Effect of long-term supplementation of low molecular weight chitosan oligosaccharide (GO2KA1) on fasting blood glucose and HbA1c in db/db mice model and elucidation of mechanism of action.

BACKGROUND: Type 2 diabetes is a serious problem for developed countries. Prevention of prediabetes progression to type 2 diabetes with the use of natural products appears to a cost-effective solution. Previously we showed that enzymatically digested low molecular weight chitosan-oligosaccharide with molecular weight (MW) below 1,000 Da (GO2KA1) has potential for hyperglycemia management. METHODS: In this study we evaluated the effect of long-term supplementation of GO2KA1 on hyperglycemia using a db/db mice model. Additionally, we evaluated the effect of GO2KA1 on sucrase and glucoamylase activities and expression, using the same db/db mice model. RESULTS: After 42 days we observed that GO2KA1 supplementation reduced both the blood glucose level and HbA1c in a similar manner with a known anti-diabetic drug, acarbose. When the sucrase and glucoamylase activities of GO2KA1 and control mice were evaluated using enzymatic assay, we observed that GO2KA1 significantly inhibited sucrase in all 3 parts of the intestine, while glucoamylase activity was significantly reduced only in the middle and lower part. When the sucrase-isomaltase (SI) complex expression on mRNA level was evaluated, we observed that GO2KA1 had minimal inhibitory effect on the upper part, more pronounced inhibitory effect on the middle part, while the highest inhibition was observed on the lower part. Our findings suggest that long-term GO2KA1 supplementation in db/db mice results to significant blood glucose and HbA1c reduction, to levels similar with those of acarbose. Furthermore, our findings confirm previous in vitro observations that GO2KA1 has inhibitory effect on carbohydrate hydrolysis enzymes, namely sucrase, maltase and SI complex. CONCLUSIONS: Results from this study provide a strong rationale for the use of GO2KA1 for type 2 diabetes prevention, via inhibition of carbohydrate hydrolysis enzymes. Based on the findings of this animal trial, clinical trials will be designed and pursued.

Molecular weight dependent glucose lowering effect of low molecular weight Chitosan Oligosaccharide (GO2KA1) on postprandial blood glucose level in SD rats model.

This research investigated the effect of enzymatically digested low molecular weight (MW) chitosan oligosaccharide on type 2 diabetes prevention. Three different chitosan oligosaccharide samples with varying MW were evaluated in vitro for inhibition of rat small intestinal α-glucosidase and porcine pancreatic α-amylase (GO2KA1; <1000 Da, GO2KA2; 1000-10,000 Da, GO2KA3; MW > 10,000 Da). The in vitro results showed that all tested samples had similar rat α-glucosidase inhibitory and porcine α-amylase inhibitory activity. Based on these observations, we decided to further investigate the effect of all three samples at a dose of 0.1 g/kg, on reducing postprandial blood glucose levels in Sprague-Dawley (SD) rat model after sucrose loading test. In the animal trial, all tested samples had postprandial blood glucose reduction effect, when compared to control, however GO2KA1 supplementation had the strongest effect. The glucose peak (Cmax) for GO2KA1 and control was 152 mg/dL and 193 mg/dL, respectively. The area under the blood glucose-time curve (AUC) for GO2KA1 and control was 262 h mg/dL and 305 h mg/dL, respectively. Furthermore, the time of peak plasma concentration of blood glucose (Tmax) for GO2KA1 was significantly delayed (0.9 h) compared to control (0.5 h). These results suggest that GO2KA1 could have a beneficial effect for blood glucose management relevant to diabetes prevention in normal and pre-diabetic individuals. The suggested mechanism of action is via inhibition of the carbohydrate hydrolysis enzyme α-glucosidase and since GO2KA1 (MW < 1000 Da) had higher in vivo effect, we hypothesize that it is more readily absorbed and might exert further biological effect once it is absorbed in the blood stream, relevant to blood glucose management.

Assessment of Sinkholes Investigations in Jangseong-Gun Area, South Korea, and Recommendations for Similar Studies.

This paper reviews the site investigation field data and access work performed between 2016 and 2019 in the study area located close to Gun-dong mine. The research was aimed at defining the cause of sinkholes and their relationship with the underlying karstic limestone bedrock and nearby mining activities. Only a limited number of small sinkholes appeared in 2014, 2016, and 2018 in the agricultural land close to the limestone mine. The previously open pit mine started its underground operations in 2007. Since then, the mine has developed, and is now comprised of, large underground excavations at several levels below the surface. The studies carried out concluded that the appearance of sinkholes may be related to a general lowering of the groundwater table because of nearby agricultural and mining activities and also due to over-extraction of water due to increased urban use. Whilst these are the best determinations, this paper identifies missing elements of the previous investigations mentioned above, some issues with the interpretation of poorly prepared borehole logs and the improper preservation of borehole cores. The authors make recommendations for a systematic approach for implementation of an investigation strategy. This paper concludes that the appearance of sinkholes is a natural phenomenon, developing over geological time. However, human intervention contributes to sinkhole formation, which in urban areas may result in human, property, and economic losses. A better understanding, based on a methodical approach and suitable technologies, can determine the causes of sinkholes and can lead to the formulation of solutions and the implementation of economically and socially acceptable mitigation measures.

