Inhibition of colon adenocarcinoma cell proliferation by flavonols is linked to a G2/M cell cycle block and reduction in cyclin D1 expression

Phytoconstituents, Antioxidant Activity and Cytotoxicity of Puya chilensis Mol. Extracts in Colon Cell Lines

Puya chilensis Mol. is a plant of the Bromeliaceae family, which has been traditionally used for medicinal applications in various digestive disorders. In this study, the phytoconstituents of six extracts of stems and flowers of P. chilensis were evaluated: phenols, flavonoids and total anthraquinones, as well as their antioxidant capacity and cytotoxicity in colon cancer cell lines HT-29. The data demonstrate that the ethyl acetate extract of P. chilensis flowers is cytotoxic in HT-29 cell lines (IC50 = 41.70 µg/mL) without causing toxic effects on healthy colon cells (IC50 > 100 µg/mL); also, this extract concentrated the highest amount of phenols (4.63 μg GAE/g d.e.), flavonoids (31.5 μg QE/g d.e.) and anthraquinones (12.60 μg EE/g d.e.) among all the extracts tested, which also correlated with its highlighted antioxidant capacity (DPPH∙IC50 = 4.15 mg/mL and FRAP 26.52 mM TEAC) over the other extracts. About thirty-five compounds were identified in this extract-the fatty acid esters present have been shown to have therapeutic effects on several types of cancer and could explain its antiproliferative activity.

The Spectrum of Pharmacological Actions of Syringetin and Its Natural Derivatives-A Summary Review

Mono- and poly-O-methylated flavonols and their glycoside derivatives belong to the group of natural plant polyphenols with a wide spectrum of pharmacological activities. These compounds are known for their antioxidant, antimutagenic, hepatoprotective, antidiabetic, and antilipogenic properties. Additionally, they inhibit carcinogenesis and cancer development. Having in mind the multidirectional biological activity of methylated flavonols, we would like to support further study on their health-promoting activities; in this review we summarized the most recent reports on syringetin and some of its structural analogues: laricitrin, ayanin, and isorhamnetin. Natural sources and biological potential of these substances were described based on the latest research papers.

Comparative analysis of the seasonal influence on polyphenolic content, antioxidant capacity, identification of bioactive constituents and hepatoprotective biomarkers by in silico docking analysis in Premna integrifolia L

The present study reports the effect of different seasons on polyphenol content and antioxidant potential of ethanolic, methanolic, ethyl acetate, and aqueous extracts of leaves, stems, and roots of Premna integrifolia. Ethyl acetate extract of leaves (EAEPI) collected in the rainy season showed potent antioxidant activity with highest total phenol (74.33 ± 2.26 µg/mg, gallic acid equivalent), and flavonoid (98.83 ± 0.26 µg/mg, rutin equivalent) content. Therefore, EAEPI extract was subjected to characterization by UHPLC-Q-TOF-MS/MS and GC-MS analysis for the identification of active constituents. UHPLC-Q-TOF-MS/MS analysis in + ve ion mode revealed the presence of eight polyphenolic compounds namely quercetin-3-D-xyloside, kaempferol-3,7-O-bis-alpha-L-rhamnoside, isorhamnetin-3-Oglucoside, luteolin-3',7-di-O-glucoside, eriodictyol-7-O-glucoside, syringetin-3-O-galactoside, petunidin-3-O-beta-glucopyranoside and vitexin-2″-O-rhamnoside. GC-MS analysis confirmed the presence of 26 compounds with six major compounds viz; citronellol, phytol acetate, campesterol, squalene, stigmasterol, and hexadecanoic acid. These compounds are reported for the first time from P. integrifolia except phytol and stigmasterol. Our previous study validates the hepatoprotective potential of P. integrifolia but there was no idea about the bioactive compound responsible for the activity. So, in present work, the major compounds identified in spectrometry analysis were subjected to in silico docking against an important liver enzyme alanine amino transaminase to confirm its hepatoprotective properties. Docking analysis validates the presence of two hepatoprotective lead compounds stigmasterol, and campesterol, which satisfy the drug-likeness criteria with good absorption, distribution, metabolism, and toxicity properties. Thus, present work gives a clear insight about the influence of season on the total polyphenolic constituent in different plant parts of P. integrifolia, their antioxidant potential and preclinical evaluation of hepatoprotective lead compounds.

