β-Cryptoxanthin Reduced Lung Tumor Multiplicity and Inhibited Lung Cancer Cell Motility by Downregulating Nicotinic Acetylcholine Receptor α7 Signaling

Negative Association of Serum β-Cryptoxanthin With Benzene and Its Derivatives

OBJECTIVE

Benzene is widely recognized as a potential carcinogen. Furthermore, the deficiency of specific nutrients may render individuals more vulnerable to cancer. For instance, β-cryptoxanthin, which possesses anti-inflammatory, antioxidant, and anticancer properties, has been identified as one such nutrient. Elevated benzene levels and reduced β-cryptoxanthin levels are reportedly correlated with an augmented susceptibility to cancer. To date, whether these 2 substances are linked with one another in the above correlation is yet to be determined.

METHOD

This study included 1358 participants with data on the serum concentration of β-cryptoxanthin as well as benzene and its derivatives. The data were sourced from the 2003-2004 National Health and Nutrition Examination Survey, a cross-sectional survey of the noninstitutionalized US population. Headspace solid-phase microextraction with gas chromatography and mass spectrometry was used to measure serum benzene and its derivatives, while high-performance liquid chromatography using multiwavelength photodiode-array absorbance detection was employed to quantify serum β-cryptoxanthin.

RESULTS

In this study, male and female participants showed average β-cryptoxanthin levels of 9.10 ± 6.35 and 9.92 ± 8.95 ug/dL, respectively (p = 0.049). Styrene exhibited the strongest correlation with the change in β-cryptoxanthin concentration (β = -3.30, p for trend <0.001) upon comparing highest-quartile participants with those in the lowest quartile, followed by benzene (β = -2.95, p for trend <0.001), toluene (β = -2.90, p for trend <0.001), and ethylbenzene (β = -1.43, p for trend = 0.09). Subgroup analysis by sex displayed a statistically significant negative correlation of β-cryptoxanthin with benzene, styrene, and toluene in both the unadjusted and multivariate-adjusted models.

CONCLUSIONS

The sera of noninstitutionalized US individuals exhibit a negative association of β-cryptoxanthin levels with benzene and its derivatives. Styrene demonstrates the strongest link with a substantial decline in serum β-cryptoxanthin levels, followed by benzene, toluene, and ethylbenzene.

Targeting Alpha7 Nicotinic Acetylcholine Receptors in Lung Cancer: Insights, Challenges, and Therapeutic Strategies

Alpha7 nicotinic acetylcholine receptor (α7 nAChR) is an ion-gated calcium channel that plays a significant role in various aspects of cancer pathogenesis, particularly in lung cancer. Preclinical studies have elucidated the molecular mechanism underlying α7 nAChR-associated lung cancer proliferation, chemotherapy resistance, and metastasis. Understanding and targeting this mechanism are crucial for developing therapeutic interventions aimed at disrupting α7 nAChR-mediated cancer progression and improving treatment outcomes. Drug research and discovery have determined natural compounds and synthesized chemical antagonists that specifically target α7 nAChR. However, approved α7 nAChR antagonists for clinical use are lacking, primarily due to challenges related to achieving the desired selectivity, efficacy, and safety profiles required for effective therapeutic intervention. This comprehensive review provided insights into the molecular mechanisms associated with α7 nAChR and its role in cancer progression, particularly in lung cancer. Furthermore, it presents an update on recent evidence about α7 nAChR antagonists and addresses the challenges encountered in drug research and discovery in this field.

Carotenoid Extraction from Plant Tissues

Carotenoids are the natural pigments available in nature and exhibit different colors such as yellow, red, and orange. These are a class of phytonutrients that have anti-cancer, anti-inflammatory, anti-oxidant, immune-modulatory, and anti-aging properties. These were used in food, pharmaceutical, nutraceutical, and cosmetic industries. They are divided into two classes: carotenes and xanthophylls. The carotenes are non-oxygenated derivatives and xanthophylls are oxygenated derivatives. The major source of carotenoids are vegetables, fruits, and tissues. Carotenoids also perform the roles of photoprotection and photosynthesis. In addition to the roles mentioned above, they are also involved and act as precursor molecules for the biosynthesis of phytohormones such as strigolactone and abscisic acid. This chapter briefly introduces carotenoids and their extraction method from plant tissue. Proposed protocol describes the extraction of carotenoid using solvents chloroform and dichloromethane. Reverse-phase HPLC can be performed with C30 columns using gradient elution. The column C30 is preferred to the C18 column because the C30 column has salient features, which include selective nature in the separation of structural isomers and hydrophobic, long-chain compounds, and shows the best compatibility with highly aqueous mobile phases. A complete pipeline for the extraction of carotenoids from plant tissue is given in the present protocol.

Opuntia ficus-indica (L.) Mill. - anticancer properties and phytochemicals: current trends and future perspectives

Cancer is a leading cause of mortality worldwide, and conventional cancer therapies such as chemotherapy and radiotherapy often result in undesirable and adverse effects. Natural products have emerged as a promising alternative for cancer treatment, with comparatively fewer side effects reported. Opuntia ficus-indica (L.) Mill., a member of the Cactaceae family, contains a diverse array of phytochemicals, including flavonoids, polyphenols, betalains, and tannins, which have been shown to exhibit potent anticancer properties. Various parts of the Opuntia plant, including the fruits, stems/cladodes, and roots, have demonstrated cytotoxic effects against malignant cell lines in numerous studies. This review comprehensively summarizes the anticancer attributes of the phytochemicals found in Opuntia ficus-indica (L.) Mill., highlighting their potential as natural cancer prevention and treatment agents. Bibliometric metric analysis of PubMed and Scopus-retrieved data using VOSviewer as well as QDA analysis provide further insights and niche to be explored. Most anticancer studies on Opuntia ficus-indica and its purified metabolites are related to colorectal/colon cancer, followed by melanoma and breast cancer. Very little attention has been paid to leukemia, thyroid, endometrial, liver, and prostate cancer, and it could be considered an opportunity for researchers to explore O. ficus-indica and its metabolites against these cancers. The most notable mechanisms expressed and validated in those studies are apoptosis, cell cycle arrest (G0/G1 and G2/M), Bcl-2 modulation, antiproliferative, oxidative stress-mediated mechanisms, and cytochrome c. We have also observed that cladodes and fruits of O. ficus-indica have been more studied than other plant parts, which again opens the opportunity for the researchers to explore. Further, cell line-based studies dominated, and very few studies were related to animal-based experiments. The Zebrafish model is another platform to explore. However, it seems like more in-depth studies are required to ascertain clinical utility of this biosustainable resource O. ficus-indica.

