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• 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]