Inhibition of matrix metalloproteinase activities and tightening of tight junctions by diallyl disulfide in AGS human gastric carcinoma cells

Diallyl disulfide in oncotherapy: molecular mechanisms and therapeutic potentials

Garlic possesses a broad spectrum of medicinal properties, such as anti-cancer, antioxidant, anti-diabetic effects, and protective effects on the heart, nervous system, and liver. Diallyl disulfide (DADS), an oil-soluble organic sulfur-containing compound in garlic, has garnered attention in recent years for its demonstrated anti-cancer efficacy in various cancer types such as leukemia, breast cancer, hepatocellular carcinoma, stomach cancer, and prostate cancer. The anticancer properties of DADS are attributed to its ability to suppress cancer cell proliferation, impede invasion and metastasis, as well as induce apoptosis, promote differentiation, and facilitate cell cycle arrest. Although many literatures have reviewed the pharmacokinetics, molecular mechanisms of anti-cancer effects and some clinical trials of DADS, the specific mechanisms and clinical-translational therapeutic potentials have not been elucidated. This comprehensive review focuses on delineating the molecular mechanisms underlying the anticancer effects of DADS, with a particular emphasis on its potential utility as a therapeutic intervention in the clinical management of cancer, and analyzes the challenges and coping strategies faced in the application of DADS as an anti-cancer drug, pointing out the directions for scientific research.

Alternative medicines in oncology: a focus on natural products against gastric cancer

There is justification for optimism about the potential contribution of alternative medicines to cancer management, which now ranks as the second leading cause of death globally. Primary carcinogens arise from several sources, including agriculture, industry, and dietary intake. Gastric cancer (GC) significantly affects an individual's health due to its classification as a malignant tumor associated with elevated mortality and morbidity rates. Chemotherapy is now widely regarded as the gold standard for treating GC. Chemotherapy, however, exerts significant detrimental effects on human health, including irreversible damage to multiple organs. Consequently, it is essential to employ innovative strategies for cancer prevention. Natural products are now the focus of intensive study due to their efficacy against cancer and low toxicity levels. Natural compounds have shown a diverse range of anti-cancer properties. This review aims to emphasize studies on natural compounds that inhibit metastasis, induce apoptosis in GC, and decrease cellular proliferation. All the natural compounds from different sources were incorporated in this review not only medicinal plants derived compounds. This review aims to examine a comprehensive array of natural therapies that may enhance human health and facilitate GC prevention without inducing discernible negative effects. Moreover, this review aims to discuss the toxic side effects of phytochemicals and shed light on mechanisms underlying the action of potential natural products against GC. This review offers a novel perspective by integrating a broad spectrum of natural compounds from diverse sources, not limited to medicinal plants, to explore their anti-cancer properties against gastric cancer.

Diallyl Disulfide: A Bioactive Garlic Compound with Anticancer Potential

Cancer is a life-threatening disease caused by the uncontrolled division of cells, which culminates in a solid mass of cells known as a tumor or liquid cancer. It is the leading cause of mortality worldwide, and the number of cancer patients has been increasing at an alarming rate, with an estimated 20 million cases expected by 2030. Thus, the use of complementary or alternative therapeutic techniques that can help prevent cancer has been the subject of increased attention. Garlic, the most widely used plant medicinal product, exhibits a wide spectrum of biological activities, including antibacterial, hypo-lipidemic, antithrombotic, and anticancer effects. Diallyl disulfide (DADS) is a major organosulfur compound contained within garlic. Recently, several experimental studies have demonstrated that DADS exhibits anti-tumor activity against many types of tumor cells, including gynecological cancers (cervical cancer, ovarian cancer), hematological cancers (leukemia, lymphoma), lung cancer, neural cancer, skin cancer, prostate cancer, gastrointestinal tract and associated cancers (esophageal cancer, gastric cancer, colorectal cancer), hepatocellular cancer cell line, etc. The mechanisms behind the anticancer action of DADS include epithelial-mesenchymal transition (EMT), invasion, and migration. This article aims to review the available information regarding the anti-cancer potential of DADS, as well as summarize its mechanisms of action, bioavailability, and pharmacokinetics from published clinical and toxicity studies.

Garlic (Allium sativum L.): Its Chemistry, Nutritional Composition, Toxicity, and Anticancer Properties

The current review discuss the chemistry, nutritional composition, toxicity, and biological functions of garlic and its bioactive compounds against various types of cancers via different anticancer mechanisms. Several scientific documents were found in reliable literature and searched in databases viz Science Direct, PubMed, Web of Science, Scopus, and Research Gate were carried out using keywords such as "garlic", "garlic bioactive compounds", "anticancer mechanisms of garlic", "nutritional composition of garlic", and others. Garlic contains several phytoconstituents with activities against cancer, and compounds such as diallyl trisulfide (DATS), allicin, and diallyl disulfide (DADS), diallyl sulfide (DAS), and allyl mercaptan (AM). The influence of numerous garlic- derived products, phytochemicals, and nanoformulations on the liver, oral, prostate, breast, gastric, colorectal, skin, and pancreatic cancers has been studied. Based on our search, the bioactive molecules in garlic were found to inhibit the various phases of cancer. Moreover, the compounds in this plant also abrogate the peroxidation of lipids, activity of nitric oxide synthase, epidermal growth factor (EGF) receptor, nuclear factor-kappa B (NF-κB), protein kinase C, and regulate cell cycle and survival signaling cascades. Hence, garlic and its bioactive molecules exhibit the aforementioned mechanistic actions, and thus, they could be used to inhibit the induction, development, and progression of cancer. The review describes the nutritional composition of garlic, its bioactive molecules, and nanoformulations against various types of cancers, as well as the potential for developing these agents as antitumor drugs.

