Salvianolic acid B induces apoptosis in human glioma U87 cells through p38-mediated ROS generation

Salvianolic acid B as a potent nano-agent for enhanced ALA-PDT of oral cancer and leukoplakia cells

BACKGROUND

Photodynamic therapy (PDT) relies on the light activation of a photosensitizers to generate reactive oxygen species such as singlet oxygen, but its effect on cancer therapy is limited dramatically by hypoxia in the tumor microenvironment.

OBJECTIVES

To determine the potential of a nano-photosensitizer loaded salvianolic acid B (SalB) and 5-aminolevulinic acid (ALA) for enhancing the efficacy of PDT in oral squamous cell carcinoma Cal27 cells and leukoplakia Leuk1 cells.

RESULTS

Singlet oxygen sensor green (SOSG) assay showed that nano-SalB-ALA generated higher levels of singlet oxygen, compared to nano-SalB and nano-ALA. Cellular uptake assay showed that nano-SalB-ALA effectively absorbed by Leuk1 cells. Importantly, cell counting kit-8 and flow cytometry revealed that PDT with nano-SalB-ALA effectively inhibited the viability and induced the apoptosis of Cal27 and Leuk1 cells, respectively. Moreover, the tumor xenograft study revealed that PDT with nano-SalB-ALA had a stronger inhibitory effect on tumor growth of nude mice, compared to control groups.

CONCLUSIONS

The novel photosensitizer nano-SalB-ALA remarkably enhanced the efficacy of PDT by improving singlet oxygen production, inhibiting cell proliferation, promoting cell apoptosis, and suppressing tumor growth. These suggest PDT with nano-SalB-ALA could be a clinically significant and potent treatment for oral cancer and leukoplakia.

Phytochemical analysis, radical scavenging and glioblastoma U87 cells toxicity studies of stem bark of buckthorn (Rhamnus pentapomica R. Parker)

BACKGROUND

During the past two decades, the correlation between oxidative stress and a variety of serious illnesses such as atherosclerosis, chronic obstructive pulmonary disease (COPD), Alzheimer disease (AD) and cancer has been established. Medicinal plants and their derived phytochemicals have proven efficacy against free radicals and their associated diseases. The current work was aimed to evaluate the phytochemical constituents of Rhamnus pentapomica R. Parker via Gas Chromatography-Mass Spectrometry (GC-MS) and its antioxidant and anti-glioblastoma potentials.

METHODS

The bioactive compounds were analysed in Rhamnus pentapomica R. Parker stem bark extracts by GC-MS analysis, and to evaluate their antioxidant and anti-glioblastoma effects following standard procedures. The stem bark was extracted with 80% methanol for 14 days to get crude methanolic extract (Rp.Cme) followed by polarity directed fractionation using solvents including ethyl acetate, chloroform, butanol to get ethyl acetate fraction (Rp.EtAc), chloroform fraction (Rp.Chf) and butanol fraction (Rp.Bt) respectively. Antioxidant assay was performed using DPPH free radicals and cell viability assay against U87 glioblastoma cancer cell lines was performed via MTT assay.

RESULTS

In GC-MS analysis, thirty-one compounds were detected in Rp.Cme, 22 in Rp.Chf, 24 in Rp.EtAc and 18 compounds were detected in Rp.Bt. Among the identified compounds in Rp.Cme, 9-Octadecenoic acid (Z)-methyl ester (7.73%), Octasiloxane (5.13%) and Heptasiloxane (5.13%), Hexadecanoic acid, methyl ester (3.76%) and Pentadecanoic acid, 14-methyl-, methyl Ester (3.76%) were highly abundant.. In Rp.Chf, Benzene, 1,3-dimethyl- (3.24%) and in Rp.EtAc Benzene, 1,3-dimethyl-(11.29%) were highly abundant compounds. Antioxidant studies revealed that Rp.Cme and Rp.EtAc exhibit considerable antioxidant potentials with IC50 values of 153.53 μg/ml and 169.62 μg/ml respectively. Both fractions were also highly effective against glioblastoma cells with IC50 of 147.64 μg/ml and 76.41ug/ml respectively.

CONCLUSION

Phytochemical analysis revealed the presence of important metabolites which might be active against free radicals and glioblastoma cells. Various samples of the plant exhibited considerable antioxidant and anti-glioblastoma potentials warranting further detailed studies.

CAP2 promotes gastric cancer metastasis by mediating the interaction between tumor cells and tumor-associated macrophages

The metastasis of cancer cells is the main cause of death in patients with gastric cancer (GC). Mounting evidence has demonstrated the vital importance of tumor-associated macrophages in promoting tumor invasion and metastasis; however, the interaction between tumor cells and macrophages in GC is largely unknown. In this study, we demonstrated that cyclase-associated protein 2 (CAP2) was upregulated in GC, especially in cases with lymph node metastasis, and was correlated with a poorer prognosis. The transcription factor JUN directly bound to the promoter region of CAP2 and activated CAP2 transcription. The N-terminal domain of CAP2 bound to the WD5 to WD7 domains of receptor for activated C kinase 1 (RACK1) and induced M2 macrophage polarization by activating the SRC/focal adhesion kinase (FAK)/ERK signaling pathway, which resulted in IL-4 and IL-10 secretion. Polarized M2 macrophages induced premetastatic niche formation and promoted GC metastasis by secreting TGFB1, which created a TGFB1/JUN/CAP2 positive-feedback loop to activate CAP2 expression continuously. Furthermore, we identified salvianolic acid B as an inhibitor of CAP2, which effectively inhibited GC cell invasion capabilities by suppressing the SRC/FAK/ERK signaling pathway. Our data suggest that CAP2, a key molecule mediating the interaction between GC cells and tumor-associated macrophages, may be a promising therapeutic target for suppressing tumor metastasis in GC.

Natural and synthetic compounds for glioma treatment based on ROS-mediated strategy

Glioma is the most frequent and most malignant tumor of the central nervous system (CNS)，accounting for about 50% of all CNS tumor and approximately 80% of the malignant primary tumors in the CNS. Patients with glioma benefit from surgical resection, chemo- and radio-therapy. However these therapeutical strategies do not significantly improve the prognosis, nor increase survival rates owing to restricted drug contribution in the CNS and to the malignant characteristics of glioma. Reactive oxygen species (ROS) are important oxygen-containing molecules that regulate tumorigenesis and tumor progression. When ROS accumulates to cytotoxic levels, this can lead to anti-tumor effects. Multiple chemicals used as therapeutic strategies are based on this mechanism. They regulate intracellular ROS levels directly or indirectly, resulting in the inability of glioma cells to adapt to the damage induced by these substances. In the current review, we summarize the natural products, synthetic compounds and interdisciplinary techniques used for the treatment of glioma. Their possible molecular mechanisms are also presented. Some of them are also used as sensitizers: they modulate ROS levels to improve the outcomes of chemo- and radio-therapy. In addition, we summarize some new targets upstream or downstream of ROS to provide ideas for developing new anti-glioma therapies.

Modulation of Cell Death Pathways for Cellular Protection and Anti-Tumoral Activity: The Role of Thymus spp. Extracts and Their Bioactive Molecules

Natural products used for their health-promoting properties have accompanied the evolution of humanity. Nowadays, as an effort to scientifically validate the health-promoting effects described by traditional medicine, an ever-growing number of bioactivities are being described for natural products and the phytochemicals that constitute them. Among them, medicinal plants and more specifically the Thymus genus spp., arise as products already present in the diet and with high acceptance, that are a source of phytochemicals with high pharmacological value. Phenolic acids, flavonoid glycoside derivatives, and terpenoids from Thymus spp. have been described for their ability to modulate cell death and survival pathways, much-valued bioactivities in the pharmaceutical industry, that continually sought-after new formulations to prevent undesired cell death or to control cell proliferation. Among these, wound treatment, protection from endogenous/exogenous toxic molecules, or the induction of selective cell death, such as the search for new anti-tumoral agents, arise as main objectives. This review summarizes and discusses studies on Thymus spp., as well as on compounds present in their extracts, with regard to their health-promoting effects involving the modulation of cell death or survival signaling pathways. In addition, studies regarding the main bioactive molecules and their cellular molecular targets were also reviewed. Concerning cell survival and proliferation, Thymus spp. present themselves as an option for new formulations designed for wound healing and protection against chemicals-induced toxicity. However, Thymus spp. extracts and some of their compounds regulate cell death, presenting anti-tumoral activity. Therefore Thymus spp. is a rich source of compounds with nutraceutical and pharmaceutical value.

