The Hydrolytic Peptides of Soybean Protein Induce Cell Cycle Arrest and Apoptosis on Human Oral Cancer Cell Line HSC-3.

Protein hydrolysates from various sources, including tuna cooking juice, soy protein isolate, sodium caseinate, wheat gluten and skin gelatin from porcine, tilapia, halibut and milkfish were analyzed to screen their antiproliferative activities against the human oral squamous carcinoma cell line, HSC-3. The soy protein isolate was selected for further investigations based on its hydrolysates with bromelain (SB) and thermolysin (ST), showing the greatest inhibition of cell growth. The SB and ST hydrolysates showed antiproliferative activities up to 35.45-76.39% against HSC-3 cells at 72 h, and their IC50 values were 0.74 and 0.60 mg/mL, respectively. SB and ST induced cell cycle arrest in the S phase through a pathway independent of p21 and p27 protein expression. Further, ST induced the apoptosis of HSC-3 cells by downregulating expression of Bcl-2, PARP, caspase 3 and caspase 9, but an upregulating expression of p53 and cleaved caspase 3. Unlike ST, SB may induce necrosis on HSC-3 cells. Thus, soybean hydrolysates may be a good source for providing antiproliferative peptides against HSC-3, while SB and ST may have the potential to be developed as functional foods.

The Protective Effects of Clams on Hypercholesterolemia in Late-Stage Triple-Transgenic Alzheimer's Diseased Mice Hearts.

To investigate a high cholesterol diet in Alzheimer's disease (AD) mice, they were fed with (2% cholesterol) in five groups with a control group, AD mice group, AD mice plus Meretrix lusoria group, AD mice plus Geloina eros group, and, AD mice plus Corbicula fluminea group for three months, and treated with the fatty acid profiles of clams by gas chromatography (GC). The results showed that treatment with clams for three months reduced Fas/L and Caspase-3 in the Meretrix lusoria and Geloina eros groups, but Fas-associated death domain (FADD) and Caspase-8 were strongly reduced in the Geloina eros group. For the mitochondria-dependent apoptotic pathway, the reduction of apoptosis proteins were observed in the hearts of clams-treated AD mice. BAK and Caspase-9 was reduced in the Meretrix lusoria group, but Caspase-3 and Cytochrome-c were reduced in Geloina eros group. Enhancement of survival proteins p-AKT, p-IGF1R, p-PI3K, Bcl-XL, Bcl2, and the longevity SIRT1 signaling proteins, p-AMPK-α, SIRT1, PGC1-α, p-FOXO3 were observed in clams-treated mice and even more strongly enhanced in the Meretrix lusoria, Geloina eros and Corbicula fluminea groups. This study observed that the ingestion of clams caused a reduction of apoptosis proteins and enhancement of survival and SIRT1 signaling proteins in the hearts.

Activation of IGF-I Survival Signaling and Its Compensative Inhibition of the Cardiac Apoptosis on Carotid Arteries Balloon-Injured Rat Hearts.

In this study, a rat carotid balloon injury-animal model was used to elucidate the temporal relation of hypertrophy in the progression of cardiac damage and the role of insulin-like growth factor (IGF)-I survival pathway on course of the cardiac damage. Rats were subjected to carotid balloon-injury and examined at different time points. We further studied the heart-weight/body-weight-ratio, histology and protein expression to understand the pathological events associated with percutaneous transluminal coronary angioplasty (PTCA) induced damages. Protein expression analysis showed increased levels of IGF-I signaling pathway and mitogen-activated protein kinase (MAPK) signaling pathway after 2 h and after 2 d of carotid balloon injury. On the other hand, apoptosis signaling pathways were enhanced after 14 d of carotid balloon injury. According to the results, rat carotid balloon injury significantly induced IGF-I survival signaling and compensated hypertrophy pathway during the initial period of injury however after 14 d the proteins involved in apoptotic cell death were elevated and the proteins of the survival pathway and compensatory hypertrophy were significantly reduced.

A study to evaluate the potential of an in silico approach for predicting dipeptidyl peptidase-IV inhibitory activity in vitro of protein hydrolysates.

