The synthesis of phenylalanine-derived C5-substituted rhodanines and their activity against selected methicillin-resistant Staphylococcus aureus (MRSA) strains

A series of rhodanine compounds containing various substituents at the N3- and C5-positions were synthesized and their in vitro activity against a panel of clinically relevant MRSA strains was determined. The anti-MRSA activity of compounds 21 (MIC=3.9 μg/mL, MBC=7.8 μg/mL) and 22 (MIC=1.95 μg/mL, MBC=7.8 μg/mL) was significantly greater than that of the lead compounds, 1-3 and reference antibiotics penicillin G (MIC=31.25 μg/mL) and ciprofloxacin (MIC=7.8 μg/mL) and comparable to that of vancomycin (MIC=0.97 μg/mL). Compounds 21 and 22 were found to be bactericidal at only 2-4-fold higher than their MIC concentrations. In addition, their MIC values remained unchanged in the presence or absence of 10% serum. Overall, the results suggest that compounds 21 and 22 may be of potential use in the treatment of MRSA infections.     

Phenolic composition and antimicrobial and antioxidant activities of Leucoagaricus leucothites (Vittad.) Wasser

Leucoagaricus leucothites (Vittad.) Wasser is an edible macrofungus found limitedly in Turkey. The ethanolic extract of L. leucothites has shown strong antimicrobial activity against some foodborne and spoilage bacteria. Therefore, the phenolic composition of L. leucothites ethanolic extract was analyzed by using high-performance liquid chromatography. Catechin (288 mg/L) was found to be the major component in the extract. Antioxidant activity of the extract was evaluated by studying the scavenging ability of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals, and chelating ability of the extract was assessed in a ferrous ion assay. The scavenging effect on DPPH radicals was 71% at 10 mg/mL, whereas the chelating effect on ferrous ions was 82% at 15 mg/mL. The total contents of phenol (3.40 ± 0.5 mg/g), ascorbic acid (2.10 ± 0.3 mg/g), β-carotene (0.02 ± 0.0 mg/g), and lycopene (0.01 ± 0.0 mg/g) in the macrofungi ethanolic extract were also determined.     

Antioxidant levels and activities of selected seeds of malaysian tropical fruits

The aims of this study are to determine and compare the antioxidant levels and activities (i.e. primary and secondary) between selected seeds of Malaysian tropical fruits - guava (Psidium guajava), mango (Mangifera indica L.) and papaya (Carica papaya L.). Seeds are among byproducts from the processing of fruitsbased products. Instead of discarding seeds as waste, seeds with high potential as antioxidants could be utilised for commercial purposes. Accordingly, the selected seeds of Malaysian tropical fruits were tested in this study for total phenolic content (TPC), free radical scavenging activity by 1, 1- diphenyl-2-picrylhydrazyl (DPPH) assay and metal ion chelating effect by ferrous ion chelating (FIC) assay. Extraction of antioxidant compounds from sample was done with 70% ethanol. TPCs of the seeds were expressed as gallic acid equivalents (GAE) in mg per 100 g fresh seed weight. TPC assay showed that mango seeds had the highest TPC (i.e. 32 ± 0.001 mg GAE) followed by guava seeds (i.e. 20 ± 0.001 mg GAE) and papaya seeds (8 ± 0.003 mg GAE). For DPPH assay, IC50 data showed that mango seed extract scavenged 50% DPPH radicals at the lowest concentration (0.11 ± 0.01 mg/mL) followed by the positive control BHA (0.13 ± 0.01 mg/mL), guava seed extract (0.26 ± 0.01 mg/mL) and papaya seed extract (0.34 ± 0.01 mg/mL). Interestingly, all seed extracts showed higher free radical scavenging activities than BHA after sample concentration of 0.60 mg/mL. However, FIC assay indicated that metal ion chelating effects of all seed extracts were weaker than BHA suggesting that the fruit seeds are not sources of good metal ion chelators. Overall, present results suggest that TPC of the seeds show strong negative correlation with their primary antioxidant activity (r= -0.985, R2= 0.970), and not all compounds in extracts which could scavenge DPPH radicals are good metal ion chelators. Mango seeds relatively showed the highest antioxidant level and primary antioxidant activity followed by guava seeds and papaya seeds.     