Phyto-targeting the CEMIP Expression as a Strategy to Prevent Pancreatic Cancer Metastasis

INTRODUCTION

Metastasis of primary pancreatic cancer (PC) to adjacent or distant organs is responsible for the poor survival rate of affected individuals. Chemotherapy, radiotherapy, and immunotherapy are currently being prescribed to treat PC in addition to surgical resection. Surgical resection is the preferred treatment for PC that leads to 20% of 5-year survival, but only less than 20% of patients are eligible for surgical resection because of the poor prognosis. To improve the prognosis and clinical outcome, early diagnostic markers need to be identified, and targeting them would be of immense benefit to increase the efficiency of the treatment. Cell migration-inducing hyaluronan-binding protein (CEMIP) is identified as an important risk factor for the metastasis of various cancers, including PC. Emerging studies have pointed out the crucial role of CEMIP in the regulation of various signaling mechanisms, leading to enhanced migration and metastasis of PC.

METHODS

The published findings on PC metastasis, phytoconstituents, and CEMIP were retrieved from Pubmed, ScienceDirect, and Cochrane Library. Computational tools, such as gene expression profiling interactive analysis (GEPIA) and Kaplan-Meier (KM) plotter, were used to study the relationship between CEMIP expression and survival of PC individuals.

RESULTS

Gene expression analysis using the GEPIA database identified a stupendous increase in the CEMIP transcript in PC compared to adjacent normal tissues. KM plotter analysis revealed the impact of CEMIP on the overall survival (OS) and disease-free survival (DFS) among PC patients. Subsequently, several risk factors associated with PC development were screened, and their ability to regulate CEMIP gene expression was analyzed using computational tools.

CONCLUSION

The current review is focused on gathering information regarding the regulatory role of phytocomponents in PC migration and exploring their possible impact on the CEMIP expression.

Biological Functions of Diallyl Disulfide, a Garlic-Derived Natural Organic Sulfur Compound

Garlic is widely accepted as a functional food and an excellent source of pharmacologically active ingredients. Diallyl disulfide (DADS), a major bioactive component of garlic, has several beneficial biological functions, including anti-inflammatory, antioxidant, antimicrobial, cardiovascular protective, neuroprotective, and anticancer activities. This review systematically evaluated the biological functions of DADS and discussed the underlying molecular mechanisms of these functions. We hope that this review provides guidance and insight into the current literature and enables future research and the development of DADS for intervention and treatment of multiple diseases.

Garlic constituents for cancer prevention and therapy: From phytochemistry to novel formulations

Garlic (Allium sativum L.) is one of the oldest plants cultivated for its dietary and medicinal values. This incredible plant is endowed with various pharmacological attributes, such as antimicrobial, antiarthritic, antithrombotic, antitumor, hypoglycemic, and hypolipidemic activities. Among the various beneficial pharmacological effects of garlic, the anticancer activity is presumably the most studied. The consumption of garlic provides strong protection against cancer risk. Taking into account the multi-targeted actions and absence of considerable toxicity, a few active metabolites of garlic are probably to play crucial roles in the killing of cancerous cells. Garlic contains several bioactive molecules with anticancer actions and these include diallyl trisulfide, allicin, diallyl disulfide, diallyl sulfide, and allyl mercaptan. The effects of various garlic-derived products, their phytoconstituents and nanoformulations have been evaluated against skin, prostate, ovarian, breast, gastric, colorectal, oral, liver, and pancreatic cancers. Garlic extract, its phytocompounds and their nanoformulations have been shown to inhibit the different stages of cancer, including initiation, promotion, and progression. Besides, these bioactive metabolites alter the peroxidation of lipid, activity of nitric oxide synthetase, nuclear factor-κB, epidermal growth factor receptor, and protein kinase C, cell cycle, and survival signaling. The current comprehensive review portrays the functions of garlic, its bioactive constituents and nanoformulations against several types of cancers and explores the possibility of developing these agents as anticancer pharmaceuticals.

The Effects of Medicinal Plants and Bioactive Natural Compounds on Homocysteine

BACKGROUND

Among non-communicable diseases, cardiovascular diseases (CVDs) are the leading cause of mortality and morbidity in global communities. By 2030, CVD-related deaths are projected to reach a global rise of 25 million. Obesity, smoking, alcohol, hyperlipidemia, hypertension, and hyperhomocysteinemia are several known risk factors for CVDs. Elevated homocysteine is tightly related to CVDs through multiple mechanisms, including inflammation of the vascular endothelium. The strategies for appropriate management of CVDs are constantly evolving; medicinal plants have received remarkable attention in recent researches, since these natural products have promising effects on the prevention and treatment of various chronic diseases. The effects of nutraceuticals and herbal products on CVD/dyslipidemia have been previously studied. However, to our knowledge, the association between herbal bioactive compounds and homocysteine has not been reviewed in details. Thus, the main objective of this study is to review the efficacy of bioactive natural compounds on homocysteine levels according to clinical trials and animal studies.