Pro-inflammatory genes as biomarkers and therapeutic targets in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is a major health problem worldwide, and patients have a particularly poor 5-year survival rate. Thus, identification of the molecular targets in OSCC and subsequent innovative therapies are greatly needed. Prolonged exposure to alcohol, tobacco, and pathogenic agents are known risk factors and have suggested that chronic inflammation may represent a potential common denominator in the development of OSCC. Microarray analysis of gene expression in OSCC cell lines with high basal NF-κB activity and OSCC patient samples identified dysregulation of many genes involved in inflammation, wound healing, angiogenesis, and growth regulation. In particular IL-8, CCL5, STAT1, and VEGF gene expression was up-regulated in OSCC. Moreover, IL-8 protein levels were significantly higher in OSCC cell lines as compared with normal human oral keratinocytes. Targeting IL-8 expression by siRNA significantly reduced the survival of OSCC cells, indicating that it plays an important role in OSCC development and/or progression. Inhibiting the inflammatory pathway by aspirin and the proteasome/NF-κB pathway by bortezomib resulted in marked reduction in cell viability in OSCC lines. Taken together our studies indicate a strong link between inflammation and OSCC development and reveal IL-8 as a potential mediator. Treatment based on prevention of general inflammation and/or the NF-κB pathway shows promise in OSCCs.

Non-Dispersive Anti-Washout Grout Design Based on Geotechnical Experimentation for Application in Subsidence-Prone Underwater Karstic Formations.

A new non-dispersive, anti-washout grout consisting of ordinary Portland cement, slag, superplasticizer, and methylbenzyl cellulose is proposed herein for the treatment of open karst, jointed and fractured rock, open-work gravel, and permeable sediments. A series of laboratory experiments were performed to design an anti-wash out grout suitable for grout injection of coarse aggregates depicting partially and open-jointed saturated rock mass and grouting concrete aggregates for underwater construction. The Taguchi orthogonal array was used to obtain nine different grout mix ratios. A total of four variables were considered, each with three different levels of the water-cement ratio, slag, and dosage of additives such as the superplasticizer and methyl benzyl cellulose. The laboratory determination of grout characteristics recording of mini slump, temperature, pH, visual assessment of grout dispersion, bleeding, and initial setting time and as well as uniaxial compressive strengths and permeabilities of the hardened grout samples were tested. To evaluate the suitability of the grout mixes, an analysis of variance was used for factor analysis and Grey relational analysis (GRA) was used to determine the optimal grout mix design. Based on the GRA, the following levels of the factors afforded the best results: water level 1 (0.3%), SP level 3 (0.01%), methylbenzyl cellulose level 2 (0.002%), and slag level 3 (0.1%). This paper describes the research methodology, detailed research observations, and analyses involved in designing the appropriate concrete mix. Based on the conclusions, relevant commendations regarding the suitability of grout testing equipment and grout mix designs are presented.

Interferon-resistant Daudi cell line with a Stat2 defect is resistant to apoptosis induced by chemotherapeutic agents.

Interferon-alpha (IFNalpha) has shown promise in the treatment of various cancers. However, the development of IFN resistance is a significant drawback. Using conditions that mimic in vivo selection of IFN-resistant cells, the RST2 IFN-resistant cell line was isolated from the highly IFN-sensitive Daudi human Burkitt lymphoma cell line. The RST2 cell line was resistant to the antiviral, antiproliferative, and gene-induction actions of IFNalpha. Although STAT2 mRNA was present, STAT2 protein expression was deficient in RST2 cells. A variant STAT2 mRNA, which resulted from alternative splicing within the intron between exon 19 and 20, was expressed in several human cell lines but at relatively high levels in RST2 cells. Most importantly, the RST2 line showed an intrinsic resistance to apoptosis induced by a number of chemotherapeutic agents (camptothecin, staurosporine, and doxorubicin). Expression of STAT2 in RST2 cells not only rescued their sensitivity to the biological activities of IFNs but also restored sensitivity to apoptosis induced by these chemotherapeutic agents. The intrinsic resistance of the RST2 cells to IFN as well as chemotherapeutic agents adds a new dimension to our knowledge of the role of STAT2 as it relates to not only biological actions of IFN but also resistance to chemotherapy-induced apoptosis.

The complete mitochondrial genome of a yellow-bellied sea snake (Hydrophis platurus) (Squamata, Elapidae).

In this study, we provide the first report of the complete mitochondrial genomic sequencing of a yellow-bellied sea snake (Hydrophis platurus) that has the broadest distribution range of all Squamata species. The mitogenome length was 18,101 bp and consisted of 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and 3 non-coding regions. The sequence presented could be very useful for further phylogenetic and evolutionary studies.

Complete mitochondrial genome of the Ijima's Sea Snake (Emydocephalus ijimae) (Squamata, Elapidae).

