Characterization and biological activity of the main flavonoids from Swiss Chard (Beta vulgaris subspecies cycla)

The effect of supplemental LED lighting in the range of UV, blue, and red wavelengths at different ratios on the accumulation of phenolic compounds in pak choi and swiss chard

Phenolic compounds are known for their health-promoting effects on humans. Pak choi (Brassica rapa ssp. chinensis) and Swiss chard (Beta vulgaris subsp. vulgaris) are used here as model plants, as they are eaten raw as baby leaf lettuce and differ in their phenolic compound profile while showing similar morphology. In a greenhouse an artificial light source with UV-B (215 mW m-2), blue (104 μmol m-2 s-1) and red (245 μmol m-2 s-1) LEDs was implemented to increase phenolic compounds during the last days before harvest. Pak choi shows an increase or trend towards an increase in the monoacylated triglycosides of kaempferol and quercetin after 4 days of irradiation for 4 h each. For example kaempferol-3-caffeoyl-sophoroside-7-glucoside was increased at low PAR values in the third run and red-dominated light treatment by up to 120 %. In addition, it was observed that the red variety 'Amur' has higher concentrations of quercetin glycosides which were increased often. In swiss chard, on the other hand, there was only a sporadic increase in vitexin glycosides. Despite very different concentrations in some samples, 2″-glucosyl-vitexin and 2″-glucosyl-6″-malonyl-vitexin showed significant increases of up to 350 % in the two chard varieties Lukullus and Rhubarb chard. The results suggest that the exposure time or intensity of UV-B radiation needs to be optimized for each species and has not yet consistently led to an increase but trends in phenolic compounds and in antioxidant activity in this study.

Determination of flavonoid content in Grammatophyllum speciosum and in vitro evaluation of their anti-skin cancer and antibacterial activities

Grammatophyllum speciosum Blume, a plant of significant pharmacological and cultural importance in its native regions, has been the subject of traditional medicinal use. This study, however, delves deeper into the unique attributes of G. speciosum aerial part and root extracts, particularly their phytochemical content, antioxidant potential, antibacterial activity, and anticancer properties against human skin cancer cells. The results unveiled a promising aspect-higher flavonoid and phenolic compound levels in the aerial part compared to the root extracts. Both aerial part and root extracts demonstrated significant antioxidant activities, as evidenced by their ability to scavenge DPPH radicals and reduce ferric ions in the FRAP assay. Moreover, the ethanolic extract derived from G. speciosum aerial parts showed promising antibacterial activity against both gram-positive and gram-negative bacteria, hinting at its potential therapeutic efficacy. Notably, this extract also demonstrates a capacity to impede the viability of human skin cancer cells (A375). Collectively, these results demonstrated the potential applications of the G. speciosum aerial part extracts. Further investigation is imperative to elucidate the intricate molecular mechanisms underpinning these diverse effects, thereby contributing to a deeper understanding of the pharmacological potential of G. speciosum and its prospective applications in medicine and beyond.

Polyphenols in edible plant leaves: an overview of their occurrence and health properties

Edible plant leaves (EPLs) constitute a major renewable functional plant biomass available all year round, providing an essential source of polyphenols in the global diet. Polyphenols form a large family of antioxidant molecules. They protect against the harmful effects of free radicals, strengthen immunity and stimulate the body's natural defenses thanks to their antibacterial and antiviral functions. This study refers to phenolic compounds from 50 edible plant leaves divided into four categories: green leafy vegetables, underutilized leafy vegetables, leafy spices and leafy drinks. It provides data on the identification, occurrence and pharmacological functions of polyphenols contained in EPLs, and provides a better understanding of trends and gaps in their consumption and study. Certain EPLs, such as moringa (Moringa oleifera Lam.), tea (Camellia sinensis L.) and several leafy spices of the Lamiaceae family, reveal important characteristics and therapeutic potential. The polyphenol composition of EPLs makes them functional plants that offer relevant solutions in the fight against obesity, the management of food insecurity and the prevention of chronic diseases.

Chemical Characterization of Flowers and Leaf Extracts Obtained from Turnera subulata and Their Immunomodulatory Effect on LPS-Activated RAW 264.7 Macrophages

The anti-inflammatory properties of Turnera subulata have been evaluated as an alternative drug approach to treating several inflammatory processes. Accordingly, in this study, aqueous and hydroalcoholic extracts of T. subulata flowers and leaves were analyzed regarding their phytocomposition by ultrafast liquid chromatography coupled to mass spectrometry, and their anti-inflammatory properties were assessed by an in vitro inflammation model, using LPS-stimulated RAW-264.7 macrophages. The phytochemical profile indicated vitexin-2-O-rhamnoside as an important constituent in both extracts, while methoxyisoflavones, some bulky amino acids (e.g., tryptophan, tyrosine, phenylalanine), pheophorbides, and octadecatrienoic, stearidonic, and ferulic acids were detected in hydroalcoholic extracts. The extracts displayed the ability to modulate the in vitro inflammatory response by altering the secretion of proinflammatory (TNF-α, IL-1β, and IL-6) and anti-inflammatory (IL-10) cytokines and inhibiting the PGE-2 and NO production. Overall, for the first time, putative compounds from T. subulata flowers and leaves were characterized, which can modulate the inflammatory process. Therefore, the data highlight this plant as an option to obtain extracts for phytotherapic formulations to treat and/or prevent chronic diseases.

