The Microalga Skeletonema marinoi Induces Apoptosis and DNA Damage in K562 Cell Line by Modulating NADPH Oxidase

Chronic myeloid leukemia (CML) is a myeloproliferative disease that activates multiple signaling pathways, causing cells to produce higher levels of reactive oxygen species (ROS). Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs) are a major generator of ROS in leukemia, and marine natural products have shown promising activities for the treatment of hematopoietic malignancies. In the present study, we investigated the effect of the marine microalga Skeletonema marinoi (S.M.), a ubiquitous diatom that forms massive blooms in the oceans, on the human leukemia cell line K562. The effects of S.M. extract on cell viability, production of ROS, nitric oxide (NO), and apoptosis were examined. In this preliminary work, S.M. was able to decrease cell viability (p < 0.05) and increase apoptosis levels (p < 0.05) in K562 cells after 48 h of treatment. In addition, the levels of NOX, NO, and malondialdehyde (MDA) were reduced in K562-treated cells (p < 0.05), whereas the levels of SOD, CAT, and GPx increased during treatment (p < 0.05). Finally, analyzing Bax and Bcl-2 expression, we found a significant increase in the proapoptotic protein Bax and a sustained decrease in the antiapoptotic protein Bcl-2 (p < 0.05) in the K562-treated cells.     

N′叔丁氨基羰基-N-(5-取代苯基-2-呋喃甲酰基)硫脲的合成及对白血病K562细胞增殖的影响

合成;N′-叔丁氨基羰基-N-（取代苯基呋喃甲酰基）硫脲;MTT法;白血病K562细胞     

N'-叔丁氨基羰基-N-(5-取代苯基-2-呋喃甲酰基)硫脲的合成及对白血病K562细胞增殖的影响

将活性基团5-取代苯基呋喃环和叔丁氨基引入酰基硫脲的分子骨架中,设计合成了8个未见文献报道的N'-叔丁氨基羰基-N-(5-取代苯基-2-呋喃甲酰基)硫脲类化合物(5a～5h),结构经元素分析、IR和 1H NMR等测试技术得到确证. 经MTT(溴化3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑)法观察,首次发现目标化合物对白血病K562细胞的增殖有明显的抑制作用. 在药物浓度为100×10-6 g/mL时,大部分目标化合物对白血病K562细胞生长的抑制率超过了70%,化合物5a对白血病K562细胞生长的抑制率达到77.14%. 其中,目标化合物5f和5h对白血病K562细胞有诱导作用,进一步的测试正在进行中.     

Protective Effects of Ginseng Leaf Extract Using Enzymatic Extraction Against Oxidative Damage of UVA-Irradiated Human Keratinocytes

UVA is responsible for numerous biological effects on the skin, including premature aging characterized by wrinkles, leathery texture, and mottled pigmentation. The objective of this study was evaluating the protective effect of ginseng leaf extract prepared by Ultraflo L on skin from photodamage. Anti-wrinkle effect of ginseng leaf extract with or without Ultraflo L treatment were tested on human keratinocyte cells (HaCaT) irradiated with ultraviolet (UV) A. Ginseng leaves inhibited ROS generation, GHS depletion, and expression of MMP-2 and MMP-9 induced by UVA irradiation. The glutathione (GSH) content of the cells was significantly increased by over 25 μg mL^?1 of Ultraflo-treated extract (UTGL) as well as by over 100 μg mL^?1 of nonenzyme-treated extract (NEGL) compared to control. UTGL and NEGL treatments significantly decreased expression of metalloproteinase (MMP)-2 and 9 compared with control, but inhibitory effects of two groups on expression of MMPs were not significantly different. Overall, ULtraflo L-treated ginseng leaves inhibited ROS generation, GHS depletion, and expression of MMP-2 and MMP-9 in UVA photodamaged HaCat cells. From these results, enzyme-treated ginseng leaf extract has advantages over untreated ginseng leaves and have potential as a skin protective ingredient against UVA-induced photodamage.     

In Vitro Activity of Organochalcogen Compounds: II. Cytotoxic Effect of 2-Aminobenzo[b]thiophenes Against K562 and HeLa Tumor Cell Lines

Russian Journal of General Chemistry - In vitro antitumor activity of some benzo[b]thiophenes with a tertiary amino group in the second position was studied against erythroleukemia (K562) and...     