β-Cryptoxanthin Attenuates Cigarette-Smoke-Induced Lung Lesions in the Absence of Carotenoid Cleavage Enzymes (BCO1/BCO2) in Mice

High dietary intake of β-cryptoxanthin (BCX, an oxygenated provitamin A carotenoid) is associated with a lower risk of lung disease in smokers. BCX can be cleaved by β-carotene-15,15'-oxygenase (BCO1) and β-carotene-9',10'-oxygenase (BCO2) to produce retinol and apo-10'-carotenoids. We investigated whether BCX has protective effects against cigarette smoke (CS)-induced lung injury, dependent or independent of BCO1/BCO2 and their metabolites. Both BCO1^-/-/BCO2^-/- double knockout mice (DKO) and wild type (WT) littermates were supplemented with BCX 14 days and then exposed to CS for an additional 14 days. CS exposure significantly induced macrophage and neutrophil infiltration in the lung tissues of mice, regardless of genotypes, compared to the non-exposed littermates. BCX treatment significantly inhibited CS-induced inflammatory cell infiltration, hyperplasia in the bronchial epithelium, and enlarged alveolar airspaces in both WT and DKO mice, regardless of sex. The protective effects of BCX were associated with lower expression of IL-6, TNF-α, and matrix metalloproteinases-2 and -9. BCX treatment led to a significant increase in hepatic BCX levels in DKO mice, but not in WT mice, which had significant increase in hepatic retinol concentration. No apo-10'-carotenoids were detected in any of the groups. In vitro BCX, at comparable doses of 3-OH-β-apo-10'-carotenal, was effective at inhibiting the lipopolysaccharide-induced inflammatory response in a human bronchial epithelial cell line. These data indicate that BCX can serve as an effective protective agent against CS-induced lung lesions in the absence of carotenoid cleavage enzymes.

Dietary Phytochemicals as Potential Chemopreventive Agents against Tobacco-Induced Lung Carcinogenesis

Lung cancer is the second most common cancer in the world. Cigarette smoking is strongly connected with lung cancer. Benzo[a]pyrene (BaP) and 4-(N-methyl-N-nitrosamine)-1-(3-pyridyl)-butanone (NNK) are the main carcinogens in cigarette smoking. Evidence has supported the correlation between these two carcinogens and lung cancer. Epidemiology analysis suggests that lung cancer can be effectively prevented through daily diet adjustments. This review aims to summarize the studies published in the past 20 years exploring dietary phytochemicals using Google Scholar, PubMed, and Web of Science databases. Dietary phytochemicals mainly include medicinal plants, beverages, fruits, vegetables, spices, etc. Moreover, the perspectives on the challenges and future directions of dietary phytochemicals for lung cancer chemoprevention will be provided. Taken together, treatment based on the consumption of dietary phytochemicals for lung cancer chemoprevention will produce more positive outcomes in the future and offer the possibility of reducing cancer risk in society.

Dietary Antioxidants and Lung Cancer Risk in Smokers and Non-Smokers

Smoking is considered a major risk factor in the development of lung diseases worldwide. Active smoking and secondhand (passive) smoke (SHS) are related to lung cancer (LC) risk. Oxidative stress (OS) and/or lipid peroxidation (LP) induced by cigarette smoke (CS) are found to be involved in the pathogenesis of LC. Meta-analyses and other case-control/prospective cohort studies are inconclusive and have yielded inconsistent results concerning the protective role of dietary vitamins C and E, retinol, and iron intake against LC risk in smokers and/or non-smokers. Furthermore, the role of vitamins and minerals as antioxidants with the potential in protecting LC cells against CS-induced OS in smokers and non-smokers has not been fully elucidated. Thus, this review aims to summarize the available evidence reporting the relationships between dietary antioxidant intake and LC risk in smokers and non-smokers that may be used to provide suggestions for future research.

Intake of vegetables and fruits rich in provitamin A is positively associated with aryl hydrocarbon receptor repressor DNA methylation in a Japanese population

DNA methylation can be affected by numerous lifestyle factors, including diet. Tobacco smoking induces aryl hydrocarbon receptor repressor (AHRR) DNA hypomethylation, which increases the risk of lung and other cancers. However, no lifestyle habits that might increase or restore percentage of AHRR DNA methylation have been identified. We hypothesized that dietary intakes of vegetables/fruits and serum carotenoid concentrations are related to AHRR DNA methylation. A total of 813 individuals participated in this cross-sectional study. A food frequency questionnaire was used to assess dietary intake of vegetables and fruits. AHRR DNA methylation in peripheral blood mononuclear cells were measured using pyrosequencing method. In men, dietary fruit intake was significantly and positively associated with AHRR DNA methylation among current smokers (P for trend = .034). A significant positive association of serum provitamin A with AHRR DNA methylation was observed among current smokers (men: standardized β = 0.141 [0.045 to 0.237], women: standardized β = 0.570 [0.153 to 0.990]). However, compared with never smokers with low provitamin A concentrations, percentages of AHRR DNA methylation were much lower among current smokers, even those with high provitamin A concentrations (men: β = -19.1% [-33.8 to -19.8], women: β = -6.0% [-10.2 to -1.7]). Dietary intake of vegetables and fruits rich in provitamin A may increase percentage of AHRR DNA methylation in current smokers. However, although we found a beneficial effect of provitamin A on AHRR DNA methylation, this beneficial effect could not completely remove the effect of smoking on AHRR DNA demethylation.