A total of 294 edible protein sequences and 5 commercial proteases listed in the BIOPEP database were analyzed in silico. The frequency (A), a parameter in silico described previously, was examined further to calculating the ratio of truncated peptides with Xaa-proline and/or Xaa-alanine to all peptide fragments in a protein hydrolyzed with a protease, using the BIOPEP database. Then the in vitro DPP-IV inhibitory activity was determined using the same 15 protein and protease combinations to evaluate their relationship. The result shows that A values considering the number of Xaa-proline+Xaa-alanine exhibited a strong correlation with in vitro DPP-IV inhibition rates by Pearson's correlation analysis (r=0.6993; P<0.05). Therefore, the in silico approach is effective to predict DPP-IV inhibitory activities in vitro of protein hydrolysates.

Down-regulation of ß-catenin and the associated migration ability by Taiwanin C in arecoline and 4-NQO-induced oral cancer cells via GSK-3ß activation.

Cancer is one of the leading causes of death worldwide, and oral squamous cell carcinoma (OSCC) accounts for almost a sixth of all reported cancers. Arecoline, from areca nut is known to enhance carcinogenesis in oral squamous cells. The objective of this study is to determine the effect of Taiwanin C, from Taiwania cryptomerioides Hayata against Arecoline-associated carcinogenesis. An OSCC model was created in C57BL/6J Narl mice by administrating 0.5 mg mL-1 arecoline with 0.2 mg mL-1 4-NQO carcinogen for 8 and 28 wk to mimic the etiology of oral cancer patients in Asia. Mice were sacrificed and two cell lines, T28 from the tumor and N28 cancerous cell line from the surrounding non tumor area, were established. Taiwanin C showed effective anti-tumor activity in nude mice models. Taiwanin C significantly inhibited the cell viability of T28 cells in a dose dependent manner, but did not inflict any effect on N28 normal cells. Taiwanin C treatment inhibited the migration ability of T28 cells in a dose dependent manner as determined by wound healing and migration assays. Taiwanin C also reduced the levels of ß-catenin and its downstream metastatic proteins, Tbx3 and c-Myc. Besides, Taiwanin C inhibited the nuclear accumulation of ß-catenin and induced ß-catenin degradation via proteasome-mediated pathway. Moreover, Taiwanin C enhanced GSK-3ß and reduced the p-ser9 GSK-3ß protein level to inactivate Wnt signaling. Taken together, Taiwanin C blocked the cell migration effects of T28 cells mediated through the activation of GSK-3ß to enhance protein degradation and reduce nuclear accumulation of ß-catenin. © 2016 Wiley Periodicals, Inc.

In silico, in vitro and in vivo analyses of dipeptidyl peptidase IV inhibitory activity and the antidiabetic effect of sodium caseinate hydrolysate.

The frequency (A), a novel in silico parameter, was developed by calculating the ratio of the number of truncated peptides with Xaa-proline and Xaa-alanine to all peptide fragments from a protein hydrolyzed with a specific protease. The highest in vitro DPP-IV inhibitory activity (72.7%) was observed in the hydrolysate of sodium caseinate by bromelain (Cas/BRO), and the constituent proteins of bovine casein also had relatively high A values (0.10-0.17) with BRO hydrolysis. 1CBR (the <1 kDa fraction of Cas/BRO) showed the greatest in vitro DPP-IV inhibitory activity of 77.5% and was used for in vivo test by high-fat diet-fed and low-dose streptozotocin-induced diabetic rats. The daily administration of 1CBR for 6 weeks was effective to improve glycaemic control in diabetic rats. The results indicate that the novel in silico method has the potential as a screening tool to predict dietary proteins to generate DPP-IV inhibitory and antidiabetic peptides.

Isolation of prolyl endopeptidase inhibitory peptides from a sodium caseinate hydrolysate.

