Synergistic anticancer activity of capsaicin and 3,3'-diindolylmethane in human colorectal cancer

Capsaicin: A chili pepper bioactive phytocompound with a potential role in suppressing cancer development and progression

Cancer profoundly influences morbidity and fatality rates worldwide. Patients often have dismal prognoses despite recent improvements in cancer therapy regimens. However, potent biomolecules derived from natural sources, including medicinal and dietary plants, contain biological and pharmacological properties to prevent and treat various human malignancies. Capsaicin is a bioactive phytocompound present in red hot chili peppers. Capsaicin has demonstrated many biological effects, including antioxidant, anti-inflammatory, antimicrobial, and anticarcinogenic capabilities. This review highlights the cellular and molecular pathways through which capsaicin exhibits antineoplastic activities. Our work also depicts the synergistic anticancer properties of capsaicin in conjunction with other natural bioactive components and approved anticancer drugs. Capsaicin inhibits proliferation in various cancerous cells, and its antineoplastic actions in numerous in vitro and in vivo carcinoma models impact oncogenesis, tumor-promoting and suppressor genes, and associated signaling pathways. Capsaicin alone or combined with other phytocompounds or approved antineoplastic drugs triggers cell cycle progression arrest, generating reactive oxygen species and disrupting mitochondrial membrane integrity, ultimately stimulating caspases and promoting death. Furthermore, capsaicin alone or in combination can promote apoptosis in carcinoma cells by enhancing the p53 and c-Myc gene expressions. In conclusion, capsaicin alone or in combination can have enormous potential for cancer prevention and intervention, but further high-quality studies are needed to firmly establish the clinical efficacy of this phytocompound.

S. M, Birudala G, Jamous YF, Alshargi O, Kotha KK, Sudhan HH, Mani RR, Muthumanickam A, Niranjan D, Jain NK, Agrawal A, Jadon AS, Mayasa V, Jha NK, Kolesarova A, Slama P, Roychoudhury S. Reactive oxygen species mediated apoptotic death of colon cancer cells: therapeutic potential of plant derived alkaloids

Colorectal cancer (CRC) is one of the most deaths causing diseases worldwide. Several risk factors including hormones like insulin and insulin like growth factors (e.g., IGF-1) have been considered responsible for growth and progression of colon cancer. Though there is a huge advancement in the available screening as well as treatment techniques for CRC. There is no significant decrease in the mortality of cancer patients. Moreover, the current treatment approaches for CRC are associated with serious challenges like drug resistance and cancer re-growth. Given the severity of the disease, there is an urgent need for novel therapeutic agents with ideal characteristics. Several pieces of evidence suggested that natural products, specifically medicinal plants, and derived phytochemicals may serve as potential sources for novel drug discovery for various diseases including cancer. On the other hand, cancer cells like colon cancer require a high basal level of reactive oxygen species (ROS) to maintain its own cellular functions. However, excess production of intracellular ROS leads to cancer cell death via disturbing cellular redox homeostasis. Therefore, medicinal plants and derived phytocompounds that can enhance the intracellular ROS and induce apoptotic cell death in cancer cells via modulating various molecular targets including IGF-1 could be potential therapeutic agents. Alkaloids form a major class of such phytoconstituents that can play a key role in cancer prevention. Moreover, several preclinical and clinical studies have also evidenced that these compounds show potent anti-colon cancer effects and exhibit negligible toxicity towards the normal cells. Hence, the present evidence-based study aimed to provide an update on various alkaloids that have been reported to induce ROS-mediated apoptosis in colon cancer cells via targeting various cellular components including hormones and growth factors, which play a role in metastasis, angiogenesis, proliferation, and invasion. This study also provides an individual account on each such alkaloid that underwent clinical trials either alone or in combination with other clinical drugs. In addition, various classes of phytochemicals that induce ROS-mediated cell death in different kinds of cancers including colon cancer are discussed.

Antioxidant potential and factors influencing the content of antioxidant compounds of pepper: A review with current knowledge

The use of natural food items as antioxidants has gained increasing popularity and attention in recent times supported by scientific studies validating the antioxidant properties of natural food items. Peppers (Capsicum spp.) are also important sources of antioxidants and several studies published during the last few decades identified and quantified various groups of phytochemicals with antioxidant capacities as well as indicated the influence of several pre- and postharvest factors on the antioxidant capacity of pepper. Therefore, this review summarizes the research findings on the antioxidant activity of pepper published to date and discusses their potential health benefits as well as the factors influencing the antioxidant activity in pepper. The major antioxidant compounds in pepper include capsaicinoids, capsinoids, vitamins, carotenoids, phenols, and flavonoids, and these antioxidants potentially modulate oxidative stress related to aging and diseases by targeting reactive oxygen and nitrogen species, lipid peroxidation products, as well as genes for transcription factors that regulate antioxidant response elements genes. The review also provides a systematic understanding of the factors that maintain or improve the antioxidant capacity of peppers and the application of these strategies offers options to pepper growers and spices industries for maximizing the antioxidant activity of peppers and their health benefits to consumers. In addition, the efficacy of pepper antioxidants, safety aspects, and formulations of novel products with pepper antioxidants have also been covered with future perspectives on potential innovative uses of pepper antioxidants in the future.

