Combining structure-based pharmacophore modeling and machine learning for the identification of novel BTK inhibitors.

Bruton's tyrosine kinase (BTK) is a critical enzyme which is involved in multiple signaling pathways that regulate cellular survival, activation, and proliferation, making it a major cancer therapeutic target. We applied the novel integrated structure-based pharmacophore modeling, machine learning, and other in silico studies to screen the Korean chemical database (KCB) to identify the potential BTK inhibitors (BTKi). Further evaluation of these inhibitors on three different human cancer cell lines showed significant cell growth inhibitory activity. Among the 13 compounds shortlisted, four demonstrated consistent cell inhibition activity among breast, gastric, and lung cancer cells (IC50 below 3 µM). The selected compounds also showed significant kinase inhibition activity (IC50 below 5 µM). The current study suggests the potential of these inhibitors for targeting BTK malignant tumors.

Comparative proteomic analysis uncovers potential biomarkers involved in the anticancer effect of Scutellarein in human gastric cancer cells.

Scutellarein (SCU), a flavone that belongs to the flavonoid family and abundantly present in Scutellaria baicalensis a flowering plant in the family Lamiaceae, has been reported to exhibit anticancer effects in several cancer cell lines including gastric cancer (GC). Although our previous study documented the mechanisms of Scutellarein­induced cytotoxic effects, the literature shows that the proteomic changes that are associated with the cellular response to SCU have been poorly understood. To avoid adverse side­effects and significant toxicity of chemotherapy in patients who react poorly, biomarkers anticipating therapeutic responses are imperative. In the present study, we utilized a comparative proteomic analysis to identify proteins associated with Scutellarein (SCU)­induced cell death in GC cells (AGS and SNU484), by integrating two­dimensional gel electrophoresis (2­DE), mass spectrometry (MS), and bioinformatics to analyze the proteins. Proteomic analysis between SCU­treated and DMSO (control) samples successfully identified 41 (AGS) and 31 (SNU484) proteins by MALDI­TOF/MS analysis and protein database search. Comparative proteomics analysis between AGS and SNU484 cells treated with SCU revealed a total of 7 protein identities commonly expressed and western blot analysis validated a subset of identified critical proteins, which were consistent with those of the 2­DE outcome. Molecular docking studies also confirmed the binding affinity of SCU towards these critical proteins. Phosphatidylinositol 4,5­bisphosphate 3­kinase catalytic subunit ß isoform (PIK3CB) protein expression was accompanied by a distinct group of cellular functions, including cell growth, and proliferation. Cancerous inhibitor of protein phosphatase 2A (CIP2A), is one of the oncogenic molecules that have been shown to promote tumor growth and resistance to apoptosis and senescence­inducing therapies. In the present study, both PIK3CB and CIP2A proteins were downregulated in SCU­treated cells, which boosts our previous results of SCU to induce apoptosis and inhibits GC cell growth by regulating these critical proteins. The comparative proteomic analysis has yielded candidate biomarkers of response to SCU treatment in GC cell models and further validation of these biomarkers will help the future clinical development of SCU as a novel therapeutic drug.

Artemisia iwayomogi (Dowijigi) inhibits lipopolysaccharide-induced inflammation in RAW264.7 macrophages by suppressing the NF-κB signaling pathway.

Inflammatory diseases are an important health concern and have a growing incidence worldwide. Thus, developing novel and safe drugs to treat these disorders remains an important pursuit. Artemisia iwayomogi, locally known as Dowijigi (DJ), is a perennial herb found primarily in Korea and is used to treat various diseases such as hepatitis, inflammation and immune disorders. In the present study, the anti-inflammatory effects of a polyphenolic extract from the DJ flower (PDJ) in lipopolysaccharide (LPS)-stimulated mouse macrophage RAW264.7 cells were investigated. Cell cytotoxicity was assessed using the MTT assay. The production of nitric oxide (NO) and prostaglandin E2 (PGE2) was measured by Griess and ELISA analysis, respectively. The expression levels of inducible nitric oxide (iNOS) and cyclooxygenase-2 (COX2) were examined by western blot analysis. Reverse transcription-quantitative PCR was performed to detect the mRNA expression levels of pro-inflammatory cytokines, including tumor necrosis factor α (TNFα), interleukin (IL)-6 and IL-1ß, as well as COX2 and iNOS. The production of NO and PGE2 was significantly decreased following treatment with PDJ. The mRNA expression levels of TNFα, IL-6, IL-1ß, COX2 and iNOS were significantly decreased in LPS-induced PDJ co-treated cells compared with the group treated with LPS alone. Western blot analysis indicated that PDJ downregulated the LPS-induced expression of iNOS and COX2, as well as the expression of NF-κB proteins. In conclusion, the present study demonstrated that PDJ exerted anti-inflammatory effects in LPS-induced macrophage cells by suppressing the NF-κB signaling pathway. Therefore, PDJ may be used as a potential therapeutic agent in inflammation.