Prolyl endopeptidase (PEP) has been associated with neurodegenerative disorders, and the PEP inhibitors can restore the memory loss caused by amnesic compounds. In this study, we investigated the PEP inhibitory activity of the enzymatic hydrolysates from various food protein sources, and isolated and identified the PEP inhibitory peptides. The hydrolysate obtained from sodium caseinate using bromelain (SC/BML) displayed the highest inhibitory activity of 86.8% at 5 mg mL(-1) in the present study, and its IC50 value against PEP was 0.77 mg mL(-1). The F-5 fraction by RP-HPLC (reversed-phase high performance liquid chromatography) from SC/BML showed the highest PEP inhibition rate of 88.4%, and 9 peptide sequences were identified. The synthetic peptides (1245.63-1787.94 Da) showed dose-dependent inhibition effects on PEP as competitive inhibitors with IC50 values between 29.8 and 650.5 µM. The results suggest that the peptides derived from sodium caseinate have the potential to be PEP inhibitors.

Development of standardized methodology for identifying toxins in clinical samples and fish species associated with tetrodotoxin-borne poisoning incidents.

Tetrodotoxin (TTX) is a naturally occurring toxin in food, especially in puffer fish. TTX poisoning is observed frequently in South East Asian regions. In TTX-derived food poisoning outbreaks, the amount of TTX recovered from suspicious fish samples or leftovers, and residual levels from biological fluids of victims are typically trace. However, liquid chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry methods have been demonstrated to qualitatively and quantitatively determine TTX in clinical samples from victims. Identification and validation of the TTX-originating seafood species responsible for a food poisoning incident is needed. A polymerase chain reaction-based method on mitochondrial DNA analysis is useful for identification of fish species. This review aims to collect pertinent information available on TTX-borne food poisoning incidents with a special emphasis on the analytical methods employed for TTX detection in clinical laboratories as well as for the identification of TTX-bearing species.

Plancitoxin I from the venom of crown-of-thorns starfish (Acanthaster planci) induces oxidative and endoplasmic reticulum stress associated cytotoxicity in A375.S2 cells.

The crown-of-thorns starfish Acanthaster planci is a venomous starfish whose venom provokes strong cytotoxicity. In the present study, the purified cytotoxic toxin of A. planci venom (CAV) was identified as plancitoxin I protein by mass spectrum analyses. This study aims to investigate the molecular mechanism underlying the cytotoxicity function of plancitoxin I by focusing on the oxidative stress, mitochondrial dysfunction and endoplasmic reticulum (ER) stress pathway in human melanoma A375.S2 cells. The results indicated that after being treated with CAV toxin, A375.S2 cells significantly decreased viability in a dose-dependent manner. The CAV was found to reduce the cellular antioxidant enzymes such as SOD and CAT, and there was a significant decrease in total thiol level and mtDNA integrity, and it enhanced the lipid peroxidation. In addition, CAV increased cytosolic Ca(2+) concentration, and enhanced the expression of the ER molecular chaperones GRP78 and CHOP in a dose-dependent manner. CAV significantly elevated the activity of caspase-3, -8 and -9, and reduced the ratio of Bcl-2/Bax. The cells exhibited apoptosis were determined by using propidium iodide (PI) staining of DNA fragmentation (sub-G1 peak). In summary, the results demonstrated that plancitoxin I inhibits the proliferation of A375.S2 cells through induction of oxidative stress, mitochondrial dysfunction and ER stress associated apoptosis.

Taurine resumed neuronal differentiation in arsenite-treated N2a cells through reducing oxidative stress, endoplasmic reticulum stress, and mitochondrial dysfunction.

The goal of the study is to investigate the preventive effect of taurine against arsenite-induced arrest of neuronal differentiation in N2a cells. Our results revealed that taurine reinstated the neurite outgrowth in arsenite-treated N2a cells. Meanwhile, arsenite-induced oxidative stress and mitochondrial dysfunction as well as degradation of mitochondria DNA (mtDNA) were also inhibited by co-treatment of taurine. Since oxidative stress and mitochondrial dysfunction is closely associated with endoplasmic reticulum (ER) stress, we further examined indicators of ER stress, 78 kDa glucose-regulated protein (GRP78), and C/EBP-homologous protein (CHOP) protein expression. The results demonstrated that taurine significantly reduced arsenite-induced ER stress in N2a cells. In the parallel experiment, arsenite-induced disruption of intracellular calcium homeostasis was also ameliorated by taurine. The proven bio-function of taurine preserved a preventive effect against deleteriously cross-talking between oxidative stress, mitochondria, and ER. Overall, the results of the study suggested that taurine reinstated neuronal differentiation by inhibiting oxidative stress, ER stress, and mitochondrial dysfunction in arsenite-treated N2a cells.