Chemical Study on Protective Effect Against Hydroxyl‐induced DNA Damage and Antioxidant Mechanism of Myricitrin

Excessive reactive oxygen species (ROS) can oxidatively damage DNA to cause severe biological consequences. In the study, a natural flavonoid, myricitrin (myricetin‐3‐O‐α‐L‐rhamnopyranoside), was found to have a protective effect against hydroxyl‐induced DNA damage (IC₅₀ 159.86 ± 54.24 μg/mL). To investigate the mechanism, it was determined by various antioxidant assays. The results revealed that myricitrin could effectively scavenge ·OH, ·O₂^?, DPPH· (1,1‐diphenyl‐2‐picrylhydrazyl radical), and ABTS⁺· (2,2′‐Azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) radicals (IC₅₀ values were respectively 69.71 ± 5.93, 69.71 ± 5.93, 25.34 ± 2.14, and 1.71 ± 0.09 μg/mL), and bind Cu²⁺ (IC₅₀ 27.33 ± 2.36 μg/mL). Based on the mechanistic analysis, it can be concluded that: (i) myricitrin can effectively protect against hydroxyl‐induced DNA oxidative damage via ROS scavenging and deoxynucleotide radicals repairing approaches. Both approaches can be attributed to its antioxidant. From a structure‐activity relationship viewpoint, its antioxidant ability can be attributed to the ortho‐dihydroxyl moiety, and ultimately to the stability of its oxidized form ortho‐benzoquinone; (ii) its ROS scavenging is mediated via metal‐chelating, and direct radical‐scavenging which is through donating hydrogen (H·) and electron (e); and (iii) its protective effect against DNA oxidative damage may be primarily responsible for the pharmacological effects, and offers promise as a new therapeutic reagent for diseases from DNA oxidative damage.     

Microbiological and Antioxidant Activity of Phenolic Compounds in Olive Leaf Extract

According to many reports, phenolic compounds isolated from olive leaves have very good biological activities, especially antimicrobial. Presently, the resistance of microorganisms to antibiotics is greater than ever. Therefore, there are numerous recent papers about alternative solutions for inhibiting their influence on human health. Olive leaf is studied as an important source of antimicrobials with low cost and used in medicine. Numerous publications on involving green technologies for isolation of active compounds from olive leaves have appeared over the past few decades. The present review reports on current knowledge of the most isolated phenolic compounds from olive leaf extract as well as methods for their isolation and characterization. This paper uses recent research findings with a wide range of study models to describe the antimicrobial potential of phenolic compounds. It also describes the vast range of information about methods for determination of antimicrobial potential focusing on effects on different microbes. Additionally, it serves to highlight the role of olive leaf extract as an antioxidants and presents methods for determination of antioxidant potential. Furthermore, it provides an overview of presence of enzymes. The significance of olive leaves as industrial and agricultural waste is emphasized by means of explaining their availability, therapeutic and nutritional effects, and research conducted on this field.     

Anticancer Effects of the Corchorus olitorius Aqueous Extract and Its Bioactive Compounds on Human Cancer Cell Lines

Corchorus olitorius is a common, leafy vegetable locally known as “Saluyot” in the Philippines. Several studies have reported on its various pharmacological properties, such as antioxidant, anti-inflammatory, analgesic, and anticancer properties. However, little is known about its effects on angiogenesis. This study aimed to evaluate the anticancer properties, such as the antiproliferative, anti-angiogenic, and antitumor activities, of the C. olitorius aqueous extract (CO) and its bioactive compounds, chlorogenic acid (CGA) and isoquercetin (IQ), against human melanoma (A-375), gastric cancer (AGS), and pancreatic cancer (SUIT-2), using in vitro and in ovo biological assays. The detection and quantification of CGA and IQ in CO were achieved using LC-MS/MS analysis. The antiproliferative, anti-angiogenic, and antitumor activities of CO, CGA, and IQ against A-375, AGS, and SUIT-2 cancer cell lines were evaluated using MTT and CAM assays. CGA and IQ were confirmed to be present in CO. CO, CGA, and IQ significantly inhibited the proliferation of A-375, AGS, and SUIT-2 cancer cells in a dose-dependent manner after 48 h of treatment. Tumor angiogenesis (hemoglobin levels) of A-375 and AGS tumors was significantly inhibited by CO, CGA, IQ, and a CGA–IQ combination. The growth of implanted A-375 and AGS tumors was significantly reduced by CO, CGA, IQ, and a CGA–IQ combination, as measured in tumor weight. Our investigation provides new evidence to show that CO has promising anticancer effects on various types of human cancer cells. CO and its compounds are potential nutraceutical products that could be used for cancer treatment.     

