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Background: Doxorubicin (DOX) is a broad-spectrum anti-tumor drug that has been associated with cardiotoxicity. Plant extracts have been shown to confer protection against DOX-induced cardiotoxicity. Apocynum venetum L. belongs to the Apocynaceae family. Flavonoid extracted from Apocynum venetum L. possess various biological effects, such as lowering blood pressure levels, sedation, diuresis, anti-aging, and improving immunity.Purpose: This study investigated the mechanism by which dry leaf extract of Apocynum venetum L. (AVLE) alleviates DOX-induced cardiomyocyte apoptosis.Methods: HPLC-MS/MS and HPLC methods were used to analyze the components of AVLE. The effects of DOX and AVLE on apoptosis of H9c2 and HMC cells were assessed using the MTT assay. Calcein AM/PI, TUNEL, and flow cytometry were carried out to determine the effects of AVLE on DOX-induced apoptosis. The effect of AVLE on DOX-induced oxidative stress in cardiomyocytes was investigated using ELISA test. Mito-Tracker Red CMXRos, JC-1, and RT-qPCR assays were performed to evaluate the impact of AVLE on DOX-induced cardiomyocyte mitochondrial activity and membrane permeability. Western blot assay was carried out to determine the activation of multiple signaling molecules, including phosphorylated-protein kinase B (p-AKT), Cytochrome c, Bcl-2 family, and caspase family in the apoptosis pathway. The AKT inhibitor was used to block AKT/Bcl-2 signaling pathway to investigate the role of AKT in the protection conferred by AVLE against DOX-induced cardiotoxicity.Results: A total of 8 compounds, including rutin, hyperoside, isoquercetin, unidentified compounds, myricetin, quercetin, quercetin-3-O-glucuronide and kaempferol, were detected in AVLE. Of note, DOX suppressed lactate dehydrogenase (LDH) levels, aggravated oxidative stress, and promoted cardiomyocyte apoptosis. It also upregulated the mRNA expression levels of voltage-dependent anion channel 1 (VDAC1), adenosine nucleotide transporter 1 (ANT1), and cyclophilin D (CYPD), while suppressing mitochondrial activity and mitochondrial membrane permeability. Treatment with DOX altered the expression levels of apoptosis-associated proteins, Bcl-2 and Bax. However, AVLE treatment alleviated DOX-induced effects on cardiomyocytes. In addition, application of AKT inhibitors promoted DOX-induced apoptosis and reversed the inhibitory effects of AVLE on DOX-induced apoptosis.Conclusions: AVLE confer cardio protection by suppressing oxidative stress and apoptosis of cardiomyocytes via AKT/Bcl-2 signaling pathway. [ABSTRACT FROM AUTHOR]

Background and Purpose: Gastric cancer is one of the major malignancies worldwide. Epiberberine (EPI) is a major alkaloid from Coptis chinensis Franch and the antitumor property of EPI remains poorly understood.Method: The inhibition on gastric cancer cells was observed by MTT assays and colony formation experiments. The apoptosis, cell cycle, and reactive oxygen species (ROS) and mitochondrial membrane potential (ΔΨm) in gastric cancer cells were analyzed by Flow cytometry. The anti-tumor effect of EPI was evaluated with the MKN-45-beraring nude mice, and the potential mechanisms were explored by RNA-seq, qPCR, siRNA silencing and western blotting.Results: EPI inhibited the proliferation of human gastric cancer cell lines MKN-45 (harboring wild-type p53) and HGC-27 (harboring mutant p53) in a dose dependent manner. EPI induced the apoptosis and cell cycle arrest in these two cell lines, of which MKN-45 cells are more sensitive to EPI than HGC-27 cells. Further experiments indicated that EPI induced the accumulation of ROS and decreased of ΔΨm in MKN-45 cells. The significant differentially expressed genes obtained by RNA-seq were distinctly enriched in the p53 signaling pathway. The apoptosis induced by EPI in MKN-45 cells would be effectively inhibited with the treatment of p53 siRNA and p53 inhibitor PFT-α. Western blotting demonstrated that EPI diminished the expression of Bcl-2 and XIAP, and increased those of p53, Bax, p21, p27, Cytochrome C and Cleaved-caspase 3. Animal experiments confirmed that EPI significantly alleviated tumor growth in MKN-45 xenograft mice via p53/Bax pathway.Conclusions: These data indicated that EPI could be a novel anti-tumor candidate against MKN-45-related gastric cancer via targeting p53-dependent mitochondria-associated pathway. [ABSTRACT FROM AUTHOR]