Chemoprevention effect of the Mediterranean diet on colorectal cancer: Current studies and future prospects

Colorectal cancer (CRC) is the third most common cancer and the second most deadly cancer worldwide. Nevertheless, more than 70% of CRC cases are resulted from sporadic tumorigenesis and are not inherited. Since adenoma-carcinoma development is a slow process and may take up to 20 years, diet-based chemoprevention could be an effective approach in sporadic CRC. The Mediterranean diet is an example of a healthy diet pattern that consists of a combination of nutraceuticals that prevent several chronic diseases and cancer. Many epidemiological studies have shown the correlation between adherence to the Mediterranean diet and low incidence of CRC. The goal of this review is to shed the light on the anti-inflammatory and anti-colorectal cancer potentials of the natural bioactive compounds derived from the main foods in the Mediterranean diet.

Diindolylmethane Derivatives: New Selective Blockers for T-Type Calcium Channels

The natural product indole-3-carbinol (I3C) and its major digestive product 3,3′-diindolylmethane (DIM) have shown clinical promise in multiple forms of cancer including breast cancer. In this study, we explored the calcium channel activity of DIM, its synthetic derivative 3,3′-Diindolylmethanone (DIM-one) and related I3C and DIM-one analogs. For the first time, DIM, DIM-one and analog IX were identified as selective blockers for T-type Ca_V3.3 (IC₅₀s DIM 2.09 µM; DIM-one 9.07 µM) while compound IX inhibited both Ca_V3.2 (6.68 µM) and Ca_V3.3 (IC₅₀ = 3.05 µM) using a FLIPR cell-based assay to measure inhibition of T-type calcium channel window current. Further characterization of DIM by electrophysiology revealed it inhibited inward Ca²⁺ current through Ca_V3.1 (IC₅₀ = 8.32 µM) and Ca_V3.3 (IC₅₀ = 9.63 µM), while IX partially blocked Ca_V3.2 and Ca_V3.3 inward Ca²⁺ current. In contrast, DIM-one preferentially blocked Ca_V3.1 inward Ca²⁺ current (IC₅₀ = 1.53 µM). The anti-proliferative activities of these compounds revealed that oxidation of the methylene group of DIM shifted the selectivity of DIMs from breast cancer cell line MCF-7 to colon cancer cell line HT-29.

Capsaicin: A Two-Decade Systematic Review of Global Research Output and Recent Advances Against Human Cancer

Capsaicin (8-methyl-N-vanillyl-6-nonenamide) is one of the most important natural products in the genus Capsicum. Due to its numerous biological effects, there has been extensive and increasing research interest in capsaicin, resulting in increased scientific publications in recent years. Therefore, an in-depth bibliometric analysis of published literature on capsaicin from 2001 to 2021 was performed to assess the global research status, thematic and emerging areas, and potential insights into future research. Furthermore, recent research advances of capsaicin and its combination therapy on human cancer as well as their potential mechanisms of action were described. In the last two decades, research outputs on capsaicin have increased by an estimated 18% per year and were dominated by research articles at 93% of the 3753 assessed literature. In addition, anti-cancer/pharmacokinetics, cytotoxicity, in vivo neurological and pain research studies were the keyword clusters generated and designated as thematic domains for capsaicin research. It was evident that the United States, China, and Japan accounted for about 42% of 3753 publications that met the inclusion criteria. Also, visibly dominant collaboration nodes and networks with most of the other identified countries were established. Assessment of the eligible literature revealed that the potential of capsaicin for mitigating cancer mainly entailed its chemo-preventive effects, which were often linked to its ability to exert multi-biological effects such as anti-mutagenic, antioxidant and anti-inflammatory activities. However, clinical studies were limited, which may be related to some of the inherent challenges associated with capsaicin in the limited clinical trials. This review presents a novel approach to visualizing information about capsaicin research and a comprehensive perspective on the therapeutic significance and applications of capsaicin in the treatment of human cancer.