Association of Retinol and Carotenoids Content in Diet and Serum With Risk for Colorectal Cancer: A Meta-Analysis

Background

Colorectal cancer (CRC) risk is linked to serum and dietary retinol and carotenoids, according to clinical and epidemiological research. However, the findings are not consistent. As a result, we did this meta-analysis to determine the link between them.

Methods

From 2000 through 2022, the PubMed, Web of Science, and Embase databases, as well as pertinent article references, were searched and filtered based on inclusion and exclusion criteria and literature quality ratings. High and low intake were used as controls, and OR (odds ratio) or RR (relative risk) and 95% confidence interval were extracted. The extracted data were plotted and analyzed using Stata12.0 software.

Results

A total of 22 relevant studies were included, including 18 studies related to diet and 4 studies related to serum. For high and low intake or concentration controls, the pooled OR was as follows: β-carotene (OR = 0.89, 95% CI: 0.78–1.03), α-carotene (OR = 0.87, 95% CI: 0.72–1.03), lycopene (OR = 0.93, 95% CI: 0.81–1.07), lutein/zeaxanthin (OR = 0.96, 95% CI: 0.87–1.07), β-cryptoxanthin (OR = 0.70, 95% CI: 0.48–1.01), total carotenoids (OR = 0.97, 95% CI: 0.81–1.15), retinol (OR = 0.99, 95% CI: 0.89–1.10), serum carotenoids (OR = 0.73, 95% CI: 0.58–0.93), serum retinol (OR = 0.62, 95% CI: 0.26–1.49). Subgroup analysis was performed according to tumor type, study type and sex.

Conclusion

Total carotenoid intake and Lutein/Zeaxanthin intake were not associated with CRC risk. High β-carotene, α-carotene, lycopene, and β-cryptoxanthin all tended to reduce CRC risk. Serum carotenoid concentrations were significantly inversely associated with CRC risk.

Mmp12 Is Upregulated by in utero Second-Hand Smoke Exposures and Is a Key Factor Contributing to Aggravated Lung Responses in Adult Emphysema, Asthma, and Lung Cancer Mouse Models

Matrix metalloproteinase-12 (Mmp12) is upregulated by cigarette smoke (CS) and plays a critical role in extracellular matrix remodeling, a key mechanism involved in physiological repair processes, and in the pathogenesis of emphysema, asthma, and lung cancer. While cigarette smoking is associated with the development of chronic obstructive pulmonary diseases (COPD) and lung cancer, in utero exposures to CS and second-hand smoke (SHS) are associated with asthma development in the offspring. SHS is an indoor air pollutant that causes known adverse health effects; however, the mechanisms by which in utero SHS exposures predispose to adult lung diseases, including COPD, asthma, and lung cancer, are poorly understood. In this study, we tested the hypothesis that in utero SHS exposure aggravates adult-induced emphysema, asthma, and lung cancer.

Methods: Pregnant BALB/c mice were exposed from gestational days 6–19 to either 3 or 10mg/m³ of SHS or filtered air. At 10, 11, 16, or 17weeks of age, female offspring were treated with either saline for controls, elastase to induce emphysema, house-dust mite (HDM) to initiate asthma, or urethane to promote lung cancer. At sacrifice, specific disease-related lung responses including lung function, inflammation, gene, and protein expression were assessed.

Results: In the elastase-induced emphysema model, in utero SHS-exposed mice had significantly enlarged airspaces and up-regulated expression of Mmp12 (10.3-fold compared to air-elastase controls). In the HDM-induced asthma model, in utero exposures to SHS produced eosinophilic lung inflammation and potentiated Mmp12 gene expression (5.7-fold compared to air-HDM controls). In the lung cancer model, in utero exposures to SHS significantly increased the number of intrapulmonary metastases at 58weeks of age and up-regulated Mmp12 (9.3-fold compared to air-urethane controls). In all lung disease models, Mmp12 upregulation was supported at the protein level.

Conclusion: Our findings revealed that in utero SHS exposures exacerbate lung responses to adult-induced emphysema, asthma, and lung cancer. Our data show that MMP12 is up-regulated at the gene and protein levels in three distinct adult lung disease models following in utero SHS exposures, suggesting that MMP12 is central to in utero SHS-aggravated lung responses.

Anti-Inflammatory and Anticancer Effects of Microalgal Carotenoids

Acute inflammation is a key component of the immune system’s response to pathogens, toxic agents, or tissue injury, involving the stimulation of defense mechanisms aimed to removing pathogenic factors and restoring tissue homeostasis. However, uncontrolled acute inflammatory response may lead to chronic inflammation, which is involved in the development of many diseases, including cancer. Nowadays, the need to find new potential therapeutic compounds has raised the worldwide scientific interest to study the marine environment. Specifically, microalgae are considered rich sources of bioactive molecules, such as carotenoids, which are natural isoprenoid pigments with important beneficial effects for health due to their biological activities. Carotenoids are essential nutrients for mammals, but they are unable to synthesize them; instead, a dietary intake of these compounds is required. Carotenoids are classified as carotenes (hydrocarbon carotenoids), such as α- and β-carotene, and xanthophylls (oxygenate derivatives) including zeaxanthin, astaxanthin, fucoxanthin, lutein, α- and β-cryptoxanthin, and canthaxanthin. This review summarizes the present up-to-date knowledge of the anti-inflammatory and anticancer activities of microalgal carotenoids both in vitro and in vivo, as well as the latest status of human studies for their potential use in prevention and treatment of inflammatory diseases and cancer.