Natural Products as Anticancer Agents: Current Status and Future Perspectives

Natural products have been an invaluable and useful source of anticancer agents over the years. Several compounds have been synthesized from natural products by modifying their structures or by using naturally occurring compounds as building blocks in the synthesis of these compounds for various purposes in different fields, such as biology, medicine, and engineering. Multiple modern and costly treatments have been applied to combat cancer and limit its lethality, but the results are not significantly refreshing. Natural products, which are a significant source of new therapeutic drugs, are currently being investigated as potential cytotoxic agents and have shown a positive trend in preclinical research and have prompted numerous innovative strategies in order to combat cancer and expedite the clinical research. Natural products are becoming increasingly important for drug discovery due to their high molecular diversity and novel biofunctionality. Furthermore, natural products can provide superior efficacy and safety due to their unique molecular properties. The objective of the current review is to provide an overview of the emergence of natural products for the treatment and prevention of cancer, such as chemosensitizers, immunotherapeutics, combinatorial therapies with other anticancer drugs, novel formulations of natural products, and the molecular mechanisms underlying their anticancer properties.

Salvianolic acid B from Salvia miltiorrhiza bunge: A potential antitumor agent

Salvia miltiorrhiza Bunge (Lamiaceae) is a perennial herb widely found in China since ancient times with a high economic and medicinal value. Salvianolic acid B (Sal-B) is an important natural product derived from Salvia miltiorrhiza and this review summarizes the anticancer activity of Sal-B. Sal-B inhibits tumor growth and metastasis by targeting multiple cell signaling pathways. This review aims to review experimental studies to describe the possible anticancer mechanisms of Sal-B and confirm its potential as a therapeutic drug.

Triphlorethol-A attenuates U251 human glioma cancer cell proliferation and ameliorates apoptosis through JAK2/STAT3 and p38 MAPK/ERK signaling pathways

Glioma is the foremost recurrent type of brain tumor in humans; in particular, glioblastoma (GBM) is the main form of brain tumor (GBM) that is highly proliferative and impervious to apoptosis. Triphlorethol-A (TA), a phlorotannin isolated from Ecklonia cava, exhibited cytoprotective, antioxidant, and anticancer properties. However, the exact molecular action of TA in the U251 human GBM cells remains unknown. This may be the first report on the antiproliferative and apoptotic mechanisms of TA on GBM. The cytotoxicity, intracellular reactive oxygen species (ROS), matrix metalloproteinase (MMP), and cell apoptosis activity of TA have been evaluated by the MTT assay and by DCFH-DA, Rh-123, AO/EB, and western blot analysis. The results obtained showed that TA abridged the viability of U251 cells, while MMP increased apoptosis by increasing the ROS levels in a time-dependent manner. The results showed that a reduction in U251 cell proliferation was associated with the regulation of JAK2/STAT3 and p38 MAPK/ERK signaling pathways. TA was found to suppress pJAK, pSTAT3, p38 MAPK, and pERK phosphorylation, thereby causing Bax/Bcl-2 imbalance, activating the caspase cascade and cytochrome c, and inducing apoptosis. Our findings showed that the suppression of JAK2/STAT3 and p38 MAPK/ERK signaling by TA results in cell growth arrest and stimulation of apoptosis in GBM cells. These studies justify the protective remedy of TA against GBM.

Tanshinol suppresses osteosarcoma by specifically inducing apoptosis of U2-OS cells through p53-mediated mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

Radix Salviae miltiorrhizae (also called Danshen in traditional Chinese medicine) is a famous herbal medicine, which has been frequently used to treat blood stasis syndrome including osteosarcoma (OS) in traditional Chinese medicine. Main components of Danshen have been assumed to exhibit anti-OS capacity. Nevertheless, tanshinol (TS, main component of Danshen)'s efficacy and mechanism in OS hasn't been clearly described ever since. This drew our attention, since OS is the most frequent primary bone carcinomas in children and adolescents, with a high incidence and fatality rate. Unfortunately, chemotherapy for OS has faced many clinical challenges due to the increasing chemoresistance and recurrence. This study was then designed to deeply explore TS's role in OS therapy.

AIM OF THE STUDY

To explore the anti-OS efficacy and mechanism of TS, we conducted in vivo and in vitro experiments by using a zebrafish xenograft model and U2-OS cells.

MATERIALS AND METHODS

CCK-8 assay, DAPI and γ-H2A.X immunofluorescence staining, and flow cytometry (apoptosis verification) were employed to determine the anti-proliferative and pro-apoptotic effects of TS. qPCR and Western blot were used to examine TS's molecular actions and mechanism on apoptosis of U2-OS cells.

RESULTS

The in vivo data showed that TS significantly inhibited U2-OS tumor growth in larval zebrafish from 2 to 20 ng/mL. In vitro data indicated that TS exerted significant anti-proliferative and pro-apoptotic effects on U2-OS cells in a dose-dependent manner. Moreover, TS has no inhibitory effect on bMSCs, suggesting its safety on normal bone-forming cells. Molecular data illustrated that TS obviously activated the p53 signaling-related proteins (p-p53, Bax, CASP3, CASP9) and its upstream JNK (p-JNK, p-c-JUN) and ATM (p-ATM) signaling molecules through phosphorylation and cleavage, followed by up-regulation of the pro-apoptotic genes, NOXA, PUMA, TP53, BAX, and BIM, and down-regulation of Bcl-2 protein.

CONCLUSION

In sum, TS specifically induced apoptosis of U2-OS cells by activating p53 signaling pathways, indicating TS as a promising candidate for OS treatment.

Better Bioactivity, Cerebral Metabolism and Pharmacokinetics of Natural Medicine and Its Advanced Version

Currently, many people are afflicted by cerebral diseases that cause dysfunction in the brain and perturb normal daily life of people. Cerebral diseases are greatly affected by cerebral metabolism, including the anabolism and catabolism of neurotransmitters, hormones, neurotrophic molecules and other brain-specific chemicals. Natural medicines (NMs) have the advantages of low cost and low toxicity. NMs are potential treatments for cerebral diseases due to their ability to regulate cerebral metabolism. However, most NMs have low bioavailability due to their low solubility/permeability. The study is to summarize the better bioactivity, cerebral metabolism and pharmacokinetics of NMs and its advanced version. This study sums up research articles on the NMs to treat brain diseases. NMs affect cerebral metabolism and the related mechanisms are revealed. Nanotechnologies are applied to deliver NMs. Appropriate delivery systems (exosomes, nanoparticles, liposomes, lipid polymer hybrid nanoparticles, nanoemulsions, protein conjugation and nanosuspensions, etc.) provide better pharmacological and pharmacokinetic characteristics of NMs. The structure-based metabolic reactions and enzyme-modulated catalytic reactions related to advanced versions of NMs alter the pharmacological activities of NMs.