A review on the relationship of mast cells and macrophages in breast cancer - Can herbs or natural products facilitate their anti-tumor effects?

Breast cancer is an inflammation-related cancer whose tumor microenvironment is largely infiltrated by inflammatory cells. These inflammatory cells including mast cells and macrophages have been elucidated to be vital participants in breast tumor proliferation, survival, invasion and migration. However, the functions of mast cells and macrophages in breast cancer are quite distinct based on recent data. Mast cells exhibit both anti-tumoral and pro-tumoral functions on breast cancer, while high number of tumor-associated macrophages (TAMs) are strongly correlated with poor prognosis and higher risk of distant metastasis in breast cancer patients. Besides, many natural products/extracts have been reported to regulate mast cells and macrophages. In this review, the roles of mast cells and macrophages play in breast cancer are discussed and a summary of those natural products/herbs regulating the functions of mast cells or macrophages is also presented.

Tailoring the Functional Potential of Red Beet Purées by Inoculation with Lactic Acid Bacteria and Drying

This study was focused on a comparative analysis of two drying methods, such as convective and infrared drying, on the red beetroot purées with lactic acid bacteria, as a strategy for tailoring the health benefits of the selected plant. For both varieties, the total betalain contents varied from 13.95 ± 0.14 mg/g dry weight in Beta vulgaris var. cylindra when compared with 11.09 ± 0.03 mg/g dry weight in Beta vulgaris var. vulgaris, whereas significant differences were found in total phenolic and flavonoid contents. Significant drying induced changes were found in selected bioactives, in terms of total betalains, flavonoids, and polyphenols, which influenced the antioxidant activities of the purées, structure, and color parameters. In general, infrared technology was more protective, leading to an increase of 20% in flavonoids content. One logarithmic decrease in cell viability was observed in all powders samples. After the in vitro digestion, the betalains decreased, in both gastric and intestinal simulated juices, with a more pronounced profile in infrared processed purées. Textural and rheological analysis of the dried purées highlighted that the infrared drying is milder compared to the conventional one, allowing us to obtain powders with enhanced functional properties, in terms of bioactives content, cell viability, color, and structural and rheological behavior.

Antiviral Properties of Flavonoids and Delivery Strategies

This review summarizes the latest advancements in phytochemicals as functional antiviral agents. We focused on flavonoids, like apigenin, vitexin, quercetin, rutin and naringenin, which have shown a wide range of biological effects including antiviral activities. The molecular mechanisms of their antiviral effects mainly consist in the inhibition of viral neuraminidase, proteases and DNA/RNA polymerases, as well as in the modification of various viral proteins. Mixtures of different flavonoids or combination of flavonoids with antiviral synthetic drugs provide an enhancement of their antiviral effects. Recent strategies in drug delivery significantly contribute to overcoming the low bioavailability of flavonoids. Frequent viral infections worldwide have led to the need for new effective antiviral agents, which can be identified among the various phytochemicals. In this light, screening the antiviral activities of a cocktail of flavonoids would be advantageous in order to prevent viral infections and improve current antiviral therapies.

Bioactive compounds and nutritional composition of Swiss chard (Beta vulgaris L. var. cicla and flavescens): a systematic review

Swiss chard (Beta vulgaris L. var. cicla or flavescens) is a green leafy vegetable whose bioactive compounds have been studied due to its effects on health. We systematically reviewed the nutritional profile and bioactive composition of Swiss chard and reported their concentrations. Four main databases were searched for studies analyzing the chemical composition of Swiss chard. Screening, selection of articles, and data extraction were carried out by two independent reviewers. Twenty-eight articles of 1102 records identified by bibliographic search met our inclusion criteria for final analysis. We found a total of 192 chemical compounds categorized into 23 groups. The cicla variety was the most studied, and nutrients and phytochemicals were reported mainly on leaves. Betalains with 20% of the reported data, fats (16%), flavonoids (11%), non-flavonoid phenolics (11%), terpenes and derivatives (8%), carbohydrates (7%), and minerals (6%) were among the most reported categories. Swiss chard leaves have the highest content of fiber, sodium, magnesium, flavonoids, and vitamin C, while stems are high in potassium. Swiss chard should be considered a source of nutrients and phytochemicals, and further research is needed on identifying and quantifying other bioactive compounds and understanding their impact on health.