Efficient Anti-Glioma Therapy Through the Brain-Targeted RVG15-Modified Liposomes Loading Paclitaxel-Cholesterol Complex

Background

Glioma is the most common primary malignant brain tumor with a dreadful overall survival and high mortality. One of the most difficult challenges in clinical treatment is that most drugs hardly pass through the blood–brain barrier (BBB) and achieve efficient accumulation at tumor sites. Thus, to circumvent this hurdle, developing an effectively traversing BBB drug delivery nanovehicle is of significant clinical importance. Rabies virus glycoprotein (RVG) is a derivative peptide that can specifically bind to nicotinic acetylcholine receptor (nAChR) widely overexpressed on BBB and glioma cells for the invasion of rabies virus into the brain. Inspired by this, RVG has been demonstrated to potentiate drugs across the BBB, promote the permeability, and further enhance drug tumor-specific selectivity and penetration.

Methods

Here, we used the RVG15, rescreened from the well-known RVG29, to develop a brain-targeted liposome (RVG15-Lipo) for enhanced BBB permeability and tumor-specific delivery of paclitaxel (PTX). The paclitaxel-cholesterol complex (PTX-CHO) was prepared and then actively loaded into liposomes to acquire high entrapment efficiency (EE) and fine stability. Meanwhile, physicochemical properties, in vitro and in vivo delivery efficiency and therapeutic effect were investigated thoroughly.

Results

The particle size and zeta potential of PTX-CHO-RVG15-Lipo were 128.15 ± 1.63 nm and −15.55 ± 0.78 mV, respectively. Compared with free PTX, PTX-CHO-RVG15-Lipo exhibited excellent targeting efficiency and safety in HBMEC and C6 cells, and better transport efficiency across the BBB in vitro model. Furthermore, PTX-CHO-RVG15-Lipo could noticeably improve the accumulation of PTX in the brain, and then promote the chemotherapeutic drugs penetration in C6^luc orthotopic glioma based on in vivo imaging assays. The in vivo antitumor results indicated that PTX-CHO-RVG15-Lipo significantly inhibited glioma growth and metabasis, therefore improved survival rate of tumor-bearing mice with little adverse effect.

Conclusion

Our study demonstrated that the RVG15 was a promising brain-targeted specific ligands owing to the superior BBB penetration and tumor targeting ability. Based on the outstanding therapeutic effect both in vitro and in vivo, PTX-CHO-RVG15-Lipo was proved to be a potential delivery system for PTX to treat glioma in clinic.

Medicinal Prospects of Antioxidants From Algal Sources in Cancer Therapy

Though cancer therapeutics can successfully eradicate cancerous cells, the effectiveness of these medications is mostly restricted to several deleterious side effects. Therefore, to alleviate these side effects, antioxidant supplementation is often warranted, reducing reactive species levels and mitigating persistent oxidative damage. Thus, it can impede the growth of cancer cells while protecting the normal cells simultaneously. Moreover, antioxidant supplementation alone or in combination with chemotherapeutics hinders further tumor development, prevents chemoresistance by improving the response to chemotherapy drugs, and enhances cancer patients' quality of life by alleviating side effects. Preclinical and clinical studies have been revealed the efficacy of using phytochemical and dietary antioxidants from different sources in treating chemo and radiation therapy-induced toxicities and enhancing treatment effectiveness. In this context, algae, both micro and macro, can be considered as alternative natural sources of antioxidants. Algae possess antioxidants from diverse groups, which can be exploited in the pharmaceutical industry. Despite having nutritional benefits, investigation and utilization of algal antioxidants are still in their infancy. This review article summarizes the prospective anticancer effect of twenty-three antioxidants from microalgae and their potential mechanism of action in cancer cells, as well as usage in cancer therapy. In addition, antioxidants from seaweeds, especially from edible species, are outlined, as well.

Pouteria sapota (Red Mamey Fruit): Chemistry and Biological Activity of Carotenoids

BACKGROUND

Red mamey fruit known as P. sapota, comes from trees found in Mesoamerica and Asia. This fruit is considered a nutraceutical food due to it's a food and has multiple beneficial health including anti-amyloidogenic activity and potential anti-tumorigenic property. Red mamey fruit contain a variety of carotenoids including novel ketocarotenoids such as sapotexanthin and cryptocapsin. A ketocarotenoid is a chemical compound with a carbonyl group present in the β-ring or in the double bond chain of a carotenoid. In red mamey, the 3'-deoxy-k-end group in sapotexanthin has proved to be an important pro-vitamin A source, which is essential for maintaining a healthy vision and cognitive processes.

OBJECTIVE

Summarize the chemistry and biological activity of the studied carotenoids present in this fruit until now.

METHOD

An exhaustive extraction is the most usual methodology to isolate and thoroughly characterize the carotenoids present in this fruit. High performance liquid chromatography is used to determine the profile of total carotenoid and its purity. Atmospheric pressure chemical ionization is used to determine the molecular weight of carotenoid. Nuclear magnetic resonance is used to determine the structure of carotenoids.

RESULT

For each 100 g of fresh weight, 0.12 mg of total carotenoid from this fruit can be obtained. Out of the more than 47 reported carotenoids in red mamey, only 34 have a detailed characterization.

CONCLUSION

it is important to continue studying the chemical composition and biological activity of this unique tropical fruit with commercial and nutritional value.