Development of Gluten-Free Cupcakes Enriched with Almond, Flaxseed, and Chickpea Flours

Background. The mixing of cereals and legumes with nuts and seeds can produce various products that can be optimal for consumption with respect to their nutritional density. The use of legumes in gluten-free foods is becoming very prominent with increase in advancement in food engineering and technology. This study was aimed to develop a gluten-free product (cupcake) enriched with chick pea flour, almonds, and flaxseeds for celiac disease patients. Materials and Methods. The procured raw material including almonds, chickpea flour, and flaxseeds was mixed in appropriate amounts, and cupcakes were formulated following a specified recipe. The cupcakes were divided in five groups based on their recipe. First one was wheat based; 2nd one was corn and rice based; and next 3 were chickpea, almond, and flaxseed based, respectively. The cupcakes were checked for their proximate analysis parameters (carbohydrate, protein, and nitrogen-free extract), gluten and heavy metals (lead, chromium, and arsenic), bacterial load (E. coli, total coliforms, salmonella, yeast, and molds), fatty acid, texture parameters (firmness, cohesiveness, gumminess, and chewiness), and physical parameters (weight, height, volume, and specific volume). All these parameters were compared with wheat-based cupcakes to assess the product’s quality. Results. The volume of intervention cupcakes was a bit low compared to wheat/rice-based cupcakes but the specific volume was comparable. In texture analysis, firmness, gumminess, and chewiness were enhanced in intervention cupcakes compared to control but cohesiveness was comparable also. The carbohydrate contents were significantly lower in intervention cupcakes 22–30% compared to control cupcakes. Protein, fiber, and fat contents were significantly higher 11–14, 8–10, and 40%, respectively, with improvement (2-3 folds) in calcium, zinc, and iron contents in intervention cupcakes. All the safety parameters including heavy metals and bacterial and fungal load were found normal. The sensory attributes like size and color were found to be less acceptable but odor and taste were comparatively high in formulated products. Conclusion. The use of chickpeas, almonds, and flaxseeds in high concentration was first-time used to formulate a recipe of gluten-free cupcake. These cupcakes were more nutritious compared to available conventional recipes. Apparently, no health hazard was found in these cupcakes. Some sensory characteristics of cupcakes were slightly lower and comparable to wheat/rice-based cupcakes.

Anti-Adipogenic Activity of High-Phenolic Sorghum Brans in Pre-Adipocytes

Obesity is one of the leading public health problems that can result in life-threatening metabolic and chronic diseases such as cardiovascular diseases, diabetes, and cancer. Sorghum (Sorghum bicolor (L.) Moench) is the fifth most important cereal crop in the world and certain genotypes of sorghum have high polyphenol content. PI570481, SC84, and commercially available sumac sorghum are high-polyphenol genotypes that have demonstrated strong anti-cancer activities in previous studies. The objective of this study was to explore a potential anti-obesity use of extracts from sorghum bran in the differentiation of 3T3-L1 preadipocytes and to investigate cellular and molecular responses in differentiated adipocytes to elucidate related mechanisms. None of the four different sorghum bran extracts (PI570481, SC84, Sumac, and white sorghum as a low-polyphenol control) caused cytotoxicity in undifferentiated and differentiated 3T3-L1 cells at doses used in this study. Sorghum bran extracts (PI570481, SC84, and Sumac) reduced intracellular lipid accumulation and expression of adipogenic and lipogenic proteins in a dose-dependent manner in differentiated 3T3-L1 cells. The same polyphenol containing sorghum bran extracts also repressed production of reactive oxygen species (ROS) and MAPK signaling pathways and repressed insulin signaling and glucose uptake in differentiated 3T3-L1 cells. These data propose a potential use of high-phenolic sorghum bran for the prevention of obesity.

Polyphenol Containing Sorghum Brans Exhibit an Anti-Cancer Effect in Apc Min/+ Mice Treated with Dextran Sodium Sulfate

Colon cancer (CC) is considered a high-risk cancer in developed countries. Its etiology is correlated with a high consumption of red meat and low consumption of plant-based foods, including whole grains. Sorghum bran is rich in polyphenols. This study aimed to determine whether different high-phenolic sorghum brans suppress tumor formation in a genetic CC rodent model and elucidate mechanisms. Tissue culture experiments used colorectal cancer cell lines SW480, HCT-116 and Caco-2 and measured protein expression, and protein activity. The animal model used in this study was APC Min+/mouse model combined with dextram sodium sulfate. High phenolic sorghum bran extract treatment resulted in the inhibition of proliferation and induced apoptosis in CC cell lines. Treatment with high phenolic sorghum bran extracts repressed TNF-α-stimulated NF-κB transactivation and IGF-1-stimulated PI3K/AKT pathway via the downregulation of β-catenin transactivation. Furthermore, high-phenolic sorghum bran extracts activated AMPK and autophagy. Feeding with high-phenolic sorghum bran for 6 weeks significantly suppressed tumor formation in an APC Min/+ dextran sodium sulfate promoted CC mouse model. Our data demonstrates the potential application of high-phenolic sorghum bran as a functional food for the prevention of CC.