Molecular networking aided metabolomic profiling of beet leaves using three extraction solvents and in relation to its anti-obesity effects

In the present study, the efficiency of three different solvents (H2O, acidified H2O, and 70% Methanol) for metabolites extraction from the leaves of sugar beet (Beta vulgaris subsp. vulgaris var. rubra) was investigated along with their inhibitory activity on pancreatic α-amylase and lipase for obesity management. The metabolic profile of the three extracts was analyzed by ultra-performance liquid chromatography (UPLC) coupled with electrospray ionization high-resolution mass spectrometric (ESI-HRMS-MS). Mass spectrometry-based molecular networking was employed to aid in metabolites annotation and for the visual investigation of the known metabolites and their analogues. The study led to the tentative identification of 45 metabolites including amino acids, purine derivatives, phenolic acids, flavonoids, fatty acids, and an alkaloid, articulating 24 compounds as a first time report from beet leaves along with 2 new putatively identified compounds: a flavone feruloyl conjugate (39) and a malonylated acacetin diglycoside (40). The three extracting systems exhibited comparable efficiency for pulling out the secondary metabolites from the beet leaves. The in vitro study supported this finding and demonstrated that the three extracts inhibited the activity of both pancreatic α-amylase and lipase enzymes with no significant difference observed regarding the percentage of the inhibition of the enzymes. Conclusively, the extraction protocol has a minimal effect on the anti-obesity properties of beet leaves.

Protective effects of beet (Beta vulgaris) leaves extract against oxidative stress in endothelial cells in vitro

Beetroot is an herb used worldwide as a food product, raw material for food industry, ethanol production and source of food coloring. Beet leaves are an unconventional food with antioxidant properties, which might neutralize reactive oxygen species (ROS) induced by oxidized Low-Density Lipoprotein (LDL) present in dyslipidemias. This study aimed to elucidate the effects of beet leaves on the suppression of LDL oxidative processes. Beet leaves extract was produced, characterized, and tested for its antioxidant capacity using endothelial cells in vitro. A model of human umbilical vein endothelial cells was used in various tests, including viability assay, molecular analysis of antioxidant genes, ROS labeling, and macrophage adhesion assay. The extract improved the antioxidative protection of endothelial cells against different agents including oxidized LDL-cholesterol and H₂ O₂ . It acted on ROS directly due to its high content of natural antioxidants, but also due to the activation and improvement of cellular defenses such as Superoxide dismutase 1, Superoxide dismutase 2, and catalase. The inhibition of LDL-mediated oxidative effects on endothelial cells may turn this unconventional food a functional food with great potential for phytotherapy of atherosclerosis as an adjuvant for medicinal treatments.

Grown to be Blue-Antioxidant Properties and Health Effects of Colored Vegetables. Part II: Leafy, Fruit, and Other Vegetables

The current trend for substituting synthetic compounds with natural ones in the design and production of functional and healthy foods has increased the research interest about natural colorants. Although coloring agents from plant origin are already used in the food and beverage industry, the market and consumer demands for novel and diverse food products are increasing and new plant sources are explored. Fresh vegetables are considered a good source of such compounds, especially when considering the great color diversity that exists among the various species or even the cultivars within the same species. In the present review we aim to present the most common species of colored vegetables, focusing on leafy and fruit vegetables, as well as on vegetables where other plant parts are commercially used, with special attention to blue color. The compounds that are responsible for the uncommon colors will be also presented and their beneficial health effects and antioxidant properties will be unraveled.

Antibacterial and Potential Antidiabetic Activities of Flavone C-glycosides Isolated from Beta vulgaris Subspecies cicla L. var. Flavescens (Amaranthaceae) Cultivated in Egypt

BACKGROUND

Diabetes mellitus is the most common disease in Egypt. In this context, Beta vulgaris subspecies cicla L. var. flavescens is an edible plant that has been used in traditional medicine as a therapy for treating some diseases.

OBJECTIVES

The current study was performed to evaluate the antibacterial and potential anti-diabetic activities of different extracts and isolated flavone C-glycoside compounds isolated from Beta vulgaris subspecies cicla L. var. flavescens leaves.

METHODS

Phytochemical investigation of n-butanol extract led to the isolation of five phytoconstituents. Their structures were determined by spectroscopic tools, including 1D-NMR (1H- & 13C-NMR) and 2D-NMR (HMQC & HMBC) besides the comparison of the data with the literature. The extracts and phytoconstituents were evaluated in vitro for their activity against some bacterial pathogens, which represent prominent human pathogens, particularly in hospital settings. The antibacterial activity was examined against three Gram-positive bacterial strains (Staphylococcus aureus, Staphylococcus epidermidis & Enterococcus faecalis) and five Gram-negative ones (Pseudomonas aeruginosa, Proteus vulgaris, Klebsiella pneumoniae, Proteus mirabilis & Salmonella typhimurium) relative to Ciprofloxacin as a reference drug. Furthermore, the in vitro antidiabetic activity (Type II) was evaluated using the alpha-glucosidase inhibitory assay.

