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Bacillus amyloliquefaciens is a probiotic for animals. Evidence suggests that diets supplemented with B. amyloliquefaciens can reduce inflammation; however, the underlying mechanism is unclear and requires further exploration. The exopolysaccharides of B. amyloliquefaciens amy-1 displayed hypoglycemic activity previously, suggesting that they are bioactive molecules. In addition, they counteracted the effect of lipopolysaccharide (LPS) on inducing cellular insulin resistance in exploratory tests. Therefore, this study aimed to explore the anti-inflammatory effect and molecular mechanisms of the exopolysaccharide preparation of amy-1 (EPS). Consequently, EPS reduced the expression of proinflammatory factors, the phagocytic activity and oxidative stress of LPS-stimulated THP-1 cells. In animal tests, EPS effectively ameliorated ear inflammation of mice. These data suggested that EPS possess anti-inflammatory activity. A mechanism study revealed that EPS inhibited the nuclear factor-κB pathway, activated the mitogen-activated protein kinase (MAPK) p38, and prohibited the extracellular signal-regulated kinase 1/2, but had no effect on the c-Jun-N-terminal kinase 2 (JNK). EPS also activated the anti-oxidative nuclear factor erythroid 2–related factor 2 (Nrf2) pathway. Evidence suggested that p38, but not JNK, was involved in activating the Nrf2 pathway. Together, these mechanisms reduced the severity of inflammation. These findings support the proposal that exopolysaccharides may play important roles in the anti-inflammatory functions of probiotics.

The vines and leaves of Momordica charantia L. are used as herbal medicines to treat inflammation-related disorders. However, their safety profile remains uncharacterized, and the constituents in their extracts that exert anti-inflammatory and adverse effects remain unclear. This study isolated the characteristic cucurbitane-type triterpenoid species in the vines and leaves of M. charantia L. and analyzed their cytotoxicity, anti-inflammatory effects, and underlying mechanisms. Four structurally related triterpenoids—momordicines I, II, IV, and (23E) 3β,7β,25-trihydroxycucurbita-5,23-dien-19-al (TCD)—were isolated from the triterpenoid-rich fractions of extracts from the vines and leaves of M. charantia. Momordicine I was cytotoxic on normal cells, momordicine II exerted milder cytotoxicity, and momordicine IV and TCD had no obvious adverse effects on cell growth. TCD had anti-inflammatory activity both in vivo and in vitro. In lipopolysaccharide-stimulated RAW 264.7 cells, TCD inhibited the inhibitor kappa B kinase/nuclear factor-κB pathway and enhanced the expression of nuclear factor erythroid 2-related factor 2, heme oxygenase-1, and glutamate-cysteine ligase modifier subunit through the extracellular signal-regulated kinase1/2 and p38. Thus, the vines and leaves of M. charantia should be used with caution. An extraction protocol that can enrich TCD but remove momordicine I would likely enhance the safety of the extract.

The triterpenes 3β,25-dihydroxy-7β-methoxycucurbita-5,23(E)-diene (DHM) and 3β,7β,25-trihydroxycucurbita-5,23(E)-dien-19-al (THC) were previously isolated from Momordica charantia (bitter melon) and identified as hypoglycaemic principles. This study further investigated their hypoglycaemic mechanisms. FL83B cells were treated with tumour necrosis factor-α to result in insulin resistance, a feature of type 2 diabetes. DHM and THC increased the tyrosine phosphorylation of insulin receptor substrate isoform 1 and the phosphorylation of Akt only in the presence of insulin in insulin-resistant cells, suggesting that they are insulin sensitizers. However, they enhanced the phosphorylation of AS160 (Akt substrate of 160 kDa), the migration of glucose transporter-4 and the glucose uptake of insulin-resistant cells in the absence of insulin, suggesting that they can substitute for insulin to promote glucose clearance. The insulin substitution function was blocked by an AMP-activated protein kinase (AMPK) inhibitor, whereas the insulin-sensitizing function may involve the inhibition of protein-tyrosine phosphatase-1B (PTP-1B). The IC50 of DHM and THC to PTP-1B is 92.84 µM and 25.42 µM, respectively. In summary, DHM and THC have insulin-sensitizing and insulin-substitution functions, which are likely correlated with their effects on inhibiting PTP-1B and activating AMPK, respectively.

Pumpkin has been suggested to have an antidiabetic effect, but the bioactives involved and molecular mechanisms mediating its hypoglycaemic activity are not clear. This study characterized some of the hypoglycaemic constituents in the crude extract of the Cucurbita moschata stem and investigated the mechanisms of their action. The C. moschata stem extract showed a hypoglycaemic effect in vivo in streptozotocin-induced diabetic mice. Several hypoglycaemic fractions of the extract were identified via cell-based screening, and two of them were confirmed to have hypoglycaemic activities in vivo. Ten compounds were afforded from the 2 fractions. Compounds 9 [(22E,24R)-24-methyl-6β-methoxy-5α-cholesta-7,22-diene-3β,5-diol] and 10 [3β-hydroxy-(22E,24R)-ergosta-5,8,22-trien-7-one] showed an insulin-like activity in normal cells that may be mediated by AMP-activated protein kinase. Compounds 4 (ferulic acid), 8 (syringaresinol) and 9 exhibited an insulin sensitizing and/or insulin substitution function in insulin-resistant cells. Thus, the C. moschata stem contains compounds with potential for managing type 1 or type 2 diabetes.