LC-MS/MS characterization, anti-inflammatory effects and antioxidant activities of polyphenols from different tissues of Korean Petasites japonicus (Meowi).

The Korean Petasites japonicus is a perennial plant used in folk medicine as a remedy for many diseases and popularly consumed as spring greens. Ten polyphenols were characterized from the leaves, stems and roots of this plant via high-performance liquid chromatography-tandem mass spectrometry. Individual polyphenols were quantified for the first time using calibration curves of six structurally related external standards. Validation data indicated that coefficients of determinations (R2 ) were ≥0.9702 for all standards. Recoveries measured at 50 and 100 mg/L were 80.0-91.9 and 80.3-105.3%, respectively. Precisions at these two concentration levels were 0.7-6.1 and 1.1-5.5%, respectively. The total number of identified components was largest for the leaves and smallest for the stems. The leaf and root polyphenolic extracts showed anti-inflammatory effects by inducing LPS-activated COX-2 and iNOS protein levels in mouse macrophage RAW 264.7 cells. The antioxidant capacity of the polyphenols, when evaluated for DPPH (α,α-diphenyl-ß-picrylhydrazyl)ˑ , ABTS+ [2-2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] and superoxide radical scavenging activities, and in ferric reducing ability of plasma (FRAP) assays, was highest in the leaf and lowest in the stem. This trend suggests that the antioxidant capacities depend primarily on polyphenol concentration in each tissue. The current findings suggest that polyphenols derived from P. japonicas tissues could have potential as functional health foods.

Flavonoids isolated from Citrus platymamma induced G2/M cell cycle arrest and apoptosis in A549 human lung cancer cells.

Citrus platymamma hort. ex Tanaka belongs to the Rutaceae family and is widely used in folk medicines in Korea due to its anti-proliferative, anti-cancer, anti-oxidant, anti-inflammatory and anti-diabetic activities. However, the molecular mechanism of its anti-cancer effect is not well understood. The present study was conducted to elucidate the anti-cancer effect and molecular mechanism of flavonoids from Citrus platymamma (FCP) on A549 cells. FCP displayed concentration-dependent inhibition on A549 cells proliferation. Further, flow cytometry revealed that FCP significantly increased the sub-G1 (apoptotic cell population) and G2/M phase population, and the total number of apoptotic cells, in a dose-dependent manner. Nuclear condensation and fragmentation were also observed upon staining with Hoechst 33342 in FCP-treated A549 cells. Immunoblotting demonstrated a dose-dependent downregulation of cyclin B1, cyclin-dependent kinase 1, cell division cycle 25c, pro-caspases -3, -6, -8 and -9, and poly (adenosine diphosphate-ribose) polymerase (PARP) in FCP-treated A549 cells. In addition, FCP induced caspase-3 activation and subsequent PARP cleavage, and increased the B-cell lymphoma (Bcl)-2-associated X protein/Bcl-extra large ratio in A549 cells. These findings suggest that FCP induced G2/M arrest and apoptosis of A549 cells. The present study provides evidence that FCP may be useful in the treatment of human lung cancer.

Mitochondrial Dysfunction and Ca(2+) Overload Contributes to Hesperidin Induced Paraptosis in Hepatoblastoma Cells, HepG2.

Paraptosis is a programmed cell death which is morphologically and biochemically different from apoptosis. In this study, we have investigated the role of Ca(2+) in hesperidin-induced paraptotic cell death in HepG2 cells. Increase in mitochondrial Ca(2+) level was observed in hesperidin treated HepG2 cells but not in normal liver cancer cells. Inhibition of inositol-1,4,5-triphosphate receptor (IP3 R) and ryanodine receptor also block the mitochondrial Ca(2+) accumulation suggesting that the release of Ca(2+) from the endoplasmic reticulum (ER) may probably lead to the increase in mitochondrial Ca(2+) level. Pretreatment with ruthenium red (RuRed), a Ca(2+) uniporter inhibitor inhibited the hesperidin-induced mitochondrial Ca(2+) overload, swelling of mitochondria, and cell death in HepG2 cells. It has also been demonstrated that mitochondrial Ca(2+) influxes act upstream of ROS and mitochondrial superoxide production. The increased ROS production further leads to mitochondrial membrane loss in hesperidin treated HepG2 cells. Taken together our results show that IP3 R and ryanodine receptor mediated release of Ca(2+) from the ER and its subsequent influx through the uniporter into mitochondria contributes to hesperidin-induced paraptosis in HepG2 cells.