RESULTS

Five flavone C-glycosides namely; Apigenin 8-C-β-D-glucopyranoside (vitexin) (1), 2''-Oxylopyranosylvitexin (2), acacetin 8-C-β-D-glucopyranoside (3), acacetin 8-C-α-L-rhamnoside (4), and 6,8-di-C-β-D-glucopyranosylapigenin (vecinin-II) (5) were isolated from n-butanol extract of B. vulgaris subspecies cicla L. var. flavescens. Compound 1 showed a promising antibacterial activity against most of the test bacterial strains with respect to the minimum inhibitory concentration values (MIC) ranged from 1.95 to 15.63 µg ml-1. On the other hand, compounds 1 and 3 demonstrated superior antidiabetic activities with IC50 values of 35.7 and 42.64 µg ml-1, respectively, while an inferior potential antidiabetic activity was recorded for compound 4 (IC50 = 145.5 µg ml-1) in comparison with Acarbose as a reference drug.

CONCLUSION

B. vulgaris L. is an edible plant, which could be used as a natural source of antibiotic and hypoglycemic drugs.

Functional quality in novel food sources: Genotypic variation in the nutritive and phytochemical composition of thirteen microgreens species

Compositional variation was examined across 13 microgreens species/subspecies representing Brassicaceae, Chenopodiaceae, Lamiaceae, Malvaceae and Apiaceae, grown in controlled environment. Macro-mineral concentrations were determined by ion chromatography, chlorophyll and ascorbate concentrations, and hydrophilic/lipophilic antioxidant potentials by spectrophotometry, and major carotenoids by HPLC-DAD. Nitrate hyper-accumulators and wide genotypic differences in Na, K and S concentrations were identified. Antioxidant capacity was highest in brassicaceous microgreens and significant genotypic variation was demonstrated in chlorophyll and carotenoid concentrations. High phenolic content was confirmed in Lamiaceae microgreens, with significant varietal differences, and alternative phenolics-rich microgreens from the Apiaceae were identified. Twenty-eight phenolic compounds were variably detected and quantitated through Orbitrap LC-MS/MS with flavonol glycosides, flavones and flavone glycosides, and hydroxycinnamic acids representing 67.6, 24.8 and 7.6% of the mean total phenolic content across species, respectively. The obtained information is critical for selecting new species/varieties of microgreens that may satisfy demand for both taste and health.

Beta vulgaris - A Mini Review of Traditional Uses in Iran, Phytochemistry and Pharmacology

BACKGROUND

Beta vulgaris (family: Chenopodiaceae) is now widely is used more in the food industry as a rich source of sugar but it is less considered in medicine. Beet has been used in traditional medicine for hundreds of years to treat a variety of diseases such as constipation, decreased libido, gut and joint pain and dandruff.

METHODS

This study introduced the benefits of Beta vulgaris by reviewing Iranian traditional documents from the 10th century until now and also compared modern phytotherapy of plant beet from the electronic data banks such as ISI, Pub Med and Scopus with findings that extracted from traditional literature.

RESULTS

This plant is known in Iranian Traditional Medicine (ITM) as Selgh (Arabic) or Choghondar (Farsi) and its leaves are used to develop treatments. Results confirmed that the plant referred to as Selgh in traditional books is that the plant Beta vulgaris in contemporary studies. Treatments that have not been evaluated in modern phytotherapy but do appear in traditional treatments include fever, as well as psychological and psychiatric issues. This article tells the history of beet in ITM and can confirm use of plant Beta vulgaris in medicinal practice. The report can be applied for certification of plant Beta vulgaris for researchers and experts.

CONCLUSION

The findings of this study can help the researchers in producing therapeutic products and new application.

Betacyanins enhance vitexin-2-O-xyloside mediated inhibition of proliferation of T24 bladder cancer cells

Betacyanins (BC) were purified from beetroot (Beta vulgaris var. rubra L.) and tested, alone or in combination with vitexin-2-O-xyloside (XVX) from Beta vulgaris var. cicla L., for their ability to reduce the proliferation rate in T24 bladder cancer cells. Combination of BC and XVX exhibited a synergistic effect concerning the inhibition of proliferation in T24 cancer cells at 24 and 48 h but not after 72 h of incubation. The induction of apoptosis was evidenced by means of fluorescence activated cell sorting (FACS) analysis, as well as through the increase in caspase 3 and 8 activities. Using RTqPCR experiments, it was shown that the combination of XVX + BC was able to enhance the expression levels of pro-apoptotic BAX and downregulate anti-apoptotic BIRC5 (survivin), as well as pro-survival CTNNB1 (β-catenin). The most evident effect of BC was the increase of the activity of caspase 8, leading to induction of extrinsic apoptosis. Moreover, XVX, BC and their combination showed no cytotoxic effect on normal human skin NCTC 2544 keratinocytes. These results demonstrated the efficacy and the mechanisms of the action of BC and XVX, extracted from edible plants, and suggested that a diet or a nutrition supplement, enriched with these bioactive molecules, could be used in the prevention of human bladder cancer.