Mechanistic understanding of β-cryptoxanthin and lycopene in cancer prevention in animal models

To better understand the potential function of carotenoids in the chemoprevention of cancers, mechanistic understanding of carotenoid action on genetic and epigenetic signaling pathways is critically needed for human studies. The use of appropriate animal models is the most justifiable approach to resolve mechanistic issues regarding protective effects of carotenoids at specific organs and tissue sites. While the initial impetus for studying the benefits of carotenoids in cancer prevention was their antioxidant capacity and pro-vitamin A activity, significant advances have been made in the understanding of the action of carotenoids with regards to other mechanisms. This review will focus on two common carotenoids, provitamin A carotenoid β-cryptoxanthin and non-provitamin A carotenoid lycopene, as promising chemopreventive agents or chemotherapeutic compounds against cancer development and progression. We reviewed animal studies demonstrating that β-cryptoxanthin and lycopene effectively prevent the development or progression of various cancers and the potential mechanisms involved. We highlight recent research that the biological functions of β-cryptoxanthin and lycopene are mediated, partially via their oxidative metabolites, through their effects on key molecular targeting events, such as NF-κB signaling pathway, RAR/PPARs signaling, SIRT1 signaling pathway, and p53 tumor suppressor pathways. The molecular targets by β-cryptoxanthin and lycopene, offer new opportunities to further our understanding of common and distinct mechanisms that involve carotenoids in cancer prevention. This article is part of a Special Issue entitled Carotenoids recent advances in cell and molecular biology edited by Johannes von Lintig and Loredana Quadro.

Xanthophyll β-Cryptoxanthin Inhibits Highly Refined Carbohydrate Diet-Promoted Hepatocellular Carcinoma Progression in Mice

SCOPE

β-Cryptoxanthin (BCX) can be cleaved by both β-carotene 15,15'-oxygenase (BCO1) and β-carotene 9',10'-oxygenase (BCO2), generating biological active vitamin A and apocarotenoids. We examined whether BCX feeding could inhibit diethylnitrosamine (DEN)-initiated, highly refined carbohydrate diet (HRCD)-promoted hepatocellular carcinoma (HCC) development, dependent or independent of BCO1/BCO2 activity.

METHODS AND RESULTS

Two-week-old male wild-type (WT) and BCO1^-/- /BCO2^-/- double knockout (DKO) mice are given a single intraperitoneal injection of DEN (25 mg kg^-1 body weight) to initiate hepatic carcinogenesis. At 6 weeks of age, all animals are fed HRCD (66.5% of energy from carbohydrate) with or without BCX for 24 weeks. BCX feeding increases hepatic vitamin A levels in WT mice, but not in DKO mice that shows a significant accumulation of hepatic BCX. Compared to their respective HRCD littermates, both WT and DKO fed BCX have significantly lower HCC multiplicity, average tumor size, and total tumor volume, and the steatosis scores. The chemopreventive effects of BCX are associated with increased p53 protein acetylation and decreased protein levels of lactate dehydrogenase and hypoxia-inducible factor-1α in tumors.

CONCLUSION

This study suggests that BCX feeding may alleviate HRCD-promoted HCC progression by modulating the acetylation of p53, hypoxic tumor microenvironment, and glucose metabolism, independent of BCO1/BCO2.

cis/trans Carotenoid Extraction, Purification, Detection, Quantification, and Profiling in Plant Tissues

Reverse phase high-performance liquid chromatography (HPLC) is the method of choice used in biological, health, and food research to identify, quantify, and profile carotenoid species. The identification and quantification of cis- and/or trans-carotene and xanthophyll isomers in plant tissues can be affected by the method of sample preparation and extraction, as well as the HPLC column chemistry and the solvent gradient. There is a high degree of heterogeneity in existing methods in terms of their ease, efficiency, and accuracy. We describe a simple carotenoid extraction method and two different optimised HPLC methods utilizing C18 or C30 reverse-phase columns. We outline applications, advantages, and disadvantages for using these reverse phase columns to detect xanthophylls and cis-carotenes in wild-type photosynthetic leaves and mutant dark-grown etiolated seedlings, respectively. Resources are provided to profile individual species based upon their spectral properties and retention time, as well as quantify carotenoids by their composition and absolute levels in different plant tissues.

Nicotinic-nAChR signaling mediates drug resistance in lung cancer

Lung cancer is the leading cause of cancer death worldwide. Cigarette smoking is the most common risk factor for lung carcinoma; other risks include genetic factors and exposure to radon gas, asbestos, secondhand smoke, and air pollution. Nicotine, the primary addictive constituent of cigarettes, contributes to cancer progression through activation of nicotinic acetylcholine receptors (nAChRs), which are membrane ligand-gated ion channels. Activation of nicotine/nAChR signaling is associated with lung cancer risk and drug resistance. We focused on nAChR pathways activated by nicotine and its downstream signaling involved in regulating apoptotic factors of mitochondria and drug resistance in lung cancer. Increasing evidence suggests that several sirtuins play a critical role in multiple aspects of cancer drug resistance. Thus, understanding the consequences of crosstalk between nicotine/nAChRs and sirtuin signaling pathways in the regulation of drug resistance could be a critical implication for cancer therapy.