Characterization of anticancer, antimicrobial, antioxidant properties and chemical compositions of Peperomia pellucida leaf extract

Peperomia pellucida leaf extract was characterized for its anticancer, antimicrobial, antioxidant activities, and chemical compositions. Anticancer activity of P. pellucida leaf extract was determined through Colorimetric MTT (tetrazolium) assay against human breast adenocarcinoma (MCF-7) cell line and the antimicrobial property of the plant extract was revealed by using two-fold broth micro-dilution method against 10 bacterial isolates. Antioxidant activity of the plant extract was then characterized using α, α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging method and the chemical compositions were screened and identified using gas chromatography-mass spectrometry (GC-MS). The results of present study indicated that P. pellucida leaf extract possessed anticancer activities with half maximal inhibitory concentration (IC(50)) of 10.4 ± 0.06 μg/ml. The minimum inhibitory concentration (MIC) values were ranged from 31.25 to 125 mg/l in which the plant extract was found to inhibit the growth of Edwardsiella tarda, Escherichia coli, Flavobacterium sp., Pseudomonas aeruginosa and Vibrio cholerae at 31.25 mg/l; Klebsiella sp., Aeromonas hydrophila and Vibrio alginolyticus at 62.5 mg/l; and it was able to control the growth of Salmonella sp. and Vibrio parahaemolyticus at 125 mg/l. At the concentration of 0.625 ppt, the plant extract was found to inhibit 30% of DPPH, free radical. Phytol (37.88%) was the major compound in the plant extract followed by 2-Naphthalenol, decahydro- (26.20%), Hexadecanoic acid, methyl ester (18.31%) and 9,12-Octadecadienoic acid (Z,Z)-, methyl ester (17.61%). Findings from this study indicated that methanol extract of P. pellucida leaf possessed vast potential as medicinal drug especially in breast cancer treatment.     

Identification of antioxidant and antimicrobial compounds of Lippia species by bioautography

The methanolic extracts of the leaves of Lippia species (L. pseudo-thea, L. hermannioides, L. alba, L. rubella, and L. sidoides) were tested for their antibacterial, antifungal, and antioxidant activity. Cytotoxicity was determined by using brine shrimp lethality bioassay. Phytochemical screening was also performed. The extracts showed a minimum inhibitory concentration (MIC) ranging from 78 to 5000 μg/mL for antibacterial activity against at least 2 species of bacteria, although none was active against Escherichia coli. Antifungal activity was found only for L. pseudo-thea (MIC, 625?μg/mL for Candida albicans) and L. sidoides (MIC, 625 μg/mL for both C. albicans and C. neoformans). The bioautography showed that flavonoids and coumarins are responsible for the antioxidant activity of the extracts and that the antimicrobial properties are due to flavonoids and terpenoids. The cytotoxic activity was stronger for L rubella extract. To our knowledge, this is the first report of the biological and chemical constituents of L. pseudo-thea, L. hermannioides, and L. rubella.     

