Quercetin: Antitumor activity and pharmacological manipulations for increased therapeutic gains

Hyaluronic Acid Nanohydrogel Loaded With Quercetin Alone or in Combination to a Macrolide Derivative of Rapamycin RAD001 (Everolimus) as a New Treatment for Hormone-Responsive Human Breast Cancer

The aim of this study is based on the evaluation of anticancer, anti-inflammatory activities, and cellular uptake of hyaluronic acid nanohydrogel of quercetin tested alone and in combination to a macrolide derivative of rapamycin RAD001 (everolimus) on hormone-responsive breast cancer cell line MCF-7. Biological investigations were focused on the receptor mediated cellular internalization of the nanohydrogel and its abilities to reduce secretion of several cytokines (IL-8, IL-6, IL-19), VEGF, and metalloproteases (MMP-2, MMP-9) under pro-inflammatory conditions. Nanohydrogel show a CD44 dependent endocytosis with evident time dependent cytoplasmatic accumulation with abilities to reduce secretion of all cytokines of ∼60% compared to untreated cells. Combination of formulated quercetin and everolimus leads to a synergistic cytotoxic effects with a Combination Index of 0.38. These results highlights the importance of synergistic effect of the hyaluronic acid nanohydrogel of quercetin with everolimus in the regulation of human breast cancer cell proliferation and emphasize the antitumor and anti-inflammatory properties of the nanocarrier. J. Cell. Physiol. 232: 2063-2074, 2017. © 2016 Wiley Periodicals, Inc.

Selective antitumoural action of pressurized mango leaf extracts against minimally and highly invasive breast cancer

Mango leaves, traditionally used to reduce inflammation, have been proved to possess antitumoral action against different types of breast cancer (hormone receptor-positive or negative).

Novel synthesised flavone derivatives provide significant insight into the structural features required for enhanced anti-proliferative activity

Synthesis and antiproliferative evaluation of a library of 76 methoxy and hydroxy flavones, and their 4-thio analogues showed that the novel thioflavones 15f and 16f exhibit 7–46 fold greater anti-proliferative potency than the natural flavone chrysin (2d).

Site-specific anticancer effects of dietary flavonoid quercetin

Food-derived flavonoid quercetin, widely distributed in onions, apples, and tea, is able to inhibit growth of various cancer cells indicating that this compound can be considered as a good candidate for anticancer therapy. Although the exact mechanism of this action is not thoroughly understood, behaving as antioxidant and/or prooxidant as well as modulating different intracellular signalling cascades may all play a certain role. Such inhibitory activity of quercetin has been shown to depend first of all on cell lines and cancer types; however, no comprehensive site-specific analysis of this effect has been published. In this review article, cytotoxicity constants of quercetin measured in various human malignant cell lines of different origin were compiled from literature and a clear cancer selective action was demonstrated. The most sensitive malignant sites for quercetin revealed to be cancers of blood, brain, lung, uterine, and salivary gland as well as melanoma whereas cytotoxic activity was higher in more aggressive cells compared to the slowly growing cells showing that the most harmful cells for the organism are probably targeted. More research is needed to overcome the issues of poor water solubility and relatively low bioavailability of quercetin as the major obstacles limiting its clinical use.

Cyclamen exerts cytotoxicity in solid tumor cell lines: a step toward new anticancer agents?

Cyclamen coum is a traditional medicinal plant in the Turkey. Its anticancer properties and whether cyclamen extract induces any cytotoxicity in solid cancer cell lines have not been thoroughly investigated previously. Therefore we examined cytotoxic effects on cervical cancer, HeLa, and non small cell lung cancer cell, H1299, lines. Cyclamen extract induced cellular death of both HeLa and H1299 cells in a dose dependent manner. We also analyzed the capacity of cyclamen extract to induce apoptosis by the TUNEL method. Here, we for the first time report that the extract of Cyclamen coum, an endemic plant for Turkey, can induce cytotoxicity via apoptosis in HeLa and H1299 cells. These results imply that cyclamen extract can be further analyzed to potentially find novel anticancer compounds.

