Acid Free Radical Research Articles

Phytochemical analysis and evaluation of the antioxidant and antimicrobial properties of selected herbs cultivated in Greece

In this study, we investigated the bioactivity of extracts of Lamiaceae and Asteraceae family plants after sequential extraction with petroleum ether (PE), diethyl ether (DE) and methanol (ME). The phytochemical analysis showed that the major components identified in the PE extracts were volatile compounds. DE extracts were rich in aglycone flavonoids and terpene derivatives and in ME extracts phenolic acids and flavonoids glycosides, were found. ME extracts presented stronger scavenging activity towards 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3- ethylbenzthiazoline)-6-sulfonic acid (ABTS+) free radicals than PE and DE extracts. Fourier-Transform Infrared Spectroscopy (FTIR) combined with principal component analysis (PCA) revealed that exposure of the target cells of oral pathogens to the ME extracts caused major alterations of cellular components. Lemon balm and chamomile ME extracts reduced biofilm formation of Streptococcus mutans and Streptococcus sobrinus strains. This study highlights that ME extracts may be good candidates as plant-derived antioxidants and antimicrobial agents.

Volatile composition, antioxidant activity, and antioxidant components in saffron cultivated in Turkey

ABSTRACTOven dried cut stigmas of Crocus sativus L. cultivated in Eskisehir and Safranbolu regions of Turkey were subjected to micro distillation to extract steam volatiles. They were then analysed by Gas Chromatography and Gas Chromatography/Mass Spectrometry, simultaneously. The colour compounds were extracted with 80% methanol and analysed by High Pressure Liquid Chromatography HPLC/DAD and HPLC/MS/MS. The activities of the extracts of saffron against 2,2ʹ-azinobis-3-ethylbenzothiazoline-6-sulphonic acid free radical (ABTS●+) were investigated using on-line (HPLC-ABTS●+) and off-line methods. Safranal (62.1 and 49.3%) and α-isophorone (10.0 and 16.3%) were found as the characteristic aromatic volatiles in the Eskisehir and Safranbolu samples, respectively. Crude saffron extracts showed high total antioxidant activity against ABTS●+ radical.

Phenolics from Mikania micrantha and Their Antioxidant Activity.

A phytochemical study on the aerial parts of Mikania micrantha led to the isolation of two new phenolic compounds, benzyl 5-O-β-d-glucopyranosyl-2,5-dihydroxybenzoate (1) and (7S,8R)-threo-dihydroxydehydrodiconiferyl alcohol 9-acetate (2), together with twelve known compounds, benzyl 2-O-β-d-glucopyranosyl-2,6-dihydroxybenzoate (3), 4-allyl-2,6-dimethoxyphenol glucoside (4), (+)-isolariciresinol (5), icariol A2 (6), 9,10-dihydroxythymol (7), 8,9,10-trihydroxythymol (8), caffeic acid (9), p-coumaric acid (10), ethyl protocatechuate (11), procatechuic aldehyde (12), 4-hydroxybenzoic acid (13), and hydroquinone (14). Their structures were elucidated on the basis of extensive spectroscopic analysis. Except 8 and 9, all the other compounds were isolated from this plant species for the first time. The antioxidant activity of those isolated compounds were evaluated using three different assays. Compounds 1, 2, 3, 9, 10, 13, and 14 demonstrated significant 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) free radical cation scavenging activity ranging from SC50 0.31 to 4.86 µM, which were more potent than l-ascorbic acid (SC50 = 10.48 µM). Compounds 5, 9, 11, and 12 exhibited more potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (SC50 = 16.24–21.67 µM) than l-ascorbic acid (39.48 µM). Moreover, the ferric reducing antioxidant power (FRAP) of compounds 2, 5, 9, and 11 were discovered to be also comparable to or even more potent than l-ascorbic acid.

SCREENING OF BIOPROTECTIVE PROPERTIES OF VARIOUS PLANT EXTRACTS AND GAS CHROMATOGRAPHY-MASS SPECTROMETRY PROFILING OF ADENANTHERA PAVONINA STEM EXTRACT