单独和合用硒化壳聚糖与阿霉素对K562细胞作用的研究

应用MTT法和AO／EB荧光染色法观察单独和合用硒化壳聚糖与阿霉素对K562细胞株的影响,结果发现硒化壳聚糖和阿霉素均可有效地抑制K562细胞生长。且两药联合使用效果更佳。硒化壳聚糖可诱导细胞凋亡。两药合用诱导细胞凋亡效果更好。     

Antimutagenic,Cytoprotective and Antioxidant Properties of Ficus deltoidea Aqueous Extract In Vitro

Ficus deltoidea var. deltoidea is used as traditional medicine for diabetes, inflammation, and nociception. However, the antimutagenic potential and cytoprotective effects of this plant remain unknown. In this study, the mutagenic and antimutagenic activities of F. deltoidea aqueous extract (FDD) on both Salmonella typhimurium TA 98 and TA 100 strains were assessed using Salmonella mutagenicity assay (Ames test). Then, the cytoprotective potential of FDD on menadione-induced oxidative stress was determined in a V79 mouse lung fibroblast cell line. The ferric-reducing antioxidant power (FRAP) assay was conducted to evaluate FDD antioxidant capacity. Results showed that FDD (up to 50 mg/mL) did not exhibit a mutagenic effect on either TA 98 or TA 100 strains. Notably, FDD decreased the revertant colony count induced by 2-aminoanthracene in both strains in the presence of metabolic activation (p < 0.05). Additionally, pretreatment of FDD (50 and 100 µg/mL) demonstrated remarkable protection against menadione-induced oxidative stress in V79 cells significantly by decreasing superoxide anion level (p < 0.05). FDD at all concentrations tested (12.5–100 µg/mL) exhibited antioxidant power, suggesting the cytoprotective effect of FDD could be partly attributed to its antioxidant properties. This report highlights that F. deltoidea may provide a chemopreventive effect on mutagenic and oxidative stress inducers.     

Antitumor Activity and Mechanism of Action of the Antimicrobial Peptide AMP-17 on Human Leukemia K562 Cells

Cancer is one of the most common malignant diseases in the world. Hence, there is an urgent need to search for novel drugs with antitumor activity against cancer cells. AMP-17, a natural antimicrobial peptide derived from Musca domestica, has antimicrobial activity against Gram-positive bacteria, Gram-negative bacteria, and fungi. However, its antitumor activity and potential mechanism of action in cancer cells remain unclear. In this study, we focused on evaluating the in vitro antitumor activity and mechanism of AMP-17 on leukemic K562 cells. The results showed that AMP-17 exhibited anti-proliferative activity on K562 cells with an IC₅₀ value of 58.91 ± 3.57 μg/mL. The membrane integrity of K562 was disrupted and membrane permeability was increased after AMP-17 action. Further observation using SEM and TEM images showed that the cell structure of AMP-17-treated cells was disrupted, with depressions and pore-like breaks on the cell surface, and vacuolated vesicles in the cytoplasm. Furthermore, further mechanistic studies indicated that AMP-17 induced excessive production of reactive oxygen species and calcium ions release in K562 cells, which led to disturbance of mitochondrial membrane potential and blocked ATP synthesis, followed by activation of Caspase-3 to induce apoptosis. In conclusion, these results suggest that the antitumor activity of AMP-17 may be achieved by disrupting cell structure and inducing apoptosis. Therefore, AMP-17 is expected to be a novel potential agent candidate for leukemia treatment.     