Xanthophyll: Health benefits and therapeutic insights

Xanthophylls constitute a major part of carotenoids in nature. They are an oxidized version of carotenoid. Xanthophyll has widely drawn scientists' attentions in terms of its functionality, bioavailability and diversity. An assortment of xanthophyll varieties includes lutein, zeaxanthin, β-cryptoxanthin, capsanthin, astaxanthin, and fucoxanthin. Chemically, lutein and zeaxanthin are dipolar carotenoids with hydroxyl groups at both ends of their molecules that bestow hydrophilic properties to them. Hydrophilic affinity in lutein and zeaxanthin makes better bioavailability in reaction with singlet oxygen in water phase, whereas non-polar carotenoids have shown to have less efficiency in scavenging free radicals. Xanthophylls have been studied for their effects in a wide variety of diseases including neurologic, ophthalmologic, oral, allergic and immune diseases. This review highlights pharmaco-pharmaceutical applications of xanthophylls as well asits drug interactions with beta-carotene. Different types of xanthophylls have been shown to have neuroprotective effects. Fucoxanthin demonstrated potent antiplasmodial activity. Lutein and zeaxanthin prevent the progression of age related macular degeneration. They have also demonstrated promising effects on uveitis, retinitis pigmentosa, scleritis, cataracts, glaucoma, retinal ischemia and choroideremia. Astaxanthin showed to have skin protecting effects against ultraviolet light injury. Astaxanthin have anti-allergic activity against the contact dermatitis especially to treat the patients having adverse reactions induced by steroids. Astaxanthin has been reported to exert beneficial effects in preventing oral lichen planus and early stage cancers. β-cryptoxanthin has been considered a good candidate for prevention of bone loss via osteoblastic bone formation and inhibiting osteoclastic bone resorption. There is also some concern that higher dose of xanthophylls may be linked to increased risk of skin cancer and gastric adenocarcinoma. However this increased risk was not statistically significant when adjusted for confounding factors. Further researches including clinical studies are needed to better evaluate the efficacy and safety of xanthophylls in prevention and treatment of different diseases.

Dietary β-Cryptoxanthin Inhibits High-Refined Carbohydrate Diet-Induced Fatty Liver via Differential Protective Mechanisms Depending on Carotenoid Cleavage Enzymes in Male Mice

BACKGROUND

β-Cryptoxanthin (BCX), a provitamin A carotenoid shown to protect against nonalcoholic fatty liver disease (NAFLD), can be cleaved by β-carotene-15,15'-oxygenase (BCO1) to generate vitamin A, and by β-carotene-9',10'-oxygenase (BCO2) to produce bioactive apo-carotenoids. BCO1/BCO2 polymorphisms have been associated with variations in plasma carotenoid amounts in both humans and animals.

OBJECTIVES

We investigated whether BCX feeding inhibits high refined-carbohydrate diet (HRCD)-induced NAFLD, dependent or independent of BCO1/BCO2.

METHODS

Six-week-old male wild-type (WT) and BCO1-/-/BCO2-/- double knockout (DKO) mice were randomly fed HRCD (66.5% of energy from carbohydrate) with or without BCX (10 mg/kg diet) for 24 wk. Pathological and biochemical variables were analyzed in the liver and mesenteric adipose tissues (MATs). Data were analyzed by 2-factor ANOVA.

RESULTS

Compared to their respective HRCD controls, BCX reduced hepatic steatosis severity by 33‒43% and hepatic total cholesterol by 43‒70% in both WT and DKO mice (P < 0.01). Hepatic concentrations of BCX, but not retinol and retinyl palmitate, were 33-fold higher in DKO mice than in WT mice (P < 0.001). BCX feeding increased the hepatic fatty acid oxidation protein peroxisome proliferator-activated receptor-α, and the cholesterol efflux gene ATP-binding cassette transporter5, and suppressed the lipogenesis gene acetyl-CoA carboxylase 1 (Acc1) in the MAT of WT mice but not DKO mice (P < 0.05). BCX feeding decreased the hepatic lipogenesis proteins ACC and stearoyl-CoA desaturase-1 (3-fold and 5-fold) and the cholesterol synthesis genes 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase and HMG-CoA synthase 1 (2.7-fold and 1.8-fold) and increased the cholesterol catabolism gene cholesterol 7α-hydroxylase (1.9-fold) in the DKO but not WT mice (P < 0.05). BCX feeding increased hepatic protein sirtuin1 (2.5-fold) and AMP-activated protein kinase (9-fold) and decreased hepatic farnesoid X receptor protein (80%) and the inflammatory cytokine gene Il6 (6-fold) in the MAT of DKO mice but not WT mice (P < 0.05).

CONCLUSION

BCX feeding mitigates HRCD-induced NAFLD in both WT and DKO mice through different mechanisms in the liver-MAT axis, depending on the presence or absence of BCO1/BCO2.

β-Cryptoxanthin induced anti-proliferation and apoptosis by G0/G1 arrest and AMPK signal inactivation in gastric cancer

β-Cryptoxanthin has been associated with reduced-risk of some cancers. However, the mechanisms of β-cryptoxanthin still remain unclearly understood in gastric cancer (GC). In this study, we examined the effect of β-cryptoxanthin on AMPK signal in human gastric cancer cells. AGS and SGC-7901 cells were treated with β-cryptoxanthin (0-40 μM) and AGS cells were injected in BALB/c (nu/nu) mice to analyze the effect of β-cryptoxanthin on GC. We found that β-cryptoxanthin induced inhibitory effect on the cell viability in a time- and concentration-dependent manner. The number of migrated cells and protein levels of matrix metalloproteinase (MMP) -2 and MMP-9 were obviously decreased. β-Cryptoxanthin treatment induced G0/G1 arrest, and reduced the expression of Cyclin E, Cyclin D1, cyclin-dependent kinases (CDK) of CDK4 and CDK6, and increased the expression of p53 and p21 in the two GC cells. Additionally, β-cryptoxanthin induced apoptosis and increased the expression of cleaved caspase-3, -8, -9 as well as cytochrome C (cyt C). β-Cryptoxanthin induced AMP-activated protein kinase (AMPK) signal inactivation by the down-regulation of protein kinase A (PKA), p-AMPK, eukaryotic elongation factor 2 kinase (eEF2k). Furthermore, β-cryptoxanthin inhibited tumor growth through suppressing the tumor volume and weight, inducing apoptotic cells. Besides, β-cryptoxanthin induced significant reductions of vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9). In conclusion, our data provide the novel evidence to understand the mechanism of anti-pcancer of β-cryptoxanthin and indicate that β-cryptoxanthin can serve as a promising chemopreventive agent against gastric cancer.