• Cucurbitacin IIb (CuIIb) exhibited the proliferation inhibitory activity in A549 cells. • CuIIb induced apoptosis via STAT3 pathway. • CuIIb suppressed the cell cycle and resulted G2/M phase cell cycle arrest. • Leu694 and Met769 are key amino acids for EGFR-CuIIb binding. • CuIIb inhibited the kinase activity of EGFR and may serve as a potential EGFR TKI. Epidermal growth factor receptor (EGFR) is considered as a valid target in the clinical trials of anticancer therapy and tyrosine kinase inhibitors (TKIs) of EGFR are approved for cancer treatments. In present work, cucurbitacin IIb (CuIIb) was confirmed to exhibit the proliferation inhibitory activity in A549 cells. CuIIb induced apoptosis via STAT3 pathway, which was mitochondria-mediated and caspase-dependent. CuIIb also suppressed the cell cycle and induced G2/M phase cell cycle arrest. CuIIb was capable of suppressing the signal transmitting of the EGFR/mitogen-activated protein kinase (MAPK) pathway which was responsible for the apoptosis and cell cycle arrest. Homogeneous time-resolved fluorescence (HTRF) analysis demonstrated that the kinase activity of EGFR was inhibited by CuIIb. Molecular docking suggested that the CuIIb-EGFR binding fundamentally depends on the contribution of both hydrophobic and hydrogen-bonding interactions. Hence CuIIb may serve as a potential EGFR TKI. [ABSTRACT FROM AUTHOR]

• An anti-leukemia polysaccharide (APS-2I) was isolated from Chinese Angelica root. • The APS-2I digested fraction (G-4) exhibits higher anti-leukemia effect than APS-2I in vitro and vivo. • APS-2I and G-4 bind to Gal-3 with Kd of 9.35 ± 0.3 μM and 1.97 ± 0.7 μM respectively. • Backbone of APS-2I contains 1,4-Gal p A, 1,4-Gal p 6Me,1,3-Rha p , 1,2,6-Man p, 1,6-Gal p and 1,2-Man p. • Branches of APS-2I contains T-Ara f, 1,4-Gal p , 1,3-Ara f , 1,5-Ara f and 1,3,5-Ara f , 1,6-Gal p. Galectin-3 (Gal-3) is a potential target for acute myeloid leukemia therapeutics which contains a carbohydrate-recognition domain. However, the development of polysaccharide inhibitors against Gal-3 is insufficient. In this research, we found a polysaccharide from Angelica sinensis (Oliv.) Diels, named APS-2I, that can bind to Gal-3 with dissociation constant (Kd) of 9.35 ± 0.3 μM and activate the intrinsic apoptosis pathways to induce leukemia cells apoptosis. APS-2I is a homogeneous polysaccharide with a molecular weight of 7.2 × 105 Da, that composes of mannose, rhamnose, galacturonic acid, glucose, galactose and arabinose with a ratio of 4:5:1:10:23:39. In addition, a galactosidase digested fraction of APS-2I named G-4 showed higher affinity to Gal-3 with the Kd of 1.97 ± 0.7 μM and higher apoptosis inducing effect on leukemia cells, which demonstrated that G-4 contains the bio-active structural region of APS-2I. This study provides effective basis for structural analysis and the anti-leukemia mechanism of Angelica polysaccharide APS-2I. [ABSTRACT FROM AUTHOR]