RESULTS

Based on animal studies, black and green tea, cinnamon, resveratrol, curcumin, garlic extract, ginger, and soy significantly reduced the homocysteine levels. According to the clinical trials, curcumin and resveratrol showed favorable effects on serum homocysteine. In conclusion, this review highlighted the beneficial effects of medicinal plants as natural, inexpensive, and accessible agents on homocysteine levels based on animal studies. Nevertheless, the results of the clinical trials were not uniform, suggesting that more well-designed trials are warranted.

The Potential Application of Allium Extracts in the Treatment of Gastrointestinal Cancers

Herbal medicine is currently widely practiced, since natural resources are reported to alleviate side effects during oncological treatment while modifying cancer cell responses at the same time. Allium vegetables and their constituents have recently been extensively investigated due to the numerous possible beneficial properties, establishing them as an additional treatment modality in different cancers. According to the epidemiological evidence, as well as many in vivo and in vitro studies, the abovementioned substances seem to be effective in the prevention and inhibition of the progression of carcinogenesis. Due to high concentrations of organosulfur compounds, which exhibit anticarcinogenic, antimicrobial, as well as anti-inflammatory properties, Allium constituents are believed to constitute a promising prevention and supportive therapy for oncological patients. Besides, it was demonstrated that a combination of Allium extracts with chemotherapy provided satisfactory clinical outcomes while at the same time being cost-effective. The aim of this review was to present and discuss currently investigated Allium extracts and their effects on several gastrointestinal cancers including gastric, colon, liver, esophageal, and pancreatic cancer.

Antioxidant-Rich Diet, GSTP1 rs1871042 Polymorphism, and Gastric Cancer Risk in a Hospital-Based Case-Control Study

Background

Chronic gastritis along with Helicobacter pylori (H. pylori) infection has been implicated in inflammatory response-related genes linked to the causation of gastric cancer. Glutathione S-transferase Pi (GSTP1) plays a role in regulating oxidative stress and detoxification against carcinogenesis. In this study, we aimed to determine whether an antioxidant-rich diet is associated with gastric cancer risk and identify how this association could be altered by GSTP1 genetic variants.

Methods

This study included 1,245 participants (415 cases and 830 controls) matched for age and sex. The dietary antioxidant capacity was estimated based on the oxygen radical absorbance capacity (ORAC) incorporated with a semiquantitative food frequency questionnaire. Five single nucleotide polymorphisms (SNPs) of GSTP1 (rs1695, rs749174, rs1871042, rs4891, and rs947895) were selected among the exome array genotype data.

Results

High dietary ORAC was inversely associated with gastric cancer (hydrophilic ORAC OR _{T3vs. T1}, 95% CI = 0.57, 0.39–0.82, P = 0.004; lipophilic ORAC = 0.66, 0.45–0.95, P = 0.021; total phenolics = 0.57, 0.39–0.83, P = 0.005). The polymorphism rs1871042 increased the risk of gastric cancer (OR, 95% CI = 1.55, 1.10–2.16, P = 0.01, CT+TT vs. CC). A remarkably reduced risk of gastric cancer was observed among those who had a high dietary ORAC according to rs1871042 polymorphism (hydrophilic ORAC OR _{T3vs. T1}, 95% CI = 0.36, 0.17–0.78, P for trend = 0.013; lipophilic ORAC = 0.58, 0.37–0.93, P for trend = 0.021; total phenolics = 0.38, 0.17–0.83, P for trend = 0.019).

Conclusions

Our findings indicate that dietary ORAC intake may be inversely associated with the risk of gastric cancer altered by genetic variants of GSTP1, providing new intervention strategies for gastric cancer patients.

Design and in silico screening of aryl allyl mercaptan analogs as potential histone deacetylases (HDAC) inhibitors

The Zn⁺² HDACIs show promising anticancer activity. Allyl mercaptan (AM), a metastabilzed monomeric form of diallyl disulphide (DADS) shows better HDACI activity. The present work screens a dataset of aryl AM derivatives 1(a-g) for potential HDACI action viain silico models. DFT calculations predicted the geometrical parameters and frontier orbital calculations suggested better chemical reactivity. Negative chemical potential and NBO hyper conjugative interactions predicted their chemical stability. ADME study confirmed favourable drug likeliness. Molecular docked models suggested the formation of coordinate bond between sulphur of allylmercaptan and Zn²⁺ cofactor of HDAC8. Besides, models also predicted the dominance of hydrophobic interactions. The aryl AM analogs docked perfectly with HDAC3 as well. The glide score and S-Zn distance of compounds 1a, 1f and 1g were found to be better than allylmercaptan. Therefore, the designed aryl AM analogs filtered as better HDACIs. These could be further used for design and synthesis of new improved HDACIs.

