[en] Published in summary form only

No abstract available

[en] The current in vitro study was designed to investigate the anti-inflammatory, cytotoxic and antioxidant activities of boesenbergin A (BA), a chalcone derivative of known structure isolated from Boesenbergia rotunda. Human hepatocellular carcinoma (HepG2), colon adenocarcinoma (HT-29), non-small cell lung cancer (A549), prostate adenocarcinoma (PC3), and normal hepatic cells (WRL-68) were used to evaluate the cytotoxicity of BA using the MTT assay. The antioxidant activity of BA was assessed by the ORAC assay and compared to quercetin as a standard reference antioxidant. ORAC results are reported as the equivalent concentration of Trolox that produces the same level of antioxidant activity as the sample tested at 20 µg/mL. The toxic effect of BA on different cell types, reported as IC_5_0, yielded 20.22 ± 3.15, 10.69 ± 2.64, 20.31 ± 1.34, 94.10 ± 1.19, and 9.324 ± 0.24 µg/mL for A549, PC3, HepG2, HT-29, and WRL-68, respectively. BA displayed considerable antioxidant activity, when the results of ORAC assay were reported as Trolox equivalents. BA (20 µg/mL) and quercetin (5 µg/mL) were equivalent to a Trolox concentration of 11.91 ± 0.23 and 160.32 ± 2.75 µM, respectively. Moreover, the anti-inflammatory activity of BA was significant at 12.5 to 50 µg/mL and without any significant cytotoxicity for the murine macrophage cell line RAW 264.7 at 50 µg/mL. The significant biological activities observed in this study indicated that BA may be one of the agents responsible for the reported biological activities of B. rotunda crude extract

[en] Indonesia is a country known for its useful natural resources, especially for a health maintenance and treatment of diseases. Some of the plants that can be used as traditional medicine are kratom (Mitragyna speciosa Korth) and Senggani (Melastoma malabathrium L.). The purpose of this research was to determine the total phenolic content, total flavonoids content, and total tannins content in the ethanol extract of kratom stems and flowers using the UV-Vis spectrophotometric method. The comparator used in determining the phenolic content was gallic acid, for the flavonoid content was quercetin, and for the tannin content was tannic acid. The results of this study showed that the total phenolic content in the kratom stem extract was 23.59 mg/gram of extract, while in the senggani flower was 43.97 mg/gram of extract. The total flavonoid content in the kratom stem extract was 10.65 mg/gram of extract, while the senggani flower was 11.26 mg/gram of extract. Lastly, the total tannin content in the kratom stem extract was 17.99 mg/gram of extract, while in the senggani flower it was 13.74 mg/g extract. (paper)

[en] In the present study, we introduced the nitrogenated heterocycles and fluorine atoms into the 2,5′-dibromo-4,5,2′-trihydroxyl diphenylmethanone (LM49), a bromophenol analog previously reported for its strong antioxidant ability involving in the Keap1–Nrf2 pathway. Twenty-seven fluorophenols 6a–6g, 8a–8k, 10a–10g, and 12a–12b were prepared, evaluated for their antioxidant activity in EA.hy926 cells, and investigated their interacted approach and probable mode of action with key protein Keap1 by molecular docking. Fluorophenols 6f, 8d, 8f, 8h, and 8i with EC₅₀ values ranging from 0.82 to 6.71 µM were found to be more active compared with the standard control quercetin (EC₅₀ = 18 µM). Among them, compound 8h with an EC₅₀ value of 0.82 µM showed the identical activity to lead compound LM49 (EC₅₀ = 0.7 µM). Moreover, the preferable water solubility and forming salt possibility of 8h contribute to its druggability. Further molecular docking of the optimal compound 8h with key protein Keap1 indicated that 8h stably bonded to the receptor protein by the formation of hydrogen bonds, the conjugated six-membered ring was close to the key residue Arg-415 attached to the Nrf2 on Keap1-Kelch, affecting its properties, and the change leaded to the dissociation of Nrf2 from the junction with Keap1-Kelch into the nucleus exerting its antioxidant protective effect. This study introduced a class of fluorophenols containing nitrogenated heterocycles for the development of novel Keap1-Nrf2 protein–protein interaction (PPI) inhibitors. Keap1-Kelch is suggested the most potential target protein for such class of halophenols.