In vitro antioxidant and hypoglycemic activities of Ethiopian spice blend Berbere

The metal chelating activity, antioxidant properties, and the effect on carbohydrate-hydrolyzing enzymes of Ethiopian spice blend Berbere have been investigated. Berbere contains a total amount of phenols corresponding to 71.3 mg chlorogenic acid equivalent per gram of extract and a total flavonoid content of 32.5 mg quercetin equivalent per gram of extract. An increase of the resistance towards forced oxidation was obtained when Berbere was added to sunflower oil. In order to evaluate the bioactivity of the non-polar constituents, an n-hexane extract was obtained from Berbere. The gas chromatography-mass spectrometry analysis revealed the presence of 19 fatty acids constituents (98.1% of the total oil content). Among them, linoleic acid was the major component (72.0% of the total lipids). The ethanolic extract had the highest ferric-reducing ability power (35.4 μM Fe(II)/g) and DPPH scavenging activity with a concentration giving 50% inhibition (IC(50)) value of 34.8 μg/ml. Moreover, this extract exhibited good hypoglycemic activity against α-amylase (IC(50) = 78.3 μg/ml). In conclusion, Ethiopian spice blend Berbere showed promising antioxidant and hypoglycemic activity via the inhibition of carbohydrate digestive enzymes. These activities may be of interest from functional point of view and for the revalorization of the spice blend in gastronomy also outside the African country.     

Anthocyanins in Red Jasmine Rice (Oryza sativa L.) Extracts and Efficacy on Inhibition of Herpes Simplex Virus,Free Radicals and Cancer Cell

Rice is one of the most important food crops in many countries, with nutritional value and health benefits. In this study, the ethanolic and aqueous extracts of red jasmine rice from Chiang Mai, Thailand were examined for their anthocyanins and phenolic contents. The antioxidant and antiviral activity against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), as well as anticancer activity, were investigated. The total anthocyanins content of 708.03 ± 11.56 mg Cy-3-glc equivalent/g extract, determined from the ethanolic extract, was higher than the aqueous extract. However, the aqueous extract showed the highest total phenolic compound of 81.91 ± 0.51 mg GAE/g extract. In addition, the ethanolic extract demonstrated higher antioxidant activity than aqueous extract using DPPH, ABTS, and FRAP assays by 28.91 ± 3.26 mg GAE/g extract, 189.45 ± 11.58 mg 24 TEAC/g extract, and 3292.46 ± 259.64 g FeSO₄/g extract, respectively. In the antiviral assay, it was found that the ethanolic extract of red jasmine rice could inhibit HSV-1 more effectively than HSV-2 when treated before, during, and after the viral attachment on Vero cells, with 50% effective doses of 227.53 ± 2.41, 189.59 ± 7.76, and 192.62 ± 2.40 µg/mL, respectively. The extract also demonstrated the highest reduction of HSV-1 particles at 4 h after treatment and the inhibition of HSV-1 replication. The ethanolic extract exhibited a higher toxicity level than the aqueous extract, as well as the potential to induce DNA fragmentation by intrinsic and extrinsic apoptosis pathways on the Caco-2 cells. These findings suggest that red jasmine rice extract demonstrates nutritional value and biological activity on HSV, free radicals, and cancer cell inhibition.     

Jacaranda cuspidifolia Mart. (Bignoniaceae) as an antibacterial agent

This study evaluated, in vitro, the antimicrobial activity of the hexane extract (JCHE), methanol extract (JCME), and chloroform fraction (JCCF) of bark from Jacaranda cuspidifolia Mart. (Family Bignoniaceae), a Brazilian medicinal plant, traditionally used as anti-syphilis and anti-gonorrhea treatment. The antimicrobial activity was evaluated using the disc diffusion method followed by the determination of minimum inhibitory concentration (MIC) values. JCHE was not active against the bacteria evaluated. JCME presented antibacterial activity against Streptococcus pyogenes, Staphylococcus aureus, and Neisseria gonorrhoeae with MIC values of 16.3 mg/mL, 9.1 mg/mL, and 25.2 mg/mL, respectively. JCCF was active against Staphylococcus epidermidis, S. aureus, Proteus mirabilis, Serratia marcescens, S. pyogenes, Enterobacter aerogenes, and N. gonorrhoeae with MIC values of 18.3 mg/mL, 9.3 mg/mL, 6.3 mg/mL, 6.1 mg/mL, 9.2 mg/mL, 6.2 mg/mL, and 25.2 mg/mL, respectively. Phytochemical analysis of JCME and JCCF gave positive results for saponins, coumarins, flavonoids, tannins, quinones, alkaloids, triterpenes, and steroids. Verbascoside was isolated and identified as a major peak in JCME and JCCF high-performance liquid chromatography fingerprints and might contribute to the observed antimicrobial activity.     