Garlic and its Active Compounds: A Potential Candidate in The Prevention of Cancer by Modulating Various Cell Signalling Pathways

BACKGROUND

Cancer is a multi-factorial disease including alterations in the cell signalling pathways. Currently, several drugs are in use to treat cancer but such drugs show negative side effects on normal cells and cause severe toxicity.

METHODS

The current research is mainly focused on medicinal plants with potential therapeutic efficacy in the treatment of cancer without any adverse effects on normal cells. In this regard, garlic and its active compounds including diallyl sulfide, diallyl trisulfide, ajoene, and allicin have been established to suppress the growth of cancer and killing of cancer cells.

RESULT

The review focuses on garlic and its active compounds chemopreventive effect through modulating various cell signalling pathways. Additionally, garlic and its active compound were established to induce cell cycle arrest at the G0/G1 phase and G2/M phases in cancer cells, increase the expression of tumor suppressor genes, inhibit the angiogenesis process, induction of apoptosis and modulation of various other genetic pathways.

CONCLUSION

This review sketches the diverse chemopreventive activities of garlic and their active ingredients in the management of cancer mainly focusing on cell signalling pathways.

Phytochemicals for the Prevention and Treatment of Gastric Cancer: Effects and Mechanisms

Gastric cancer is the fifth most common cancer, and the third most prevalent cause of cancer-related deaths in the world. Voluminous evidence has demonstrated that phytochemicals play a critical role in the prevention and management of gastric cancer. Most epidemiological investigations indicate that the increased intake of phytochemicals could reduce the risk of gastric cancer. Experimental studies have elucidated the mechanisms of action, including inhibiting cancer cell proliferation, inducing apoptosis and autophagy, and suppressing angiogenesis as well as cancer cell metastasis. These mechanisms have also been related to the inhibition of Helicobacter pylori and the modulation of gut microbiota. In addition, the intake of phytochemicals could enhance the efficacy of anticancer chemotherapeutics. Moreover, clinical studies have illustrated that phytochemicals have the potential for the prevention and the management of gastric cancer in humans. To provide an updated understanding of relationships between phytochemicals and gastric cancer, this review summarizes the effects of phytochemicals on gastric cancer, highlighting the underlying mechanisms. This review could be helpful for guiding the public in preventing gastric cancer through phytochemicals, as well as in developing functional food and drugs for the prevention and treatment of gastric cancer.

Diallyl disulphide suppresses the cannonical Wnt signaling pathway and reverses the fibronectin-induced epithelial mesenchymal transition of A549 lung cancer cells

Globally, non-small cell lung cancer is a leading cause of cancer-related mortality and about 40% of these cancers are detected in the metastatic stage. Epithelial mesenchymal transition (EMT) plays a critical role during malignant transformation, and the extracellular matrix component, fibronectin (FN), is a known inducer of invasion and metastasis. Diallyl disulphide (DADS), a bioactive component of garlic, exhibits a wide spectrum of biological activities including the inhibition of cancer cell migration and invasion. The present study was aimed at deciphering the effect of DADS on the regulation of FN-induced EMT in A549 lung cancer cells. DADS suppressed the FN-induced invasion and migration potential of A549 cells which may be attributed to the reduced activity of gelatinases. DADS suppressed the FN-aggravated EMT of A549 cells by the upregulation of the epithelial markers, E-cadherin and cytokeratin-18, and the downregulation of the mesenchymal markers, N-cadherin and vimentin, and the transcription factors, snail, slug and twist. DADS was effective in inhibiting the nuclear translocation of β-catenin and the phosphorylation of glycogen synthase kinase-3β and in suppressing the activity of dishevelled homolog 2 and T-cell-factor/lymphoid enhancer factor in FN-induced A549 cells. Cumulatively, this study indicated that DADS might be able to reverse FN-induced EMT in A549 cells via the suppression of Wnt signaling.

Recent progress in natural dietary non-phenolic bioactives on cancers metastasis

From several decades ago to now, cancer continues to be the leading cause of death worldwide, and metastasis is the major cause of cancer-related deaths. For health benefits, there is a great desire to use non-chemical therapy such as nutraceutical supplementation to prevent pathology development. Over 10,000 different natural bioactives or phytochemicals have been known that possessing potential preventive or supplementary effects for various diseases including cancer. Previously, the in vitro and in vivo anti-invasive and anti-metastatic activities of phenolic acids, monophenol, polyphenol and their derivatives and flavonoids and their derivatives have been reviewed. However, a vast number of natural dietary compounds other than phenolics have been demonstrated to potentially possess the ability to inhibit the invasion and metastasis of various cancers. In this review, we summarize the studies in recent decade on in vitro and in vivo effects and molecular mechanisms of natural bioactives, excluding the phenolics in food, in cancer invasion and metastasis. By combining this review of non-phenolics with the previous phenolics reviews, the puzzle for the contribution of natural dietary bioactives on cancer invasive or/and metastatic progress will be almost complete and more clear.