Determination of Mineral Constituents, Phytochemicals and Antioxidant Qualities of Cleome gynandra, Compared to Brassica oleracea and Beta vulgaris

The study compared mineral, chemical and antioxidant qualities of Cleome gynandra, a wild leafy vegetable, with two widely consumed commercial vegetables, Brassica oleracea and Beta vulgaris. Mineral nutrients were quantified with inductively coupled plasma mass spectrometry (ICP-MS), phenolic compounds using ultra-high performance liquid chromatography coupled to a mass spectrometer (UHPLC-MS) and β-carotene and vitamin C using high performance liquid chromatography with a photodiode array detector (HPLC-PDA). The antioxidant potential was evaluated using 2,2-diphenyl-1-picryl hydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) assays. Cleome gynandra had highest concentrations of phosphorus, potassium, calcium, iron, zinc, ascorbic acid, total phenolics, and flavonoids; whereas sodium, magnesium, manganese, copper and β-carotene were higher for B. vulgaris. The significantly higher antioxidant activity (P ≤ 0.05) exhibited by C. gynandra in comparison to the two commercial vegetables may be due to its significantly high levels of vitamin C and phenolic acids. These findings on the mineral, chemical and antioxidant properties of C. gynandra provide compelling scientific evidence of its potential in adding diversity to the diet and contributing toward the daily nutritional requirements of millions of people for food and nutritional security.

Identification of a flavonoid C-glycoside as potent antioxidant

Flavonoids have been documented to have good antioxidant activities in vitro. However, reports on the cellular antioxidant activities of flavonoid C-glycosides are very limited. In this work, an apigenin C-glycoside was purified from Artocarpus heterophyllus by column chromatography and was identified to be 2″-O-β-D-xylosylvitexin by nuclear magnetic resonance spectroscopy. The cellular antioxidant activity and anticancer activity of 2″-O-β-D-xylosylvitexin were evaluated for the first time. The quantitative structure-activity relationship was analysed by molecular modeling. Apigenin presented an unexpected cellular antioxidation behaviour. It had an antioxidant activity at low concentration and a prooxidant activity at high concentration, whereas 2″-O-β-D-xylosylvitexin showed a dose-dependent cellular antioxidant activity. It indicated that C-glycosidation improved the cellular antioxidation performance of apigenin and eliminated the prooxidant effect. The ortho-dihydroxyl at C-3'/C-4' and C-3 hydroxyl in the flavonoid skeleton play important roles in the antioxidation behaviour. The cell proliferation assay revealed a low cytotoxicity of 2″-O-β-D-xylosylvitexin.

Histochemistry and immunolocalisation of glucokinin in antidiabetic plants used in traditional Mexican medicine

Mexico is a megadiverse country that has 3,600 to 4,000 species of medicinal plants, of which approximately 800 are used to treat conditions related to diabetes mellitus (DM). DM is a chronic degenerative disease of energy metabolism that exists as two types: type 1 (DM1) and type 2 (DM2). DM is considered a public health problem that affects 7% of the Mexican population older than 20 years. DM is clinically controlled with hypoglycaemic drugs, alpha-glucosidase inhibitors, insulin secretion stimulants or the direct application of insulin. The hypoglycaemic effectiveness of specific molecules has been determined only for some medicinal plants in Mexico used to treat DM2. The presence of molecules called glucokinins, wich are similar to animal insulin molecules, has been reported in some plant species; glucokinins act as both growth factors and regulators of glucose metabolism in plants. Therefore, we hypothesized that the hypoglycaemic effectiveness of some of the popularly used species for the control of DM could be due to the presence of glucokinin, as reported for Bauhinia variegata. The goal of this work was to use histochemistry to detect, the accumulation of protein that is immunocytochemically compatible with glucokinin in slide sections of hypoglycaemic species used as remedies for DM2. The top fourteen most used medicinal plants in Mexico were selected for study via microscopic sections. Proteins were histochemically detected using naphthol blue black and Johansen's quadruple stain, and the immunocytochemical correspondence of the proteins with glucokinin was investigated using an insulin antibody. All species studied reacted positively to proteins and glucokinin in the same structures. The presence of glucokinin in these structures and the corresponding hypoglycaemic effects are discussed in the contex of the actions of other compounds.

C-Glycosyl Flavonoids from Beta vulgaris Cicla and Betalains from Beta vulgaris rubra: Antioxidant, Anticancer and Antiinflammatory Activities-A Review

The green beet (Beta vulgaris var. cicla L.) and red beetroot (B. vulgaris var. rubra L.) contain phytochemicals that have beneficial effects on human health. Specifically, the green beet contains apigenin, vitexin, vitexin-2-O-xyloside and vitexin-2-O-rhamnoside, while the red beetroot is a source of betaxanthins and betacyanins. These phytochemicals show considerable antioxidant activity, as well as antiinflammatory and antiproliferative activities. Vitexin-2-O-xyloside, in combination with betaxanthins and betacyanins, exerts antiproliferative activity in breast, liver, colon and bladder cancer cell lines, through the induction of both intrinsic and extrinsic apoptotic pathways. A significant body of evidence also points to the role of these phytochemicals in the downregulation of the pro-survival genes, baculoviral inhibitor of apoptosis repeat-containing 5 and catenin beta-1, as well as the genes controlling angiogenesis, hypoxia inducible factor 1A and vascular endothelial growth factor A. The multi-target action of these phytochemicals enhances their anticancer activity. Vitexin-2-O-xyloside, betaxanthins and betacyanins can be used in combination with conventional anticancer drugs to reduce their toxicity and overcome the multidrug resistance of cancer cells. In this review, we describe the molecular mechanisms that enable these dietary phytochemicals to block the proliferation of tumor cells and inhibit their pro-survival pathways. Copyright © 2017 John Wiley & Sons, Ltd.