Beta-Cryptoxanthin Inhibits Lipopolysaccharide-Induced Osteoclast Differentiation and Bone Resorption via the Suppression of Inhibitor of NF-κB Kinase Activity

Beta-cryptoxanthin (β-cry) is a typical carotenoid found abundantly in fruit and vegetables such as the Japanese mandarin orange, persimmon, papaya, paprika, and carrot, and exerts various biological activities (e.g., antioxidant effects). We previously reported that β-cry suppressed lipopolysaccharide (LPS)-induced osteoclast differentiation via the inhibition of prostaglandin (PG) E₂ production in gingival fibroblasts and restored the alveolar bone loss in a mouse model for periodontitis in vivo. In this study, we investigated the molecular mechanism underlying the inhibitory effects of β-cry on osteoclast differentiation. In mouse calvarial organ cultures, LPS-induced bone resorption was suppressed by β-cry. In osteoblasts, β-cry inhibited PGE₂ production via the downregulation of the LPS-induced mRNA expression of cyclooxygenase (COX)-2 and membrane-bound PGE synthase (mPGES)-1, which are PGE synthesis-related enzymes, leading to the suppression of receptor activator of NF-κB ligand (RANKL) mRNA transcriptional activation. In an in vitro assay, β-cry directly suppressed the activity of the inhibitor of NF-κB kinase (IKK) β, and adding ATP canceled this IKKβ inhibition. Molecular docking simulation further suggested that β-cry binds to the ATP-binding pocket of IKKβ. In Raw264.7 cells, β-cry suppressed RANKL-mediated osteoclastogenesis. The molecular mechanism underlying the involvement of β-cry in LPS-induced bone resorption may involve the ATP-competing inhibition of IKK activity, resulting in the suppression of NF-κB signaling.

Acetylcholine signaling system in progression of lung cancers

The neurotransmitter acetylcholine (ACh) acts as an autocrine growth factor for human lung cancer. Several lines of evidence show that lung cancer cells express all of the proteins required for the uptake of choline (choline transporter 1, choline transporter-like proteins) synthesis of ACh (choline acetyltransferase, carnitine acetyltransferase), transport of ACh (vesicular acetylcholine transport, OCTs, OCTNs) and degradation of ACh (acetylcholinesterase, butyrylcholinesterase). The released ACh binds back to nicotinic (nAChRs) and muscarinic receptors on lung cancer cells to accelerate their proliferation, migration and invasion. Out of all components of the cholinergic pathway, the nAChR-signaling has been studied the most intensely. The reason for this trend is due to genome-wide data studies showing that nicotinic receptor subtypes are involved in lung cancer risk, the relationship between cigarette smoke and lung cancer risk as well as the rising popularity of electronic cigarettes considered by many as a "safe" alternative to smoking. There are a small number of articles which review the contribution of the other cholinergic proteins in the pathophysiology of lung cancer. The primary objective of this review article is to discuss the function of the acetylcholine-signaling proteins in the progression of lung cancer. The investigation of the role of cholinergic network in lung cancer will pave the way to novel molecular targets and drugs in this lethal malignancy.

Intrinsic and Extrinsic Factors Impacting Absorption, Metabolism, and Health Effects of Dietary Carotenoids

Carotenoids are orange, yellow, and red lipophilic pigments present in many fruit and vegetables, as well as other food groups. Some carotenoids contribute to vitamin A requirements. The consumption and blood concentrations of specific carotenoids have been associated with reduced risks of a number of chronic conditions. However, the interpretation of large, population-based observational and prospective clinical trials is often complicated by the many extrinsic and intrinsic factors that affect the physiologic response to carotenoids. Extrinsic factors affecting carotenoid bioavailability include food-based factors, such as co-consumed lipid, food processing, and molecular structure, as well as environmental factors, such as interactions with prescription drugs, smoking, or alcohol consumption. Intrinsic, physiologic factors associated with blood and tissue carotenoid concentrations include age, body composition, hormonal fluctuations, and variation in genes associated with carotenoid absorption and metabolism. To most effectively investigate carotenoid bioactivity and to utilize blood or tissue carotenoid concentrations as biomarkers of intake, investigators should either experimentally or statistically control for confounding variables affecting the bioavailability, tissue distribution, and metabolism of carotene and xanthophyll species. Although much remains to be investigated, recent advances have highlighted that lipid co-consumption, baseline vitamin A status, smoking, body mass and body fat distribution, and genetics are relevant covariates for interpreting blood serum or plasma carotenoid responses. These and other intrinsic and extrinsic factors are discussed, highlighting remaining gaps in knowledge and opportunities for future research. To provide context, we review the state of knowledge with regard to the prominent health effects of carotenoids.

Selected Methods of Extracting Carotenoids, Characterization, and Health Concerns: A Review

Carotenoids are the most powerful nutrients (medicine) on earth due to their potent antioxidant properties. The ability of these tetraterpenoids in obviating human chronic ailments like cancer, cardiovascular disease, osteoporosis, and diabetes has drawn public attention toward these novel compounds. Conventionally, carotenoids have been extracted from plant materials and agro-industrial byproduct using different solvents, but these procedures result in contaminating the target compound (carotenoids) with extraction solvents. Furthermore, some utilized solvents are not safe and hence are harmful to the environment. This has attracted criticism from consumers, ecologists, environmentalists, and public health workers. However, there is clear consumer preference for carotenoids from natural origin without traces of extracting solvent. Therefore, this review seeks to discuss methods for higher recovery of pure carotenoids without contamination from a solvent. Methods such as enzyme-based extraction, supercritical fluid extraction, microwave-assisted extraction, Soxhlet extraction, ultrasonic extraction, and postextraction treatment (saponification) are discussed. Merits and demerits of these methods along with health concerns during intake of carotenoids were also considered.