Ability of garlic-derived diallyl disulfide and diallyl trisulfide supplemented by oral gavage to mitigate effects of an acute postweaning feed and water deprivation event in nursery pigs

Compounds in garlic have been shown to contain anti-inflammatory, antioxidant, and immune modulatory properties that may be able to mitigate the effects of nursery pig stressors. The objective of the current experiment was to determine if oral gavage of garlic-derived diallyl disulfide (DADS) and diallyl trisulfide (DATS) could mitigate the effects of a 24-h postweaning feed + water deprivation event in nursery pigs. Pigs (6.0 ± 0.05 kg and 21 d old) were allotted to 4 treatments in a randomized complete block design at weaning with 8 replicate pens per treatment that consisted of with or without a 24-h postweaning feed + water deprivation event and with or without an oral gavage containing 3.6 mg DADS + DATS/kg BW. Growth performance and morbidity were recorded throughout the experiment, and on 1, 6, and 21 d after weaning, 1 pig per pen was selected, blood was collected, the pig was euthanized, and a segment of the distal ileum was subsequently excised for morphological and gene and protein expression measurements. Mucosal gene expression was conducted by reverse transcription PCR for immune, antioxidant, and cellular integrity markers. Furthermore, activity of mucosal superoxide dismutase was measured by colorimetric assay. Immediately following the feed + water deprivation event, there was a decrease ( < 0.01) in growth performance and an increase ( = 0.01) in serum cortisol. The feed + water deprivation event tended ( = 0.10) to decrease ileal villus height and supplementation of DADS + DATS by oral gavage increased ( = 0.03) villus height 1 d after weaning. Supplementation of DADS + DATS by oral gavage decreased ( = 0.03) and tended to decrease ( = 0.08) gene expression of on 6 and 21 d after weaning, respectively. Furthermore, at 1 d after weaning, ileal mucosa SOD activity was decreased ( = 0.01) by the feed + water deprivation and increased ( = 0.04) by oral supplementation of DADS + DATS. Expression of the tight junction genes and were reduced ( ≤ 0.05) due to the feed + water deprivation event 1 d after weaning. Results from the current study show that an acute feed + water deprivation event can impact growth performance, intestinal characteristics, and antioxidant status in nursery pigs, which can be partially mitigated by oral supplementation of garlic compounds DADS + DATS.

Effects of dietary supplementation of cinnamaldehyde and formic acid on growth performance, intestinal microbiota and immune response in broiler chickens

An experiment was conducted to investigate the effects of replacing antibiotic growth promoter (AGP) with a combination of essential oil and organic acids (EO + OA) on growth performance, gut microbiota and immune response in broiler chickens. In Experiment 1, 320 day-old broiler chicks were randomly distributed to 32 pens with 10 birds in each pen and the pens were equally allotted to four treatment groups. In Experiment 2, 120 day-old chicks were divided into the same four treatment groups, each group containing three replicated pens with 10 birds in each pen. The groups were (1) Negative Control (NC) without AGP or other growth-promoting feed additives; (2) AGP (NC + enramycin; 125 mg/kg feed; (3) OA (NC + OA; 500 mg/kg feed); and (4) EO + OA (NC + a combination of cinnamaldehyde and calcium formate; 500 mg/kg feed). Experiment 1 lasted for 40 days, whereas Experiment 2 continued for 28 days. In Experiment 2, all birds were orally challenged with Escherichia coli (108 bacteria/bird) on Day 14. Overall intake, growth and feed conversion ratio (FCR) on Day 40 had no difference (P > 0.05) among the groups in Experiment 1. In Experiment 2, growth, feed intake and FCR were not affected by any dietary treatments until Day 14, but after being challenged with E. coli, bodyweight gain and FCR improved (P < 0.05) for AGP and EO + OA compared with NC. Mortality rate was also lower (P < 0.05) for AGP and EO + OA than NC in Experiment 2. Villi height was higher (P < 0.001) in OA and EO + OA groups compared with NC and AGP groups. Any treatment did not affect (P > 0.05) the counts of total bacteria, E. coli and Lactobacillus in the contents of ileum and caecum. However, Salmonella counts in the ileal and caecal contents decreased (P < 0.001) for AGP, OA and EO + OA compared with NC group. Clostridium counts were lower for EO + OA group than for NC and AGP groups in the ileum, and for AGP, OA and EO + OA groups than for NC in the caeca (P < 0.05). Antibody titer on Day 35 against Newcastle disease vaccine was higher in EO + OA group than in NC, AGP and OA groups (P < 0.001). In conclusion, EO + OA did not affect growth and FCR in broilers. However, AGP and EO + AO improved growth performance and FCR after being challenged with E. coli. Moreover, EO + OA was effective in reducing the Clostridium count in the small intestine and caecum and increasing the villus height and antibody titer against Newcastle disease vaccine.

Diallyl disulfide suppresses epithelial-mesenchymal transition, invasion and proliferation by downregulation of LIMK1 in gastric cancer