[en] Emerging evidence has indicated that transforming growth factor-beta 1 (TGF-β1) induces the epithelial–mesenchymal transition (EMT) in cancer cells, thus promoting their motility and invasiveness. Quercetin, a member of the polyphenolic flavonoid family, has been reported to display anticancer activity against a broad range of cancer cell types. Indeed, numerous studies have shown the cancer preventive effects and molecular mechanisms of quercetin in vitro using diverse cell model systems. However, the potential effect of quercetin on EMT remains unclear. In this study, we identified a unique function of quercetin in inhibiting the EMT process induced by TGF-β1. In particular, quercetin rescued the morphological changes and EMT-like phenotypes in TGF-β1-activated SW480 cells, and this inhibition of TGF-β1-induced EMT was mediated via the suppression of Twist1 expression. In addition, quercetin strongly suppressed TGF-β1-induced invasion of SW480 cells. Thus, quercetin may be considered a novel therapeutic agent for the treatment of patients with refractory cancer and for the prevention of the metastatic cascade initiated by EMT.

[en] We have shown that quercetin forms 2:1 complexes (M:Q = 2:1) with Fe²⁺, Fe³⁺, Cu²⁺, and Pb²⁺. Fe³⁺ can oxidize quercetin to quercetin quinone in the pH region of 2 to 4, whose characteristic absorption peak appears at ca. 300 nm. Above pH 5, Fe³⁺ forms a complex with quercetin with an absorption peak at 425 nm. It is also possible to electrochemically produce quercetin quinone. In strongly acidic solutions, none of studied ions can form a complex with quercetin. The slow quercetin oxidation by hydrogen peroxide is accelerated in the presence of Fe³⁺. Polyphenols having a benzo-γ-pyrone structure constitute a family known as flavonoids. Flavonoids are widely distributed among higher plants. By virtue of astringent taste, they are believed to serve as defensive molecules, protecting plant tissues from herbivorous attack. Depending on a multiplicity of phenolic groups, flavonoids are classified into several groups, such as flavones, flavonols (quercetin, kaempferol), flavanones (naringenin), and flavanes (catechin), displaying functional diversities and complexities. Flavonoids have been best known as antioxidants and radical scavengers. While this beneficial effect mainly comes from their ability to accept free radicals, complexation properties with metal ions have also been recognized to contribute to the total biological activity

No abstract available

[en] The cyanidin-3-O-xylosylrutinoside (cya-3-O-xylrut) is one of the most abundant anthocyanin, which is responsible for the red, purple, and blue colors of most fruits and vegetable, in the fruit of Schisandra chinensis Baillon and raspberries. Especially the cya-3- O-xylrut is a major anthocyanin accounting for about 94% in the fruits of S. chinensis, which is a unique source of highly pure cya-3-O-xylrut, and exhibits high antioxidant activity. Previously, we reported that the red color of the S. chinensis fruit extract dramatically disappeared in a dose-dependent manner of gamma irradiation. The color of S. chinensis was effectively removed at 2 kGy of gamma irradiation, even at 1 kGy resulted in a 50% reduction. Interestingly, the destruction of cya-3-O-xylrut by gamma irradiation led to generate flavonoids such as quercetin and unknown compounds. Quercetin, a typical flavonoltype flavonoid, is one of the most prominent dietary antioxidants. It is ubiquitously present in fruits and vegetables. Quercetin exhibits various biological activities such as anti-oxidative, anti-inflammatory, anti-allergic, vasodilating, and anti-cancer effects. In the present study our purpose is to develop a promising tool for bio-conversion of organic compounds by combination treatment of H₂O₂ and gamma ray

[en] We sought to evaluate the transdermal permeation potential of quercetin-loaded ethosomes. Quercetinloaded ethosomes were prepared and characterized with regard to particle size, loading efficiency, stability, and in vitro skin permeation. The optimized formulation of ethosomes was confirmed using 2% egg phosphatidylcholine and hydrated 20% ethanol. After quercetin was applied using this formulation, the stability of the ethosomes was determined when loaded with up to 0.04% quercetin. We observed that loading efficiency was improved with increasing concentrations of quercetin. Ethosomes loaded with 0.04% quercetin showed both the greatest loading efficiency (63.9%±6.0%) and an optimal size range (132±32 nm). Ethosomes loaded with quercetin were superior in skin permeation ability (29.5±7.0 µg/cm"2) compared to either ethanolic solution or liposomes. Therefore, we concluded that quercetin-loaded ethosomes increased the skin delivery of quercetin. Our results suggest that quercetin-loaded ethosomes may enhance the effect of cosmetic materials