Mutagenicity of Photodynamic Therapy as Compared to UVC and Ionizing Radiation in Human and Murine Lymphoblast Cell Lines

Abstract— The mutagenicity of photodynamic therapy (PDT) using red light and either Photofrin® (porfimer sodium) (PF) or aluminum phthalocyanine (AIPc) as the photosensitizer was determined at the thymidine kinase (TK) locus in the human lymphoblastic cell lines, TK6 and WTK1, and was compared to the mutagenicity of UVC and X-radia-tion in these cells as well as the mutagenicity of PDT in murine L5178Y lymphoblastic cell lines. Photodynamic therapy was found not to be mutagenic in TK6 cells, which possess an active p53 gene and which are relatively deficient in recombination and repair of DNA double-strand breaks. In contrast, PDT with either sensitizer was significantly mutagenic in WTK1 cells, which harbor an inactivating mutation in the p53 gene and are relatively efficient in recombination and double-strand break repair as compared to TK6 cells. The induced mutant frequency in WTK1 cells with PF as the photosensitizer was similar to that induced by UVC radiation but lower than that induced by X-radiation at equitoxic faiences/ doses. The mutant frequency induced by PDT in WTK1 cells with either photosensitizer was much lower than that induced in murine lymphoblasts at equitoxic fluences. The TK6 and WTK1 cells did not differ in their sensitivity to the cytotoxic effects of PDT, but the level of PDT-induced apoptosis was greater in TK6 than in WTK1 cells. These results indicate that the mutagenicity of PDT varies in different types of cells and may be related to the repair capabilities as well as the p53 status of the cells.     

硒化壳聚糖抗K562细胞的实验研究

用MTT法和AO/EB荧光染色法观察了硒化壳聚糖对K 562肿瘤细胞株生长的影响。结果发现,硒化壳聚糖可有效地抑制K 562细胞生长,并呈量效、时效关系。经硒化壳聚糖作用后的细胞可明显出现核固缩、碎裂等凋亡形态改变。硒化壳聚糖可诱导K 562细胞凋亡,抑制其生长。     

In Vitro Activity of Organochalcogen Compounds: I. Cytotoxic Effect of 4-(1,2,3-Thiadiazol-4-yl)furans Against K562 and HeLa Tumor Cell Lines

Russian Journal of General Chemistry - In vitro antitumor activity of some 4-(1,2,3-thiadiazol-4-yl)furans was studied against erythroleukemia (K562) and cervical carcinoma (HeLa) cell lines.     

Determination of Cobalt(II)-Hydrogen Peroxide-Induced DNA Oxidative Damage and Preventive Antioxidant Activity by CUPRAC Colorimetry

Abstract

The classical Fenton system composed of Fe(II) and H₂O₂ uses harsh oxidative conditions and cannot realistically simulate physiological oxidations which are less severe. Here, reactive oxygen species (ROS) were generated with a combination of CoSO₄ and H₂O₂ to provide milder conditions. DNA was used as a biologically meaningful probe for monitoring the oxidative conversion. Oxidative hazard on DNA was accomplished in ammonia/ammonium chloride buffer at 37?°C, and the Fenton reaction was stopped with trichloroacetic acid (TCA). A suitable aliquot of this solution was added to cupric ion reducing antioxidant capacity (CUPRAC) reaction mixture, and the absorbance at 450?nm was recorded. The oxidized species derived from DNA were CUPRAC-reactive while intact DNA was not. The protective effects of antioxidants (AOxs), known to have radical scavenging effects, were tested; green tea and a synthetic fetal bovine serum (FBS) were also successfully used as real ROS scavengers. Although the classical iron-based Fenton procedure applied in ethanol medium generated CUPRAC-responsive products, the proposed system was perfectly ethanol-tolerant, enabling the CUPRAC measurement of DNA oxidation products against an unaffected reagent blank. The protective effects of phenolic antioxidants, perfectly solubilized in ethanol, could also be measured.     

In Vitro Human Skin Penetration,Antioxidant and Antimicrobial Activity of Ethanol-Water Extract of Fireweed (Epilobium angustifolium L.)