Sweet pepper and its principle constituent capsiate: functional properties and health benefits

Capsiate is a non-pungent analogue of capsaicin. It belongs to the family of capsinoids which are esters of vanillyl alcohol with fatty acids while capsaicin belongs to the family of capsaicinoids that are amides of vanillylamine with a variety of branched-chain fatty acids. While capsaicin is extensively reported for plethora of pharmacological actions, capsiate remains much less explored. Extracted from various species of Capsicum plant, the molecule has also been chemically synthesized via a number of synthetic and enzymatic routes. Based on its action on transient receptor potential vanilloid subfamily member 1 receptors, recent research has focused on its potential roles in treatment of obesity, metabolic disorders, cancer, cardiovascular disorders and gastro-intestinal disorders. Its toxicity profile has been reported to be much safe. The molecule, however, faces the challenge of low aqueous solubility and stability. It has been commercialized for its use as a weight loss supplement. However, the therapeutic potential of the compound which is much beyond boosting metabolism remains unexplored hitherto. This comprehensive review summarizes the studies demonstrating the therapeutic potential of capsiate in various pathological conditions. Discussed also are potential future directions for formulation strategies to develop efficient, safe and cost-effective dosage forms of capsiate to explore its role in various disease conditions. The databases investigated include Cochrane library, Medline, Embase, Pubmed and in-house databases. The search terms were "capsiate," "capsinoids," "thermogenesis," and their combinations. The articles were screened for relevance by going through their abstract. All the articles pertaining to physicochemical, physiological, pharmacological and therapeutic effects of capsiate have been included in the manuscript.

Capsaicin Inhibits Proliferation and Induces Apoptosis in Breast Cancer by Down-Regulating FBI-1-Mediated NF-κB Pathway

Background

As a natural compound extracted from a variety of hot peppers, capsaicin has drawn increasing attention to its anti-cancer effects against multiple human cancers including breast cancer. FBI-1 is a major proto-oncogene negatively regulating the transcription of many tumor suppressor genes, and plays a vital role in tumorigenesis and progression. However, whether FBI-1 is involved in capsaicin-induced breast cancer suppression has yet to be ascertained. This study aimed to investigate the effects of capsaicin on proliferation and apoptosis and its association with FBI-1 expression in breast cancer.

Methods

CCK-8 and morphological observation assay were employed to detect cell proliferation. Flow cytometry and TUNEL assay were conducted to detect cell apoptosis. RNA interference technique was used to overexpress or silence FBI-1 expression. qRT-PCR and/or Western blot analysis were applied to detect the protein expression of FBI-1, Ki-67, Bcl-2, Bax, cleaved-Caspase 3, Survivin and NF-κB p65. Xenograft model in nude mice was established to assess the in vivo effects.

Results

Capsaicin significantly inhibited proliferation and induced apoptosis in breast cancer in vitro and in vivo, along with decreased FBI-1, Ki-67, Bcl-2 and Survivin protein expression, increased Bax protein expression and activated Caspase 3. Furthermore, FBI-1 overexpression obviously attenuated the capsaicin-induced anti-proliferation and pro-apoptosis effect, accompanied with the above-mentioned proteins reversed, whereas FBI-1 silencing generated exactly the opposite response. In addition, as a target gene of FBI-1, NF-κB was inactivated by p65 nuclear translocation suppressed with capsaicin treatment, which was perceptibly weakened with FBI-1 overexpression or enhanced with FBI-1 silencing.

Conclusion

This study reveals that FBI-1 is closely involved in capsaicin-induced anti-proliferation and pro-apoptosis of breast cancer. The underlying mechanism may be related to down-regulation of FBI-1-mediated NF-κB pathway. Targeting FBI-1 with capsaicin may be a promising therapeutic strategy in patients with breast cancer.

Capsaicin lacks tumor-promoting effects during colon carcinogenesis in a rat model induced by 1,2-dimethylhydrazine

Capsaicin (CPS, 8-methyl-N-vanillyl-trans-6-nonenamide), a pungent alkaloid from chili peppers, has contradictory effects in both experimental and human carcinogenesis. Thus, we evaluated the modifying effects of chronic CPS during the promotion and progression stages of rat colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH). Male Wistar rats were given four subcutaneous injections of DMH (40 mg/body weight (b.w.)) twice a week, for 2 weeks. After DMH-induced tumor initiation, the animals were treated with CPS at 5 or 50 mg/kg b.w. by gavage for 24 weeks (three times a week). High-dose CPS reduced both cell proliferation in adjacent "normal-appearing" colonic crypts and the total number of preneoplastic aberrant crypt foci (ACF) but did not change the number of dysplastic ACF or ACF multiplicity. Although the proportion of adenomas was increased, and tubular adenocarcinomas decreased in high-dose CPS, both CPS interventions exerted no effects on total tumor incidence, volume, multiplicity, cell proliferation (Ki-67), and apoptosis (caspase-3). In accordance, high-dose CPS treatment had discrete effects on gene expression in colon tumors, as only 3/94 (3.19%) genes were significantly modified (downregulation of Cebpd and Fasl, and upregulation of Jag1). The findings of the present study show that CPS does not impact on the promotion/progression stages of rat colon carcinogenesis. Therefore, CPS at a high-dose intervention showed to be a safe food ingredient.