Flavonoids of Korean Citrus aurantium L. Induce Apoptosis via Intrinsic Pathway in Human Hepatoblastoma HepG2 Cells.

Korean Citrus aurantium L. has long been used as a medicinal herb for its anti-inflammatory, antioxidant, and anticancer properties. The present study investigates the anticancer role of flavonoids extracted from C. aurantium on human hepatoblastoma cell, HepG2. The Citrus flavonoids inhibit the proliferation of HepG2 cells in a dose-dependent manner. This result was consistent with the in vivo xenograft results. Apoptosis was detected by cell morphology, cell cycle analysis, and immunoblot. Flavonoids decreased the level of pAkt and other downstream targets of phosphoinositide-3-kinase/Akt pathway - P-4EBP1 and P-p70S6K. The expressions of cleaved caspase 3, Bax, and Bak were increased, while those of Bcl-2 and Bcl-xL were decreased with an increase in the expression of Bax/Bcl-xL ratio in treated cells. Loss of mitochondrial membrane potential was also observed in flavonoid-treated HepG2 cells. It was also observed that the P-p38 protein level was increased both dose and time dependently in flavonoid-treated cells. Collectively, these results suggest that flavonoid extracted from Citrus inhibits HepG2 cell proliferation by inducing apoptosis via an intrinsic pathway. These findings suggest that flavonoids extracted from C. aurantium L. are potential chemotherapeutic agents against liver cancer.

Poncirin Induces Apoptosis in AGS Human Gastric Cancer Cells through Extrinsic Apoptotic Pathway by up-Regulation of Fas Ligand.

Poncirin, a natural bitter flavanone glycoside abundantly present in many species of citrus fruits, has various biological benefits such as anti-oxidant, anti-microbial, anti-inflammatory and anti-cancer activities. The anti-cancer mechanism of Poncirin remains elusive to date. In this study, we investigated the anti-cancer effects of Poncirin in AGS human gastric cancer cells (gastric adenocarcinoma). The results revealed that Poncirin could inhibit the proliferation of AGS cells in a dose-dependent manner. It was observed Poncirin induced accumulation of sub-G1 DNA content, apoptotic cell population, apoptotic bodies, chromatin condensation, and DNA fragmentation in a dose-dependent manner in AGS cells. The expression of Fas Ligand (FasL) protein was up-regulated dose dependently in Poncirin-treated AGS cells Moreover, Poncirin in AGS cells induced activation of Caspase-8 and -3, and subsequent cleavage of poly(ADP-ribose) polymerase (PARP). Inhibitor studies' results confirm that the induction of caspase-dependent apoptotic cell death in Poncirin-treated AGS cells was led by the Fas death receptor. Interestingly, Poncirin did not show any effect on mitochondrial membrane potential (ΔΨm), pro-apoptotic proteins (Bax and Bak) and anti-apoptotic protein (Bcl-xL) in AGS-treated cells followed by no activation in the mitochondrial apoptotic protein caspase-9. This result suggests that the mitochondrial-mediated pathway is not involved in Poncirin-induced cell death in gastric cancer. These findings suggest that Poncirin has a potential anti-cancer effect via extrinsic pathway-mediated apoptosis, possibly making it a strong therapeutic agent for human gastric cancer.

Naringin induces autophagy-mediated growth inhibition by downregulating the PI3K/Akt/mTOR cascade via activation of MAPK pathways in AGS cancer cells.