Hepatoprotective property of ethanolic and aqueous extracts of fluted pumpkin (Telfairia occidentalis) leaves against garlic-induced oxidative stress

Fluted pumpkin (Telfairia occidentalis) leaf is a darkish-green leafy vegetable popularly used in soup and in herbal preparations for the management of many diseases in Nigeria. In this study, the hepatoprotective property of ethanolic and aqueous extracts of T. occidentalis leaf (earlier confirmed to have a high level of antioxidant activity) against garlic induced-oxidative stress in rat hepatocytes was investigated. Oxidative stress was induced in Wistar strain albino rats by overdosing them with raw garlic (4%) for 14 days, and this caused a significant increase (P < .05) in serum alkaline phosphatase (ALP), glutamate oxaloacetate transaminase (GOT), and glutamate pyruvate transaminase (GPT), while there was no significant change (P > .05) in serum bilirubin, albumin, globulin, and total proteins. However, intubation of some of the rats fed raw garlic with 5 mg or 10 mg/0.5 mL of T. occidentalis leaf extract (ethanolic or aqueous) caused a significant decrease (P < .05) in serum ALP, GOT, and GPT when compared with rats fed raw garlic without intubation with the T. occidentalis leaf extract. Moreover, 10 mg/0.5 mL of extract was more effective than 5 mg/0.5 mL of extract, while the aqueous extracts appeared to be more effective than the ethanolic extracts in protecting hepatocytes. It could be inferred that both aqueous and ethanolic extracts of T. occidentalis leaf have hepatoprotective properties, although the aqueous extract is more effective than the ethanolic extract, which could be attributed to the higher antioxidant activity of the aqueous extract than the ethanolic extracts of T. occidentalis leaves.     

Influence of Elicitation and Drying Methods on Anti-Metabolic Syndrome,and Antimicrobial Properties of Extracts and Hydrolysates Obtained from Elicited Lovage (Levisticum officinale Koch)

This research aims to investigate the influence of elicitation and drying methods (natural, convection, microwave, and freeze-drying), with jasmonic acid (JA) and yeast extract (YE) on the biological activity of extracts and hydrolysates from lovage (Levisticum officinale Koch) leaves. The results indicate that the highest TPC was determined for hydrolysates obtained from JA-elicited microwave-dried lovage (24.96 mg/gDW). The highest ACE and lipase inhibitory activity was noted for PBS extract obtained from JA-elicited lovage after microwave drying (EC₅₀ = 0.16 and 0.12 mg/mL, respectively). Ethanolic extract from JA-elicited lovage after freeze-drying was characterized by the highest α-amylase inhibitory activity (EC₅₀ = 3.92 mg/mL) and the highest α-glucosidase inhibitory activity (EC₅₀ = 1.43 mg/mL) was noted for hydrolysates from control plants subjected to freeze-drying. The highest antimicrobial activity towards C. albicans yeasts was observed for microwave ethanolic extracts with minimal inhibition (MIC) and lethal (MLC) concentrations of 0.625 and 1.25 mg/mL, respectively.     