An approach to unsymmetrical 3,3′-diindolylmethanes through Pd-catalyzed cascade Heck cyclization of allenamides and o-ethynylanilines

A highly efficient synthesis of unsymmetrical 3,3′-diindolylmethanes has been developed by palladium-catalyzed cascade Heck/cyclization reaction.

Natural compounds against doxorubicin-induced cardiotoxicity: A review on the involvement of Nrf2/ARE signaling pathway

Cardiotoxicity is the main concern for long-term use of the doxorubicin (DOX). Reactive oxygen species (ROS) generation leads to oxidative stress that significantly contributes to the cardiac damage induced by DOX. The nuclear factor erythroid 2-related factor (Nrf2) acts as a protective player against DOX-induced myocardial oxidative stress. Several natural compounds (NCs) with anti-oxidative effects, were examined to suppress DOX cardiotoxicity such as asiatic acid, α-linolenic acid, apigenin, baicalein, β-lapachone, curdione, dioscin, ferulic acid, Ganoderma lucidum polysaccharides, genistein, ginsenoside Rg3, indole-3-carbinol, naringenin-7-O-glucoside, neferine, p-coumaric acid, pristimerin, punicalagin, quercetin, sulforaphane, and tanshinone IIA. The present article, reviews NCs that showed protective effects against DOX-induced cardiac injury through induction of Nrf2 signaling pathway.

Nanostructured Lipid-Based Delivery Systems as a Strategy to Increase Functionality of Bioactive Compounds

Acquisition of a healthy lifestyle through diet has driven the food manufacturing industry to produce new food products with high nutritional quality. In this sense, consumption of bioactive compounds has been associated with a decreased risk of suffering chronic diseases. Nonetheless, due to their low solubility in aqueous matrices, high instability in food products during processing and preparation as well as poor bioavailability, the use of such compounds is sometimes limited. Recent advancements in encapsulation and protection of bioactive compounds has opened new possibilities for the development of novel food products. In this direction, the present review is attempting to describe encapsulation achievements, with special attention to nanostructured lipid-based delivery systems, i.e., nanoemulsions, multi-layer emulsions and liposomes. Functionality of bioactive compounds is directly associated with their bioavailability, which in turn is governed by several complex processes, including the passage through the gastrointestinal tract and transport to epithelial cells. Therefore, an overview of recent research on the properties of these nanostructured lipid-based delivery systems with a strong impact on the functionality of bioactive compounds will be also provided. Nanostructured lipid-based delivery systems might be used as a potential option to enhance the solubility, stability, absorption and, ultimately, functionality of bioactive compounds. Several studies have been performed in this line, modifying the composition of the nanostructures, such as the lipid-type or surfactants. Overall, influencing factors and strategies to improve the efficacy of encapsulated bioactive compounds within nanostructures have been successfully identified. This knowledge can be used to design effective targeted nanostructured lipid-based delivery systems for bioactive compounds. However, there is still a lack of information on food interactions, toxicity and long-term consumption of such nanostructures.

Progress in understanding role of capsaicin in prevention and treatment of digestive system tumors

Radiation and chemotherapy are still the main treatments for malignant tumors, but their side effects are significant. Thus, searching natural active substances for the prevention and treatment of tumor has attracted wide attention. Capsaicin (Cap) is the main active ingredient in chili hot material. Since the 20th century, more and more studies have been performed on the clinical effects of Cap, and its antitumor function has become a currently hot research topic. The antitumor mechanism of Cap is complex, and it can cause tumor cell proliferation inhibition, apoptosis, and autophagy, inhibit tumor cell migration and invasion, and have an anti-angiogenesis property. As a potential anti-tumor drug, Cap has a broad prospect to increase the efficacy of other chemotherapy drugs. This paper reviews the role of Cap in the prevention and treatment of digestive system tumors and discusses the possible mechanisms involved.