α7 nicotinic acetylcholine receptors in lung cancer

Lung cancer has one of the highest mortality rates among malignancies globally, and smoking has been documented as the main cause of lung cancer. Nicotinic acetylcholine receptors (nAChRs) were initially identified as notable regulators of the nervous system. In addition to their function in the brain, accumulating evidence indicates that nAChRs perform a host of diverse functions in almost all non-neuronal mammalian cells. The homomeric α7nAChR, a subtype of nAChRs, is responsible for the proliferative, pro-angiogenic and pro-metastatic effects of nicotine in lung cancer. Provided the association of cigarette smoking with several disease types such as cardiovascular disease, the α7nAChR-mediated signaling pathway has been implicated in the pathophysiology of lung cancer. Currently, strategies that target the α7nAChR including α7nAChR antagonists are considered to be potentially useful anticancer drugs for therapeutic purposes. Thus, the present review assesses current understanding of the function and underlying molecular mechanisms of α7nAChR in lung cancer and evaluates how targeting α7nAChR may result in novel therapeutic methods.

Establishment of an Arabidopsis callus system to study the interrelations of biosynthesis, degradation and accumulation of carotenoids

The net amounts of carotenoids accumulating in plant tissues are determined by the rates of biosynthesis and degradation. While biosynthesis is rate-limited by the activity of PHYTOENE SYNTHASE (PSY), carotenoid losses are caused by catabolic enzymatic and non-enzymatic degradation. We established a system based on non-green Arabidopsis callus which allowed investigating major determinants for high steady-state levels of β-carotene. Wild-type callus development was characterized by strong carotenoid degradation which was only marginally caused by the activity of carotenoid cleavage oxygenases. In contrast, carotenoid degradation occurred mostly non-enzymatically and selectively affected carotenoids in a molecule-dependent manner. Using carotenogenic pathway mutants, we found that linear carotenes such as phytoene, phytofluene and pro-lycopene resisted degradation and accumulated while β-carotene was highly susceptible towards degradation. Moderately increased pathway activity through PSY overexpression was compensated by degradation revealing no net increase in β-carotene. However, higher pathway activities outcompeted carotenoid degradation and efficiently increased steady-state β-carotene amounts to up to 500 μg g-1 dry mass. Furthermore, we identified oxidative β-carotene degradation products which correlated with pathway activities, yielding β-apocarotenals of different chain length and various apocarotene-dialdehydes. The latter included methylglyoxal and glyoxal as putative oxidative end products suggesting a potential recovery of carotenoid-derived carbon for primary metabolic pathways. Moreover, we investigated the site of β-carotene sequestration by co-localization experiments which revealed that β-carotene accumulated as intra-plastid crystals which was confirmed by electron microscopy with carotenoid-accumulating roots. The results are discussed in the context of using the non-green calli carotenoid assay system for approaches targeting high steady-state β-carotene levels prior to their application in crops.

Apo-10'-lycopenoic acid inhibits cancer cell migration and angiogenesis and induces peroxisome proliferator-activated receptor γ

SCOPE

We have previously shown that apo-10'-lycopenoic acid (ALA), a derivative of lycopene through cleavage by carotene-9',10'-oxygenase, inhibits tumor progression and metastasis in both liver and lung cancer animal models. The underlying mechanism remains unknown. We hypothesized that ALA inhibits cancer cell motility and angiogenesis by up-regulating peroxisome proliferator-activated receptor γ (PPARγ) which is involved in controlling angiogenesis, tumor progression and metastasis.

METHODS AND RESULTS

ALA treatment, in dose-dependent manner, was effective at inhibiting migration and invasion of liver and lung cancer cells (HuH7 and A549) in both Transwell and wound-healing models, as well as suppressing actin remodeling and ruffling/lamellipodia formation in HuH7 and immortalized lung BEAS-2B cells. ALA treatment resulted in suppression of angiogenesis in both tube formation and aortic ring assays and inhibition of matrix metalloproteinase-2 expression and activation in both HuH7 and A549 cells. Additionally, ALA dose-dependently increased the mRNA expression and protein levels of PPARγ in human THLE-2 liver cells.

CONCLUSION

ALA inhibits cancer cell motility and angiogenesis and induces PPARγ expression, which could be one of the potential mechanisms for ALA protecting against tumor progression.

β-Cryptoxanthin Inhibits Angiogenesis in Human Umbilical Vein Endothelial Cells Through Retinoic Acid Receptor

SCOPE

β-Cryptoxanthin is an abundant carotenoid in fruits and vegetables that can be quantified in human blood serum. Yet, contrary to other carotenoids, its effects on endothelial cells and angiogenesis remain unknown.

METHODS AND RESULTS

Human umbilical vein endothelial cells (HUVEC) are treated with 0.01, 0.1, or 1 μm of β-cryptoxanthin. Antioxidant activity is determined by its free radical scavenging and oxygen-radical absorbance capacity. The effect on migration and formation of tubular structures is studied. Additionally, effect on angiogenesis is also analyzed using an in vivo model. β-Cryptoxanthin exhibits scavenging ability, having an antioxidant effect on HUVEC. Interestingly, β-cryptoxanthin reduces their migration and angiogenesis, even in the presence of vascular endothelial growth factor (VEGF). Additionally, such carotenoid inhibits in vivo angiogenesis induced by VEGF. In addition, treatment of HUVEC with LE540 (retinoic acid receptor [RAR] panantagonist) inhibits β-cryptoxanthin antiangiogenic effect on HUVEC.

CONCLUSION

β-Cryptoxanthin inhibits angiogenesis through RAR. Thus, this carotenoid and food containing it may be useful for the prevention and treatment of angiogenic pathologies. That includes tumoral growth and wet macular degeneration associated with aging. To the best of our knowledge, this is the first report of the antioxidant effect and antiangiogenic activity of this carotenoid on HUVEC, both in vitro and in vivo.