Objective: The search for various phytotherapeutic compounds is on rise due to a complex multifactorial phenomenon called drug resistance. The present study investigates the cytotoxic, antioxidant, and antiproliferative potential of methanolic extracts of Clitorea ternatea, Averrhoa bilimbi, Phyllanthus acidus, Tecoma stans, Curcuma aromatica, Anethum graveolens, Adhatoda vasica, Markhamia lutea, Spathodea companulata, and Adenanthera pavonina.Methods: The plant parts were extracted with methanol and screened for 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3- ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging abilities. The cytotoxic activity of the extracts was investigated on HeLa and HCT116 cells through 3-(4,5-dimethylthiazol2yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, and cell cycle was analyzed by flow cytometry to determine the antiproliferative activity of the extracts. The stem extract of A. pavonina was further subjected to gas chromatography-mass spectrometry (GC-MS) analysis for purification of the compounds of interest. A two-way ANOVA was done to estimate the effect of the extract between samples remembered at p<0.05 level.Results: Among all the studied samples, the extract of A. pavonina (stem) showed significant scavenging activity of 70.23% and 76.32% of scavenging compared to 74.58 % and 81.13% of that of reference standard in ABTS and DPPH assay, respectively. GC-MS analysis of the extract revealed the presence of 17 phytocompounds. MTT assay revealed that this extract (SB19) had promising cytotoxic activity against the two cancer cell lines, HCT116 and HeLa with inhibitory concentration 50% IC50 values of 25.86±0.21 μg/ml and 39.89±0.11 μg/ml, respectively. The extract treatment caused significant arrest in G2M phase of cell cycle.Conclusion: A. pavonina (stem) extract displayed significant antioxidant and antiproliferative activity and can be considered as a potential candidate drug for anticancer studies.

Reaction Kinetics of Phenolic Antioxidants toward Photoinduced Pyranine Free Radicals in Biological Models.

8-Hydroxy-1,3,6-pyrenetrisulfonic acid (pyranine, PyOH) free radicals were induced by laser excitation at visible wavelengths (470 nm). The photochemical process involves photoelectron ejection from PyO- to produce PyO• and PyO•- with maxima absorption at 450 and 510 nm, respectively. The kinetic rate constants for phenolic antioxidants with PyO•, determined by nanosecond time-resolved spectroscopy, were largely reliant on the ionic strength depending on the antioxidant phenol/phenolate dissociation constant. Further, the apparent rate constant measured in the presence of Triton X100 micelles was influenced by the antioxidant partition between the micelle and the dispersant aqueous media but limited by its exit rates from the micelle. Similarly, the rate reaction between ascorbic acid and PyO• was markedly affected by the presence of human serum albumin responding to the dynamic of the ascorbic acid binding to the protein.

Antioxidant cosmetotextiles: Cotton coating with nanoparticles containing vitamin E

Abstract In the present study, we coated cotton fabrics with protein-based nanoparticles containing vitamin E (α-tocopherol) by the pad-cure method. Scanning electron microscopy, Fourier transform infra-red spectroscopy, and air permeability analysis of coated samples confirmed the fixation of the nanoparticles onto the fabric’s surface. The antioxidant activity of the coated fabrics was evaluated by 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals reduction. Samples coated with nanoparticles containing the highest amount of encapsulated vitamin E (20% of the oil phase) showed the highest antioxidant activity. The protein-based coating was maintained for at least 10 washing cycles, demonstrating the reliability of the pad-cure method for the fixation of nanoparticles onto cotton surfaces. A methodology for nanoparticles release from the coated surfaces and their transfer to other substrates was demonstrated by the simple crock meter rubbing in the presence of sweat and protease. A high amount of material can be transferred and released to other substrates, such as textiles and skin, through the synergistic effect of sweat/protease and abrasion. An array of cosmetic and medical applications are possible with the developed coating and release methodology in which vitamin E would impart vital benefits as skin protection, anti-ageing product, or skin moisturizer.

Fractionation, amino acid profiles, antimicrobial and free radical scavenging activities of Citrullus lanatus seed protein

In the present study, a modified Osborne fractionation method was followed to isolate albumin (Calb), globulin (Cglo), prolamin (Cpro) and glutelin (Cglu) successively from seeds of Citrullus lanatus (watermelon). This research work was undertaken to investigate the antimicrobial and antioxidant activities of isolated protein fractions of C. lanatus seed. Amino acid composition and molecular weight distribution were determined to establish their relationship with antimicrobial and antioxidant activity. Among all the fractions, Cpro was found to be most effective against A. baumannii followed by Calb and Cglo. The results showed that growth of inhibition of these protein fractions differ significantly from each other (p ≤ 0.05). In view of antioxidant potential, Cglo exhibited strongest antioxidant capacity while Cglu showed weakest antioxidant potential.