In vivo antitumor effect, induction of apoptosis and safety of Remirea maritima Aubl. (Cyperaceae) extracts

BACKGROUND

Remirea maritima has been widely used in the treatment of diarrhea, kidney disease, and high fever and for therapeutic purposes, such as an analgesic and anti-inflammatory. However, few scientific research studies on its medicinal properties have been reported.

PURPOSE

The present study aimed to investigate the anticancer potential of aqueous extract (AE), 40% hydroalcoholic extracts (40HA) and 70% (70HA) from R. maritima in experimental models and to identify its phytochemical compounds.

METHODS

The chemical composition of AE, 40HA and 70HA was assessed by HPLC-DAD and ESI-IT-MS/MS. In vitro activity was determined on cultured tumor cell, NCI-H385N (Broncho-alveolar carcinoma), OVCAR-8 (Ovarian carcinoma) and PC-3M (prostate carcinoma) by the MTT assay, and the in vivo antitumor activity was assessed in Sarcoma 180-bearing mice. Toxicological parameters were also evaluated as well as the humoral immune response.

RESULTS

Among the aqueous and hydroalcoholic extracts of R. maritima, only 40HA showed in vitro biological effect potential, presenting IC50 values of 27.08, 46.62 and >50µg/ml for OVCAR-8, NCI-H385M and PC-3M cells lines, respectively. Regarding chemical composition, a mixture of isovitexin-2''-O-β-D-glucopyranoside, vitexin-2''-O-β-D-glucopyranoside, luteolin-7-O-glucuronide and 1-O-(E)-caffeoyl-β-D-glucose were identified as the major phytochemical compounds of the extracts. In the in vivo study, the tumor inhibition rates were 57.16-62.57% at doses of 25mg/kg and 50mg/kg, respectively, and the tumor morphology presented increasing numbers of apoptotic cells. Additionally, 40HA also demonstrated significantly increased of OVA-specific total Ig.

CONCLUSIONS

40HA exhibited in vitro and in vivo anticancer properties without substantial toxicity that could be associated with its immunostimulating properties.

Application of alkyl polyglycoside surfactant in ultrasonic-assisted extraction followed by macroporous resin enrichment for the separation of vitexin-2″-O-rhamnoside and vitexin from Crataegus pinnatifida leaves

An alkyl polyglycoside (APG) surfactant was used in ultrasonic-assisted extraction to effectively extract vitexin-2″-O-rhamnoside (VOR) and vitexin (VIT) from Crataegus pinnatifida leaves. APG0810 was selected as the surfactant. The extraction process was optimized for ultrasonic power, the APG concentration, ultrasonic time, soaking time, and liquid-solid ratio. The proposed approach showed good recovery (99.80-102.50% for VOR and 98.83-103.19% for VIT) and reproducibility (relative standard deviation, n=5; 3.7% for VOR and 4.2% for VIT) for both components. The proposed sample preparation method is both simple and effective. The use of APG for extraction of key herbal ingredients shows great potential. Ten widely used commercial macroporous resins were evaluated in a screening study to identify a suitable resin for the separation and purification of VOR and VIT. After comparing static and dynamic adsorption and desorption processes, HPD100B was selected as the most suitable resin. After column adsorption and desorption on this resin, the target compounds VOR and VIT can be effectively separated from the APG0810 extraction solution. Recoveries of VOR and VIT were 89.27%±0.42% and 85.29%±0.36%, respectively. The purity of VOR increased from 35.0% to 58.3% and the purity of VIT increased from 12.5% to 19.9%.

Effect of a barley-vegetable soup on plasma carotenoids and biomarkers of cardiovascular disease

Functional foods that provide benefits beyond their traditional nutritional value have attracted much interest. Aim of the study was to evaluate the nutritional and the functional properties of a frozen ready-to-eat soup containing barley and pigmented vegetables. Both glycaemic index and the glyceamic load of ready-to-eat soup were evaluated in vivo. Moreover the bioavailability of carotenoids (lutein and beta-carotene) and the effect on lipid profile and lipid peroxidation were studied in 38 volunteers whose diet was supplemented for two weeks with a daily portion (250 g) of the ready-to-eat soup. Plasma levels of carotenoids (lutein and beta-carotene) and plasma total antioxidant capacity significantly increased after 2 weeks of treatment. Furthermore, we observed a decrease in the levels of lipids (total cholesterol and low density lipoprotein-cholesterol) and of markers of lipid peroxidation (oxidized low density lipoprotein and lipid hydroperoxides) in plasma of all subjects. The glyceamic index of the product was 36, therefore it could be considered a low glyceamic index food. An accurate selection of vegetable foods results in a palatable and healthy product that provides benefits on plasma lipids and lipid peroxidation (Protocol number 211525).

