Anti-inflammatory Effects of S. cumini Seed Extract on Gelatinase-B (MMP-9) Regulation against Hyperglycemic Cardiomyocyte Stress.

Black berry (Syzygium cumini) fruit is useful in curing diabetic complications; however, its role in diabetes-induced cardiomyopathy is not yet known. In this study, we investigated the regulation of gelatinase-B (MMP-9) by S. cumini methanol seed extract (MSE) in diabetic cardiomyopathy using real-time PCR, RT-PCR, immunocytochemistry, gel diffusion assay, and substrate zymography. The regulatory effects of MSE on NF-κB, TNF-α, and IL-6 were also examined. Identification and estimation of polyphenol constituents present in S. cumini extract were carried out using reverse-phase HPLC. Further, in silico docking studies of identified polyphenols with gelatinase-B were performed to elucidate molecular level interaction in the active site of gelatinase-B. Docking studies showed strong interaction of S. cumini polyphenols with gelatinase-B. Our findings indicate that MSE significantly suppresses gelatinase-B expression and activity in high-glucose- (HG-) stimulated cardiomyopathy. Further, HG-induced activation of NF-κB, TNF-α, and IL-6 was also remarkably reduced by MSE. Our results suggest that S. cumini MSE may be useful as an effective functional food and dietary supplement to regulate HG-induced cardiac stress through gelatinase.

Structure-Activity Relationship of Phytoestrogen Analogs as ERα/ß Agonists with Neuroprotective Activities.

A set of isoflavononid and flavonoid analogs was prepared and evaluated for estrogen receptor α (ERα) and ERß transactivation and anti-neuroinflammatory activities. Structure-activity relationship (SAR) study of naturally occurring phytoestrogens, their metabolites, and related isoflavone analogs revealed the importance of the C-ring of isoflavonoids for ER activity and selectivity. Docking study suggested putative binding modes of daidzein 2 and dehydroequol 8 in the active site of ERα and ERß, and provided an understanding of the promising activity and selectivity of dehydroequol 8. Among the tested compounds, equol 7 and dehydroequol 8 were the most potent ERα/ß agonists with ERß selectivity and neuroprotective activity. This study provides knowledge on the SAR of isoflavonoids for further development of potent and selective ER agonists with neuroprotective potential.

Discovery of Tricyclic Pyranochromenone as Novel Bruton's Tyrosine Kinase Inhibitors with in Vivo Antirheumatic Activity.

Bruton's tyrosine kinase (BTK) is an attractive target for treating patients with B cell malignancies and autoimmune diseases. Many BTK inhibitors have been identified; however, like other kinase inhibitors, they lack diversity in their core structures. Therefore, it is important to secure a novel scaffold that occupies the adenine-binding site of BTK. We screened an in-house library of natural products and their analogs via a biochemical assay to identify a novel scaffold for targeting BTK. A pyranochromenone scaffold, derived from a natural active component decursin, was found to be effective at targeting BTK and was selected for further optimization. A series of pyranochromenone analogs was synthesized through the modification of pyranochromenone at the C7 position. Pyranochromenone compounds with an electrophilic warhead exhibited promising BTK inhibitory activity, with IC50 values in the range of 0.5-0.9 µM. A docking study of the representative compound 8 provided a reasonable explanation for compound activity. Compound 8 demonstrated good selectivity over other associated kinases and decreased the production of proinflammatory cytokines in THP cells. Moreover, compound 8 presented significant in vivo efficacy in a murine model of collagen-induced arthritis.

Stilbenoids from Rheum undulatum Protect Hepatocytes Against Oxidative Stress Through AMPK Activation.

Oxidative stress promotes several diseases, including liver disease. We have isolated several stilbenoids from Rheum undulatum to investigate their hepatoprotective activities and mechanism. Stilbenoids from R. undulatum protects hepatocytes against arachidonic acid + iron (AA + Fe) induced oxidative stress. Pterostilbene (compound 5) shows stronger activity than the others. Trimethoxystilbenoid (compound 6) shows best activity on protection of HepG2 cells from AA + Fe-induced oxidative stress, and trans-stilbenoid (compound 7) shows weak activity. These stilbenoids suppress ROS generation in AA + Fe-treated HepG2 cells and also suppress AA + Fe-induced MMP disruption. Their protective effects on AA + Fe-induced MMP disruption were abrogated by treatment of AMP-activated protein kinase (AMPK) inhibitor, compound C or transfection of dominant negative form of AMPK. Taken together, stilbenoids from R. undulatum protect hepatocytes against AA + Fe-induced oxidative stress through AMPK activation. And the methoxy groups in the aryl groups are important for their cytoprotective activity.