Patchouli Alcohol, a Compound from Pogostemon cablin, Inhibits Obesity

Obesity predisposes people to a variety of chronic metabolic diseases. Identification of natural factors that prevent the development of obesity is likely to be the most successful means of ameliorating the current obesity epidemic. Patchouli alcohol is a sesquiterpene alcohol found in Pogostemon cablin and possesses health benefit activities. This study was designed to examine if patchouli alcohol affects adipogenesis, and investigates the underlying mechanisms whereby patchouli alcohol exerts antiobesity effect. 3T3-L1 adipocytes were differentiated with treatment of different concentrations of patchouli alcohol. An in vivo study was performed to test the effect of patchouli alcohol gavage on a high-fat diet (HFD)-induced obesity. Treatment of patchouli alcohol reduced lipid accumulation in 3T3-L1 adipocytes in a dose-dependent manner without toxicity. Regarding mechanism, treatment of patchouli alcohol reduced expression of peroxisome proliferator-activated receptor-gamma (PPARγ) and CCAAT-enhancer-binding protein-alpha (C/EBPα) and increased expression of total and active β-catenin in 3T3-L1 adipocytes. Oral gavage of patchouli alcohol led to a significant reduction of body weight and fat accumulation in the mice fed with HFD. Transcriptome analysis indicates that smad7 is most highly activated gene in patchouli alcohol-treated 3T3-L1 cells. Patchouli alcohol possesses health benefit effect through inhibiting adipogenesis and fat tissue development.

[Combined treatment with myo-inositol and luteolin selectively suppresses growth of human lung cancer A549 cells possibly by suppressing activation of PDK1 and Akt]

OBJECTIVE

To study the effects of myo-inositol and luteolin on human lung cancer A549 cells and explore the possible mechanisms.

METHODS

A549 cells were treated with different concentrations of myo-inositol and luteolin, either alone or in combination, and the cell viability was examined using MTT assay. A549 cells and human bronchial epithelial Beas-2B cells were treated for 48 h with 10 mmol/L myo-inositol and 20 μmol/L luteolin, alone or in combination, and the cell proliferation was detected using MTT assay; the colony formation and migration of the cells were examined with colony formation assay and wound healing assay, respectively. The protein expression levels in A549 cells were detected using Western blotting.

RESULTS

Both myo-inositol and luteolin could dose-dependently inhibit the viability of A549 cells. Treatments with 10 mmol/L myo-inositol, 20 μmol/L luteolin, and both for 48 h caused significant reduction in the cell viability (92%, 83% and 70% of the control level, respectively) and colony number (79%, 73% and 43%, respectively), and significantly lowered the wound closure rate (24.61%, 13.08% and 8.65%, respectively, as compared with 29.99% in the control group). Similar treatments with myoinositol and luteolin alone or in combination produced no significant inhibitory effect on the growth, colony formation or migration of Beas-2B cells. The expressions of p-PDK1 and p-Akt in myo-inositol-treated A549 cells and the expression of pPDK1 in luteolin-treated cells were significantly decreased (P < 0.05), and the decrements were more obvious in the combined treatment group (P < 0.05).

CONCLUSIONS

Luteolin combined with myo-inositol can selectively inhibit the proliferation and migration of A549 cells, and these effects are probably mediated, at least in part, by suppressing the activation of PDK1 and Akt.

Chemoprevention of Colorectal Cancer by Dietary Compounds

Colorectal cancer is one of the leading causes of death, and the third most diagnosed type of cancer, worldwide. It is most common amongst men and women over 50 years old. Risk factors include smoking, alcohol, diet, physical inactivity, genetics, alterations in gut microbiota, and associated pathologies (diabetes, obesity, chronic inflammatory bowel diseases). This review will discuss, in detail, the chemopreventive properties of some dietary compounds (phenolic compounds, carotenoids, iridoids, nitrogen compounds, organosulfur compounds, phytosterols, essential oil compounds, polyunsaturated fatty acids and dietary fiber) against colorectal cancer. We present recent data, focusing on in vitro, laboratory animals and clinical trials with the previously mentioned compounds. The chemopreventive properties of the dietary compounds involve multiple molecular and biochemical mechanisms of action, such as inhibition of cell growth, inhibition of tumor initiation, inhibition of adhesion, migration and angiogenesis, apoptosis, interaction with gut microbiota, regulation of cellular signal transduction pathways and xenobiotic metabolizing enzymes, etc. Moreover, this review will also focus on the natural dietary compounds' bioavailability, their synergistic protective effect, as well as the association with conventional therapy. Dietary natural compounds play a major role in colorectal chemoprevention and continuous research in this field is needed.