Secondhand smoke exposure toxicity accelerates age-related cardiac disease in old hamsters.

BACKGROUND: Aging is associated with physiological or pathological left ventricular hypertrophy (LVH) cardiac changes. Secondhand smoke (SHS) exposure is associated with pathological LVH. The action mechanism in cardiac concentric hypertrophy from SHS exposure is understood, but the transition contributed from SHS exposure is not. To determine whether exposure to SHS has an impact on age-induced LVH we examined young and old hamsters that underwent SHS exposure in a chamber for 30 mins. METHODS: Morphological and histological studies were then conducted using hematoxylin and eosin (H&E) and Masson's trichrome staining. Echocardiographic analysis was used to determine left ventricular wall thickness and function. LVH related protein expression levels were detected by western blot analysis. RESULTS: The results showed that both young and aged hamsters exposed to SHS exhibited increased heart weights and left ventricular weights, left ventricular posterior wall thickness and intraventricular septum systolic and diastolic pressure also increased. However, left ventricular function systolic and diastolic pressure deteriorated. H&E and Masson's trichrome staining results showed LV papillary muscles were ruptured, resulting in lower cardiac function at the myocardial level. LV muscle fiber arrangement was disordered and collagen accumulation occurred. Concentric LVH related protein molecular markers increased only in young hamsters exposed to SHS. However, this declined with hamster age. By contrast, eccentric LVH related proteins increased in aging hamsters exposed the SHS. Pro-inflammatory proteins, IL-6, TNF-α, JAK1, STAT3, and SIRTI expression increased in aging hamsters exposed to SHS. CONCLUSIONS: We suggest that SHS exposure induces a pro-inflammatory response that results in concentric transition to aging eccentric LVH.

Antioxidative and anticancer activities of various ethanolic extract fractions from crown-of-thorns starfish (Acanthaster planci).

Many studies currently researching marine invertebrates to determine the therapeutic potential of their bioactive materials have been showing very promising results. The crown-of-thorns starfish Acanthaster planci, an Echinodermata of the class Asteroidea, is infamous as the unique venomous starfish and as a destroyer of coral reefs. Starfish possesses many useful pharmacological and biological characteristics. In this study, A. planci was extracted with 70% ethanol and lyophilized to obtain an ethanol fraction. The ethanol fraction was dissolved with water and defatted with petroleum ether to obtain a non-polar fraction. The residual solution was successively partitioned with ethylacetate and butanol to obtain an ethylacetate fraction and butanol fraction, respectively. Four fractions were used to examine the antioxidant and anticancer properties. The ethanol fraction of A. planci contained the highest antioxidant effects such as ABTS, DPPH, Fe(2+) chelating activity and reducing power when compared with four fractions. Among the four fractions, the butanol fraction was especially shown to inhibit human malignant melanoma A375.S2 cells' proliferation, which is involved in the apoptotic progression. This fraction could induce apoptosis and even necrosis in A375.S2 cells as evidenced by double staining with an Annexin V-FITC and PI assay and DNA fragmentation analysis. These results indicated that the starfish A. planci is a good resource for obtaining the biologically active substances for antioxidant and anticancer effects.

Toxin and species identification of toxic octopus implicated into food poisoning in Taiwan.

A food poisoning incident due to ingestion of unknown octopus occurred in Taipei in December, 2010. The serum and urine from victims (male 38 and 43 years old) were collected, determined the toxicity, and identified tetrodotoxin (TTX) by high-performance liquid chromatography with tandem mass spectrometry (LC-MS/MS). It was found that only urine contained the trace of TTX. Then, two retained specimen (one without blue ring in the skin and another with small blue ring in the skin) were collected from victims and examined for the toxicity and toxin. Meanwhile, 6 specimens of octopus without blue ring in the skin and 4 specimens of octopus with blue ring in the skin were re-collected from the market. Both retained octopus samples were found to contain TTX. However, re-collected market's octopus without blue ring in the skin did not show to contain TTX the and was identified as Octopus aegina by using the analysis of cytochrome b gene (Cyt b) and cytochrome c oxidase subunit I gene (COI). Only octopus with blue ring in the skin contained TTX and was identified as Hapalochlaena fasciata by using the analysis of Cyt b and COI. Therefore, this octopus food poisoning was caused by toxic octopus H. fasciata and the causative agent was TTX.