In this study, we provide the first report of the complete mitochondrial genome of Emydocephalus ijimae. The mitogenome length is 18,259 bp and includes 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and three non-coding regions. The sequence presented could be very useful for further phylogenetic and evolutionary study.

Talosins A and B: new isoflavonol glycosides with potent antifungal activity from Kitasatospora kifunensis MJM341. I. Taxonomy, fermentation, isolation, and biological activities.

In our screening program for new antifungal agents from microbial secondary metabolites, we isolated two new isoflavonol glycosides, genistein 7-alpha-L-6-deoxy-talopyranoside (talosin A) and genistein 4',7-di-alpha-L-6-deoxy-talopyranoside (talosin B), from the culture broth of Kitasatospora kifunensis MJM341. The talosins exhibited strong antifungal activity against Candida albicans, Aspergillus niger and Cryptococcus neoformans with minimal inhibitory concentrations (MIC) in the range of 3- 15 microg/ml while genistein and genistein-7-glucopyranoside did not show antifungal activity at 100 microg/ml. These talosins are the first isoflavonol glycosides with a 6-deoxy-talose sugar component and they may be useful as antifungal agents with low toxicity because of no visible cytotoxicity against the human hepatic HepG2 cell.

Novel alpha-glucosidase inhibitors, CKD-711 and CKD-711a produced by Streptomyces sp. CK-4416. I. Taxonomy, fermentation and isolation.

New alpha-glucosidase inhibitors, CKD-711 and CKD-711a were produced from the fermentation broth of Streptomyces sp. CK-4416 which was isolated from a forest soil of Jeju Island, South Korea. CKD-711 and CKD-711a were purified by Dowex 50W-2X and Sephadex G-10 column chromatography. In in vitro studies, CKD-711 showed a potent inhibitory activity against a-glucosidase from mammalian, but less inhibition against a-amylase from microorganism and mammalian. CKD-711a showed a lower inhibitory activity than CKD-711.

Novel alpha-glucosidase inhibitors, CKD-711 and CKD-711a produced by Streptomyces sp. CK-4416. II. Biological properties.

CKD-711 and CKD-711a are aminooligosaccharide alpha-glucosidase inhibitors discovered during the bioactive material screening for antibacterial agent. Their inhibitory activities were studied and compared with those of acarbose in vitro and in vivo with animals. In in vitro study, CKD-711 showed similar effects to acarbose on porcine intestinal maltase and sucrase, IC50s of 2.5 and 0.5 microg/ml, respectively, whereas it had about 2 fold lower alpha-amylase inhibitory activity (IC50, 78.0 microg/ml) than acarbose (IC50, 36 microg/ml). CKD-711a showed less inhibitory activity than CKD-711 against all the enzymes tested. In rat fed on starch and sucrose meals, the dose of CKD-711 which reduced the postprandial blood glucose increment by 50 percent in comparison to control rats (ED50) were 3.07 and 1.15 mg/kg, respectively, and acarbose had ED50s of 1.94 and 1.15 mg/kg, respectively. CKD-711 and CKD-711a also showed antibacterial activity against Comamonas terrigena.

Novel alpha-glucosidase inhibitors, CKD-711 and CKD-711a produced by Streptomyces sp. CK-4416. III. Physico-chemical properties and structure elucidation.

We have isolated two novel a-glucosidase inhibitors, O-[4-deoxy-4-(2,3-epoxy-3-hydroxymethyl-4,5,6-trihydroxycyclohexane-1-yl-amino)-alpha-D-glucopyranosyl]-(1-->4)-O-alpha-D-glucopyranosyl-(1-->4)-alpha-D-glucopyranose (named CKD-711) and its hexameric analog CKD-711a, from the fermentation broth of Streptomyces sp. CK-4416. HRFAB-MS and NMR analyses reveal that molecular formulae of CKD-711 and CKD-711a are C25H43NO20 and C37H63NO30, respectively with the latter containing two more glucose moieties than the former. Detailed chemical structures of both compounds have been characterized by high-resolution two-dimensional NMR methods.

Role of nuclear factor-kappaB in the antiviral action of interferon and interferon-regulated gene expression.

Interferons (IFNs) play critical roles in host defense by modulating the expression of various genes via tyrosine phosphorylation of STAT transcription factors. IFN-alpha/beta activates another important transcription factor, nuclear factor-kappaB (NF-kappaB), but its role in IFN-mediated activity is poorly understood. Sensitivity to the antiviral and gene-inducing effects of IFN was examined in normal fibroblasts and in NF-kappaB knockout fibroblasts from p50- and p65-null mice. Antiviral assays demonstrated that NF-kappaB knockout fibroblasts were sensitized to the antiviral action of IFN. Moreover, analysis of IFN-stimulated gene expression by real-time PCR demonstrated selective effects of NF-kappaB on gene expression. Our results demonstrate that a subset of IFN-stimulated genes is regulated through an NF-kappaB-dependent pathway and that NF-kappaB may regulate the sensitivity of cells to IFN-mediated antiviral activity.