Synergistic Combinations of Curcumin, Sulforaphane, and Dihydrocaffeic Acid against Human Colon Cancer Cells

Dietary isothiocyanates and anticancer agents: exploring synergism for improved cancer management

Human studies have shown the anticancer effects of dietary isothiocyanates (ITCs), but there are some inconsistencies, and more evidence supports that such anticancer effect is from higher doses of ITCs. The inconsistencies found in epidemiological studies may be due to many factors, including the biphasic dose-response (so called hormetic effect) of ITCs, which was found to be more profound under hypoxia conditions. In this comprehensive review, we aim to shed light on the intriguing synergistic interactions between dietary ITCs, focusing on sulforaphane (SFN) and various anticancer drugs. Our exploration is motivated by the potential of these combinations to enhance cancer management strategies. While the anticancer properties of ITCs have been recognized, our review delves deeper into understanding the mechanisms and emphasizing the significance of the hormetic effect of ITCs, characterized by lower doses stimulating both normal cells and cancer cells, whereas higher doses are toxic to cancer cells and inhibit their growth. We have examined a spectrum of studies unraveling the multifaceted interaction and combinational effects of ITCs with anticancer agents. Our analysis reveals the potential of these synergies to augment therapeutic efficacy, mitigate chemoresistance, and minimize toxic effects, thereby opening avenues for therapeutic innovation. The review will provide insights into the underlying mechanisms of action, for example, by spotlighting the pivotal role of Nrf2 and antioxidant enzymes in prevention. Finally, we glimpse ongoing research endeavors and contemplate future directions in this dynamic field. We believe that our work contributes valuable perspectives on nutrition and cancer and holds promise for developing novel and optimized therapeutic strategies.

Evaluation of the synergistic effects of curcumin-resveratrol co-loaded biogenic silica on colorectal cancer cells

Colorectal cancer (CRC) remains a significant global health concern, being the third most diagnosed cancer in men and the second most diagnosed cancer in women, with alarming mortality rates. Natural phytochemicals have gained prominence among various therapeutic avenues explored due to their diverse biological properties. Curcumin, extracted from turmeric, and resveratrol, a polyphenol found in several plants, have exhibited remarkable anticancer activities. However, their limited solubility and bioavailability hinder their therapeutic efficacy. To enhance the bioavailability of these compounds, nanomaterials work as effective carriers with biogenic silica (BS) attracting major attention owing to their exceptional biocompatibility and high specific surface area. In this study, we developed Curcumin-resveratrol-loaded BS (Cur-Res-BS) and investigated their effects on colorectal cancer cell lines (HCT-116 and Caco-2). Our results demonstrated significant concentration-dependent inhibition of cell viability in HCT-116 cells and revealed a complex interplay of crucial proto-onco or tumor suppressor genes, such as TP53, Bax, Wnt-1, and CTNNB1, which are commonly dysregulated in colorectal cancer. Notably, Cur-Res-BS exhibited a synergistic impact on key signaling pathways related to colorectal carcinogenesis. While these findings are promising, further investigations are essential to comprehensively understand the mechanisms and optimize the therapeutic strategy. Moreover, rigorous safety assessments and in vitro studies mimicking the in vivo environment are imperative before advancing to in vivo experiments, ensuring the potential of Cur-Res-BS as an efficient treatment for CRC.

Developing a rapid analytical method for simultaneous determination of apigenin and gallic acid: validation and application in a nanoliposomal formulation

OBJECTIVE

Apigenin and gallic acid are natural compounds that are useful as antioxidant, anti-inflammatory and anticancer agents, especially when used together in combination. Therefore, the development and validation of a simultaneous method of analysis for both compounds in pure form and when encapsulated in an advanced delivery system such as liposomes would be useful.

METHODS

Analysis was performed using C18 column under isocratic conditions. The mobile phase was acetonitrile: water containing 0.2% orthophosphoric acid at a ratio of 67:33, flow rate 1 ml/min, and detection wavelength 334 nm for apigenin and 271 nm for gallic acid.

RESULTS

The assay method was linear at the concentration range (5-600 µg/mL) with R2 of 1 for both drugs. The method was also shown to be precise and robust with RSD less than 2% with LOD (0.12, 0.1 µg/mL) and LOQ (4.14, 3.58 µg/mL) for apigenin and gallic acid respectively. The method was also applicable for the determination of the entrapment efficiency of both drugs when co-loaded in a nanoliposomal formulation.

CONCLUSION

The described HPLC method was shown to be suitable, sensitive, and reproducible for the simultaneous identification and quantification of apigenin and gallic acid. The analytical results were accurate and precise, with good recovery, low limit of detection, and the chromatographic assay was accomplished in less than 3 min, suggesting the suitability of the method for routine analysis of both drugs in pharmaceutical formulations.