Antiproliferative Effect and Mediation of Apoptosis in Human Hepatoma HepG2 Cells Induced by Djulis Husk and Its Bioactive Compounds

The antiproliferative effect and mediation of apoptosis in human hepatoma HepG2 cells induced by djulis husk and its bioactive compounds was investigated. The ethanolic extracts of djulis husk (EEDH) at 50, 250, and 500 µg/mL induced remarkable cytotoxicity on HepG2 cells. By flow cytometry analysis, EEDH slowed down the cell cycle at the Sub-G0 phase after 24 h of incubation. Moreover, all EEDH treatment induced an apoptotic response in HepG2 cells. EEDH-induced apoptosis was associated with the attenuation of mitochondrial transmembrane potentials (ΔΨ_m), an increase in Bax/Bcl-2 ratio, activation of caspase-3, and poly(ADP-ribose)polymerase (PARP) cleavage, as well as an increase in reactive oxygen species (ROS) generation. According to the HPLC-DAD and HPLC-MS/MS analysis, quercetin and kaempferol derivatives and another sixteen compounds were present in EEDH. Quercetin and kaempferol at 25–150 μM showed antiproliferative action and induced apoptosis on HepG2 cells, which may in part account for the anticancer activity of EEDH. Overall, EEDH may be a potent chemopreventive agent due to apoptosis in HepG2 cells.

Antiproliferative and cytotoxic effects of grape pomace and grape seed extracts on colorectal cancer cell lines

Grape pomace is the source of bioactive compounds (anthocyanins, flavonols, flavan-3-ols, and stilbenes) which exhibit antiproliferative actions on cell cultures. We have investigated the antitumoral effects of grape pomace and grape seed extracts on colon cancer cells (Caco-2, HT-29) and fibroblasts. Crude extracts prepared from white and red pomace, and grape seeds, reduced the viability and proliferation of Caco-2. HT-29 cells were resistant to these actions. Purified extracts were then prepared from the same sources and compared with the LDH test; again, all three extracts were active and purified extract from grape seed was the most potent and specific on Caco-2 cells. HT-29 cells were more sensitive to these purified extracts. The biological activity resided almost exclusively in the flavonol and flavan-3-ols subfractions, rather than the anthocyanin subfraction. Preliminary results on the mechanisms involved in these effects revealed downregulation of Myc gene expression in HT-29 and upregulation of Ptg2 in Caco-2 cells.

The inhibitory effect of Manuka honey on human colon cancer HCT-116 and LoVo cell growth. Part 1: the suppression of cell proliferation, promotion of apoptosis and arrest of the cell cycle

Numerous investigations have been made on plant phenolic compounds and cancer prevention in recent decades. Manuka honey (MH) represents a good source of phenolic compounds such as luteolin, kaempferol, quercetin, gallic acid and syringic acid. The aim of this work was to evaluate the chemopreventive effects of MH on human colon cancer HCT-116 and LoVo cells. Both cells were exposed to different concentrations of MH (0-20 mg mL-1 for HCT-116 cells and 0-50 mg mL-1 for LoVo cells) for 48 h to measure apoptosis and cell cycle arrest as well as apoptosis and cell cycle regulatory gene and protein expression. MH exhibited profound inhibitory effects on cellular growth by reducing the proliferation ability, inducing apoptosis and arresting the cell cycle in a dose-dependent manner. Interestingly, MH treatment in non-malignant cells did not exert any significant toxicity at similar concentrations. The apoptosis event was associated with the increasing expression of p53, cleaved-PARP and caspase-3 and with the activation of both intrinsic (caspase-9) and extrinsic (caspase-8) apoptotic pathways. MH induced cell cycle arrest in the S phase in HCT-116 cells, and simultaneously, in LoVo cells, it occurred in the G2/M phase through the modulation of cell cycle regulator genes (cyclin D1, cyclin E, CDK2, CDK4, p21, p27 and Rb). The expression of p-Akt was suppressed while the expression of p-p38MAPK, p-Erk1/2 and endoplasmic stress markers (ATF6 and XBP1) was increased for apoptosis induction. Overall, these findings indicate that MH could be a promising preventive or curative food therapy for colon cancer.

Potential antiproliferative activity of polyphenol metabolites against human breast cancer cells and their urine excretion pattern in healthy subjects following acute intake of a polyphenol-rich juice of grumixama (Eugenia brasiliensis Lam.)

The bioavailability and metabolism of anthocyanins and ellagitannins following acute intake of grumixama fruit, native Brazilian cherry, by humans, and its in vitro antiproliferative activity against breast cancer cells (MDA-MB-231) were investigated. A single dose of grumixama juice was administered to healthy women (n = 10) and polyphenol metabolites were analyzed in urine and plasma samples collected over 24 h. The majority of the metabolites circulating and excreted in urine were phenolic acids and urolithin conjugates, the gut microbiota catabolites of both classes of polyphenols, respectively. According to pharmacokinetic parameters, the subjects were divided into two distinct groups, high and low urinary metabolite excretors. The pool of polyphenol metabolites found in urine samples showed a significant inhibition of cell proliferation and G2/M cell cycle arrest in MDA-MB-231 cells. Our findings demonstrate the large interindividual variability concerning the polyphenol metabolism, which possibly could reflect in health promotion.