Naringin, one of the major bioflavonoid of Citrus, has been demonstrated as potential anticancer agent. However, the underlying anticancer mechanism still needs to be explored further. This study investigated the inhibitory effect of Naringin on human AGS cancer cells. AGS cell proliferation was inhibited by Naringin in a dose- and time-dependent manner. Naringin did not induce apoptotic cell death, determined by no DNA fragmentation and the reduced Bax/Bcl-xL ratio. Growth inhibitory role of Naringin was observed by western blot analysis demonstrating downregulation of PI3K/Akt/mTOR cascade with an upregulated p21CIPI/WAFI. Formation of cytoplasmic vacuoles and autophagosomes were observed in Naringin-treated AGS cells, further confirmed by the activation of autophagic proteins Beclin 1 and LC3B with a significant phosphorylation of mitogen activated protein kinases (MAPKs). Collectively, our observed results determined that anti-proliferative activity of Naringin in AGS cancer cells is due to suppression of PI3K/Akt/mTOR cascade via induction of autophagy with activated MAPKs. Thus, the present finding suggests that Naringin induced autophagy- mediated growth inhibition shows potential as an alternative therapeutic agent for human gastric carcinoma.

Flavonoids isolated from Citrus platymamma induce mitochondrial-dependent apoptosis in AGS cells by modulation of the PI3K/AKT and MAPK pathways.

Citrus platymamma hort. ex Tanaka (Rutaceae family) has been widely used in Korean folk medicine for its wide range of medicinal benefits including an anticancer effect. In the present study, we aimed to investigate the molecular mechanism of the anticancer effects of flavonoids isolated from Citrus platymamma (FCP) on AGS cells. FCP treatment significantly inhibited AGS cell growth in a dose­dependent manner. Furthermore, FCP significantly increased the percentage of cells in the sub-G1 phase (apoptotic cell population), and apoptosis was confirmed by Annexin V double staining. Chromatin condensation and apoptotic bodies were also noted in the FCP-treated AGS cells. Moreover, immunoblotting results showed that FCP treatment significantly decreased the expression of procaspase-3, -6, -8 and -9, and PARP and increased cleaved caspase-3, cleaved PARP and the Bax/Bcl-xL ratio in a dose-dependent manner. In addition, the phosphorylation of AKT was significantly decreased, whereas extracellular signal-related kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinases (MAPKs) were significantly increased in the FCP-treated AGS cells. Taken together, the cell death of AGS cells in response to FCP was mitochondrial-dependent via modulation of the PI3K/AKT and MAPK pathways. These findings provide new insight for understanding the mechanism of the anticancer effects of FCP. Thus, FCP may be a potential chemotherapeutic agent for the treatment of gastric cancer.

Proteome profiling of lipopolysaccharide induced L6 rat skeletal muscle cells response to flavonoids from Scutellaria baicalensis Georgi.

BACKGROUND: Scutellaria baicalensis Georgi is a commonly used medicinal herb in several Asian countries like Korea, China and Japan for thousands of years. It has been reported to have various medicinal properties such as anti-microbial, anti-inflammatory and anti-cancer effects. However, the anti-inflammatory mechanism of S. baicalensis G at proteome level has not yet been reported. Hence, we performed a proteome analysis to study differentially expressed proteins and its anti-inflammatory role in lipopolysaccharide (LPS) stimulated L6 skeletal muscle cells response to flavonoids isolated from S. baicalensis G. METHODS: For that, 150 µg of proteins from the L6 cells of the control (Vehicle only), LPS treated and flavonoid treated groups were separated using 18 cm, pH 4-7 IPG strips in the first dimension and resolved by 12% linear gradient SDS-polyacrylamide gel electrophoresis (SDS-PAGE). The silver stained gels were analyzed by using progenesis SameSpots software and twenty six differentially expressed protein spots (≥ 2 fold, p < 0.05) were selected for matrix assisted laser desorption ionization- time of flight mass spectroscopy/mass spectrometry (MALDI-TOF/MS) analysis. Also, the expression of COX-2, iNOS and Annexin A2 proteins were analyzed by western blot. RESULTS: Totally, 12 differentially expressed proteins were successfully identified by MALDI-TOF/MS and database searching, that's involved in inflammatory responses such vimentin, T-box transcription factor TBX3, annexin A1, annexin A2 and annexin A5. In addition, flavonoids inhibited the expression of COX-2, iNOS and Annexin A2 proteins in LPS-stimulated L6 skeletal muscle cells. CONCLUSIONS: The findings revealed that the flavonoids from S. baicalensis G. directly protect the LPS stimulated inflammation process in L6 cells and, would be helpful to study further the muscle cell inflammatory mechanism. This is the first proteome study provide the anti-inflammatory mechanism of flavonoids from S. baicalensis G. in LPS stimulated L6 skeletal muscle cells.