Sulforaphane: An emergent anti-cancer stem cell agent

Cancer is a major public health concern worldwide responsible for high morbidity and mortality rates. Alternative therapies have been extensively investigated, and plant-derived compounds have caught the attention of the scientific community due to their chemopreventive and anticancer effects. Sulforaphane (SFN) is one of these naturally occurring agents, and studies have shown that it is able to target a specific cancer cell population displaying stem-like properties, known as cancer stem cells (CSCs). These cells can self-renewal and differentiate to form highly heterogeneous tumor masses. Notably, most of the conventional chemotherapeutic agents cannot target CSCs once they usually exist in a quiescent state and overall, the available cytotoxic drugs focus on highly dividing cells. This is, at least in part, one of the reasons why some oncologic patients relapse after standard therapy. In this review we bring together studies supporting not only the chemopreventive and anticancer properties of SFN, but especially the emerging anti-CSCs effects of this natural product and its potential to be used with conventional antineoplastic drugs in the clinical setting.

Natural Polyphenols for Treatment of Colorectal Cancer

Colorectal cancer (CRC) is a prevalent and serious gastrointestinal malignancy with high mortality and morbidity. Chemoprevention refers to a newly emerged strategy that uses drugs with chemopreventive properties to promote antioxidation, regulate cancer cell cycle, suppress proliferation, and induce cellular apoptosis, so as to improve cancer treatment outcomes. Natural polyphenols are currently recognized as a class of chemopreventive agents that have shown remarkable anticarcinogenic properties. Numerous in vitro and in vivo studies have elucidated the anti-CRC mechanisms of natural polyphenols, such as regulation of various molecular and signaling pathways. Natural polyphenols are also reportedly capable of modulating the gut microbiota and cancer stem cells (CSCs) to suppress tumor formation and progression. Combined use of different natural polyphenols is recommended due to their low bioavailability and instability, and combination treatment can exert synergistical effects, reduce side effects, and avoid drug resistance in CRC treatment. In summary, the application of polyphenols in the chemoprevention and treatment of CRC is promising. Further clinical evaluation of their effectiveness is warranted and anticipated.

Tissue-wide metabolomics reveals wide impact of gut microbiota on mice metabolite composition

The essential role of gut microbiota in health and disease is well recognized, but the biochemical details that underlie the beneficial impact remain largely undefined. To maintain its stability, microbiota participates in an interactive host-microbiota metabolic signaling, impacting metabolic phenotypes of the host. Dysbiosis of microbiota results in alteration of certain microbial and host metabolites. Identifying these markers could enhance early detection of certain diseases. We report LC-MS based non-targeted metabolic profiling that demonstrates a large effect of gut microbiota on mammalian tissue metabolites. It was hypothesized that gut microbiota influences the overall biochemistry of host metabolome and this effect is tissue-specific. Thirteen different tissues from germ-free (GF) and conventionally-raised (MPF) C57BL/6NTac mice were selected and their metabolic differences were analyzed. Our study demonstrated a large effect of microbiota on mammalian biochemistry at different tissues and resulted in statistically-significant modulation of metabolites from multiple metabolic pathways (p ≤ 0.05). Hundreds of molecular features were detected exclusively in one mouse group, with the majority of these being unique to specific tissue. A vast metabolic response of host to metabolites generated by the microbiota was observed, suggesting gut microbiota has a direct impact on host metabolism.

Structure-Activity Relationship of Hydroxycinnamic Acid Derivatives for Cooperating with Carnosic Acid and Calcitriol in Acute Myeloid Leukemia Cells

Plant phenolic compounds have shown the ability to cooperate with one another at low doses in producing enhanced anticancer effects. This may overcome the limitations (e.g., poor bioavailability and high-dose toxicity) in developing these agents as cancer medicines. We have previously reported that the hydroxycinnamic acid derivative (HCAD) methyl-4-hydroxycinnamate and the phenolic diterpene carnosic acid (CA) can synergistically induce massive calcium-dependent apoptosis in acute myeloid leukemia (AML) at non-cytotoxic concentrations of each agent. Here, we explored the chemical nature of the synergy between HCADs and either CA, in inducing cytotoxicity, or the active metabolite of vitamin D (calcitriol), in enhancing the differentiation of AML cells. This was done by determining the structure–activity relationship of a series of hydroxycinnamic acids and their derivatives (methyl hydroxycinnamates and hydroxybenzylideneacetones) in combination with CA or calcitriol. The HCAD/CA synergy required the following critical structural elements of an HCAD molecule: (a) the para-hydroxyl on the phenolic ring, (b) the carbon C7–C8 double bond, and (c) the methyl-esterified carboxyl. Thus, the only HCADs capable of synergizing with CA were found to be methyl-4-hydroxycinnamate and methyl ferulate, which also most potently enhanced calcitriol-induced cell differentiation. Notably, the C7–C8 double bond was the major requirement for this HCAD/calcitriol cooperation. Our findings may contribute to the rational design of novel synergistically acting AML drugs based on prototype combinations of HCADs with other agents studied here.