Diallyl disulfide (DADS) has been shown to have multi-targeted antitumor activities. We have previously discovered that it has a repressive effect on LIM kinase-1 (LIMK1) expression in gastric cancer MGC803 cells. This suggests that DADS may inhibit epithelial-mesenchymal transition (EMT) by downregulating LIMK1, resulting in the inhibition of invasion and growth in gastric cancer. In this study, we reveal that LIMK1 expression is correlated with tumor differentiation, invasion depth, clinical stage, lymph node metastasis, and poor prognosis. DADS downregulated the Rac1-Pak1/Rock1-LIMK1 pathway in MGC803 cells, as shown by decreased p-LIMK1 and p-cofilin1 levels, and suppressed cell migration and invasion. Knockdown and overexpression experiments performed in vitro demonstrated that downregulating LIMK1 with DADS resulted in restrained EMT that was coupled with decreased matrix metalloproteinase-9 (MMP-9) and increased tissue inhibitor of metalloproteinase-3 (TIMP-3) expression. In in vitro and in vivo experiments, the DADS-induced suppression of cell proliferation was enhanced and antagonized by the knockdown and overexpression of LIMK1, respectively. Similar results were observed for DADS-induced changes in the expression of vimentin, CD34, Ki-67, and E-cadherin in xenografted tumors. These results indicate that downregulation of LIMK1 by DADS could explain the inhibition of EMT, invasion and proliferation in gastric cancer cells.

2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside suppresses human colorectal cancer cell metastasis through inhibiting NF-κB activation

2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside (THSG), a major component of Polygonum multiflorum Thunb (He-Shou-Wu), has been reported to exhibit antioxidant and anti-inflammatory effects. However, its anti-metastatic effect against colorectal cancer is still unclear. In this study, cell migration, invasion and adhesion abilities as well as metastasis-associated protein and NF-κB pathway signaling factor expression were analyzed after treating HT-29 cells with THSG. According to the results, the migration and invasiveness of HT-29 cells were reduced after treatment with 5 or 10 mM THSG (p<0.05). Additionally, the levels of matrix metalloproteinase-2 (MMP-2) and phosphorylated VE-cadherin in HT-29 cells were reduced and the transepithelial electrical resistance (TEER) of EA.hy926 endothelial cell monolayers was increased after incubation in THSG for 24 h (p<0.05). Cell adhesion ability and the E-selectin and intercellular adhesion molecule-1 (ICAM-1) protein levels were reduced when EA.hy926 endothelial cells were treated with THSG (p<0.05). In addition, the cytoplasmic phosphorylation of IκB, the nuclear p65 level and the DNA-binding activity of NF-κB were reduced after treating HT-29 or EA.hy926 cells with 5 or 10 mM THSG (p<0.05). These results suggest that THSG inhibits HT-29 cell metastasis by suppressing cell migration, invasion and adhesion. Furthermore, THSG inhibits metastasis-associated protein expression by suppressing NF-κB pathway activation.

Diallyl disulfide inhibits growth and metastatic potential of human triple-negative breast cancer cells through inactivation of the β-catenin signaling pathway

SCOPE

Although diallyl disulfide (DADS), an important garlic (Allium sativum) derivative, has exhibited potential anticancer activity, the molecular mechanism of this activity remains unknown. In this study, we evaluated the antitumor activity of DADS in triple-negative breast cancer (TNBC) cell lines based in vitro and in vivo models.

METHODS AND RESULTS

We found that treatment with DADS resulted in decreased viability, increased apoptosis, and suppression of metastatic potential in TNBC cells. Furthermore, DADS induced dysregulation of B-cell lymphoma (Bcl)-2 family members, downregulation of matrix metalloproteinase (MMP)-9 and reversal of the epithelial-mesenchymal transition (EMT). Interestingly, DADS significantly inhibited activation of the β-catenin signaling pathway, which regulated Bcl-2 family members, MMP-9 and EMT in TNBC cells. Consistent with these in vitro findings, we also verified the anticancer potential of DADS in MDA-MB-231 xenograft mice. Treatment with DADS significantly reduced tumor volume and weight and increased apoptosis in these mice, while the expression of active β-catenin was decreased, and the downstream molecules were dysregulated.

CONCLUSION

Our results show that the antitumor effect of DADS on TNBC cells is mediated by the β-catenin pathway, suggesting that DADS could be used as a potential therapeutic agent for treating or preventing breast cancer.

Identification of potential targets for diallyl disulfide in human gastric cancer MGC-803 cells using proteomics approaches

Diallyl disulfide (DADS) is characterized as an effective agent for the prevention and therapy of cancer, however, mechanisms regarding its anticancer effects are not fully clarified. In the present study, we compared the protein expression profile of gastric cancer MGC-803 cells subjected to DADS treatment with that of untreated control cells to explore potential molecules regulated by DADS. Using proteomic approaches, we identified 23 proteins showing statistically significant differences in expression, including 9 upregulated and 14 downregulated proteins. RT-PCR and western blot analysis confirmed that retinoid-related orphan nuclear receptor α (RORα) and nM23 were increased by DADS, whereas LIM kinase-1 (LIMK1), urokinase-type plasminogen activator receptor (uPAR) and cyclin-dependent kinase-1 (CDK1) were decreased. DADS treatment and knockdown of uPAR caused suppression of ERK/Fra-1 pathway, downregulation of urokinase-type plasminogen activator (uPA), matrix metalloproteinase-9 (MMP-9) and vimentin, and upregulation of tissue inhibitor of metalloproteinase-3 (TIMP-3) and E-cadherin, concomitant with inhibition of cell migration and invasion. Moreover, knockdown of uPAR potentiated the effects of DADS on MGC-803 cells. These data demonstrate that downregulation of uPAR may partially be responsible for DADS-induced inhibition of ERK/Fra-1 pathway, as well as cell migration and invasion. Thus, the discovery of DADS-induced differential expression proteins is conducive to reveal unknown mechanisms of DADS anti-gastric cancer.