Inhibitory Effect of Salvia miltiorrhiza Extract and Its Active Components on Cervical Intraepithelial Neoplastic Cells

The effective treatment of cervical intraepithelial neoplasia (CIN) can prevent cervical cancer. Salvia miltiorrhiza is a medicinal and health-promoting plant. To identify a potential treatment for CIN, the effect of S. miltiorrhiza extract and its active components on immortalized cervical epithelial cells was studied in vitro. The H8 cell was used as a CIN model. We found that S. miltiorrhiza extract effectively inhibited H8 cells through the CCK8 method. An HPLC-MS analysis revealed that S. miltiorrhiza extract contained salvianolic acid H, salvianolic acid A, salvianolic acid B, monomethyl lithospermate, 9‴-methyl lithospermate B, and 9‴-methyl lithospermate B/isomer. Salvianolic acid A had the best inhibitory effect on H8 cells with an IC50 value of 5.74 ± 0.63 μM. We also found that the combination of salvianolic acid A and oxysophoridine had a synergistic inhibitory effect on H8 cells at molar ratios of 4:1, 2:1, 1:1, 1:2, and 1:4, with salvianolic acid A/oxysophoridine = 1:2 having the best synergistic effect. Using Hoechst33342, flow cytometry, and Western blotting analysis, we found that the combination of salvianolic acid A and oxysophoridine can induce programmed apoptosis of H8 cells and block the cell cycle in the G2/M phase, which was correlated with decreased cyclinB1 and CDK1 protein levels. In conclusion, S. miltiorrhiza extract can inhibit the growth of H8 cells, and the combination of salvianolic acid A (its active component) and oxysophoridine has a synergistic inhibitory effect on H8 cells and may be a potential treatment for cervical intraepithelial neoplasia.

Bioactive constituents of Salvia przewalskii and the molecular mechanism of its antihypoxia effects determined using quantitative proteomics

Context: Environmental hypobaric hypoxia induces several physiological or pathological responses in individuals in high-altitude regions. Salvia przewalskii Maxim (Labiatae) (SPM) is a traditional Chinese herbal medicine and has known antibacterial, antiviral, antioxidant, anti-thrombotic, and anti-depressant activities.Objective: This study examined the antihypoxia effects of SPM in vivo.Materials and methods: The dried and pulverised of SPM was extracted from root crude drug with 70% ethanol with ultrasound. Male Sprague-Dawley rats were divided into three groups (n = 10): normal group, hypoxia group (altitude of 4260 m), and hypoxia + SPM group (altitude of 4260 m, SPM of 1.0 g/kg/day). The experiment persisted for 4 weeks. The mean pulmonary arterial pressure (mPAP), hypoxia-inducible factor-1α (HIF-1α) mRNA, and lung pathology were analysed using pulmonary artery pressure recorder, quantitative polymerase chain reaction, and histopathological analysis. Moreover, the effects of SPM on lung proteomes during hypoxia were observed by a TMT-based proteomic approach.Results: Pre-treatment with SPM decreased mPAP (24.86%) and HIF-1α (31.24%), and attenuated the pathological changes in lung tissues. In addition, a total of 28 proteins were differentially expressed in lung of hypoxia + SPM group (fold change > ± 1.2 and p < 0.05). The differentially altered proteins were primarily associated with antioxidative stress, as evidenced by the downregulated expression of Adh7, Cyp2d1, Plod2, Selenow, ND3, and Fabp1, and fructose metabolism, as evidenced by the downregulated expression of Khk and Aldob.Discussion and conclusions: These results suggested that SPM is a promising drug for antihypoxia. The mechanism of action might be related to increasing antioxidant capacity and inhibiting fructose metabolism.

Possible applications of salvianolic acid B against different cancers

Cancer is the second death causing disease worldwide after cardiovascular abnormalities. The difficulty in treating tumor cells with more precise targeted interventions and recurrence of cancer after treatment may pose great difficulty in developing sustainable therapeutic regimens. These limitations have prompted the need to explore several compounds with ability to cease tumor growth while at the same time induce apoptosis of tumor cells. Several studies have emphasized the use of natural compounds as antitumor agents due to their high efficacy against cancer cells and low toxicity in normal cells. Salvianolic acid B (SAB), a naturally occurring phenolic compound extracted from the radix of Chinese herb Salvia miltiorrhiza can induce apoptosis in different types of tumor cells. It can be used to treat cardiovascular and neurodegenerative disorders, hepatic fibrosis, and cancers. Several studies have shown that SAB can mitigate tumorigenesis by modulating MAPK, PI3K/AKT, and NF-ĸB signaling pathways. It also sensitizes the tumor cells to different anti-cancer agents by reversing the multi-drug resistance mechanisms found in tumor cells. This review summarizes the studies showing antitumor potential of SAB in different types of cancer cell lines, animal models and highlights the possible mechanisms through which SAB can induce apoptosis, inhibit growth and metastasis in tumor cells. Moreover, the possible role of nano-technological approaches to induce targeted delivery of SAB to eradicate tumor cells has been also discussed.

Salvianolic Acid B Improves Postresuscitation Myocardial and Cerebral Outcomes in a Murine Model of Cardiac Arrest: Involvement of Nrf2 Signaling Pathway

Survival and outcome of cardiac arrest (CA) are dismal despite improvements in cardiopulmonary resuscitation (CPR). Salvianolic acid B (Sal B), extracted from Salvia miltiorrhiza, has been investigated for its cardioprotective properties in cardiac remodeling and ischemic heart disease, but less is known about its role in CA. The aim of this study was to learn whether Sal B improves cardiac and neurologic outcomes after CA/CPR in mice. Female C57BL/6 mice were subjected to eight minutes of CA induced by an intravenous injection of potassium chloride (KCl), followed by CPR. After 30 seconds of CPR, mice were blindly randomized to receive either Sal B (20 mg/kg) or vehicle (normal saline) intravenously. Hemodynamic variables and indices of left ventricular function were determined before CA and within three hours after CPR, the early postresuscitation period. Sal B administration resulted in a remarkable decrease in the time required for the return of spontaneous circulation (ROSC) in animals that successfully resuscitated compared to the vehicle-treated mice. Myocardial performance, including cardiac output and left ventricular systolic (dp/dt_max) and diastolic (dp/dt_min) function, was clearly ameliorated within three hours of ROSC in the Sal B-treated mice. Moreover, Sal B inhibited CA/CPR-induced cardiomyocyte apoptosis and preserved mitochondrial morphology and function. Mechanistically, Sal B dramatically promoted Nrf2 nuclear translocation through the downregulation of Keap1, which resulted in the expression of antioxidant enzymes, including HO-1 and NQO1, thereby counteracted the oxidative damage in response to CA/CPR. The aforementioned antiapoptotic and antioxidant effects of Sal B were impaired in the setting of gene silencing of Nrf2 with siRNA in vitro model. These improvements were associated with better neurological function and increased survival rate (75% vs. 40%, p < 0.05) up to 72 hours postresuscitation. Our findings suggest that the administration of Sal B improved cardiac function and neurological outcomes in a murine model of CA via activating the Nrf2 antioxidant signaling pathway, which may represent a novel therapeutic strategy for the treatment of CA.

Salvia bowleyana Dunn root is a novel source of salvianolic acid B and displays antitumor effects against gastric cancer cells

Salvianolic acid B (Sal-B) is widely used in China for the treatment of numerous diseases. Currently, Salvia miltiorrhiza Bunge is the main source of this compound, but Salvia bowleyana Dunn, a surrogate of S. miltiorrhiza Bge, may provide a novel source for obtaining more Sal-B. In the present study, a simple method for separation and purification of phenolic compounds from S. bowleyana Dunn roots was employed. Sal-B was subsequently purified and its inhibitory effect on the gastric cancer HGC-27 and AGS cell lines was investigated. Sal-B extracted from S. bowleyana Dunn displayed significant antitumor activity in proliferation and apoptosis assays. Overall, it was found that S. bowleyana Dunn has a higher Sal-B content than S. miltiorrhiza Bge and may be used as a novel source of this potential anti-gastric cancer compound.