Polycystic ovary syndrome (PCOS) is characterized by reproductive, endocrine, and metabolic disorders. Icariin has been shown to regulate endocrine and metabolic imbalances. This study aimed to determine the therapeutic effect and pharmacological mechanism of icariin in PCOS rats. Rats were fed a high-fat diet and gavaged with letrozole to induce PCOS. Thirty-six female rats were randomly divided into four groups: control, model, low-dose, and high-dose icariin. After 30 days of treatment, we evaluated the therapeutic effects on weight and diet, sex hormone levels, ovarian morphology, estrous cycle, inflammatory factors, and indicators of glucolipid metabolism. Combined with the ovarian transcriptome, we verified the key markers of apoptosis and the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway by RT-qPCR for mRNA level, western blot, and immunohistochemistry for protein expression. Icariin significantly improved ovarian function and reproductive endocrine disorders by regulating sex hormones, restoring the estrous cycle, and reducing ovarian morphological damage in PCOS rats. Icariin-treated rats had lower weight gain and reduced triglycerides, fasting insulin, HOMA-IR, TNF-α, and interleukin-6 with higher high-density lipoprotein cholesterol levels than PCOS rats. TUNEL staining showed icariin improved apoptosis in the ovaries. This was supported by an increase in Bcl2 and a decrease in Bad and Bax. Icariin decreased the ratios of p-JAK2/JAK2, p-STAT1/STAT1, p-STAT3/STAT3, and p-STAT5a/STAT5a, decreased IL-6, gp130 expression, and increased cytokine-inducible SH2-containing protein (CISH) and suppressor of cytokine signaling 1 (SOCS1) expression. The pharmacological mechanism may be related to the reduction in ovarian apoptosis and inhibition of the IL-6/gp130/JAK2/STATs pathway. [ABSTRACT FROM AUTHOR]

Cerebral ischemic stroke has long been recognized as a prevalent and serious neurological disease that was associated with high mortality and morbidity. However, the current therapeutic protocols remain suboptimal with major mechanisms underlying stroke urgently warranted. Inhibitor of DNA binding/differentiation 2 (Id2) is found to be up-regulated in neuronal cells following hypoxia/ischemia (H/I). This study was aimed to investigate whether knockdown of Id2 in neuronal cells could protect them from hypoxic and ischemic injury both in vitro and in vivo . Flow cytometric analysis was employed to assess neuronal apoptosis in CoCl 2 -treated neuroblastoma B35 cells engineered to overexpress or knockdown Id2 expression. In vivo knockdown of Id2 was performed in Sprague-Dawley rats by a single intracerebroventricular injection of Cy3-labeled and cholesterol-modified Id2-siRNA. We found that knockdown of Id2 attenuated H/I-induced neuronal apoptosis in vitro while overexpression of Id2 produced an opposite effect. In a rat model of middle cerebral artery occlusion (MCAO), in vivo knockdown of Id2 significantly improved neurological deficits, reduced the volume of ischemic infarction and diminished the neuronal apoptosis in the penumbra area. Double immunofluorescence staining showed less co-localization of retinoblastoma tumor suppressor protein (Rb)-Id2 but greater co-localization of Rb-E2F1 in the penumbra area. Cell cycle assay further demonstrated that Id2 knockdown induced G0/G1 cell cycle arrest in CoCl 2 -treated B35 cells. The present data support the implication of Id2 in the modulation of H/I-induced neuronal apoptosis and may provide a potential therapeutic option to protect brain tissues from ischemic injury by inhibition of its expression. [ABSTRACT FROM AUTHOR]

Highlights: [•] Id2 mRNA and protein are up-regulated in neuronal cells in vivo and in vitro. [•] The increased expression of Id2 might be associated with neuronal apoptosis. [•] The up-regulation of Id2 is consistent with the enhanced expression of Bax. [•] Co-localization of Id2, TUNEL and NeuN was observed in ischemic neurons. [ABSTRACT FROM AUTHOR]