Nine new derivatives of oleanane triterpenoids isolated from Fatsia polycarpa Hayata were synthesized through chemical transformations. Acetylation was effected by reaction with acetic anhydride in pyridine to afford compounds 1–5, while compound 6 was obtained using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl) in CH2Cl2. The others derivatives 7–9 were obtained in reactions of the corresponding triterpenoids with EDC·HCl, 4-N,N-dimethylaminopyridine hydrochloride and 4-N,N-dimethylaminopyridine in CH2Cl2. The structures of 1–9 were elucidated from extensive spectroscopic and HRESIMS data, while the structure of 9 was further confirmed by X-ray diffraction analysis. The cytotoxic, anti-hepatitis B virus (HBV), antibacterial, hypoglycaemic and Wnt signaling activities of these derivatives were evaluated in vitro.

Results reveal that among the nine tryptophan residues investigated, residues Trp(sup)54 and Trp(sup)203 may play an important role in mediating the catalytic function of Fibrobacter succinogenes 1,3-1,4-beta-D-glucanase. Besides, Trp(sup)141 and Trp(sup)148 residues are involved in maintaining the structural integrity of the substrate binding cleft of the enzyme.

Nine new derivatives of oleanane triterpenoids isolated from Fatsia polycarpa Hayata were synthesized through chemical transformations. Acetylation was effected by reaction with acetic anhydride in pyridine to afford compounds 1-5, while compound 6 was obtained using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl) in CH2Cl2. The others derivatives 7-9 were obtained in reactions of the corresponding triterpenoids with EDC·HCl, 4-N,N-dimethylaminopyridine hydrochloride and 4-N,N-dimethylaminopyridine in CH2Cl2. The structures of 1-9 were elucidated from extensive spectroscopic and HRESIMS data, while the structure of 9 was further confirmed by X-ray diffraction analysis. The cytotoxic, anti-hepatitis B virus (HBV), antibacterial, hypoglycaemic and Wnt signaling activities of these derivatives were evaluated in vitro. [ABSTRACT FROM AUTHOR]

Abstract  It was attempted in this work to establish a cell line in which senescent cells can be readily and directly identified in situ in live culture. Transcriptional activation of p21Cip1/Waf1 gene is known to be one of the key steps in the development of cellular senescence, whereas the elements within the p21Cip1/Waf1 promoter that regulate the transcriptional activation of p21Cip1/Waf1 during cellular senescence have not been clearly defined. Thus, several reporter plasmids were constructed in each of which the gene of green fluorescent protein was placed under the control of a selected fragment of p21Cip1/Waf1 promoter, and stably transfected into BHK-21 cells. The transfected cells were induced to become senescence-like by camptothecin and assayed for fluorescence intensity. It was shown that the reporter system constructed with bases ?2504 to +406 of the p21Cip1/Waf1 promoter was very efficient in reflecting the senescence of BHK-21 cells by increased cytosolic fluorescence, and the fluorescence intensity of senescent cells was easily distinguished from that of quiescent cells. [ABSTRACT FROM AUTHOR]

Describes the structural and catalytic functions of tryptophan amino acid residues in Fibrobacter succinogenes. Mutations of tryptophan amino acids; Localization of tryptophan amino acid in cellulose-binding domains of glucanases and xylanases; Transformation of mutated plasmids into Escherichia coli.

Reports on the identity of a lens membrane-associated protein kinase, casein kinase I. Immunoprecipitation of lens fiber cell-specific gap junction protein connexin49; Phosphorylation of lens membranes with purified casein kinase I and casein kinase II; Purification of connexin49 protein kinase activity; Identification of protein kinase I isoforms.

The cAMP-dependent protein-kinase-catalyzed phosphorylation of the two major intrinsic lens fiber cell plasma membrane proteins, MP20 and MP26, is likely restricted to the inner cortical and nuclear regions of the lens in vivo. The ovine-lens-specific connexin, MP70, that has been identified as Cx50 in mice and Cx45.6 in the chick, is also a protein kinase substrate although it does not appear to be phosphorylated by a number of protein kinases including cAMP-dependent protein kinase, calmodulin-dependent protein kinase or protein kinase C. Rather, an extrinsic lens membrane fraction was isolated which contained protein kinase activity that catalyzed the phosphorylation of MP70; this protein kinase activity was cAMP-independent, Ca2+-independent, Mg2+-dependent, phosphorylated MP70 on a serine residue(s) and migrated with a molecular mass of 35 kDa on a gel filtration column. Both MP70 phosphorylation and the endogenous protein kinase activity were restricted to the lens outer cortical region. This membrane-associated protein kinase activity that catalyzes the phosphorylation of a lens connexin protein. The phosphatase-induced shift in the elctrophoretic mobility of MP70 is not reversed by this protein kinase, indicating that MP70 is likely phosphorylation on different residues by two or more protein kinases. [ABSTRACT FROM AUTHOR]