance would significantly enhance the clinical utility in combating DOX-induced cardiotoxicity. The present review renders an overview of cardioprotective effects of plant-derived small molecules and their purported mechanisms against DOX-induced cardiotoxicity. Phytochemicals serve as the reservoirs of pharmacophore which can be utilized as templates for developing safe and potential novel cardioprotective agents in combating DOX-induced cardiotoxicity.

Ginseng Purified Dry Extract, BST204, Improved Cancer Chemotherapy-Related Fatigue and Toxicity in Mice

Cancer related fatigue (CRF) is one of the most common side effects of cancer and its treatments. A large proportion of cancer patients experience cancer-related physical and central fatigue so new strategies are needed for treatment and improved survival of these patients. BST204 was prepared by incubating crude ginseng extract with ginsenoside-β-glucosidase. The purpose of the present study was to examine the effects of BST204, mixture of ginsenosides on 5-fluorouracil (5-FU)-induced CRF, the glycogen synthesis, and biochemical parameters in mice. The mice were randomly divided into the following groups: the naïve normal (normal), the HT-29 cell inoculated (xenograft), xenograft and 5-FU treated (control), xenograft + 5-FU + BST204-treated (100 and 200 mg/kg) (BST204), and xenograft + 5-FU + modafinil (13 mg/kg) treated group (modafinil). Running wheel activity and forced swimming test were used for evaluation of CRF. Muscle glycogen, serum inflammatory cytokines, aspartic aminotransferase (AST), alanine aminotransferase (ALT), creatinine (CRE), white blood cell (WBC), neutrophil (NEUT), red blood cell (RBC), and hemoglobin (HGB) were measured. Treatment with BST204 significantly increased the running wheel activity and forced swimming time compared to the control group. Consistent with the behavioral data, BST204 markedly increased muscle glycogen activity and concentrations of WBC, NEUT, RBC, and HGB. Also, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), AST, ALT, and CRE levels in the serum were significantly reduced in the BST204-treated group compared to the control group. This result suggests that BST204 may improve chemotherapy-related fatigue and adverse toxic side effects.

The pseudoginsenoside F11 ameliorates cisplatin-induced nephrotoxicity without compromising its anti-tumor activity in vivo

The clinical use of cisplatin was severely limited by its associated nephrotoxicity. In this study, we investigated whether the pseudoginsenoside F11 had protective effects against cisplatin-induced nephrotoxicity. To clarify it, one in vivo model of cisplatin-induced acute renal failure was performed. The results showed that pretreatment with F11 reduced cisplatin-elevated blood urea nitrogen and creatinine levels, as well as ameliorated the histophathological damage. Further studies showed that F11 could suppress P53 activation, inverse the ratio of Bax/Bcl2 and the anti-oxidative and free radical levels induced by cisplatin, which in turn inhibited tubular cell apoptosis. Importantly, F11 enhanced rather than inhibited the anti-tumor activity of cispaltin in murine melanoma and Lewis lung cancer xenograft tumor models. Our findings suggested that administering F11 with cisplatin might alleviate the associated nephrotoxicity without compromising its therapeutic efficiency. This finding provides a novel potential strategy in the clinical treatment of cancer.

Angiotensin II protects cortical neurons against oxygen-glucose deprivation-induced injury in vitro

Ischemic cerebrovascular disease is a common type of cerebrovascular disease and the leading cause of disability and mortality worldwide. Therefore, it is crucial to elucidate its pathogenesis and develop novel therapeutic strategies. This study was performed to investigate whether angiotensin (Ang) II exerts a protective effect against cerebral ischemia/reperfusion (I/R) injury in vitro. The primary cultured neurons were prepared and an I/R model was established by incubation of cortical neurons with Na₂S₂O₄, followed by culture in fresh medium. The protective effect of Ang II and its underlying mechanisms were investigated by morphology observation, MTT assay, flow cytometry analysis and reverse transcription-polymerase chain reaction (RT-PCR). The data demonstrated that Ang II significantly ameliorated the neuronal injury caused by oxygen-glucose deprivation. Furthermore, Ang II increased cell viability through inhibiting cell apoptosis. The RT-PCR results revealed that Ang II was able to reverse the increased bax mRNA and the decreased bcl2 mRNA expression. Of note, the protective activity of Ang II may be attenuated by co-treatment with Ang II type 2 (AT2) receptor blockade (PD123319), but not Ang II type 1 (AT1) receptor blockade (valsartan). These findings suggested that Ang II exerted a protective effect against neuronal injury induced by oxygen-glucose deprivation through decreasing cell apoptosis. Therefore, Ang II may be used as a potential therapeutic target in the future.