Effects of Wounding Stress and Storage Temperature on the Accumulation of Chlorogenic Acid Isomers in Potatoes (Solanum tuberosum)

Wounding stress is an effective strategy to increase the content of bioactive compounds in horticultural crops. Potato tubers subjected to wounding stress accumulate chlorogenic acid (CGA) and CGA isomers (neo-CGA and crypto-CGA), which are phenolics that prevent and treat different chronic and degenerative diseases. In this study, the effects of wounding stress and storage temperature (10 °C and 20 °C for 168 h) on the accumulation of CGA isomers in potatoes were evaluated. Results indicated that CGA accumulation was favored when wounded potatoes were stored at 20 °C for 120 h, obtaining a 1923.1% higher concentration when compared with samples before storage. Furthermore, wounded potatoes stored at 10 °C for 120 h showed the highest neo-CGA increase in concentration (712.2%). Likewise, the highest crypto-CGA concentration (84.9% higher than control samples) was quantified in wounded potatoes stored at 20 °C for 144 h. Based on the results from both the present study and previous reports, a strategy that summarizes effective postharvest stress conditions that induce the accumulation of specific CGA isomers in potatoes is presented. The tissue with an increased content of bioactive compounds could be used as raw material to produce functional foods or could be subjected to downstream processing to produce dietary supplements.

Gold nanoparticles enhance microRNA 31 detection in colon cancer cells after inhibition with chlorogenic acid

In the present study, the inhibitory effect of chlorogenic acid (CGA), a phenolic compound with potential antitumor effects, on circulating microRNA 31 (miR-31), was evaluated in RKO colon cancer cells. The capacity of gold nanoparticles (AuNPs) to enhance miR-31 quantification after treatment with CGA was assessed. RKO cells were treated with different concentrations of CGA for 24, 48 and 72 h, after which AuNPs coupled to CD81 were added to the supernatants. Total RNA was extracted, and miR-31 was quantified by reverse transcription-quantitative PCR. The results revealed an 85% decrease in miR-31 level following treatment with 1,000 µM CGA for 72 h, and the highest capacity to detect miR-31 (after treatment and isolation with AuNPs + CD81) was observed at 24 h. Furthermore, CGA decreased the expression of the miR-31 oncogene in an in vitro colon cancer model, and the use of AuNPs enhanced the levels of miRNA detection. The results suggest that miR-31 inhibition is one mechanism by which CGA decreases colon cancer cell proliferation. Moreover, AuNPs can increase the capacity of miR-31 quantification, representing a new strategy to develop non-invasive tools for the molecular diagnosis and monitoring of colon cancer.

Chocolate as Carrier to Deliver Bioactive Ingredients: Current Advances and Future Perspectives

Consumer demand for healthier foods with improved taste and convenience has urged the food industry to develop functional foods added with bioactive ingredients that can supplement basic nutrition (food supplement) or exert a pharmacological effect (nutraceuticals). Chocolate could be used as an ideal carrier to deliver bioactive ingredients, mainly due to its high acceptability by consumers. However, a drawback of using chocolate as functional food is its high sugar content, which impedes its commercialization with the diabetic population. Therefore, there is need to develop sugar-free chocolate formulations added with bioactive ingredients. Nevertheless, sugar replacement and bioactive ingredients addition is a major technological challenge that affects texture, rheology, and sensory properties of chocolate. This review is designed as a practical guide for researchers and food industries to develop the next generation of functional chocolates. Different functional chocolate formulations, including sugar-free, are reviewed as potential carriers for the delivery of bioactive compounds. The physicochemical properties and sensory acceptability of the functional chocolates presented are also highlighted. Finally, future perspectives, such as the use of nanotechnology to improve the bioaccessibility and bioavailability of active ingredients, as well as the need for clinical trials to validate the pharmacological effect of functional chocolates, are also discussed.