Induction of Apoptosis in Human Leukemic Cell Lines by Diallyl Disulfide via Modulation of EGFR/ERK/PKM2 Signaling Pathways

BACKGROUND

Diallyl disulfide (DADS) may exert potent anticancer action both in vitro and in vivo. Although its effects on cancer are significant, the underlying mechanisms remain unknown. In this study, we sought to elucidate possible links between DADS and pyruvate kinase (PKM2).

MATERIALS AND METHODS

KG1α, a leukemia cell line highly expressing PKM2 was used with a cell counting kit (CCK)-8 and flow cytometry (FCM) to investigate the effects of DADS. Relationships between PKM2 and DADS associated with phosphorylation of EGFR, ERK1/2 and MEK, were assessed by western blot analysis.

RESULTS

In KG1α cells highly expressing PKM2, we found that DADS could affect proliferation, apoptosis and EGFR/ERK/PKM2 signaling pathways, abrogating EGF-induced nuclear accumulation of PKM2.

CONCLUSIONS

These results suggested that DADS suppressed the proliferation of KG1α cells, providing evidence that its proapoptotic effects are mediated through the inhibition of EGFR/ERK/PKM2 signaling pathways.

Hydrogen sulfide signaling in the gastrointestinal tract

SIGNIFICANCE

The current literature regarding the effects of the gaseous signal molecule hydrogen sulfide (H2S) in the gastrointestinal system is reviewed. Bacterial, host and pharmaceutical-derived H2S are all considered and presented according to the physiological or pathophysiological effects of the gaseous signal molecule. These subjects include the toxicology of intestinal H2S with emphasis on bacterial-derived H2S, especially from sulfate-reducing bacteria, the role of endogenous and exogenous H2S in intestinal inflammation, and the roles of H2S in gastrointestinal motility, secretion and nociception.

RECENT ADVANCES

While its pro- and anti-inflammatory, smooth muscle relaxant, prosecretory, and pro- and antinociceptive actions continue to remain the major effects of H2S in this system; recent findings have expanded the potential molecular targets for H2S in the gastrointestinal tract.

CRITICAL ISSUES

Numerous discrepancies remain in the literature, and definitive molecular targets in this system have not been supported by the use of competitive antagonism.

FUTURE DIRECTIONS

Future work will hopefully resolve discrepancies in the literature and identify molecular targets and mechanisms of action for H2S. It is clear from the current literature that the long-appreciated relationship between H2S and the gastrointestinal tract continues to be strong as we endeavor to unravel its mysteries.

Inhibiting invasion into human bladder carcinoma 5637 cells with diallyl trisulfide by inhibiting matrix metalloproteinase activities and tightening tight junctions

Diallyl trisulfide (DATS), an organosulfur compound in garlic, possesses pronounced anti-cancer potential. However, the anti-invasive mechanism of this compound in human bladder carcinoma is not fully understood. In this study, we evaluated the anti-invasive effects of DATS on a human bladder carcinoma (5637) cell line and investigated the underlying mechanism. The results indicated that DATS suppressed migration and invasion of 5637 cells by reducing the activities and expression of matrix metalloproteinase (MMP)-2 and MMP-9 at both the protein and mRNA levels. DATS treatment up-regulated expression of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 in 5637 cells. The inhibitory effects of DATS on invasiveness were associated with an increase in transepithelial electrical resistance and repression of the levels of claudin family members. Although further studies are needed, our data demonstrate that DATS exhibits anti-invasive effects in 5637 cells by down-regulating the activity of tight junctions and MMPs. DATS may have future utility in clinical applications for treating bladder cancer.

Dietary plant extracts alleviate diarrhea and alter immune responses of weaned pigs experimentally infected with a pathogenic Escherichia coli

A study was conducted to evaluate the effects of 3 different plant extracts on diarrhea, immune response, intestinal morphology, and growth performance of weaned pigs experimentally infected with a pathogenic F-18 Escherichia coli (E. coli). Sixty-four weaned pigs (6.3±0.2 kg BW, and 21 d old) were housed in individual pens in disease containment chambers for 15 d: 4 d before and 11 d after the first inoculation (d 0). Treatments were in a 2×4 factorial arrangement: with or without an F-18 E. coli challenge (toxins: heat-labile toxin, heat-stable toxin b, and Shiga-like toxin 2; 10(10) cfu/3 mL oral dose; daily for 3 d from d 0) and 4 diets [a nursery basal diet (CON) or 10 ppm of capsicum oleoresin, garlic botanical, or turmeric oleoresin]. The growth performance was measured on d 0 to 5, 5 to 11, and 0 to 11. Diarrhea score (1, normal, to 5, watery diarrhea) was recorded for each pig daily. Frequency of diarrhea was the percentage of pig days with a diarrhea score of 3 or greater. Blood was collected on d 0, 5, and 11 to measure total and differential white blood cell counts and serum tumor necrosis factor (TNF)-α, IL-10, transforming growth factor (TGF)-β, C-reactive protein, and haptoglobin. On d 5 and 11, half of the pigs were euthanized to measure villi height and crypt depth of the small intestine and macrophage and neutrophil number in the ileum. The E. coli infection increased (P<0.05) diarrhea score, frequency of diarrhea, white blood cell counts, serum TNF-α and haptoglobin, and ileal macrophages and neutrophils but reduced (P<0.05) villi height and the ratio of villi height to crypt depth of the small intestine on d 5. In the challenged group, feeding plant extracts reduced (P<0.05) average diarrhea score from d 0 to 2 and d 6 to 11 and frequency of diarrhea and decreased (P<0.05) TNF-α and haptoglobin on d 5, white blood cell counts and neutrophils on d 11, and ileal macrophages and neutrophils on d 5. Feeding plant extracts increased (P<0.05) ileal villi height on d 5 but did not affect growth performance compared with the CON. In the sham group, feeding plant extract also reduced (P<0.05) diarrhea score, frequency of diarrhea, and ileal macrophages compared with the CON. In conclusion, the 3 plant extracts tested reduced diarrhea and inflammation caused by E. coli infection, which may be beneficial to pig health.