Polyphenols in Colorectal Cancer: Current State of Knowledge including Clinical Trials and Molecular Mechanism of Action

Polyphenols have been reported to have wide spectrum of biological activities including major impact on initiation, promotion, and progression of cancer by modulating different signalling pathways. Colorectal cancer is the second most major cause of mortality and morbidity among females and the third among males. The objective of this review is to describe the activity of a variety of polyphenols in colorectal cancer in clinical trials, preclinical studies, and primary research. The molecular mechanisms of major polyphenols related to their beneficial effects on colorectal cancer are also addressed. Synthetic modifications and other future directions towards exploiting of natural polyphenols against colorectal cancer are discussed in the last section.

Smart Combinations of Bioactive Compounds in Fruits and Vegetables May Guide New Strategies for Personalized Prevention of Chronic Diseases

There is ample scientific evidence suggesting that the health benefits of eating the right amounts of a variety of vegetables and fruit are the consequence of the combined action of different phytochemicals. The present review provides an update of the scientific literature on additive and synergistic effects of mixtures of phytochemicals. Most research has been carried out in in vitro systems in which synergistic or additive effects have been established on the level of cell proliferation, apoptosis, antioxidant capacity, and tumor incidence, accompanied by changes in gene and protein expression in relevant pathways underlying molecular mechanisms of disease prevention. The number of human dietary intervention studies investigating complex mixtures of phytochemicals is relatively small, but showing promising results. These studies have demonstrated that combining transcriptomic data with phenotypic markers provide insight into the relevant cellular processes which contribute to the antioxidant response of complex mixtures of phytochemicals. Future studies should be designed as short-term studies testing different combinations of vegetables and fruit, in which markers for disease outcome as well as molecular ('omics)-markers and genetic variability between subjects are included. This will create new opportunities for food innovation and the development of more personalized strategies for prevention of chronic diseases.

Arctigenin represses TGF-β-induced epithelial mesenchymal transition in human lung cancer cells

Arctigenin (ARC) is a lignan that is abundant in Asteraceae plants, which show anti-inflammatory and anti-cancer activities. The current study investigated whether ARC affects cancer progression and metastasis, focusing on EMT using invasive human non-small cell lung cancer (NSCLC) cells. No toxicity was observed in the cells treated with different doses of ARC (12-100 μM). The treatment of ARC repressed TGF-β-stimulated changes of metastatic morphology and cell invasion and migration. ARC inhibited TGF-β-induced phosphorylation and transcriptional activity of smad2/3, and expression of snail. ARC also decreased expression of N-cadherin and increased expression of E-cadherin in dose-dependent and time-dependent manners. These changes were accompanied by decreased amount of phospho-smad2/3 in nucleus and nuclear translocation of smad2/3. Moreover, ARC repressed TGF-β-induced phosphorylation of ERK and transcriptional activity of β-catenin. Our data demonstrate anti-metastatic activity of ARC in lung cancer model.

3,3'-Diindolylmethane Suppresses Adipogenesis Using AMPKα-Dependent Mechanism in 3T3-L1 Adipocytes and Caenorhabditis elegans

3,3'-diindolylmethane is a major in vivo metabolite of indole-3-carbinol, a bioactive compound found in cruciferous vegetables. Although 3,3'-diindolylmethane has been implicated to possess antitumorigenic and anti-inflammatory properties, the effect of 3,3'-diindolylmethane on adipogenesis has not been explored previously. Thus, the present study was conducted to determine if 3,3'-diindolylmethane affects adipogenesis using 3T3-L1 adipocytes and Caenorhabditis elegans. Treatment of 3,3'-diindolylmethane significantly reduced fat accumulation without affecting viability in 3T3-L1 adipocytes. 3,3'-diindolylmethane suppressed expression of peroxisome proliferator-activated receptor γ (PPARγ), CCAAT-enhancer-binding protein α (C/EBPα), fatty acid binding protein 4 (FABP4), and perilipin. In addition, 3,3'-diindolylmethane activated AMP-activated protein kinase α (AMPKα), which subsequently inactivated acetyl CoA carboxylase (ACC), resulting in reduced fat accumulation. These observations were further confirmed in C. elegans as treatment with 3,3'-diindolylmethane significantly reduced body fat accumulation, which was partly associated with aak-1, but not aak-2, orthologs of AMPKα catalytic subunits α1 and α2, respectively. The current results demonstrate that 3,3'-diindolylmethane, a biologically active metabolite of indole-3-carbinol, may prevent adipogenesis through the AMPKα-dependent pathway.

