Anticancer activity of flavonol and flavan-3-ol rich extracts from Croton celtidifolius latex

Potential Antitumor Effect of Functional Yogurts Formulated with Prebiotics from Cereals and a Consortium of Probiotic Bacteria

Various types of functional yogurts were obtained from normalized milk (with normalized lipid content) and a standardized probiotic consortium of probiotic bacteria named ABY3. All the types of yogurts obtained contained prebiotics from black or red rice; malt of barley, rye, wheat; or wheat bran. The physico-chemical analyses of all the functionalized products obtained showed that all of them met the quality standard for yogurt products. However, the sensorial analyses showed that the products obtained from black and red rice were of very good quality. The biological analyses indicated that all the types of products contained live probiotic bacteria, but wheat bran and red rice could increase their numbers. Tests performed on tumor cell line Caco-2 with corresponding postbiotics revealed cytotoxicity greater than 30% after 48 h of exposure in the case of yogurts obtained from milk with 0.8% lipid content and red rice or blond malt of barley. In the case of yogurts derived from milk with 2.5% lipid content, only the variants that contained blond malt of rye or wheat became cytotoxic against the Caco-2 cell line.

Tap the sap - investigation of latex-bearing plants in the search of potential anticancer biopharmaceuticals

Latex-bearing plants have been in the research spotlight for the past couple of decades. Since ancient times their extracts have been used in folk medicine to treat various illnesses. Currently they serve as promising candidates for cancer treatment. Up to date there have been several in vitro and in vivo studies related to the topic of cytotoxicity and anticancer activity of extracts from latex-bearing plants towards various cell types. The number of clinical studies still remains scarce, however, over the years the number is systematically increasing. To the best of our knowledge, the scientific community is still lacking in a recent review summarizing the research on the topic of cytotoxicity and anticancer activity of latex-bearing plant extracts. Therefore, the aim of this paper is to review the current knowledge on in vitro and in vivo studies, which focus on the cytotoxicity and anticancer activities of latex-bearing plants. The vast majority of the studies are in vitro, however, the interest in this topic has resulted in the substantial growth of the number of in vivo studies, leading to a promising number of plant species whose latex can potentially be tested in clinical trials. The paper is divided into sections, each of them focuses on specific latex-bearing plant family representatives and their potential anticancer activity, which in some instances is comparable to that induced by commonly used therapeutics currently available on the market. The cytotoxic effect of the plant's crude latex, its fractions or isolated compounds, is analyzed, along with a study of cell apoptosis, chromatin condensation, DNA damage, changes in gene regulation and morphology changes, which can be observed in cell post plant extract addition. The in vivo studies go beyond the molecular level by showing significant reduction of the tumor growth and volume in animal models. Additionally, we present data regarding plant-mediated biosynthesis of nanoparticles, which is regarded as a new branch in plant latex research. It is solely based on the green-synthesis approach, which presents an interesting alternative to chemical-based nanoparticle synthesis. We have analyzed the cytotoxic effect of these particles on cells. Data regarding the cytotoxicity of such particles raises their potential to be involved in the design of novel cancer therapies, which further underlines the significance of latex-bearing plants in biotechnology. Throughout the course of this review, we concluded that plant latex is a rich source of many compounds, which can be further investigated and applied in the design of anticancer pharmaceuticals. The molecules, to which this cytotoxic effect can be attributed, include alkaloids, flavonoids, tannins, terpenoids, proteases, nucleases and many novel compounds, which still remain to be characterized. They have been studied extensively in both in vitro and in vivo studies, which provide an excellent starting point for their rapid transfer to clinical studies in the near future. The comprehensive study of molecules from latex-bearing plants can result in finding a promising alternative to several pharmaceuticals on the market and help unravel the molecular mode of action of latex-based preparations.