Alcoholic Beverage Consumption and Chronic Diseases

Epidemiological and experimental studies have consistently linked alcoholic beverage consumption with the development of several chronic disorders, such as cancer, cardiovascular diseases, diabetes mellitus and obesity. The impact of drinking is usually dose-dependent, and light to moderate drinking tends to lower risks of certain diseases, while heavy drinking tends to increase the risks. Besides, other factors such as drinking frequency, genetic susceptibility, smoking, diet, and hormone status can modify the association. The amount of ethanol in alcoholic beverages is the determining factor in most cases, and beverage types could also make an influence. This review summarizes recent studies on alcoholic beverage consumption and several chronic diseases, trying to assess the effects of different drinking patterns, beverage types, interaction with other risk factors, and provide mechanistic explanations.

Myricetin: A Dietary Molecule with Diverse Biological Activities

Myricetin is a common plant-derived flavonoid and is well recognised for its nutraceuticals value. It is one of the key ingredients of various foods and beverages. The compound exhibits a wide range of activities that include strong anti-oxidant, anticancer, antidiabetic and anti-inflammatory activities. It displays several activities that are related to the central nervous system and numerous studies have suggested that the compound may be beneficial to protect against diseases such as Parkinson's and Alzheimer's. The use of myricetin as a preserving agent to extend the shelf life of foods containing oils and fats is attributed to the compound's ability to protect lipids against oxidation. A detailed search of existing literature revealed that there is currently no comprehensive review available on this important molecule. Hence, the present work includes the history, synthesis, pharmaceutical applications and toxicity studies of myricetin. This report also highlights structure-activity relationships and mechanisms of action for various biological activities.

Syringetin suppresses osteoclastogenesis mediated by osteoblasts in human lung adenocarcinoma

Bone metastasis in lung cancer results in an unfavorable outcome for patients by not only impairing the quality of life, yet also increasing the cancer-related death rates. In the present study, we discuss a novel treatment strategy that may benefit these patients. Human CD14+ monocytes treated with macrophage-colony stimulating factor (M-CSF)/receptor activator of nuclear factor κB ligand (RANKL) differentiated into osteoclasts, whereas syringetin (SGN), a flavonoid derivative found in both grapes and wine, suppressed the osteoclastogenesis in vitro in a dose-dependent manner. In addition, SGN inhibited osteoclast formation induced by human lung adenocarcinoma A549 and CL1-5 cells. The associated signaling transduction pathway in osteoclastogenesis and SGN inhibition was found to be via the AKT/mammalian target of rapamycin (mTOR) signaling pathway. Blocking AKT and mTOR by respective inhibitors significantly decreased lung adenocarcinoma-mediated osteoclastogenesis. Moreover, SGN regulated the lung adenocarcinoma-mediated interaction between osteoblasts and osteoclasts by suppressing the stimulatory effect of lung adenocarcinoma on M-CSF and RANKL production in osteoblasts, and reversing the inhibitory effect of the lung adenocarcinoma on OPG production in osteoblasts. The present study has two novel findings. It is the first to illustrate lung adenocarcinoma-mediated interaction between osteoblasts and osteoclasts, leading to osteolytic bone metastasis. It also reveals that SGN, a flavonoid derivative, directly inhibits osteoclastogenesis and reverses lung adenocarcinoma-mediated osteoclastogenesis. In conclusion, the present study suggests that SGN, a natural compound, prevents and treats bone metastasis in patients with lung cancer.

Methyl jasmonate foliar application to Tempranillo vineyard improved grape and wine phenolic content

The importance of phenolic compounds for grape and wine quality has drawn attention to studying different practices with the aim of increasing their content. Cluster application of elicitors is a viticultural practice that has shown promising results in recent years. However, cluster application requires a previous defoliation, which is time-consuming and expensive. In the present study, methyl jasmonate was foliar applied to Tempranillo grapevines in order to study its effect on grape and wine phenolic composition. Methyl jasmonate foliar application increased anthocyanin and stilbene content in both grape and wine, besides enhancing wine flavonol content. This treatment induced the synthesis of 3-O-glucosides of petunidin and peonidin and trans-p-coumaroyl derivatives of cyanidin and peonidin. For stilbenes, trans-piceid content was considerably increased in both grape and wine. The results obtained suggest that methyl jasmonate foliar application could be a simple and accessible practice to enhance grape and wine quality.