Design and synthesis of azaisoflavone analogs as phytoestrogen mimetics.

A series of azaisoflavone analogs were designed and synthesized and their transactivation activities and binding affinities for ERα and ERß were investigated. Among these compounds, 2b and 3a were the most potent with 6.5 and 1.1 µM of EC50, respectively. Molecular modeling study showed putative binding modes of the compound 3a in the active site of ERα and ERß, which were similar with that of genistein and provided insight of the effect of N-alkyl substitution of azaisoflavones on ERß activity. Also, a biphasic effect of azaisoflavone analogs on MCF-7 cell growth depending on their concentrations was investigated.

Systemic approaches identify a garlic-derived chemical, Z-ajoene, as a glioblastoma multiforme cancer stem cell-specific targeting agent.

Glioblastoma multiforme (GBM) is one of the most common brain malignancies and has a very poor prognosis. Recent evidence suggests that the presence of cancer stem cells (CSC) in GBM and the rare CSC subpopulation that is resistant to chemotherapy may be responsible for the treatment failure and unfavorable prognosis of GBM. A garlic-derived compound, Z-ajoene, has shown a range of biological activities, including anti-proliferative effects on several cancers. Here, we demonstrated for the first time that Z-ajoene specifically inhibits the growth of the GBM CSC population. CSC sphere-forming inhibition was achieved at a concentration that did not exhibit a cytotoxic effect in regular cell culture conditions. The specificity of this inhibitory effect on the CSC population was confirmed by detecting CSC cell surface marker CD133 expression and biochemical marker ALDH activity. In addition, stem cell-related mRNA profiling and real-time PCR revealed the differential expression of CSC-specific genes, including Notch, Wnt, and Hedgehog, upon treatment with Z-ajoene. A proteomic approach, i.e., reverse-phase protein array (RPPA) and Western blot analysis, showed decreased SMAD4, p-AKT, 14.3.3 and FOXO3A expression. The protein interaction map (http://string-db.org/) of the identified molecules suggested that the AKT, ERK/p38 and TGFß signaling pathways are key mediators of Z-ajoene's action, which affects the transcriptional network that includes FOXO3A. These biological and bioinformatic analyses collectively demonstrate that Z-ajoene is a potential candidate for the treatment of GBM by specifically targeting GBM CSCs. We also show how this systemic approach strengthens the identification of new therapeutic agents that target CSCs.

Anti-inflammatory activity of sulfur-containing compounds from garlic.

We identified four anti-inflammatory sulfur-containing compounds from garlic, and their chemical structures were identified as Z- and E-ajoene and oxidized sulfonyl derivatives of ajoene. The sulfur compounds inhibited the production of nitric oxide (NO) and prostaglandin E(2) (PGE(2)) and the expression of the pro-inflammatory cytokines tumor necrosis factor-α, interleukin-1ß, and interleukin-6 in lipopolysaccharide (LPS)-activated macrophages. Western blotting and reverse transcription-polymerase chain reaction analysis demonstrated that these sulfur compounds attenuated the LPS-induced expression of the inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins and mRNA. Moreover, these sulfur-containing compounds suppressed the nuclear factor-κB (NF-κB) transcriptional activity and the degradation of inhibitory-κBα in LPS-activated macrophages. Furthermore, we observed that they markedly inhibited the LPS-induced phosphorylations of p38 mitogen-activated protein kinases and extracellular signal-regulated kinases (ERK) at 20 µM. These data demonstrate that the sulfur compounds from garlic, (Z, E)-ajoene and their sulfonyl analogs, can suppress the LPS-induced production of NO/PGE(2) and the expression of iNOS/COX-2 genes by inhibiting the NF-κB activation and the phosphorylations of p38 and ERK. Taken together, these data show that Z- and E-ajoene and their sulfonyl analogs from garlic might have anti-inflammatory therapeutic potential.