Nutraceutical Supplementation Ameliorates Visual Function, Retinal Degeneration, and Redox Status in rd10 Mice

Retinitis pigmentosa (RP) is a group of inherited retinal dystrophies characterized by progressive degeneration of photoreceptor cells. Ocular redox status is altered in RP suggesting oxidative stress could contribute to their progression. In this study, we investigated the effect of a mixture of nutraceuticals with antioxidant properties (NUT) on retinal degeneration in rd10 mice, a model of RP. NUT was orally administered to rd10 mice from postnatal day (PD) 9 to PD18. At PD18 retinal function and morphology were examined by electroretinography (ERG) and histology including TUNEL assay, immunolabeling of microglia, Müller cells, and poly ADP ribose polymers. Retinal redox status was determined by measuring the activity of antioxidant enzymes and some oxidative stress markers. Gene expression of the cytokines IL-6, TNFα, and IL-1β was assessed by real-time PCR. NUT treatment delayed the loss of photoreceptors in rd10 mice partially preserving their electrical responses to light stimuli. Moreover, it ameliorated redox status and reduced inflammation including microglia activation, upregulation of cytokines, reactive gliosis, and PARP overactivation. NUT ameliorated retinal functionality and morphology at early stages of RP in rd10 mice. This formulation could be useful as a neuroprotective approach for patients with RP in the future.

Nanodelivery of natural isothiocyanates as a cancer therapeutic

Natural isothiocyanates (ITCs) are phytochemicals abundant in cruciferous vegetables with the general structure, R-NCS. They are bioactive organosulfur compounds derived from the hydrolysis of glucosinolates by myrosinase. A significant number of isothiocyanates have been isolated from different plant sources that include broccoli, Brussels sprouts, cabbage, cauliflower, kale, mustard, wasabi, and watercress. Several ITCs have been demonstrated to possess significant pharmacological properties including: antioxidant, anti-inflammatory, anti-cancer and antimicrobial activities. Due to their chemopreventive effects on many types of cancer, ITCs have been regarded as a promising anti-cancer therapeutic agent without major toxicity concerns. However, their clinical application has been hindered by several factors including their low aqueous solubility, low bioavailability, instability as well as their hormetic effect. Moreover, the typical dietary uptake of ITCs consumed for promotion of good health may be far from their bioactive (or cytotoxic) dose necessary for cancer prevention and/or treatment. Nanotechnology is one of best options to attain enhanced efficacy and minimize hormetic effect for ITCs. Nanoformulation of ITCs leads to enhance stability of ITCs in plasma and emphasize on their chemopreventive effects. This review provides a summary of the potential bioactivities of ITCs, their mechanisms of action for the prevention and treatment of cancer, as well as the recent research progress in their nanodelivery strategies to enhance solubility, bioavailability, and anti-cancer efficacy.

Cruciferous vegetables: rationale for exploring potential salutary effects of sulforaphane-rich foods in patients with chronic kidney disease

Sulforaphane (SFN) is a sulfur-containing isothiocyanate found in cruciferous vegetables (Brassicaceae) and a well-known activator of nuclear factor-erythroid 2-related factor 2 (Nrf2), considered a master regulator of cellular antioxidant responses. Patients with chronic diseases, such as diabetes, cardiovascular disease, cancer, and chronic kidney disease (CKD) present with high levels of oxidative stress and a massive inflammatory burden associated with diminished Nrf2 and elevated nuclear transcription factor-κB-κB expression. Because it is a common constituent of dietary vegetables, the salutogenic properties of sulforaphane, especially it’s antioxidative and anti-inflammatory properties, have been explored as a nutritional intervention in a range of diseases of ageing, though data on CKD remain scarce. In this brief review, the effects of SFN as a senotherapeutic agent are described and a rationale is provided for studies that aim to explore the potential benefits of SFN-rich foods in patients with CKD.

Synergistic effects of curcumin and its analogs with other bioactive compounds: A comprehensive review

Curcumin, as a natural compound, extracted from plant Curcuma longa, is abundant in the Indian subcontinent and Southeast Asia, and have been used in a diverse array of pharmacological activities. Although curcumin has some limitations like low stability and low bioavailability, it has been proved that this compound induced apoptosis signaling and is also known to block cell proliferation signaling pathway. Recently, extensive research has been carried out to study the application of curcumin as a health improving agent, and devise new methods to overcome to the curcumin limitations and incorporate this functional ingredient into foods. Combinational chemotherapy is one of the basic strategies is using for 60 years for the treatment of various health problems like cancer, malaria, inflammation, diabetes and etc. Molecular hybridization is another strategy to make multi-pharmacophore or conjugated drugs with more synergistic effect than the parent compounds. The aim of this review is to provide an overview of the pharmacological activity of curcumin and its analogs in combination with other bioactive compounds and cover more recent reports of anti-cancer, anti-malarial, and anti-inflammatory activities of these analogs.