Extract of Salvia przewalskii Repair Tissue Damage in Chronic Hypoxia Maybe through the RhoA-ROCK Signalling Pathway

Salvia przewalskii Maxim is a traditional Chinese herbal medicine and is known to have antibacterial, antiviral, anti-oxidant, anti-thrombotic and anti-depressant properties. However, the major active components of S. przewalskii and its anti-hypoxic effects are still unclear. This study probed the major active component and anti-hypoxic activity of S. przewalskii. The major active components of S. przewalskii were detected by HPLC. The anti-hypoxic effects of S. przewalskii were detected in mice and a rat model of hypoxic preconditioning. The results showed that there are eight active components, including sodium danshensu, rosmarinic acid, lithospermic acid, salvianolic acid B, dihydrotanshinone I, cryptotanshinone, tanshinone I and tanshinone IIA, and each component showed a certain anti-hypoxic effect. Moreover, S. przewalskii enhanced anti-hypoxia in mice, which was manifested as prolonged survival time in acute hypoxic preconditioning and the amelioration of acute hypoxia-induced changes in the activity of superoxide dismutase (SOD) and lactate dehydrogenase (LDH). In addition, S. przewalskii also repaired tissue damage in chronic hypoxia by downregulating hypoxia inducible factor-1α (HIF-1α), proliferating cell nuclear antigen (PCNA), Bcl-2, CDK4, CyclinD1 and P27Kip1 and inhibiting pro-inflammatory cytokines and the RhoA-Rho-associated protein kinase (ROCK) signalling pathway. Our findings provide new insight into the anti-hypoxic effect of S. przewalskii as a promising agent for high-altitude pulmonary hypertension treatment.

Salvianolic Acid B Slows the Progression of Breast Cancer Cell Growth via Enhancement of Apoptosis and Reduction of Oxidative Stress, Inflammation, and Angiogenesis

Breast cancer is the current leading cause of cancer death in females worldwide. Although current chemotherapeutic drugs effectively reduce the progression of breast cancer, most of these drugs have many unwanted side effects. Salvianolic acid B (Sal-B) is a bioactive compound isolated from the root of Danshen Radix with potent antioxidant and anti-inflammatory properties. Since free radicals play a key role in the initiation and progression of tumor cells growth and enhance their metastatic potential, the current study was designed to investigate the antitumor activity of Sal-B and compare it with the antitumor activity of the traditional anticancer drug, cisplatin. In vitro, Sal-B decreased the human breast cancer adenocarcinoma (MCF-7) cells proliferation in a concentration and time dependent manner. In vivo and similar to cisplatin treatment, Sal-B significantly reduced tumor volume and increased the median survival when compared to tumor positive control mice group injected with Ehrlich solid carcinoma cell line (ESC). Sal-B decreased plasma level of malondialdehyde as a marker of oxidative stress and increased plasma level of reduced glutathione (GSH) as a marker of antioxidant defense when compared to control ESC injected mice. Either Sal-B or cisplatin treatment decreased tumor tissue levels of tumor necrosis factor (TNF-α), matrix metalloproteinase-8 (MMP-8), and Cyclin D1 in ESC treated mice. Contrary to cisplatin treatment, Sal-B did not decrease tumor tissue Ki-67 protein in ESC injected mice. Immunohistochemical analysis revealed that Sal-B or cisplatin treatment increased the expression of the apoptotic markers caspase-3 and P53. Although Sal-B or cisplatin significantly reduced the expression of the angiogenic factor vascular endothelial growth factor (VEGF) in ESC injected mice, only Sal-B reduced expression level of COX-2 in ESC injected mice. Our data suggest that Sal-B exhibits antitumor features against breast cancer cells possibly via enhancing apoptosis and reducing oxidative stress, inflammation, and angiogenesis.

Salvianolic acid A & B: potential cytotoxic polyphenols in battle against cancer via targeting multiple signaling pathways

Nature has generously offered life-saving therapies to mankind by providing evolutionarily optimized drug-like entities in the form of natural products. These splendid gifts of nature have served as most suitable candidates for anti-cancer drug discovery due to their pleiotropic activity on target molecules. This review aims to provide an update on the natural sources and bioactivities of such gifts from nature, salvianolic acid A & B, which are major bioactive constituents of a traditional Chinses medicinal herb, Salvia miltiorrhiza. Salvianolic acid A & B have been reported to owe anti-cancer, anti-inflammatory and cardioprotective activities. Currently salvianolic acids have been emerged as potent anti-cancer molecules. Salvianolic acid A & B fight cancer progression by prompting apoptosis, halting cell cycle and adjourning metastasis by targeting multiple deregulated signaling networks of cancer. Moreover, salvianolic acid A & B display potency towards sensitizing cancer cells to chemo-drugs. The review purposes that salvianolic acid A & B supply a novel opportunity for drug discovery but further experimentation is mandatory to embellish the knowledge of their pharmacological usage and to access their toxicological limits in order to establish these compounds as potential multitarget future drugs.

Danshen: a phytochemical and pharmacological overview

Danshen, the dried root or rhizome of Salvia miltiorrhiza Bge., is a traditional and folk medicine in Asian countries, especially in China and Japan. In this review, we summarized the recent researches of Danshen in traditional uses and preparations, chemical constituents, pharmacological activities and side effects. A total of 201 compounds from Danshen have been reported, including lipophilic diterpenoids, water-soluble phenolic acids, and other constituents, which have showed various pharmacological activities, such as anti-inflammation, anti-oxidation, anti-tumor, anti-atherogenesis, and anti-diabetes. This article intends to provide novel insight information for further development of Danshen, which could be of great value to its improvement of utilization.

Biosynthesis, Chemistry, and Pharmacology of Polyphenols from Chinese Salvia Species: A Review

Salvia species find widespread application in food and pharmaceutical products owing to their large polyphenol content. The main polyphenols in Chinese Salvia species are phenolic acids and flavonoids, which exhibit anti-oxygenation, anti-ischemia-reperfusion injury, anti-thrombosis, anti-tumour, and other therapeutic effects. However, there are few peer-reviewed studies on polyphenols in Chinese Salvia species, especially flavonoids. This review is a systematic, comprehensive collation of available information on the biosynthesis, chemistry, and pharmacology of Chinese Salvia species. We believe that our study makes a significant contribution to the literature because this review provides a detailed literary resource on the currently available information on various polyphenolic components of Chinese Salvia species, including their bioactivities and structures. In addition, the study provides information that would encourage further investigation of this plant material as a natural resource with potential for a broad range of applications in various industries, such as the food and pharmaceutical industries.

Salvianolic acid B, an antioxidant derived from Salvia militarize, protects mice against γ‑radiation‑induced damage through Nrf2/Bach1

Salvianolic acid B (SB) is an antioxidant derived from Salvia militarize, and is one of the most widely used herbs in traditional Chinese medicine. SB is a potent antioxidant that has been well documented as a scavenger of oxygen free radicals, and has been used for the prevention and treatment of atherosclerosis-associated disorders. To explore its potential therapeutic effects in treating radiation damage, in this study, mice were treated with SB at different doses of 5, 12.5 and 20 mg/kg, subsequent to receiving γ-irradiation. The effects of SB on peripheral blood, bone marrow nucleated cells, spleen and thymus indices, and oxidation resistance were evaluated in both radiated mice and control groups. The results indicated that SB significantly increased the counts of peripheral white blood cells, red blood cells and platelets. The number of nucleated cells in the bone marrow and the level of protein increased as well. In addition, improved spleen and thymus indices in the bone marrow were observed. SB treatment additionally reversed the deterioration of both the thymus and spleen indices, which is associated with increased serum superoxide dismutase activity and decreasing malondialdehyde levels via nuclear factor (erythroid-derived 2)-like 2 protein/BTB and CNC homology 1 mediated antioxidant effect. Furthermore, ROS levels and Bax protein expression were also suppressed by SB. The data suggested that SB is effective in protecting mice from γ-radiation injury, and could potentially be applicable for clinical use. Notably, the present study identified a promising candidate drug for enhancing the hematopoietic and immune systems.

