Synthesis, Characterization, Antiproliferative Activity of Galloyl Derivatives and Investigation of Cytotoxic Properties in HepG2/C3A Cells.

BACKGROUND: Appropriate substituents in the galloyl group could lead to significant biological properties. OBJECTIVES: Novel galloyl-substituted compounds bearing 2-substituted-1, 3, 4-oxadiazol-5-yl, 5- substituted-1,2,4-triazol-3-yl, and carboxamide groups were synthesized and evaluated for their antiproliferative activity. Additionally, galloyl hydrazide (2) was evaluated by performing cytotoxicity, membrane integrity, cell cycle, and apoptosis assays in HepG2/C3A cells. METHODS: General procedure was used for the synthesis of galloyl-substituted (3-9, 11) and characterized by their spectroscopic data (1H and 13C NMR). The antiproliferative activity of all novel galloyl derivatives was evaluated against nine human tumors and one nontumoral cell line. Three response parameters (GI50, TGI, and LC50) were calculated. The cytotoxicity test was performed for the resazurin assay. The membrane integrity, cell cycle, and apoptosis assays were performed by flow cytometry. RESULTS: The substitution of the methoxy group of the galloyl ring system for a carboxamide group (3, 4, 5, and 6) produced compounds with moderate antitumoral activity, particularly 6, against six human cancer cell lines, K-562, PC-3, NCI-ADR/RES, OVCAR, 786-0 and NCI-H460, with GI50 values ≤ 9.45 µg/mL. Triazole derivatives 7 and 8 exhibited higher antitumoral activity toward OVCAR, MCF-7 and leukemia K-562 cell lines, exhibiting GI50 values less than 10 µg/mL. Compound 11 displayed significant activity against PC-3 (GI50 = 4.31 µg/mL), OVCAR (GI50 = 8.84 µg/mL) and K-562 (GI50 = 8.80 µg/mL) cell lines. Galloyl hydrazide (2) had cytotoxic activity in HepG2/C3A cells (IC50 = 153.7 µg/mL). In membrane permeability, cell count, cell cycle, and apoptosis assays, as determined using the IC50 of compound (2) in HepG2/C3A cells, increased membrane permeability, decreased cell count, altered cell cycle, and initial apoptosis was observed compared to the control group. CONCLUSION: Thus, our results showed for the first time the synthesis, antiproliferative activity, and cytotoxicity of galloyl-substituted compounds. Galloyl-substitution does not have a very strong synergistic effect in the inhibition of cancer cell proliferation compared with galloyl hydrazide (2). Compound 2 demonstrated promising activity in HepG2/C3A hepatocarcinoma cells.

Cashew apple (Anacardium occidentale L.) extract from a by-product of juice processing: assessment of its toxicity, antiproliferative and antimicrobial activities.

Cashew apple extract (CAE) is a product with intense yellow color obtained from residual fibers of juice processing. Although CAE is known to be rich in carotenoids and anacardic acids, the biological activities of this potential natural food colorant remain unexplored. The present study is the first to investigate the toxicity, antiproliferative and antimicrobial activities of the lyophilized CAE (L-CAE) and its encapsulated products, using maltodextrin (M-CAE) or cashew gum (CG-CAE) as carriers. In addition to their high carotenoid content, the phenolic contents in all materials was determined using UPLC-QTOF-MSE. The acute toxicity was performed using adult zebrafish (Danio rerio); antiproliferative activity was assessed using seven different human tumor cell lines [U-251 (glioblastoma), MCF-7 (breast, adenocarcinoma), NCI-ADR/RES (multidrug-resistant ovarian adenocarcinoma), NCI-H-460 (lung, large cell carcinoma), PC-3 (prostate, adenocarcinoma), OVCAR-3 (ovarian adenocarcinoma), and HT-29 (colon, adenocarcinoma)] and an immortalized human keratinocyte (HaCaT) while the antimicrobioal activity was evaluated on Staphylococcus aureus ATCC 25923, Listeria monocytogenes ATCC 19115, Escherichia coli ATCC 25922 and Salmonella Typhimurium ATCC 51812 microorganisms. Both lyophilized and encapsulated CAE samples did not exert acute toxicity against zebrafish neither antiproliferative effect against human tumor and non-tumor cell lines. Further, L-CAE showed potential antimicrobial activity against Listeria monocytogenes, which was confirmed using electron microscopy. The current findings demonstrated that CAE is a potential source of bioactive compounds to use as an additive in the food industry.

Antiproliferative activity and induction of apoptosis in PC-3 cells by the chalcone cardamonin from Campomanesia adamantium (Myrtaceae) in a bioactivity-guided study.

The Myrtaceae family is a common source of medicines used in the treatment of numerous diseases in South America. In Brazil, fruits of the Campomanesia species are widely used to make liqueurs, juices and sweets, whereas leaves are traditionally employed as a medicine for dysentery, stomach problems, diarrhea, cystitis and urethritis. Ethanol extracts of Campomanesia adamantium (Myrtaceae) leaves and fruits were evaluated against prostate cancer cells (PC-3). The compound (2E)-1-(2,4-dihydroxy-6-methoxyphenyl)-3-phenylprop-2-en-1-one, cardamonin) was isolated from ethanol extracts of C. adamantium leaves in a bioactivity-guided study and quantified by UPLC-MS/MS. In vitro studies showed that the isolated chalcone cardamonin inhibited prostate cancer cell proliferation and decreased the expression of NFkB1. Moreover, analysis by flow cytometry showed that this compound induced DNA fragmentation, suggesting an effect on apoptosis induction in the PC-3 cell line.