Protective effect of ocotillol against doxorubicin‑induced acute and chronic cardiac injury

Doxorubicin (Dox) has been clinically observed to exert marked anticancer activity. However, it is severely restricted by its associated dose‑dependent cardiotoxicity, which may be attenuated by decreasing the cumulative dosage via combining with a non‑toxic 'sensitizer'. We previously reported that ocotillol is capable of enhancing the antitumor activity of Dox; however, the effects of ocotillol on its cardiotoxicity remain unclear. In the current study, the effects of ocotillol on the toxicity of Dox were investigated, particularly its role in cardiotoxicity. In the acute injury model, pre‑administration of ocotillol prolonged the survival time. In the chronic animal model, pre‑administration of ocotillol decreased the elevated levels of plasma creatine kinase (CK) and CK‑MB, as well as attenuated the pathological changes that occurred. Pre‑treatment with ocotillol ameliorated the decreased glutathione level and reduced the cumulated malondialdehyde in the heart tissue. In addition, pre‑treatment with ocotillol restored the lowered white blood cell count. The results indicate that Dox co‑treatment with ocotillol may effectively alleviate its associated toxic injury, particularly cardiotoxicity. Thus, co‑administration of Dox with ocotillol may be a potential therapeutic strategy.

Recent biotechnological progress in enzymatic synthesis of glycosides

Glycosylation is one of the most important post-modification processes of small molecules and enables the parent molecule to have increased solubility, stability, and bioactivity. Enzyme-based glycosylation has achieved significant progress due to advances in protein engineering, DNA recombinant techniques, exploitation of biosynthetic gene clusters of natural products, and computer-based modeling programs. Our report summarizes glycosylation data that have been published within the past five years to provide an overall review of current progress. We also present the future trends and perspectives for glycosylation.

Ginsenoside RK3 Prevents Hypoxia-Reoxygenation Induced Apoptosis in H9c2 Cardiomyocytes via AKT and MAPK Pathway

Reperfusion therapy is widely utilized for acute myocardial infarction (AMI), but further injury induced by rapidly initiating reperfusion of the heart is often encountered in clinical practice. Ginsenoside RK3 (RK3) is reportedly present in the processed Radix notoginseng that is often used as a major ingredient of the compound preparation for ischemic heart diseases. This study aimed to investigate the possible protective effect of RK3 against hypoxia-reoxygenation (H/R) induced H9c2 cardiomyocytes damage and its underlying mechanisms. Our results showed that RK3 pretreatment caused increased cell viability and decreased levels of LDH leakage compared with the H/R group. Moreover, RK3 pretreatment inhibited cell apoptosis, as evidenced by decreased caspase-3 activity, TUNEL-positive cells, and Bax expression, as well as increased Bcl-2 level. Further mechanism investigation revealed that RK3 prevented H9c2 cardiomyocytes injury and apoptosis induced by H/R via AKT/Nrf-2/HO-1 and MAPK pathways. These observations indicate that RK3 has the potential to exert cardioprotective effects against H/R injury, which might be of great importance to clinical efficacy for AMI treatment.

Ocotillol Enhanced the Antitumor Activity of Doxorubicin via p53-Dependent Apoptosis

The use of doxorubicin (Dox) was severely constrained by dose-dependent side effects, which might be attenuated by combining a “sensitizer” to decrease its cumulative dosage. In this study, it was investigated whether ocotillol could enhance the antiproliferation activity of Dox. MTT assays and xenograft tumor model were firstly conducted to evaluate the effect of ocotillol on the antitumor activity of Dox. Flow cytometry and Hoechst staining assays were then performed to assess cell apoptosis. Western blot and real-time PCR were finally used to detect the expression of p53 and its target genes. Our results showed ocotillol to enhance Dox-induced cell death in p53 wild-type cancer cells. Compared with Dox alone, Dox with ocotillol (Dox-O) could induce much more cell apoptosis and activate p53 to a much greater degree, which in turn markedly increased expression of proapoptosis genes. The enhanced cytotoxic activity was partially blocked by pifithrin-α, which might be through attenuating the increased apoptosis. Furthermore, ocotillol significantly increased the antitumor activity of Dox in A549 xenograft tumor in nude mice. These findings indicated that ocotillol could potentiate the cytotoxic effect of Dox through p53-dependent apoptosis and suggested that coadministration of ocotillol with Dox might be a potential therapeutic strategy.

Isorhamnetin protects against doxorubicin-induced cardiotoxicity in vivo and in vitro

Doxorubicin (Dox) is an anthracycline antibiotic for cancer therapy with limited usage due to cardiotoxicity. Isorhamnetin is a nature antioxidant with obvious cardiac protective effect. The aim of this study is going to investigate the possible protective effect of isorhamnetin against Dox-induced cardiotoxicity and its underlying mechanisms. In an in vivo investigation, rats were intraperitoneally (i.p.) administered with Dox to duplicate the model of Dox-induced chronic cardiotoxicity. Daily pretreatment with isorhamnetin (5 mg/kg, i.p.) for 7 days was found to reduce Dox-induced myocardial damage significantly, including the decline of cardiac index, decrease in the release of serum cardiac enzymes and amelioration of heart vacuolation. In vitro studies on H9c2 cardiomyocytes, isorhamnetin was effective to reduce Dox-induced cell toxicity. A further mechanism study indicated that isorhamnetin pretreatment can counteract Dox-induced oxidative stress and suppress the activation of mitochondrion apoptotic pathway and mitogen-activated protein kinase pathway. Isorhamnetin also potentiated the anti-cancer activity of Dox in MCF-7, HepG2 and Hep2 cells. These findings indicated that isorhamnetin can be used as an adjuvant therapy for the long-term clinical use of Dox.