Antitumor properties of Salvianolic acid B against triple-negative and hormone receptor-positive breast cancer cells via ceramide-mediated apoptosis

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with limited treatment options. It is urgent to develop new therapeutics against this disease. Salvinolic acid B (Sal-B) is a leading bioactive component of Salvia miltiorrhiza Bunge, a well-known Chinese medicine for treating various diseases without appreciable adverse effects. To understand the antitumor properties of Sal-B against TNBC, we analyzed its effects on the cell viability, cell cycle and apoptosis of triple-negative MDA-MB-231 cells with the hormone receptor-positive MCF-7 cells as the control. The in vitro analysis showed that Sal-B could significantly reduce the cell viability and suppress the proliferation of both MDA-MB-231 and MCF-7 cells with decreased cyclin B1 expression, but with no noticeable cell cycle phase change. In mouse models, Sal-B markedly inhibited the growth, decreased the PCNA expression, and increased the cell apoptosis of MDA-MB-231 tumor xenografts. To understand the antitumor mechanisms, we analyzed the expression levels of ceramides, and anti-apoptotic (Bcl-xL and survivin) and pro-apoptotic (caspase-3 and caspase-8) proteins. We found that Sal-B enhanced the ceramide accumulation and inhibited the anti-apoptotic protein expression. Interestingly, the ceramide accumulation was accompanied by decreased expression of glucosylceramide and GM3 synthases, two key enzymes regulating ceramide metabolism. These findings indicate that Sal-B exerts its antitumor effects at least partially by inducing the ceramide accumulation and ceramide-mediated apoptosis via inhibiting the expression of glucosylceramide and GM3 synthases, which was independent of estrogen receptor α. Sal-B appears to be a promising therapeutic agent against TNBC.

Salvianolic acid B renders glioma cells more sensitive to radiation via Fis-1-mediated mitochondrial dysfunction

Glioma remains the leading cause of brain tumor-related death worldwide, and radiation is a standard adjuvant therapy with proven efficacy. Salvianolic acid B (SalB), a bioactive compound isolated from Radix Salviae, has been shown to exert anti-cancer effects in many cancer cell lines, including glioma. This study aimed to investigate whether SalB could affect response to radiation in human glioma cells. We found that SalB decreased cell viability of U87 cells in a-dose-dependent manner. A subthreshold dose of SalB at 0.5 μM, which had no effect on cell viability and apoptosis, significantly increased radiation sensitivity of U87 cells in a dose- and time-dependent manner, but had no effect on sensitivity to temozolomide (TMZ). Similar results were also observed in human glioma U373 cells. In addition, SalB aggravated the radiation-induced apoptosis and mitochondrial dysfunction, as measured by mitochondrial Ca²⁺ buffering capacity and mitochondrial swelling. SalB treatment markedly promoted mitochondrial fission and differently regulated the expression of fission proteins. Furthermore, downregulation of the fission protein Fis-1 using siRNA was found to partially reversed the SalB-induced effects on cell viability, apoptosis and mitochondrial fission in U87 cells. In conclusion, our results suggest that a subthreshold dose of SalB renders glioma cells more sensitive to radiation via Fis-1-mediated mitochondrial dysfunction, and radiotherapy combined with SalB might be a novel treatment for glioma patients.

Herbal Compounds Play a Role in Neuroprotection through the Inhibition of Microglial Activation

Since microglia possess both neuroprotective and neurotoxic potential, they play a crucial role in the central nervous system (CNS). Excessive microglial activation induces inflammation-mediated neuronal damage and degeneration. At present, numerous herbal compounds are able to suppress neurotoxicity via inhibiting microglial activation. Therefore, many researchers focus on pharmacological inhibitors of microglial activation to ameliorate neurodegenerative disorders. Further work should concentrate on the exploration of new herbal compounds, which characteristically inhibit microglial neurotoxicity, rather than modulating neuroprotection alone. In this review, we summarize these herbal compounds, which in the past several years have been shown to exert potential neuroprotective activity by inhibiting microglial activation. The therapeutic targets and pharmacological mechanisms of these compounds have also been discussed.

Salvianolic acid B suppresses cell proliferation and induces apoptosis in osteosarcoma through p38-mediated reactive oxygen species generation

The present study aimed to investigate the potential anticancer effect and mechanisms of salvianolic acid B on osteosarcoma. Salvianolic acid B suppressed osteosarcoma cell proliferation and induced apoptosis in the osteosarcoma MG63 cell line, and activated the expressions of cleaved caspase-3, phosphorylated-tumor protein (p)38 mitogen-activated protein kinase (p-p38 MAPK) and phosphorylated-p53 (p-p53) proteins in the MG63 cells. Additionally, Salvianolic acid B also increased the level of reactive oxygen species (ROS) generation in the MG63 cells. The silencing of p38 expression inhibited the anticancer effect of salvianolic acid B on the levels of cell proliferation, p-p53 protein expression and ROS generation level in the MG63 cells. All these data supported the hypothesis that the anticancer effect of salvianolic acid B includes the suppression of cell proliferation and induces apoptosis in MG63 cells, and that p38 is important in the anticancer effect of salvianolic acid B on osteosarcoma cells due to the direct regulation of ROS generation. These data suggest that salvianolic acid B is important in the proliferation of osteosarcoma cells due to the direct regulation of p38-mediated ROS signaling.

Salvianolic acid B, a novel autophagy inducer, exerts antitumor activity as a single agent in colorectal cancer cells

Salvianolic Acid B (Sal B), an active compound extracted from the Chinese herb Salvia miltiorrhiza, is attracting more and more attention due to its biological activities, including antioxidant, anticoagulant and antitumor effects. However, autophagy induction in cancer cells by Sal B has never been recognized. In this study, we demonstrated that Sal B induced cell death and triggered autophagy in HCT116 and HT29 cells in a dose-dependent manner. Specific inhibition of autophagy by 3-MA or shRNA targeting Atg5 rescued Sal B-induced cell death in vitro and in vivo, suggesting that Sal B-induced autophagy may play a pro-death role and contribute to the cell death of colorectal cancer cell lines. Furthermore, AKT/mTOR signaling pathway was demonstrated to be a critical mediator in regulating Sal B-induced cell death. Overexpression of AKT by the transfection with AKT plasmid or pretreatment with insulin decreased Sal B-induced autophagy and cell death. Inversely, inhibition of AKT by LY294002 treatment markedly enhanced Sal B-induced autophagy and cell death. Taken together, our results demonstrate, for the first time, that Sal B is a novel autophagy inducer and exerts its antitumor activity as a single agent in colorectal cancer cells through the suppression of AKT/mTOR pathway.

The Role of Circular RNAs in Cerebral Ischemic Diseases: Ischemic Stroke and Cerebral Ischemia/Reperfusion Injury

Cerebral ischemic diseases including ischemic stroke and cerebral ischemia reperfusion injury can result in serious dysfunction of the brain, which leads to extremely high mortality and disability. There are no effective therapeutics for cerebral ischemic diseases to date. Circular RNAs are a kind of newly investigated noncoding RNAs. It is reported that circular RNAs are enriched in multiple organs, especially abundant in the brain, which indicates that circular RNAs may be involved in cerebral physiological and pathological processes. In this chapter, we will firstly review the pathophysiology, underlying mechanisms, and current treatments of cerebral ischemic diseases including ischemic stroke and cerebral ischemia/reperfusion injury. Secondly, the characteristics and function of circular RNAs will be outlined, and then we are going to introduce the roles circular RNAs play in human diseases. Finally, we will summarize the function of circular RNAs in cerebral ischemic diseases.