In vitro antioxidant and hypoglycemic activities of Ethiopian spice blend Berbere

The metal chelating activity, antioxidant properties, and the effect on carbohydrate-hydrolyzing enzymes of Ethiopian spice blend Berbere have been investigated. Berbere contains a total amount of phenols corresponding to 71.3 mg chlorogenic acid equivalent per gram of extract and a total flavonoid content of 32.5 mg quercetin equivalent per gram of extract. An increase of the resistance towards forced oxidation was obtained when Berbere was added to sunflower oil. In order to evaluate the bioactivity of the non-polar constituents, an n-hexane extract was obtained from Berbere. The gas chromatography–mass spectrometry analysis revealed the presence of 19 fatty acids constituents (98.1% of the total oil content). Among them, linoleic acid was the major component (72.0% of the total lipids). The ethanolic extract had the highest ferric-reducing ability power (35.4 μM Fe(II)/g) and DPPH scavenging activity with a concentration giving 50% inhibition (IC₅₀) value of 34.8 μg/ml. Moreover, this extract exhibited good hypoglycemic activity against α-amylase (IC₅₀ = 78.3 μg/ml). In conclusion, Ethiopian spice blend Berbere showed promising antioxidant and hypoglycemic activity via the inhibition of carbohydrate digestive enzymes. These activities may be of interest from functional point of view and for the revalorization of the spice blend in gastronomy also outside the African country.     

Modulation of doxorubicin-induced oxidative stress by a grape (Vitis vinifera L.) seed extract in normal and tumor cells

The major limitation of Doxorubicin (Dox) clinical use is the development of chronic and acute toxic side effects induced through the generation of reactive oxygen species. The present work was designated to investigate in vitro effects of a red grape-seed hydroethanolic extract Burgund Mare (BM), in associated administration with Dox (30 min before drug administration) in normal (Hfl-1) and tumor cell lines (HepG2 and Mls). The BM concentrations administered were below the level of the extract cytotoxiciy threshold (40 μg gallic acid [GA] Eq/mL; 37.5, 25.0, and 12.5 μg GA Eq/mL). The antioxidant capacity of the BM extract was assessed by measuring the acute toxicity at 24 h, lipid peroxides (LP), and protein oxidation. In normal cells, the product statistically decreased cytotoxicity and markedly inhibited LP and protein carbonyl (PC) formation, in a dose-dependent relationship. On contrary, in tumor cells, such treatment resulted in a reversed effect, cell death, malondialdehyde, and PC contents increasing with BM dose enhancement. BM extract treatment prior to subsequent administration of Dox afforded a differential protection against Dox-negative toxic side effects in normal cells without weakening (even enhancing) Dox's antitumor activity.     

Hypoglycemic effect of basil (Ocimum basilicum) aqueous extract is mediated through inhibition of α-glucosidase and α-amylase activities: an in vitro study

The present study investigated the in vitro hypoglycemic activity of basil (Ocimum basilicum) aqueous extract. Preliminary phytochemical screening of the extract revealed the presence of reducing sugars, cardiac glycosides, tannins, saponins, glycosides, flavonoids and steroids. The total polyphenols content (TPC), flavonoids content (FC), percentage diphenylpicrylhydrazyl (DPPH( · )) radical inhibition and total antioxidant status (TAS) were estimated. The FC was 41 ± 2.2 rutin/g dry extract, the TPC was 146 ± 5.26 mg catechin/g dry extract and the TAS was 5.12 ± 0.7 mmol/L. The %DPPH( · ) free radical inhibition was 60%, 54%, 49% and 43%, respectively, for different extract concentrations; 20, 18.2, 16.3 and 14.5 mg/ml, respectively. The extract elicited significant dose-dependent pattern against rat intestinal sucrase (RIS; IC(50) = 36.72 mg/ml), rat intestinal maltase (RIM; IC(50) = 21.31 mg/ml) and porcine pancreatic α-amylase (PPA; IC(50) = 42.50 mg/ml) inhibitory activities. The inhibition was greater against maltase compared with sucrase. These effects may be attributed to the high TPC and FC levels. The linear regression analysis revealed strong significant positive correlations between %DPPH( · ) radical inhibition and each of %RIS, %RIM and %PPA inhibiting activity. Also, strong significant positive correlations between %RIS and either %RIM or %PPA inhibition activity were observed. We concluded therefore that basil aqueous extract via antioxidant and possibly α-glucosidase and α-amylase inhibiting activities, offered positive benefits to control diabetes.     