Inhibitory effects of Tualang Honey on experimental breast cancer in rats: a preliminary study

The study was conducted to determine the effect of Malaysian jungle Tualang Honey (TH) on development of breast cancer induced by the carcinogen 7,12-dimethylbenz(α)anthracene (DMBA) in rats. Forty nulliparous female Sprague-Dawley rats were given 80 mg/kg DMBA then randomly divided into four groups: Group 1 served as a Control while Groups 2, 3 and 4 received 0.2, 1.0 or 2.0 g/kg bodyweight/day of TH, respectively, for 150 days. Results showed that breast cancers in the TH-treated groups had slower size increment and smaller mean tumor size (≤ 2 cm3) compared to Controls (≤ 8 cm3). The number of cancers developing in TH-treated groups was also significantly fewer (P<0.05). Histological grading showed majority of TH-treated group cancers to be of grade 1 and 2 compared to grade 3 in controls. There was an increasing trend of apoptotic index (AI) seen in TH-treated groups with increasing dosage of Tualang Honey, however, the mean AI values of all TH-treated groups were not significantly different from the Control value (p>0.05). In conclusion, Tualang Honey exerted positive modulation effects on DMBA-induced breast cancers in rats in this preliminary study.

Antiproliferative effects of honey and of its polyphenols: a review

Honey has been used since long time both in medical and domestic needs, but only recently the antioxidant property of it came to limelight. The fact that antioxidants have several preventative effects against different diseases, such as cancer, coronary diseases, inflammatory disorders, neurological degeneration, and aging, led to search for food rich in antioxidants. Chemoprevention uses various dietary agents rich in phytochemicals which serve as antioxidants. With increasing demand for antioxidant supply in the food, honey had gained vitality since it is rich in phenolic compounds and other antioxidants like ascorbic acid, amino acids, and proteins. Some simple and polyphenols found in honey, namely, caffeic acid (CA), caffeic acid phenyl esters (CAPE), Chrysin (CR), Galangin (GA), Quercetin (QU), Kaempferol (KP), Acacetin (AC), Pinocembrin (PC), Pinobanksin (PB), and Apigenin (AP), have evolved as promising pharmacological agents in treatment of cancer. In this review, we reviewed the antiproliferative and molecular mechanisms of honey and above-mentioned polyphenols in various cancer cell lines.

Mitochondria-cytochrome C-caspase-9 cascade mediates isorhamnetin-induced apoptosis

Isorhamnetin is a flavanoid present in plants of the Polygonaceae family and is also an immediate metabolite of quercetin in mammals. Since the plasma level of isorhamnetin is maintained longer than quercetin, isorhamnetin may be a key metabolite to mediate the anti-tumor effect of quercetin. In the present study, we investigated the apoptotic mechanism of isorhamnetin in Lewis lung cancer (LLC) cells in vitro and established its in vivo anti-cancer efficacy. In cell culture, isorhamnetin significantly increased DNA fragmentation, and TUNEL positive apoptotic bodies and sub-G(1) apoptotic population in time- and dose-dependent manners. Western blot analyses revealed increased cleavage of caspase-3, and caspase-9 and PARP and increased cytosolic cytochrome C in isorhamnetin-treated cells. These events were accompanied by a reduced mitochondrial potential. Apoptosis was blocked by a general caspase inhibitor or the specific inhibitor of caspase-3 or -9. These in vitro results support mitochondria-dependent caspase activation to mediate isorhamnetin-induced apoptosis. Furthermore, an animal study revealed for the first time that isorhamnetin given by i.p. injection at a dose that is at least one order of magnitude lower than quercetin significantly suppressed the weights of tumors excised from LLC bearing mice. The in vivo anti-tumor efficacy was accompanied by increased TUNEL-positive and cleaved-caspase-3-positive tumor cells. Our data therefore support isorhamnetin as an active anti-cancer metabolite of quercetin in part through caspase-mediated apoptosis.

Antitumor Activity of the Methanol Extract of Hypericum hookerianum Stem Against Ehrlich Ascites Carcinoma in Swiss Albino Mice

A large number of plants belonging to the Hypericum family are known to possess strong antitumor properties. The methanol extract of H. hookerianum Wight and Arnott stem (MEHH) exhibited potent in vitro cytotoxic activity against various cancerous cell lines. In the present study, the high performance liquid chromatography (HPLC) standardized MEHH was tested for in vivo antitumor properties against Ehrlich ascites carcinoma (EAC) tumor bearing mice at 100, 200, and 400 mg/kg body weight doses given orally once daily for 14 days. The results indicate that administration of the extract not only increased the survival of animals with ascites tumor, decreased the body weight induced by the tumor burden, and reduced packed cell volume and viable tissue cell count, but also altered many hematological parameters changed during tumor progression, indicating the potent antitumor nature of the extract. Among the three doses tested, the 200 mg/kg body weight dose was found to be the most potent.