Spine venom of crown-of-thorns starfish (Acanthaster planci) induces antiproliferation and apoptosis of human melanoma cells (A375.S2).

The crown-of-thorns starfish (Acanthaster planci) is a venomous starfish. In this study, the extraction of A. planci spine venom (ASV) was performed by phosphate saline buffer, followed by assaying the cytotoxicity on human normal and tumor cells. It was found that human melanoma cells (A375.S2) were the most sensitive to the ASV solution. The cells, after incubation with ASV, significantly appeared to decrease cell viability and increase lactate dehydrogenase (LDH) release with a dose-dependent relationship. The extract of spine promoted loss of mitochondrial membrane potential (ΔΨm) and induced inter-nucleosomal DNA fragmentation in human melanoma cells. The cells exhibited apoptosis by using propidium iodide (PI) staining of DNA fragmentation; it was then determined by flow cytometry (sub-G1 peak). The molecular cytotoxicity of ASV was tested through evaluation of the apoptosis/necrosis ratio by double staining with annexin V and PI assay. The A. planci spine venom showed significant antiproliferation. The human melanoma cells revealed apoptosis at low dose (1.25 µg/ml), and necrosis occurred at high dose (5 µg/ml).

Glycyrrhizic acid attenuated glycative stress in kidney of diabetic mice through enhancing glyoxalase pathway.

SCOPE: Antiglycative effects of glycyrrhizic acid (GA) in kidney of diabetic mice were examined. METHODS AND RESULTS: GA at 0.05, 0.1, and 0.2% was supplied to diabetic mice for 9 wk. Results showed that GA intake increased its deposit in kidney, raised plasma insulin level, decreased plasma glucose and blood urine nitrogen levels, and improved creatinine clearance rate (p < 0.05). GA intake dose-dependently reduced renal carboxymethyllysine level, and at 0.1 and 0.2% decreased plasma HbA1c, urinary glycated albumin, and renal pentosidine levels (p < 0.05). Dietary GA intake declined renal aldose reductase activity and protein expression, as well as lowered renal fructose and sorbitol levels (p < 0.05). GA intake dose-dependently increased glyoxalase-1 activity and expression, and decreased renal methylglyoxal level (p < 0.05). This compound at 0.1 and 0.2% raised glyoxalase-2 activity and protein expression, and increased d-lactate formation (p < 0.05). GA intake dose-dependently suppressed renal expression of nuclear factor kappa B (NF-κB) p65 and p-p38, decreased reactive oxygen species production, and retained glutathione content (p < 0.05). This compound at 0.1 and 0.2% downregulated renal expression of NF-κB p50 and p-ERK1/2 (p < 0.05), and lowered renal level of monocyte chemoattractant protein-1 (MCP-1) and intercellular adhesion molecule-1 (ICAM-1). CONCLUSIONS: These findings suggest that glycyrrhizic acid is an antiglycative and renal-protective agent.

Oral Lactobacillus reuteri GMN-32 treatment reduces blood glucose concentrations and promotes cardiac function in rats with streptozotocin-induced diabetes mellitus.

Impaired regulation of blood glucose levels in diabetes mellitus (DM) patients and the associated elevation of blood glucose levels are known to increase the risk of diabetic cardiomyopathy (DC). In the present study, a probiotic bacterium, Lactobacillus reuteri GMN-32, was evaluated for its potential to reduce blood glucose levels and to provide protection against DC risks in streptozotocin (STZ)-induced DM rats. The blood glucose levels of the STZ-induced DM rats when treated with L. reuteri GMN-32 decreased from 4480 to 3620 mg/l (with 107 colony-forming units (cfu)/d) and 3040 mg/l (with 109 cfu/d). Probiotic treatment also reduced the changes in the heart caused by the effects of DM. Furthermore, the Fas/Fas-associated protein with death domain pathway-induced caspase 8-mediated apoptosis that was observed in the cardiomyocytes of the STZ-induced DM rats was also found to be controlled in the probiotic-treated rats. The results highlight that L. reuteri GMN-32 treatment reduces blood glucose levels, inhibits caspase 8-mediated apoptosis and promotes cardiac function in DM rats as observed from their ejection fraction and fractional shortening values. In conclusion, the administration of L. reuteri GMN-32 probiotics can regulate blood glucose levels, protect cardiomyocytes and prevent DC in DM rats.