β-Catenin Mediates Anti-adipogenic and Anticancer Effects of Arctigenin in Preadipocytes and Breast Cancer Cells

Arctigenin is a lignan abundant in Asteraceae plants and has anti-inflammatory, antiobesity, and anticancer activities. Obesity is one of the leading causes of several types of cancers including breast cancer. The current study was performed to investigate if arctigenin suppresses differentiation of preadipocytes and proliferation of breast cancer cells and to explore potential molecular mechanisms. Treatment of arctigenin reduced lipid accumulation in differentiated 3T3-L1 adipocytes in a dose- and time-dependent manner without toxicity. Arctigenin suppressed the expression of peroxisome proliferator-activated receptor-gamma (PPARγ), CCAAT/enhancer-binding protein-alpha (C/EBPα), perilipin, and fatty acid binding protein 4 (FABP4) in a dose-dependent manner in differentiated 3T3-L1 cells. Both total and unphosphorylated (active) β-catenin were increased in whole cell lysates and the nuclear fraction of differentiated 3T3-L1 cells treated with 25 μM arctigenin. On the other hand, arctigenin decreased proliferation of two human breast cancer cells (MCF-7 and MDA-MB-231). Arctigenin induced apoptosis and decreased expression of total and unphosphorylated (active) β-catenin and cyclin D1 in MCF-7, but not in MDA-MB-231. These data indicate that arctigenin suppressed adipogenesis in preadipocytes and activated apoptosis in estrogen receptor (ER) positive breast cancer cells through modulating expression of β-catenin.

Capsaicin Modulates the Immune Cross Talk Between Human Mononuclears and Cells from Two Colon Carcinoma Lines

BACKGROUND

Capsaicin, the pungent alkaloid of the chili peppers, has gained a worldwide reputation. In addition to its culinary assets, capsaicin possesses analgesic, anti-inflammatory, antimicrobial, and even carcinopreventive properties. Considering the linkage between chronic inflammation and tumorigenesis, the aim of the study was to evaluate the role of capsaicin in the immune interplay between human peripheral blood mononuclear cells (PBMCs) and HT-29 or RKO cells from human colon carcinoma lines.

METHODS

PBMCs were incubated for 24 hours with either HT-29 or RKO cells and concentrations of capsaicin ranging between 10 and 200 µM. Subsequently, the generation of the following cytokines was examined: tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, interferon (IFN)-γ, IL-1ra, and IL-10.

RESULTS

Capsaicin caused a concentration-dependent inhibition of colon cancer cells proliferation but had no effect on PBMC viability. 200 µM of capsaicin suppressed the production of all cytokines tested. At lower concentrations, the secretion of TNF-α, IL-1β, IFN-γ, IL-10, and IL-1ra was inhibited concentration-dependently, whereas that of IL-6 was stimulated.

CONCLUSIONS

Capsaicin causes a concentration-dependent alteration of the immune balance between PBMC and colon carcinoma cells expressed as an inhibited generation of inflammatory cytokines. These findings indicate the existence of an additional immunomodulatory mechanism by which this alkaloid may prevent tumor development.

Spices for Prevention and Treatment of Cancers

Spices have been widely used as food flavorings and folk medicines for thousands of years. Numerous studies have documented the antioxidant, anti-inflammatory and immunomodulatory effects of spices, which might be related to prevention and treatment of several cancers, including lung, liver, breast, stomach, colorectum, cervix, and prostate cancers. Several spices are potential sources for prevention and treatment of cancers, such as Curcuma longa (tumeric), Nigella sativa (black cumin), Zingiber officinale (ginger), Allium sativum (garlic), Crocus sativus (saffron), Piper nigrum (black pepper) and Capsicum annum (chili pepper), which contained several important bioactive compounds, such as curcumin, thymoquinone, piperine and capsaicin. The main mechanisms of action include inducing apoptosis, inhibiting proliferation, migration and invasion of tumors, and sensitizing tumors to radiotherapy and chemotherapy. This review summarized recent studies on some spices for prevention and treatment of cancers, and special attention was paid to bioactive components and mechanisms of action.

Harnessing the Therapeutic Potential of Capsaicin and Its Analogues in Pain and Other Diseases

Capsaicin is the most predominant and naturally occurring alkamide found in Capsicum fruits. Since its discovery in the 19th century, the therapeutic roles of capsaicin have been well characterized. The potential applications of capsaicin range from food flavorings to therapeutics. Indeed, capsaicin and few of its analogues have featured in clinical research covered by more than a thousand patents. Previous records suggest pleiotropic pharmacological activities of capsaicin such as an analgesic, anti-obesity, anti-pruritic, anti-inflammatory, anti-apoptotic, anti-cancer, anti-oxidant, and neuro-protective functions. Moreover, emerging data indicate its clinical significance in treating vascular-related diseases, metabolic syndrome, and gastro-protective effects. The dearth of potent drugs for management of such disorders necessitates the urge for further research into the pharmacological aspects of capsaicin. This review summarizes the historical background, source, structure and analogues of capsaicin, and capsaicin-triggered TRPV1 signaling and desensitization processes. In particular, we will focus on the therapeutic roles of capsaicin and its analogues in both normal and pathophysiological conditions.