Silibinin inhibits the migration and invasion of human gastric cancer SGC7901 cells by downregulating MMP-2 and MMP-9 expression via the p38MAPK signaling pathway

The objective of the present study was to observe the effects of silibinin and the p38 mitogen-activated protein kinase (MAPK) signaling pathway inhibitor SB203580 on the migration and invasion capabilities of SGC7901 cells, and to explore the underlying associated mechanisms. Scratch, Transwell and Matrigel invasion assays were performed to study the effects of silibinin on cell migration and invasion. Western blot analysis was used to determine the expression levels of p38MAPK, phosphorylated (p-)p38MAPK, matrix metalloproteinase (MMP)-2 and MMP-9. At the genomic level, quantitative polymerase chain reaction was performed to evaluate the expression levels of MMP-2 and MMP-9. The results of scratch assay indicated that silibinin inhibited the migration capabilities of human gastric cancer SGC7901 cells in a dose-dependent manner. Additionally, Matrigel invasion and Transwell migration assays revealed that silibinin and SB203580 combined treatment significantly reduced the number of invasive cells. Western blot analysis indicated a reduced phosphorylation of p38MAPK without marked changes in p38MAPK expression. In addition, the expression of MMP-2 and MMP-9 significantly decreased in the presence of silibinin, SB203580, and the combination of silibinin and SB203580. In summary, silibinin decreased the invasion and migration abilities of SGC7901 cells by downregulating the expression of MMP-2 and MMP-9 through inhibiting p38MAPK signaling cascades.

Salvianolic acid B protects against myocardial damage caused by nanocarrier TiO2; and synergistic anti-breast carcinoma effect with curcumin via codelivery system of folic acid-targeted and polyethylene glycol-modified TiO2 nanoparticles

Targeted delivery by the folate ligand is an effective way to enhance an anti-breast carcinoma effect, due to its high affinity for the folate receptor, which is overexpressed in many tumor cells. In this study, we firstly synthesized a folic acid (FA)-targeted and polyethylene glycol (PEG)-modified TiO2 nanocarrier. Then, an FA-PEG-TiO2 nanoparticle (NP) codelivery system loaded with curcumin and salvianolic acid B were prepared by emulsion evaporation-solidification at low temperature. The obtained folate-targeted NPs (FA-NPs) showed more cytotoxicity on MCF7 cells and MDA-MB-231 cells than a nontargeted NP group. Apart from a synergistic anti-breast cancer effect with curcumin, salvianolic acid B protects the cardiovascular system from oxidative injury by the TiO2 nanocarrier. With coumarin 6 as a fluorescent probe to observe cellular uptake of NPs, the results of in vitro cellular uptake demonstrated FA-NPs exhibited higher cellular uptake and accumulation in MCF7 cells and MDA-MB-231 cells than nontargeted NPs. Then, in vivo biodistribution of NPs was further qualitatively and quantitatively confirmed by in vivo imaging. More importantly, the animal study further suggested that FA-NPs had significantly stronger antitumor effects via receptor-mediated targeted delivery. Consequently, FA-PEG-TiO2 NPs loaded with curcumin and salvianolic acid B could be a promising drug-delivery system to treat breast cancer.

AKT/mTOR signaling pathway is involved in salvianolic acid B-induced autophagy and apoptosis in hepatocellular carcinoma cells

Chinese medicines are emerging as an attractive new generation of anticancer drugs. Here, we explored the impact of salvianolic acid B (Sal B), the major water-soluble compounds of Danshen, on apoptosis and autophagy of human hepatocellular carcinoma cells (HCC). We also investigated the related molecular mechanisms. We found that Sal B exhibits potent ability to inhibit HCC cells viability in a concentration-dependent manner, and to induce apoptosis via the mitochondrial apoptosis pathway. Additionally, Sal B could also induce autophagy. Furthermore, pretreatment with the autophagy inhibitor chloroquine or 3-methyladenine showed the potential in attenuating the apoptosis rate induced by Sal B. Mechanistically, Sal B treatment inhibited the AKT/mTOR signaling cascade in vitro. Overexpression of AKT abolished the effects of Sal B on HCC cells, suggesting a critical role of the AKT/mTOR signaling pathway in Sal B-induced biological effects. Our results indicated that the mitochondrial pathway was involved in Sal B-induced apoptosis of HCC cells. Moreover, the AKT/mTOR signaling pathway was involved in Sal B-induced autophagy, which promoted apoptosis. This study may provide a promising strategy for using Sal B as a chemotherapeutic agent for patients with HCC.

Roles of Reactive Oxygen Species in Anticancer Therapy with Salvia miltiorrhiza Bunge

Cancer is a leading cause of death worldwide. We aim to provide a systematic review about the roles of reactive oxygen species (ROS) in anticancer therapy with Salvia miltiorrhiza Bunge (Danshen). Danshen, including its lipophilic and hydrophilic constituents, is potentially beneficial for treating various cancers. The mechanisms of ROS-related anticancer effects of Danshen vary depending on the specific type of cancer cells involved. Danshen may enhance TNF-α-induced apoptosis, upregulate caspase-3, caspase-8, caspase-9, endoplasmic reticulum stress, P21, P53, Bax/Bcl-2, DR5, and AMP-activated protein kinase, or activate the p38/JNK, mitogen-activated protein kinase, and FasL signaling pathways. Conversely, Danshen may downregulate human telomerase reverse transcriptase mRNA, telomerase, survivin, vascular endothelial growth factor/vascular endothelial growth factor receptor 2, CD31, NF-κB, Erk1/2, matrix metalloproteinases, microtubule assembly, and receptor tyrosine kinases including epidermal growth factor receptors, HER2, and P-glycoprotein and inhibit the PI3K/Akt/mTOR or estrogen receptor signaling pathways. Therefore, Danshen may inhibit cancer cells proliferation through antioxidation on tumor initiation and induce apoptosis or autophagy through ROS generation on tumor progression, tumor promotion, and tumor metastasis. Based on the available evidence regarding its anticancer properties, this review provides new insights for further anticancer research or clinical trials with Danshen.

Salvianolic acid B protects the myelin sheath around injured spinal cord axons

Salvianolic acid B, an active pharmaceutical compound present in Salvia miltiorrhiza, exerts a neuroprotective effect in animal models of brain and spinal cord injury. Salvianolic acid B can promote recovery of neurological function; however, its protective effect on the myelin sheath after spinal cord injury remains poorly understood. Thus, in this study, in vitro tests showed that salvianolic acid B contributed to oligodendrocyte precursor cell differentiation, and the most effective dose was 20 μg/mL. For in vivo investigation, rats with spinal cord injury were intraperitoneally injected with 20 mg/kg salvianolic acid B for 8 weeks. The amount of myelin sheath and the number of regenerating axons increased, neurological function recovered, and caspase-3 expression was decreased in the spinal cord of salvianolic acid B-treated animals compared with untreated control rats. These results indicate that salvianolic acid B can protect axons and the myelin sheath, and can promote the recovery of neurological function. Its mechanism of action is likely to be associated with inhibiting apoptosis and promoting the differentiation and maturation of oligodendrocyte precursor cells.

Polyphenols: Potential source of drugs for the treatment of ischaemic heart disease

Polyphenols, which are naturally present in plants, have been studied for their chemical and pharmacological properties. Polyphenols have been found to exhibit various bioactivities such as antioxidant, free radical scavenging and anti-inflammatory effects, in addition to regulating the intracellular free calcium levels. These bioactivities are related to the underlying mechanisms of ischaemic heart diseases. Pharmacological studies have proven polyphenols to be effective in treating cardiovascular diseases in various ways, particularly ischaemic heart diseases. Based on their mode of action, we propose that some polyphenols can be developed as drugs to treat ischaemic heart diseases. For this purpose, a strategy to evaluate the therapeutic value of drugs for ischaemic heart diseases is needed. Despite several advances in percutaneous coronary intervention (PCI), the incidence of myocardial infarction and deaths due to cardiovascular diseases has not decreased markedly in China. Due to their pleiotropic properties and structural diversity, polyphenols have been of great interest in pharmacology. In the present review, we summarize the pharmacological effects and mechanisms of polyphenols reported after 2000, and we analyse the benefits or druggability of these compounds for ischaemic heart diseases.