Effect of a barley-vegetable soup on plasma carotenoids and biomarkers of cardiovascular disease

Functional foods that provide benefits beyond their traditional nutritional value have attracted much interest. Aim of the study was to evaluate the nutritional and the functional properties of a frozen ready-to-eat soup containing barley and pigmented vegetables. Both glycaemic index and the glyceamic load of ready-to-eat soup were evaluated in vivo. Moreover the bioavailability of carotenoids (lutein and beta-carotene) and the effect on lipid profile and lipid peroxidation were studied in 38 volunteers whose diet was supplemented for two weeks with a daily portion (250 g) of the ready-to-eat soup. Plasma levels of carotenoids (lutein and beta-carotene) and plasma total antioxidant capacity significantly increased after 2 weeks of treatment. Furthermore, we observed a decrease in the levels of lipids (total cholesterol and low density lipoprotein-cholesterol) and of markers of lipid peroxidation (oxidized low density lipoprotein and lipid hydroperoxides) in plasma of all subjects. The glyceamic index of the product was 36, therefore it could be considered a low glyceamic index food. An accurate selection of vegetable foods results in a palatable and healthy product that provides benefits on plasma lipids and lipid peroxidation (Protocol number 211525).

Compounds isolated from the aerial part of Crataegus azarolus inhibit growth of B16F10 melanoma cells and exert a potent inhibition of the melanin synthesis

Poor therapeutic results have been reported for treatment of malignant melanoma; therefore in this study, we have investigated inhibitory capacity of vitexin-2''-O-rhamnoside as well as the extract from which it was isolated, i.e. the ethyl acetate extract obtained from the leaves of Crataegus azarolus, on mouse melanoma (B16F10) proliferation. Cell viability was determined using the 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. In addition, amounts of melanin and tyrosinase were measured spectrophotometrically at 475nm. Ethyl acetate extract and vitexin-2''-O-rhamnoside exhibited significant anti-proliferative activity against B16F10 melanoma cells after incubation for 48hours with IC50s of 50μg/mL and 20μM, respectively. Furthermore, these two compounds have the ability to reduce the melanin content by inhibiting the tyrosinase activity of B16F10 cells. Thus, further investigations are merited to ascertain their potential application in treating hyperpigmentation disorders.

Effects of vitexin-2"-O-rhamnoside and vitexin-4"-O-glucoside on growth and oxidative stress-induced cell apoptosis of human adipose-derived stem cells

OBJECTIVES

Vitexin-2"-O-rhamnoside (VOR) and vitexin-4"-O-glucoside (VOG) are the two main flavonoid glycosides of the leaves of Cratagus pinnatifida Bge. var. major N. E. Br. that has been widely used for the treatment of cardiovascular system diseases. In this study, we simultaneously investigated the influence of VOR and VOG on human adipose-derived stem cells (hADSCs) injury induced by hydrogen peroxide (H2 O2 ) to further characterize their anti-oxidative and anti-apoptotic activity.

METHODS

hADSCs were isolated, cultured in vitro and pretreated with 62.5 μm VOR or 120 μm VOG for 24 h and then exposed to 500 μm H2 O2 for an additional 4 h.

KEY FINDINGS

Pretreatment of hADSCs with VOR and VOG was demonstrated to significantly ameliorate the toxicity and apoptosis effects, such as morphological distortion, nuclear condensation, decreased intracellular caspase-3 activity and percentage of cells in apoptosis/necrosis by using morphological assay, immunocytochemistry and flow cytometric evaluation. In addition, VOR and VOG caused no cytotoxic effect on hADSCs at concentrations up to 250 and 480 μm, respectively.

CONCLUSIONS

Our results indicated that both VOR and VOG contribute to the protection against H2 O2 -mediated oxidative stress damage and could be safely used for a wide range of concentrations.

An enzyme-linked immunosorbent assay for the measurement of plasma flavonoids in mice fed apigenin-C-glycoside

BACKGROUND

In the Chenopodiaceae family, the apigenin flavonoids vitexin-2-O-xyloside (VOX) and vitexin-2-O-rhamnoside (VOR) are important chemopreventive components. To investigate their bioavailability in in vivo animal studies an enzyme-linked immunosorbent assay (ELISA) method has been developed.

RESULTS

The ELISA was based on polyclonal antibodies elicited in mice by injecting, as an immunogen, 4',6″-O-biapigenin (hinokiflavone, HF) conjugated to bovine serum albumin (BSA-HF). A second immunogen was synthesised by coupling an equimolar mixture of VOX and VOR to BSA (BSA-F1). The BSA-HF elicited a significant antibody response, due to 17 HF hapten groups, coupled to each BSA molecule, whereas BSA-F1 provided a very low antigenicity in respect to control animals. Antiserum raised against BSA-HF showed an antibody titre of 1:1600. Antibodies were found to be specific for the flavonols. Our results show that VOX and its metabolic products reached the concentration of 3.42 ± 0.72 µg mL⁻¹ in plasma of VOX fed animals, at the net of the control value.