Automatic Identification of Players in the Flavonoid Biosynthesis with Application on the Biomedicinal Plant Croton tiglium

The flavonoid biosynthesis is a well-characterised model system for specialised metabolism and transcriptional regulation in plants. Flavonoids have numerous biological functions such as UV protection and pollinator attraction, but also biotechnological potential. Here, we present Knowledge-based Identification of Pathway Enzymes (KIPEs) as an automatic approach for the identification of players in the flavonoid biosynthesis. KIPEs combines comprehensive sequence similarity analyses with the inspection of functionally relevant amino acid residues and domains in subjected peptide sequences. Comprehensive sequence sets of flavonoid biosynthesis enzymes and knowledge about functionally relevant amino acids were collected. As a proof of concept, KIPEs was applied to investigate the flavonoid biosynthesis of the medicinal plant Croton tiglium on the basis of a transcriptome assembly. Enzyme candidates for all steps in the biosynthesis network were identified and matched to previous reports of corresponding metabolites in Croton species.

Anil Kumar N, Sharopov F, Ramírez-Alarcón K, Ruiz-Ortega A, Abdulmajid Ayatollahi S, Valere Tsouh Fokou P, Kobarfard F, Amiruddin Zakaria Z, Iriti M, Taheri Y, Martorell M, Sureda A, N. Setzer W, Durazzo A, Lucarini M, Santini A, Capasso R, Adrian Ostrander E, -ur-Rahman A, Iqbal Choudhary M, C. Cho W, Sharifi-Rad J. Antidiabetic Potential of Medicinal Plants and Their Active Components

Diabetes mellitus is one of the major health problems in the world, the incidence and associated mortality are increasing. Inadequate regulation of the blood sugar imposes serious consequences for health. Conventional antidiabetic drugs are effective, however, also with unavoidable side effects. On the other hand, medicinal plants may act as an alternative source of antidiabetic agents. Examples of medicinal plants with antidiabetic potential are described, with focuses on preclinical and clinical studies. The beneficial potential of each plant matrix is given by the combined and concerted action of their profile of biologically active compounds.

Himatanthus drasticus (Apocynaceae) latex reduces oxidative stress and modulates CD4+, CD8+, FoxP3+ and HSP-60+ expressions in Sarcoma 180-bearing mice

ETHNOPHARMACOLOGICAL RELEVANCE

In Brazil, latex of Himatanthus drasticus is used to treat inflammation, wound healing and cancer. The present study evaluated the antitumoral potential of H. drasticus latex (HdCL) in Sarcoma 180-bearing mice (S180).

MATERIALS AND METHODS

HdCL was obtained in Crato-CE, Brazil. Qualitative phytochemicals assays, nuclear magnetic resonance (NMR) and microbiological analyzes were performed. Swiss mice were divided into six groups, according to tumor forms: 1) ascitic model, GI (Control; 0.9% saline), GII (S₁₈₀asc) and GIII (S₁₈₀asc/HdCL/14 days); 2) solid model, GIV (Control; 0.9% saline), GV (S₁₈₀sol) and GVI (S₁₈₀sol/HdCL/10 days). HdCL and 0.9% saline were administered at 0.2 mL, SID, by gavage, for 10 or 14 days. For ascitic model, 0.5 mL of S180 suspension (4×10⁶ cells/mL) was inoculated intraperitoneally and for solid model, cells were inoculated subcutaneously (25 µL) on the right hind paw of mice. Blood samples were collected for hematological and oxidative stress evaluation. Thickness, volume and weight of paws were measured in solid model. After euthanasia, spleen, liver and kidney were collected in order to assess the relative organ weight. Tissue fragments of paws and popliteal lymph nodes (PLN) were analyzed by H&E and CD4⁺, CD8⁺, HSP-60⁺ and Foxp3⁺ immunohistochemistry.