Aeroallergen Der p 2 induces apoptosis of bronchial epithelial BEAS-2B cells via activation of both intrinsic and extrinsic pathway

BACKGROUND

Excessive apoptosis of airway epithelium is reported to induce airway remodeling and inhibited airway epithelium repair is highly associated with development of asthma and chronic obstructive pulmonary disease. Der p 2 is a major allergen derived from Dermatophagoides pteronyssinus and commonly causes airway hypersensitiveness and asthma; however, the connection between Der p 2 and epithelial apoptosis remains unclear. This study was aimed to explore whether Der p 2 induces apoptosis of airway epithelial cells and the underlying mechanisms.

RESULTS

Our results showed that recombinant Der p 2 (rDP2) inhibited cell growth and induced apoptosis of human bronchial epithelial cell BEAS-2B. Further investigation revealed that rDP2 increased intracellular reactive oxygen species, level of cytosolic cytochrome c and cleavage of caspase-9 and caspase-3. rDP2 also induced activation of p38 mitogen-activated protein kinase (P38) and c-Jun N-terminal kinase (JNK), and triggered proapoptotic signals including decrease of Bcl-2, increase of Bax and Bak, and upregulation of Fas and Fas ligand. In parallel, rDP2 inhibited glycogen synthase kinase 3beta and consequently enhanced degradation of cellular (FADD-like IL-1β-converting enzyme)-inhibitory protein (c-FLIP). Involvement of toll-like receptor (TLR)2 in rDP2-induced apoptosis was also demonstrated using specific small inhibitory RNA.

CONCLUSIONS

Our findings indicate that rDP2 suppresses cell growth and trigger apoptosis of BEAS-2B cells, which may attribute to induction of both intrinsic and extrinsic pathway via TLR2 and P38/JNK signaling and c-FLIP degradation. It suggests that Der p 2 may aggravate respiratory disorders through enhancement of apoptosis and the consequent airway injury.

Naringin inhibits the invasion and migration of human glioblastoma cell via downregulation of MMP-2 and MMP-9 expression and inactivation of p38 signaling pathway

Gliomas are the most common and malignant primary brain tumors. They are associated with a poor prognosis despite the availability of multiple therapeutic options. Naringin, a common dietary flavonoid abundantly present in fruits and vegetables, is believed to possess strong anti-proliferative and anti-cancer properties. However, there are no reports describing its effects on the invasion and migration of glioblastoma cell lines. Our results showed that the treatment of U251 glioma cell lines with different concentrations of naringin inhibited the invasion and migration of these cells. In addition, we revealed a decrease in the levels of matrix metalloproteinases (MMP-2) and (MMP-9) expression as well as proteinase activity in U251 glioma cells. In contrast, the expression of tissue inhibitor of metalloproteinases (TIMP-1) and (TIMP-2) was increased. Furthermore, naringin treatment decreased significantly the phosphorylated level of p38. Combined treatment with a p38 inhibitor (SB203580) resulted in the synergistic reduction of MMP-2 and MMP-9 expressions correlated with an increase of TIMP-1 and TIMP-2 expressions and the anti-invasive properties. However, p38 chemical activator (anisomycin) could block these effects produced by naringin, suggesting a direct downregulation of the p38 signaling pathway. These data suggest that naringin may have therapeutic potential for controlling invasiveness of malignant gliomas by inhibiting of p38 signal transduction pathways.

An in vivo and in vitro study: High-dosage Danshen injection induces peripheral vascular endothelial cells injury

Danshen injection, a pharmaceutical dosage form of Danshen, has been widely used in the treatment of coronary heart diseases, myocardial infarction, and hypertension. With more and more adverse drug reactions linked with Danshen injection, its safety comes under suspicion. To evaluate its safety, mice were divided into four groups: vehicle, low-, middle-, and high-Danshen group, and each group was intravenously administered with Danshen injection at a dose of 0, 0.64, 1.55, and 5.76 g/kg/day for 5 days, respectively (the low dosage was the recommended clinical dosage, the middle dosage was the most commonly used higher dosage, and the high dosage was the highest dosage used in clinic). Peripheral vascular toxicity wasn't observed in the low-dosage group, elevated serum endothelin-1 (ET-1) was observed in the middle-dosage group; and more peripheral vascular toxicities like increased vascular leakage, elevated serum nitrate and ET-1, and vascular endothelial cells apoptosis were detected in the high-dosage group. In vitro study, low-concentration Danshen injection showed protective effect to human umbilical vein endothelial cells (HUVECs), while high concentration displayed strong cytotoxic effects, including increase in nitric oxide and ET-1 production, inhibition of cell viability, and apoptosis induction. Further, the HUVECs' apoptosis induced by high-concentration Danshen injection was found along with the induction of reactive oxygen species. In conclusion, these results suggest that Danshen injection is nontoxic in its recommended clinical dosage, and the 2.4-fold as the recommended clinical dosage might be the highest safety dosage in clinic treatment. In addition, Danshen injection is a potential vascular toxic drug in its high dosage and shouldn't be used far beyond its recommended dosage in clinic treatment.

Salvianolic acid B attenuates apoptosis and inflammation via SIRT1 activation in experimental stroke rats

Silent information regulator 1 (SIRT1), a histone deacetylase, has been suggested to be effective in ischemic brain diseases. Salvianolic acid B (SalB) is a polyphenolic and one of the active components of Salvia miltiorrhiza Bunge. Previous studies suggested that SalB is protective against ischemic stroke. However, the role of SIRT1 in the protective effect of SalB against cerebral ischemia has not been explored. In this study, the rat brain was subjected to middle cerebral artery occlusion (MCAO). Before this surgery, rats were intraperitoneally administrated SalB with or without EX527, a specific SIRT1 inhibitor. The infarct volume, neurological score and brain water content were assessed. In addition, levels of TNF-α and IL-1β in the brain tissues were detected by commercial ELISA kits. And the expression levels of SIRT, Ac-FOXO1, Bcl-2 and Bax were detected by Western blot. The results suggested that SalB exerted a cerebral-protective effect, as shown by reduced infarct volume, lowered brain edema and increased neurological scores. SalB also exerted anti-inflammatory effects as indicated by the decreased TNF-α and IL-1β levels in the brain tissue. Moreover, SalB upregulated the expression of SIRT1 and Bcl-2 and downregulated the expression of Ac-FOXO1 and Bax. These effects of SalB were abolished by EX527 treatment. In summary, our results demonstrate that SalB treatment attenuates brain injury induced by ischemic stoke via reducing apoptosis and inflammation through the activation of SIRT1 signaling.

Matrine inhibits the invasive properties of human glioma cells by regulating epithelial‑to‑mesenchymal transition

Matrine is reported to be effective in tumor therapies; however, the anti‑metastatic effect and molecular mechanism(s) of matrine on glioma remain poorly understood. Therefore, the purpose of this study was to assess the effects of matrine on glioma and the associated mechanism(s). In the study, we demonstrated that matrine inhibited the proliferation of glioma cells. We also observed that matrine inhibited the migration and invasion of glioma cells at non‑toxic concentrations. Matrine also decreased the expression of E‑cadherin and increased the expression of N‑cadherin. These results suggest that the anti‑metastatic effect of matrine may be correlated with epithelial‑to‑mesenchymal transition (EMT). Moreover, matrine could reduce the phosphorylation levels of p38 and AKT proteins. In conclusion, these results suggest matrine may be a potential alternative against invasive glioma cells via the p38 MAPK and AKT signaling‑dependent inhibition of EMT.