Nutritive value, antioxidant and antimicrobial properties of Struchium sparganophora leaves

Struchium sparganophora leaf is a green leafy vegetable popularly used in soup preparations in processed and unprocessed forms in Nigeria. Fresh leaves of S. sparganophora were soaked overnight to remove its bitterness, before determination of the nutrient and antinutrient content, while sun-dried S. sparganophora leaves were extracted with rectified spirit. The antioxidant and antimicrobial properties of the extracts were subsequently determined. The result of the study revealed that the fresh leaf has high nutrient (protein, fat, crude fiber, and mineral) but low antinutrient (tannin and phytate) content. However, processing of the S. sparganophora leaf caused a significant decrease (P < .05) in both the nutrient and antinutrient contents. The ethanolic extract of the leaf contains alkaloids, tannin, saponins, phlobatannin, anthraquinone, and glycosides; furthermore, the extract has high antioxidant activity as typified by its high total phenol (5.4 g/100 g) content, reducing power (2.50 OD(700)), and free radical scavenging ability (65.2%). In addition, the extract (1.0 mg/mL) inhibited the growth of some pathogenic bacteria [Shigella dysenteriae (zone of inhibition 17.0 mm), Staphylococcus aureus (11.0 mm)] and fungi [Candida albicans (18.0 mm), Penicillium sp. (14.0 mm), Saccharomyces cerevisiae (15.0 mm)]. The inhibition of the bacterial and fungal growth was dose dependent. However, the same concentration of the extract did not inhibit the growth of Escherichia coli, Proteus sp., Pseudomonas aeruginosa, and Klebsiella sp., as well as the growth of the following fungi: Aspergillus fumigatus, Fusarium solani, and Aspergillus flavus. It could therefore be inferred that the leaf of S. sparganophora is promising both nutritionally and medicinally because of its high nutrient content, low antinutrient content, and arrays of pharmaceutically active phytochemicals with high levels of antioxidant and antimicrobial activity.     

Novel derivatives of methyl and ethyl 2-(4-oxo-8-aryl-2H-3,4,6,7-tetrahydroimidazo[2,1-c][1,2,4]triazin-3-yl)acetates from biologically active 1-aryl-2-hydrazinoimidazolines: synthesis, crystal structure and antiproliferative activity

The 1-aryl-2-hydrazinoimidazolines (2a-h) were directly obtained from appropriate 1-aryl-2-methylthioimidazolines (1a-h) by condensation reaction with hydrazine hydrate. Antimicrobial activities of two 1-aryl-2-hydrazinoimidazolines (2b and 2e) are presented. Their chemical structures were confirmed by IR, (1)H NMR, EI-MS and elemental analysis. The susceptibility of Gram-positive and Gram-negative bacterial strains, mould and yeast-like fungi strains to synthesized compounds and the MIC values against two reference strains of bacteria were determined. The strongest antibacterial activity for compound 2b in relation to reference Gram-negative Escherichia coli ATCC 25922 bacterial strain with minimal inhibitory concentration (MIC) value of 3.91micro g mL(-1) was found. Compound 2b showed superior activity (MIC) to ampicillin and comparable to chloramphenicol. A novel compound 2e was found to be effective against E. coli ATCC 25922 and Staphylococcus aureus ATCC 25923 at concentrations of 7.81micro g mL(-1) and 15.62micro g mL(-1), respectively. Compound 2e revealed antibacterial activity against E. coli ATCC 25922, superior to ampicillin and inferior to chloramphenicol. Against S. aureus ATCC 25923 strain tested, compound 2e demonstrated MIC value inferior to ampicillin and chloramphenicol. Moreover, the synthesis, crystal structure and antiproliferative activity of novel derivatives of methyl and ethyl 2-(4-oxo-8-aryl-2H-3,4,6,7-tetrahydroimidazo[2,1-c][1,2,4]triazin-3-yl)acetates (3a-f and 3g-j) are presented. These compounds were obtained from 1-aryl-2-hydrazinoimidazolines (2a-f) by the addition and cyclization reactions with fumaric acid esters. Molecular structures of these compounds were confirmed by elemental analysis, IR, (1)H NMR, (13)C NMR, EI-MS and by X-ray crystallography (for 3g). The tested imidazotriazines 3e, 3i and 3j exhibited anticancer activities towards the following cancer cells: LS180 (ECACC 87021202, human Caucasian colon adenocarcinoma cells), SiHa (ECACC 85060701, uterus cancer cells), and T47D (ECACC 85102201, human breast carcinoma cells). Compounds 3i and 3j having comparable GI values (above 50%) towards uterus cancer cell line (SiHa) at both examined concentrations (10micro g mL(-1) and 50micro g mL(-1)) were found to be the most effective against this cancer cell line; their GI factors were 53%, 51% and 62%, 55%, respectively, in both examined concentrations (10micro g mL(-1) and 50micro g mL(-1)). Furthermore, the distinctly marked lower cytotoxicity of tested imidazotriazines 3i and 3j against normal cell lines (HSF, human skin fibroblast cells and Vero African Green Monkey Kidney cells, GMK clone) and almost 2-times higher against the majority of cancer cell lines was confirmed.     