Epilobium angustifolium L. is applied as an antiseptic agent in the treatment of skin diseases. However, there is a lack of information on human skin penetration of active ingredients with antioxidative potential. It seems crucial because bacterial infections of skin and subcutaneous tissue are common and partly depend on oxidative stress. Therefore, we evaluated in vitro human skin penetration of fireweed ethanol-water extracts (FEEs) by determining antioxidant activity of these extracts before and after penetration study using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and Folin–Ciocalteu methods. Microbiological tests of extracts were done. The qualitative and quantitative evaluation was performed using gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC-UV) methods. The in vitro human skin penetration using the Franz diffusion chamber was assessed. The high antioxidant activity of FEEs was found. Gallic acid (GA), chlorogenic acid (ChA), 3,4-dihydroxybenzoic acid (3,4-DHB), 4-hydroxybenzoic acid (4-HB), and caffeic acid (CA) were identified in the extracts. The antibacterial activities were found against Serratia lutea, S. marcescens, Bacillus subtilis, B. pseudomycoides, and B. thuringiensis and next Enterococcus faecalis, E. faecium, Streptococcus pneumoniae, Pseudomonas aeruginosa, and P. fluorescens strains. In vitro penetration studies showed the penetration of some phenolic acids and their accumulation in the skin. Our results confirm the importance of skin penetration studies to guarantee the efficacy of formulations containing E. angustifolium extracts.     

Photostability of Ferulic Acid and Its Antioxidant Activity Against Linoleic Acid Peroxidation

Ferulic acid (4‐hydroxy‐3‐methoxycinnamic acid), a phenyl‐propenoid derivative of cinnamic acid, can undergo photolysis upon UV irradiation. The photodegradation kinetics of ferulic acid were thus investigated in different systems. The micellar solutions did not protect the acid from photodegradation. On the contrary, they catalyzed its degradation at a variable extent depending on the surfactant structure. The photodegradation of ferulic acid in microemulsions was slower than in micelles and near to that in water. TiO₂, habitually employed as a physical sunscreen, showed photocatalytic action toward ferulic acid degradation especially at higher initial concentration of ferulic acid. The action of ferulic acid on the peroxidation of linoleic acid in micelles and microemulsions also was evaluated. When the ferulic acid is absent the peroxidation is continuous while when it is present an induction time of 40 minutes or higher was observed. Accordingly, it is likely that linoleic acid acts as photosensitizer for ferulic acid, and that in turn ferulic acid acts as an antioxidant for linoleic acid, reducing the rate of peroxidation.     

Autooxidative Activity of Chlorogenic Acid and Damage to DNA

The interaction of chlorogenic acid with double‐stranded calf thymus DNA was investigated in solution by cyclic voltammetry at a glassy carbon electrode (GCE). The different working electrodes were prepared by covering solution containing different components onto the surface of GCE. The autooxidative activity of chlorogenic acid and inducement of DNA damage were evaluated by employing the prepared working electrode in pH 5.0, 0.10 M acetate buffer solution with differential pulse voltammetry (DPV). The influences of temperature and metal ions (cupric ions) on the extent of DNA damage were examined. Chlorogenic acid possessed autooxidative activity and could induce DNA damage under certain conditions. The increasing temperature and existing cupric ions could enhance the autooxidative capability of chlorogenic acid and enlarge the extent of DNA damage. It was possible that the DNA damage induced by chlorogenic acid preferentially took place at guanosine‐containing segments, with the formation of 8‐oxo‐deoxyguanosine (a biomarker of DNA oxidative damage). A mechanism on the autooxidative activity of chlorogenic acid and inducing DNA damage was proposed.     

Lipophilic Enhance of Vitamin C Protective Activity Against Free－radical－induced Damage in vivo

A group of experimental rats under free radical damage are given various amounts of a lipophilic vitamin C(ascorbyl-6-1aurate, VC-12), and its parent compound, vitamin C, respectively. It has been found that the effects of 1.12 mmol/kg VC-12 on decreasing triglyceride(TG), total cholesterol(TC), low density lipopro-tein cholesterol (LDL-c) and lipid peroxide (LPO), and increasing high density lipoprotein cholesterol (HDL-c) and superoxide dismutase(SOD) are similar to those of 2.27 mmol/kg vitamin C. In addition, VC-12(1.12 mmol/kg) can increase the prostacycline(PGI2) and decrease the thromboxane(TXA2) even better than vita-min C(2. 27 mmol/kg). The above facts demonstrate that the antioxidative activity of VC-12 is higher than twice that of vitamin C. So, ascorbyl-6-1aurate may be a novel antioxidant drug against free radical damage.