Ajoene, a stable garlic by-product, inhibits high fat diet-induced hepatic steatosis and oxidative injury through LKB1-dependent AMPK activation.

Hepatic steatosis, a hepatic component of metabolic syndrome, is common and may progress to steatohepatitis and cirrhosis. The liver X receptor-α (LXRα)-sterol regulatory element binding protein-1c (SREBP-1c) pathway plays a key role in hepatic steatosis. This study investigated the potential of ajoene, a stable garlic by-product, to inhibit high fat diet (HFD)-induced hepatic steatosis and the underlying mechanism. Ajoene treatment attenuated fat accumulation and induction of lipogenic genes in the liver of HFD-fed mice. Blood biochemical analyses and histopathologic examinations showed that ajoene prevented liver injury with the inhibition of oxidative stress, as evidenced by thiobarbituric acid reactive substances formation and nitrotyrosinylation. Moreover, ajoene treatment inhibited LXRα agonist (T0901317)-mediated SREBP-1c activation, and transactivation of the lipogenic target genes in hepatocytes. Ajoene was found to activate AMP-activated protein kinase (AMPK) via LKB1, responsible for the inhibition of p70 ribosomal S6 kinase-1 (S6K1). The ability of ajoene to repress T0901317-induced SREBP-1c expression was antagonized by inhibition of AMPK or activation of S6K1, supporting the role of these kinases in the antisteatotic effect. Our results demonstrate that ajoene has an effect of activating AMPK through LKB1 and inhibit S6K1 activity, contributing to the prevention of SREBP-1c-mediated hepatic lipogenesis via the inhibition of LXRα activity.

In vitro anti-inflammatory activity of lignans isolated from Magnolia fargesii.

The overproduction of nitric oxide (NO) and prostaglandin E(2) (PGE(2)) causes neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease. Four lignans, (+)-eudesmin (1), (+)-magnolin (2), (+)-yangambin (3) and a new structure named as epimagnolin B (4) were isolated from Magnolia fargesii (Magnoliaceae) as the inhibitors of NO production in LPS-activated microglia. The most potent compound 4 inhibited the production of NO and PGE(2) and the expression of respective enzyme iNOS and COX-2 through the suppression of I-kappaB-alpha degradation and nuclear translocation of p65 subunit of NF-kappaB.

Inhibition of lipopolysaccharide-induced inducible nitric oxide synthase and cyclooxygenase-2 expression by xanthanolides isolated from Xanthium strumarium.

Three sesquiterpenoids, xanthatin (1), xanthinosin (2), and 4-oxo-bedfordia acid (3) were isolated from Xanthium strumarium as inhibitors of nitric oxide synthesis in activated microglia (IC(50) values: 0.47, 11.2, 136.5 microM, respectively). Compounds 1 and 2 suppressed the expression of iNOS and COX-2 and the activity of NF-kappaB through the inhibition of LPS-induced I-kappaB-alpha degradation in microglia.

Garlic (Allium sativum) extract inhibits lipopolysaccharide-induced Toll-like receptor 4 dimerization.

Garlic has long been used as a folk medicine. Numerous studies have demonstrated that a garlic extract and its sulfur-containing compounds inhibited nuclear factor kappa B (NF-kappaB) activation induced by various receptor agonists including lipopolysaccharide (LPS). Toll-like receptors (TLRs) play a key role in sensing diverse microbial products and inducing innate immune responses. The dimerization of TLR4 is required for the activation of downstream signaling pathways, including NF-kappaB. Therefore, TLR4 dimerization may be one of the first lines of regulation in activating LPS-induced signaling pathways. We report here biochemical evidence that the ethyl acetate fraction of garlic inhibited the LPS-induced dimerization of TLR4, resulting in the inhibition of NF-kappaB activation and the expression of cyclooxygenase 2 and inducible nitric oxide synthase. Our results demonstrate for the first time that a garlic extract can directly inhibit the TLRs-mediated signaling pathway at the receptor level. These results shed a new insight into understanding how garlic modulates the immune responses that could modify the risk of many chronic diseases.