Baicalein inhibits the invasion of gastric cancer cells by suppressing the activity of the p38 signaling pathway

Baicalein, one of the major flavonoids in Scutellaria baicalensis, has been used in anti-inflammatory and anticancer therapies for a long time. However, the antimetastatic effects and related mechanism(s) in gastric cancer remain unclear. In the present study, we tested the hypothesis that administration of baicalein may inhibit the proliferation, motility and invasion of human gastric cancer cell lines by regulating the p38 signaling pathway. In the present study, we found that baicalein could inhibit migration and invasion of gastric cancer cells. Additionally, after treating with baicalein for 24 h, the expression levels of matrix metalloproteinase (MMP)-2 and -9 as well as proteinase activity in gastric cancer cells were reduced in a dose-dependent manner. Moreover, baicalein clearly reduced the phosphorylated levels of p38. Combined treatment with p38 activator partially blocked the antimetastatic effects of baicalein, while p38 inhibitor (SB203580) and baicalein resulted in a synergistic reduction in MMP-2 and -9 expression; the invasive ability of gastric cancer cells was also inhibited. In conclusion, baicalein inhibits gastric cancer cell invasion and metastasis by reducing cell motility and migration via suppression of the p38 signaling pathway, suggesting that baicalein is a potential therapeutic agent for gastric cancer.

Salvianolic acid B attenuates toxin-induced neuronal damage via Nrf2-dependent glial cells-mediated protective activity in Parkinson's disease models

Salvianolic acid B (SalB), a bioactive compound isolated from the plant-derived medicinal herb Danshen, has been shown to exert various anti-oxidative and anti-inflammatory activities in several neurological disorders. In this study, we sought to investigate the potential protective effects and associated molecular mechanisms of SalB in Parkinson’s disease (PD) models. To determine the neuroprotective effects of SalB in vitro, MPP⁺- or lipopolysaccharide (LPS)-induced neuronal injury was achieved using primary cultures with different compositions of neurons, microglia and astrocytes. Our results showed that SalB reduced both LPS- and MPP⁺-induced toxicity of dopamine neurons in a dose-dependent manner. Additionally, SalB treatment inhibited the release of microglial pro-inflammatory cytokines and resulted in an increase in the expression and release of glial cell line-derived neurotrophic factor (GDNF) from astrocytes. Western blot analysis illustrated that SalB increased the expression and nuclear translocation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2). The knockdown of Nrf2 using specific small interfering RNA (siRNA) partially reversed the SalB-induced GDNF expression and anti-inflammatory activity. Moreover, SalB treatment significantly attenuated dopaminergic (DA) neuronal loss, inhibited neuroinflammation, increased GDNF expression and improved the neurological function in MPTP-treated mice. Collectively, these findings demonstrated that SalB protects DA neurons by an Nrf-2 -mediated dual action: reducing microglia activation-mediated neuroinflammation and inducing astrocyte activation-dependent GDNF expression. Importantly the present study also highlights critical roles of glial cells as targets for developing new strategies to alter the progression of neurodegenerative disorders.

Longikaurin A, a natural ent-kaurane, induces G2/M phase arrest via downregulation of Skp2 and apoptosis induction through ROS/JNK/c-Jun pathway in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer, and is also highly resistant to conventional chemotherapy treatments. In this study, we report that Longikaurin A (LK-A), an ent-kaurane diterpenoid isolated from the plant Isodon ternifolius, induced cell cycle arrest and apoptosis in human HCC cell lines. LK-A also suppressed tumor growth in SMMC-7721 xenograft models, without inducing any notable major organ-related toxicity. LK-A treatment led to reduced expression of the proto-oncogene S phase kinase-associated protein 2 (Skp2) in SMMC-7721 cells. Lower Skp2 levels correlated with increased expression of p21 and p-cdc2 (Try15), and a corresponding decrease in protein levels of Cyclin B1 and cdc2. Overexpression of Skp2 significantly inhibited LK-A-induced cell cycle arrest in SMMC-7721 cells, suggesting that LK-A may target Skp2 to arrest cells at the G2/M phase. LK-A also induced reactive oxygen species (ROS) production and apoptosis in SMMC-7721 cells. LK-A induced phosphorylation of c-Jun N-terminal kinase (JNK), but not extracellular signal-regulated kinase and P38 MAP kinase. Treatment with, the JNK inhibitor SP600125 prevented LK-A-induced apoptosis in SMMC-7721 cells. Moreover, the antioxidant N-acetylcysteine prevented phosphorylation of both JNK and c-Jun. Taken together, these data indicate that LK-A induces cell cycle arrest and apoptosis in cancer cells by dampening Skp2 expression, and thereby activating the ROS/JNK/c-Jun signaling pathways. LK-A is therefore a potential lead compound for development of antitumor drugs targeting HCC.

Baicalein reduces the invasion of glioma cells via reducing the activity of p38 signaling pathway

Baicalein, one of the major flavonids in Scutellaria baicalensis, has historically been used in anti-inflammatory and anti-cancer therapies. However, the anti-metastatic effect and related mechanism(s) in glioma are still unclear. In this study, we thus utilized glioma cell lines U87MG and U251MG to explore the effect of baicalein. We found that administration of baicalein significantly inhibited migration and invasion of glioma cells. In addition, after treating with baicalein for 24 h, there was a decrease in the levels of matrix metalloproteinase-2 (MMP-2) and MMP-9 expression as well as proteinase activity in glioma cells. Conversely, the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2 was increased in a dose-dependent manner. Moreover, baicalein treatment significantly decreased the phosphorylated level of p38, but not ERK1/2, JNK1/2 and PI3K/Akt. Combined treatment with a p38 inhibitor (SB203580) and baicalein resulted in the synergistic reduction of MMP-2 and MMP-9 expression and then increase of TIMP-1 and TIMP-2 expression; and the invasive capabilities of U87MG cells were also inhibited. However, p38 chemical activator (anisomycin) could block these effects produced by baicalein, suggesting baicalein directly downregulate the p38 signaling pathway. In conclusion, baicalein inhibits glioma cells invasion and metastasis by reducing cell motility and migration via suppression of p38 signaling pathway, suggesting that baicalein is a potential therapeutic agent for glioma.

Salvianolic acid B attenuates spinal cord ischemia-reperfusion-induced neuronal injury and oxidative stress by activating the extracellular signal-regulated kinase pathway in rats

BACKGROUND

Salvianolic acid B (SalB), the main bioactive compound isolated from the traditional Chinese medicinal herb broad Radix Salviae Miltiorrhizae exerts a spectrum of pharmacologic activities. We investigated the effects of SalB treatment in a rat model of spinal cord ischemia and reperfusion (I/R) injury and the underlying mechanism.

MATERIALS AND METHODS

SalB was administered at 1, 10, or 50 mg/kg after spinal cord ischemia. The potential protective effects on spinal cord injury were determined by spinal cord edema, infarct volume, and motor function assessment of the hind limbs.

RESULTS

SalB treatment significantly decreased spinal cord edema and infarct volume and preserved motor function of the hind limbs in a dose-dependent manner. SalB administration ameliorated the generation of oxidative products and preserved antioxidant defense activities in the injured spinal cord at both 4 and 24 h after I/R injury. Moreover, SalB prolonged the I/R injury-induced activation of extracellular signal-regulated kinase (ERK), and blocking ERK activation with PD98059 partially prevented the neuroprotective effects of SalB.

CONCLUSIONS

These findings demonstrate the neuroprotective effects of SalB in a spinal cord I/R injury model and suggest that SalB-induced neuroprotection was mediated by ERK activation.