Inhibition of AGS human gastric cancer cell invasion and proliferation by Capsosiphon fulvescens glycoprotein

Seaweeds are increasingly being used as foodstuffs and therapeutics. Capsosiphon fulvescens (C. fulvescens) is a green sea alga which has demonstrated anti-tumor activity in various cancer cell lines. In cancer cells, homeostasis is not maintained, enabling mutations to develop and growth to continue unchecked. Overexpression of matrix metalloproteinase (MMP) and tight junction (TJ) proteins is important for cancer cell proliferation, invasion and metastasis. In addition, these proteins are closely associated with cell membrane permeability. In the current study, C. fulvescens glycoprotein (Cf-GP) was found to inhibit TJ proteins and invasion of AGS human gastric cancer cells. Cf-GP-mediated inhibition of cell proliferation and invasion was confirmed, as well as changes in TJ protein levels. In addition, MMP-2 and −9 activities were inhibited, as indicated by increased transepithelial electrical resistance. Inhibition of MMP protein expression was also found to correlate with tissue inhibitor of metalloproteinase 1 and Cf-GP treatment, as revealed by western blot analysis and RT-PCR. In conclusion, these results indicate that Cf-GP inhibits cancer cell invasion and therefore demonstrates a potential therapeutic strategy to decrease cancer metastasis.

Apoptosis induction of human prostate carcinoma DU145 cells by diallyl disulfide via modulation of JNK and PI3K/AKT signaling pathways

Diallyl disulfide (DADS), a sulfur compound derived from garlic, has various biological properties, such as anticancer, antiangiogenic and anti-inflammatory effects. However, the mechanisms of action underlying the compound’s anticancer activity have not been fully elucidated. In this study, the apoptotic effects of DADS were investigated in DU145 human prostate carcinoma cells. Our results showed that DADS markedly inhibited the growth of the DU145 cells by induction of apoptosis. Apoptosis was accompanied by modulation of Bcl-2 and inhibitor of apoptosis protein (IAP) family proteins, depolarization of the mitochondrial membrane potential (MMP, ΔΨm) and proteolytic activation of caspases. We also found that the expression of death-receptor 4 (DR4) and Fas ligand (FasL) proteins was increased and that the level of intact Bid proteins was down-regulated by DADS. Moreover, treatment with DADS induced phosphorylation of mitogen-activated protein kinases (MAPKs), including extracellular-signal regulating kinase (ERK), p38 MAPK and c-Jun N-terminal kinase (JNK). A specific JNK inhibitor, SP600125, significantly blocked DADS-induced-apoptosis, whereas inhibitors of the ERK (PD98059) and p38 MAPK (SB203580) had no effect. The induction of apoptosis was also accompanied by inactivation of phosphatidylinositol 3-kinase (PI3K)/Akt and the PI3K inhibitor LY29004 significantly increased DADS-induced cell death. These findings provide evidence demonstrating that the proapoptotic effect of DADS is mediated through the activation of JNK and the inhibition of the PI3K/Akt signaling pathway in DU145 cells.

Recent Research Progress on Garlic ( dà suàn) as a Potential Anticarcinogenic Agent Against Major Digestive Cancers

Garlic ( dà suàn; the bulb of Allium sativum), bestowed with an array of organosulfur compounds finds its application in treating many ailments including cardiovascular problems, common cold, bacterial and fungal infections and cancer. Numerous epidemiological evidences document the beneficial effects of various bioactive organosulfur compounds of garlic against different types of cancer. Studies involving the animal and cell models indicate garlic bioactive compounds could be effective in treating all the stages of cancer. This review gives an update on the recent pre-clinical and clinical trials, carried out to evaluate the efficacy of various garlic bioactive compounds along with the mechanism of action pertaining to major digestive cancers including liver, gastric and colorectal cancers. The major anti-carcinogenic mechanisms are caspase dependent and/or independent induction of apoptosis, anti-proliferative, anti-metastasis, anti-oxidant and immunomodulative properties. Form the clinical trials an increase in the garlic consumption of 20 g/day reduced the risk of gastric and colorectal cancer. In summary, increased uptake of garlic in diet may prevent the incidence of digestive cancers.