RESULTS

HdCL presented milky aspect and pinkish supernatant. Phenols, flavonols, flavanones, free steroids and cinnamoyl derivatives of lupeol, α-amyrin and β-amyrin were detected at the phytochemistry analysis. HdCL did not alter the relative weight of organs, hematological parameters and volume of ascitic fluid recovered. In solid model, HdCL reduced (P < 0.05) paw volume, but did not altered thickness, paw weight and histological parameters. S180sol induced necrosis, metastasis and destruction of bone, cartilage and muscles. Bleeding, vessel congestion and oncocytes were observed in PLN. In paw, HdCL did not alter FoxP3⁺ and HSP-60⁺ expressions but reduced the CD4⁺ and CD8⁺ expressions, while at PLN, HdCL reduced the expressions of all markers. HdCL decreased (P < 0.05) serum levels of malondialdehyde in ascitic model.

CONCLUSIONS

Treatment with HdCL reduced oxidative damage and modulated the expressions of CD4⁺, CD8⁺, FoxP3⁺and HSP-60⁺ in S180 solid tumor model, which can be associated to the presence of triterpenes, such as α-amyrin, β-amyrin and lupeol cinnamate. Present data emphasizes the importance of immune system in cancer and highlights the evaluation of the pharmacological properties of plants used by population as phytoterapics.

Biological screening of extracts from leaf and stem bark of Croton floribundus Spreng. (Euphorbiaceae)

Abstract This work describes the preliminary evaluation of cytotoxic, antimicrobial, molluscicidal, antioxidant and anticholinesterase activities from leaf (LECF) and stem bark alcoholic extracts (BECF) of the species Croton floribundus Spreng. (Euphorbiaceae), popularly known as capixingui or tapixingui. BECF presented significant toxicity (LC50 = 89.6 μg/ml) in the Artemia salina Leach, 1819 (Crustacea: Branchiopoda) bioassay, whereas LECF did not show activity (LC50 > 1000 μg/ml). From DPPH method, the values of IC50 for the LECF and BECF were 61.2 μg/ml and 62.2 μg/ml, respectively, showing that C. floribundus has an expressive antioxidant activity. Antimicrobial susceptibility was evaluated by microdilution technique and only BECF was active against Staphylococcus aureus (MIC = 39.6 μg/ml). The extracts did not present molluscicidal activity against snail Biomphalaria glabrata Say, 1818 (Gastropoda: Planorbidae). Both extracts revealed the presence of several components with an inhibiting capacity of acetylcholinesterase enzyme on the bioautographic assay. C. floribundus showed to be a promising species considering that it exhibited good biological activity in the most assays performed.

Antitumor activity of Brazilian red propolis fractions against Hep-2 cancer cell line

Continuous increases in the rates of tumor diseases have highlighted the need for identification of novel and inexpensive antitumor agents from natural sources. In this study, we investigated the effects of enriched fraction from hydroalcoholic Brazilian red propolis extract against Hep-2 cancer cell line. Initially 201 fractions were arranged in 12 groups according to their chromatographic characteristics (A-L). After an in vitro cell viability screening, J and L were further selected as promising enriched fractions for this study. The chemical characterization was performed and Biochanin A, Formononetin, and Liquiritigenin compounds were quantified. Through MTT viability assay and morphological changes observed by Giemsa and DAPI staining, the results showed that red propolis inhibited cancer cells growth. Flow cytometry results indicated effects that were partly mediated through programmed cell death as confirmed by externalization of phosphatidylserine, DNA cleaved assay, increase at SUB G1-G0 phase in cell cycle analysis and loss of mitochondrial membrane potential. In conclusion, our results demonstrated that red propolis enriched fractions promoted apoptotic effects in human cancer cells through the mechanisms involving mitochondrial perturbation. Therefore, red propolis fractions contain candidate agents for adjuvant cancer treatment, which further studies should elucidate the comprehensive mechanistic pathways.