CONCLUSIONS

By using the ELISA, the concentration of apigenin flavonoids and their metabolites can be detected in VOX- or VOR-supplemented animals. The assay represents a useful tool for rapid screening to compare bioavailability of apigenin flavonoids in respect to control animals.

Vitexin-2-O-xyloside, raphasatin and (-)-epigallocatechin-3-gallate synergistically affect cell growth and apoptosis of colon cancer cells

Cytotoxic effects of the combination of the food components vitexin-2-O-xyloside (X), raphasatin (4-methylsulphanyl-3-butenyl isothiocyanates; G) and (-)-epigallocatechin-3-gallate (E) were investigated in colon (LoVo and CaCo-2) and breast (MDA-MB-231 and MCF-7) cancer cells. Breast cancer cells were more resistant than colon cells to X, G and E inhibition. On the contrary, marked synergistic effects among X, G and E on cell growth were found in both colon cancer cells. Further analysis revealed a G0/G1 arrest of the phase cell progression and apoptosis, linked to modulation of Bax, Bcl2, caspase-9 and poly(ADP-ribose) polymerase as well as Reactive Oxygen Species (ROS) generation in both colon cancer cells, whereas apoptosis and ROS were not significantly detected in normal human lymphocytes. We conclude that the X, G and E mixture might act by mitochondrial pathway activation of apoptosis, possibly elicited by ROS and the mixture may be effective in the chemoprevention of colon cancer.

Total extract of Beta vulgaris var. cicla seeds versus its purified phenolic components: antioxidant activities and antiproliferative effects against colon cancer cells

INTRODUCTION

Beta vulgaris var. cicla (BV) leaves contain chemopreventive compounds that have been investigated for new drug discovery. These compounds belong to the family of the apigenin-glycosides. Since the leaves are seasonal products containing high percentages of water, they are easily degradable during storage in fresh conditions. To be stored they require a drying process, consuming time and a large amount of energy. The extraction of apigenin-glycosides may also be conveniently performed from BV seeds, which represent a stable and year-long available biomass.

OBJECTIVES

The present report was undertaken to find a strategy of purification of bioactive flavonoids from BV seeds and test their ability to inhibit proliferation both on human colon cancer (RKO) cells and normal human fibroblasts (HF).

MATERIALS AND METHODS

The ethyl-acetate extract of BV seeds was fractionated on a Sephadex LH 20 column. A fraction of this extract, labeled as P4, exploited a marked antiproliferative activity on RKO cells. The components of P4 were purified on an RP₁₈ column chromatography and identified by HPLC-ESI-MS as 2,4,5-trihydroxybenzaldehyde, 2,5-dihydroxybenzaldehyde, vanillic acid, xylosylvitexin, glucopyranosyl-glucopyrasyl-rhamnetin and glucopyranosyl-xylosyl-rhamnetin. All of them were tested for cytostatic and cytotoxic activity on RKO and HF cells.

RESULTS

Xylosylvitexin exhibited the strongest antiproliferative activity on RKO cells, together with an enhancement of the apoptosis, an increase of cells in the G₁ phase and a reduction of cells in the S phase; on the contrary, the proliferation of HF was significantly stimulated.

CONCLUSION

Xylosylvitexin is the main and more efficient chemopreventive compound in BV seeds, but the natural cocktail of molecules, represented by P4 fraction, showed a better compromise between the antiproliferative activity on RKO cells and the enhancement of HF proliferation.

High-performance liquid chromatographic determination and pharmacokinetic study of vitexin-2″-O-rhamnoside in rat plasma after intravenous administration

A simple and specific high-performance liquid chromatographic (HPLC) method was developed for the pharmacokinetic study of vitexin-2''-O-rhamnoside (VOR) in rat after intravenous administration. The plasma samples were deproteinized with methanol after addition of internal standard (i.s.) hesperidin. HPLC analysis was performed on a Diamonsil ODS C18 analytical column, using acetonitrile-0.3% formic acid (20:80, v/v) as the mobile phase with UV detection at 270 nm. The standard curve was linear over the range of 0.1070-21.41 microg/mL in rat plasma. The average extraction recovery of VOR was 97.9+/-3.1%, and the relative standard deviations (R.S.D.s) of the intra- and inter-day precisions were no more than 7.4 and 8.5%, respectively. The lower limit of quantification (LLOQ) was 0.1070 microg/mL. The AUC of VOR was proportional to the dose after intravenous administration of 15, 30, 60 and 120 mg/kg body weight, and the elimination half-life (t1/2beta), systemic clearance (Cl) and apparent volume of distribution (Vc) were not significantly different among the four doses, and all the results indicated that the pharmacokinetics of VOR in rat obeyed first-order kinetics.