应用胞质分裂阻滞微核细胞组学法评价三溴乙酸的遗传毒性

[目的]应用胞质分裂阻滞微核细胞组学方法[cytokinesis-block micronucleus cytome（CBMN-cyt）assay]评价三溴乙酸的遗传毒性。[方法]以小鼠淋巴瘤（L5178Y）细胞为受试细胞,分为2组。一组暴露于终浓度分别为0（阴性对照）、7．81、15．62、31．25、62．50、125．00、175．00、250．00μg／mL的三溴乙酸溶液24h,采用噻唑蓝比色法（MTF法）检测细胞毒性,并计算半数致死浓度（medianlethaldose,LC50）;另一组暴露于终浓度分别为0（阴性对照）、31．25、62．50、125．00、175．00μg／mL的三溴乙酸溶液24h,并设阳性对照（终浓度为0．10μg／mL丝裂霉素C）,采用CBMN-cyt试验检测遗传毒性。[结果]与阴性对照组相比,31．25、62．50,125．00,175．00,250．00μg／mL三澳乙酸染毒组L5178Y细胞的存活率均较低,差异有统计学意义（P〈0．05）;且随着三溴乙酸染毒浓度的升高,L5178Y细胞的存活率呈明显的下降趋势（尸〈0．01）。三溴乙酸对该细胞的LC50为135．7μg／mL。与阴性对照比较,125．00、175．00μg／mL三溴乙酸染毒L5178Y细胞的微核率均升高,各浓度三溴乙酸染毒L5178Y细胞的核质桥率也均升高,差异有统计学意义（P〈0．05）;而各浓度三溴乙酸染毒L5178Y细胞的核芽率和核分裂指数（nucleusdividedindex,NDI）无显著改变。Pearson相关分析显示,随着三溴乙酸染毒剂量的升高,L5178Y细胞的微核率、核质桥率、核芽率均呈明显的上升趋势（P〈0．01）。[结论]三溴乙酸的遗传毒性,可能与染色体损伤、DNA错误修复、染色体重组或端粒末端融合损伤有关。     

Antibacterial Effects of Artemisia afra Leaf Crude Extract Against Some Selected Multi-Antibiotic Resistant Clinical Pathogens