Involvement of three putative glucosyltransferases from the UGT72 family in flavonol glucoside/rhamnoside biosynthesis in Lotus japonicus seeds

Flavonols are one of the largest groups of flavonoids that confer benefits for the health of plants and animals. Flavonol glycosides are the predominant flavonoids present in the model legume Lotus japonicus. The molecular mechanisms underlying the biosynthesis of flavonol glycosides as yet remain unknown in L. japonicus. In the present study, we identified a total of 188 UDP-glycosyltransferases (UGTs) in L. japonicus by genome-wide searching. Notably, 12 UGTs from the UGT72 family were distributed widely among L. japonicus chromosomes, expressed in all tissues, and showed different docking scores in an in silico bioinformatics docking analysis. Further enzymatic assays showed that five recombinant UGTs (UGT72AD1, UGT72AF1, UGT72AH1, UGT72V3, and UGT72Z2) exhibit activity toward flavonol, flavone, and isoflavone aglycones. In particular, UGT72AD1, UGT72AH1, and UGT72Z2 are flavonol-specific UGTs with different kinetic properties. In addition, the overexpression of UGT72AD1 and UGT72Z2 led to increased accumulation of flavonol rhamnosides in L. japonicus and Arabidopsis thaliana. Moreover, the increase of kaempferol 3-O-rhamnoside-7-O-rhamnoside in transgenic A. thaliana inhibited root growth as compared with the wild-type control. These results highlight the significance of the UGT72 family in flavonol glycosylation and the role of flavonol rhamnosides in plant growth.

Antiproliferative activity of flavonoids from Croton sphaerogynus Baill. (Euphorbiaceae)

Croton sphaerogynus is a shrub from the Atlantic Rain Forest in southeastern Brazil. A lyophilized crude EtOH extract from leaves of C. sphaerogynus, obtained by maceration at room temperature (seven days), was suspended in methanol and partitioned with hexane. The purified MeOH phase was fractionated over Sephadex LH-20 yielding five fractions (F1–F5) containing flavonoids, as characterized by HPLC-DAD and HPLC-MS analyses. The antiproliferative activity of the crude EtOH extract, MeOH and hexane phases, and fractions F1–F5 was evaluated on in vitro cell lines NCI-H460 (nonsmall cell lung), MCF-7 (breast cancer), and U251 (glioma). The MeOH phase showed activity (mean log GI₅₀ 0.54) higher than the hexane phase and EtOH extract (mean log GI₅₀ 1.13 and 1.19, resp.). F1 exhibited activity against NCI-H460 (nonsmall cell lung) (GI₅₀ 1.2 μg/mL), which could be accounted for the presence of flavonoids and/or diterpenes. F4 showed moderate activity (mean log GI₅₀ 1.05), while F5 showed weak activity (mean log GI₅₀ 1.36). It is suggested that the antiproliferative activity of the crude EtOH extract and MeOH phase is accounted for a synergistic combination of flavonoids and diterpenes.

Oncogenes and tumor suppressors regulate glutamine metabolism in cancer cells

Several hallmarks of cancer cells are their display of metabolic changes and enhanced proliferation. Highly proliferating cells utilize glutamine as a source of nitrogen, and therefore, one of the commonly seen metabolic changes is increased glutaminolysis, or glutamine catabolism. In addition, glutamine is an important anaplerotic source by which cells support the pools of TCA cycle intermediates in Myc-expressing cancer cells. Glutamine is converted to aspartate, which forms oxaloacetate, malate, and pyruvate. These conversions increase the NADPH/NADP(+) ratio and maintain redox balance, which supports proliferation in K-ras-expressing cells. Therefore, glutamine is important for cancer cell proliferation and survival. On the other hand, glutamine stimulates the activation of the tumor suppressor p53, which induces apoptosis and tumor regression. The tumor suppressor SIRT4 inhibits glutamate dehydrogenase, which converts glutamic acid to α-ketoglutarate, an intermediate in the TCA cycle. Overall, the expression levels of oncogenes and tumor suppressors are critical to determine whether glutamine supports or suppresses proliferation and survival of cancer cells.