Ameliorative effect of Pracparatum mungo extract on high cholesterol diets in hamsters.

This study was designed to test the lipid-lowering and antioxidative activities of Pracparatum mungo extract (PME), in comparison to its components berberine and glycyrrhizin in cholesterol-fed hamsters. The PME and berberine significantly lowered the atherogenic index compared to glycyrrhizin and the control (P < 0.05). The hepatic HMG-CoA reductase activity was significantly lower in the PME and berberine groups than in the glycyrrhizin group (P < 0.05), while the hepatic ACAT activity was significantly decreased by all treatments with respect to the high cholesterol fed group (P < 0.05). The overall potential of the antioxidant system was significantly enhanced by the PME, berberine and glycyrrhizin supplements as the plasma and hepatic TBARS levels were lowered while the hepatic superoxide dismutase activity and glutathione levels, HMG-CoA reductase, LDL receptor, PPAR, SREBP-2 and CYP7A1 mRNA expressions were increased by the treatments of PME and berberine in comparison with the high cholesterol fed hamsters (P < 0.05). Collectively, these results suggest that the supplementation of PME, berberine and glycyrrhizin increased antioxidant activity in hamsters. Furthermore, we observed that PME and berberine groups promoted the excretion of neutral and acidic sterols (P < 0.05), that could contribute to explain the lower plasma and hepatic cholesterol levels found in the treated animals.

Apicidin-resistant HA22T hepatocellular carcinoma cells strongly activated the Wnt/ß-catenin signaling pathway and MMP-2 expression via the IGF-IR/PI3K/Akt signaling pathway enhancing cell metastatic effect.

The IGF-IR/PI3K/Akt signaling pathway inhibited GSK3-ß activity by phosphorylation and this promoted ß-catenin nuclear localization. Our previous study indicated that ß-catenin mRNA level was significantly higher in tumor areas than in non-tumor ones, especially in late pathologic stage tumors. However, ß-catenin inhibition resulted in significantly suppressed migration and invasion ability of HA22T cells. Thus, Wnt/ß-catenin pathway over-activation might be involved in metastatic enhancement of apicidin-resistant HA22T cell metastasis. Apicidin-resistant (AR) HA22T cells showed higher ß-catenin nuclear accumulation and significantly decreased GSK-3-ß protein level, in relation to parental cells. Results also indicated that AR cells increased abundantly in Tbx3, a downstream target of Wnt/ß-catenin that it is implicated in liver cancer. AR cells also inhibited the MEK/ERK/PEA3 pathway which promoted MMP-2 activation. But, apicidin-resistant effect was totally reversed by LY294002 and AG1024. In conclusion, Apicidin-R HA22T cells activated the Wnt/ß-catenin pathway and induced, MMP-2 expression via IGF-IR/PI3K/Akt signaling further enhancing cell the metastatic effects.

Species identification of ciguatoxin-carrying grouper implicated in food poisoning.

Food poisoning due to ingestion of an unknown red grouper occurred in southern Taiwan. To identify the species of toxic red grouper implicated in food poisoning, a 475-bp sequence of the cytochrome b gene from six species of fresh red grouper meat was amplified by using a pair of primers (L14735/H15149). This fragment could be amplified when fish meat was treated with different heating processes. After sequencing, it was found that no variation in sequences was detected among individuals within each species. The species of toxic red grouper meat implicated in food poisoning was judged to be Lutjanus bohar based on sequence analysis. In addition, restriction enzyme analysis with HaeIII rapidly distinguished these six species of red grouper and the two samples implicated in food poisoning. No toxicity of viscera in 18 specimens of six red grouper species was detected, but two food poisoning samples were found to be toxic. This study indicated that DNA sequence and restriction enzyme analysis are powerful methods for identifying potentially toxic red grouper species as L. bohar.