BackgroundDue to improper use of antibiotics, some pathogenic bacteria that cause serious and deadly infections have become resistant to commonly used broad spectrum antibiotics. This antibiotic resistance has become major global healthcare problem. Therefore, there is an urgent need to develop novel antibacterial agents; hence, much attention has been made on medicinal plants such as Artemisia afra. Thus, the current study was aimed to evaluate the antibacterial activity of ethanolic, methanolic and n-hexane extracts of this plant leaf against four multi-antibiotic resistant clinical pathogens.MethodsCrude extracts from A.afra leaf were prepared using ethanol, methanol and n-hexane and the antibacterial effect of each extract was tested against Escherichia coli, Streptococcus pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus. In addition, minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were evaluated.ResultsAmong the crude extracts, the highest zone of inhibition (25.33±0.58mm) was recorded against E. coli when methanolic extract was applied. On the other hand, the lowest inhibition was exhibited when n-hexane extract was applied against S.aureus (5.67±1.56 mm). Concerning MIC values of the different extracts, varied results were obtained. MIC value of 6.25mg/mL was recorded when methanolic extract was applied against all clinical pathogens. Moreover, both methanolic and ethanolic extracts showed MBC value of 12.5mg/mL against the four clinical pathogens. However, the methanolic extract gave MBC value of 6.25mg/mL against E. coli.ConclusionFrom this study, it can be concluded that it is possible to develop and formulate of new, efficacious, less toxic and inexpensive herbal medicine from A.afra leaf extract that act against multi-antibiotic resistant clinical pathogens.     

Estimation of phytochemicals and antioxidant activity of underutilized fruits of Andaman Islands (India)

The present study aimed to determine the antioxidant activity and phytochemical contents in 10 underutilized fruits of Andaman Islands (India) namely Malpighia glabra L., Mangifera andamanica L., Morinda citrifolia L., Syzygium aqueum (Burm.f) Alst., Annona squamosa L., Averrhoa carambola L., Averrhoa bilimbi L., Dillenia indica L., Annona muricata L. and Ficus racemosa L. The antioxidant activity varied from 74.27% to 98.77%, and the methanol extract of M. glabra showed the highest antioxidant activity (98.77%; inhibitory concentration, IC(50) = 262.46 μg/ml). Methanol was found to be a better solvent than acetone and aqueous for estimating the antioxidant activity. M. glabra was found to be rich in phytochemicals viz. polyphenol (355.74 mg/100 g), anthocyanin (91.31 mg/100 g), carotenoids (109.16 mg/100 g), tannin (24.39 mg/100 g) and ascorbic acid (394.23 mg/100 g). Carbohydrate content was estimated to be highest in M. glabra (548 mg/100 g). Phenols, tannins, anthocyanins and carotenoids contents showed positive correlation (r2 = 0.846, r2 = 0.864, r2 = 0.915 and r2 = 0.806, respectively) with antioxidant activity. The information generated in present study will be useful for bioprospecting of underutilized fruits of Andaman Islands.     

Phenolic content and antioxidant and antiacetylcholinesterase properties of honeys from different floral origins

Twenty-three honey samples of Apis mellifera L. forged on plants from northeastern Brazil were analyzed to determine total phenolic content, flavonoid content, antioxidant activity, and antiacetylcholinesterase activity. The total phenol content was determined by using the Folin-Ciocalteu method, and the flavonoid content was analyzed using by the aluminum chloride method. The antioxidant activity was evaluated using the diphenyl-1-picrylhydrazyl-scavenging test. Honey samples from Lippia sidoides Cham. (mean [±standard deviation] 50% inhibitory concentration [IC(50)], 4.20±1.07?mg/mL) and Myracrodruon urundeuva Fr. All. (IC(50), 28.27±1.41?mg/mL) showed better antioxidant activity and presented higher total phenol values (108.50±3.52?mg gallic acid equivalents/100?g for L. sidoides and 68.55±1.01?mg gallic acid equivalents/100?g for M. urundeuva). Several honey samples had relevant results on antiacetylcholinesterase assay. The biological activity of honeys is related to their floral origin, and medicinal plants constitute a useful resource for the generation of functional foods.