Preliminary characterization of a Moroccan honey with a predominance of Bupleurum spinosum pollen

Honey with Bupleurum spinosum (zandaz) as a main pollen source has not been the subject of previous detailed study. Therefore, twelve Moroccan samples of this honey were subjected to melissopalynological, physicochemical and microbiological quality characterization, as well as antioxidant activity assessment. From a quality point of view, almost all samples were within the limits established by Codex Alimentarius, and/or the European legislation. All samples presented predominance of B. spinosum pollen (more than 48%). Relatively high levels of trehalose (1.3–4.0 g/100 g) and melezitose (1.5–2.8 g/100 g) were detected. Those sugars, not common in monofloral honeys, could be used as an important factor to discriminate zandaz honey. Flavonoid content correlated positively with the honey color, melanoidin and polyphenol content, and negatively with the IC50 values of scavenging ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) free radicals, while proline amount correlated negatively with IC50 values of nitric oxide scavenging activity and chelating power. This correlation supports the use of anti-oxidant activities as important variables for PCA (principal component analysis). Both components explained 70% from the given data, and showed certain homogeneity upon analyzed samples independent of the region, suggesting the importance of B. spinosum nectar in the resulting honey characteristics.

Comparative study of herbal plants on the phenolic and flavonoid content, antioxidant activities and toxicity on cells and zebrafish embryo

Natural antioxidants derived from plants have shown a tremendous inhibitory effect on free radicals in actively metabolizing cells. Overproduction of free radicals increases the risk factor of chronic diseases associated with diabetes, cancer, arthritis and cardiovascular disease. Andrographis paniculata, Cinnamon zeylanicum, Curcuma xanthorrhiza, Eugenia polyantha and Orthosiphon stamineus are ethnomedicinal plants used in the Asian region to treat various illnesses from a common fever to metabolic disease. In this study, we have quantified the total phenolic (TPC) and flavonoid content (TFC) in these plants and its inhibitory effect on 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals as well as the cytotoxicity effect on cell lines proliferation and zebrafish embryogenesis. Results showed that Cinnamon zeylanicum and E. polyantha have the highest phenolic and flavonoid content. Furthermore, both herbs significantly inhibited the formation of DPPH and ABTS free radicals. Meanwhile, O. stamineus exhibited minimum cytotoxicity and embryotoxicity on tested models. Good correlation between IC50 of 3T3-L1 cells and LC50 embyrotoxicity was also found. This study revealed the potent activity of antioxidant against free radical and the toxicology levels of the tested herbal plants.

Effect of Microwave Treatments on Antioxidant Activity and Antigenicity of Fish Frame Protein Hydrolysates

Protein solubility, protein recovery, antioxidant activity, and antigenicity of microwave pretreatment and/or microwave-assisted hydrolysis of trout frame protein hydrolysates was investigated. Treatments consisted of (1) microwave pretreatment at low temperature (55 °C) followed by conventional enzymatic hydrolysis or (2) high temperature (90 °C) followed by conventional enzymatic hydrolysis; (3) microwave pretreatment at high temperature (90 °C) followed by microwave-assisted enzymatic hydrolysis, and (4) no microwave pretreatment followed by microwave-assisted enzymatic hydrolysis. Compared to controls, microwave treatments significantly improved (P < 0.05) protein solubility, protein recovery, degree of hydrolysis, and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) free radical scavenging radical scavenging activity. Decrease of antigenicity (55–93 %) was obtained in all microwave-treated samples. Based on the results of this study, the use of microwave pretreatment for 5 min at 90 °C, followed by conventional enzymatic hydrolysis with alcalase for 2–10 min was the best treatment condition to produce fish peptides with antioxidant activity and the lowest immunoreactivity. These peptides have potential to be applied as hypoallergenic ingredients in food formulations and nutraceuticals.

The Effects of a Short-Term High-Intensity Interval Training (HIIT) on the Levels of Serum Hypoxanthine-Guanine Phosphoribosyltransferase (HGPRT) Enzyme and Some Variables of Purine Nucleotide Cycle

Background: The enzyme HGPRT 5-phosphoribosyl converts to hypoxanthine or guanine to build up IMP or GMP as an ATP and GTP precursor in the purine nucleotides salvage pathway. This enzyme is most active in the liver, blood cells, nervous system, and skeletal muscles. In fact, the normal activity of this enzyme is involved in the salvage of 90% of free nucleotides and thereby contributes to the economy of purine in cells. Minor decrease or defect of this enzyme results in the increased xanthine, uric acid, and oxygen free radicals. Reports suggest the relationship between this enzyme and the level of physical preparation, antioxidant capacity, and low blood uric acid levels in active individuals. However, the effect of different types of exercise, especially high-intensity intermittent exercise on this enzyme is not clear. Objectives: The present study aimed to investigate the possible compatibility of this enzyme and some purine nucleotide cycle variables in a short-term high-intensity interval training. Methods: 18 healthy, untrained, male, eligible volunteers (based on their age, height, and weight) were randomly divided into control and training groups. The training group rode the bicycle ergometer with maximum intensity for 2 weeks (3 sessions per week) with 45-second repetitions and a 4-minute rest between the sets. Blood samples were collected for measuring HGPRT, hypoxanthine, xanthine, and uric acid before and 48 hours after the last training session, and data were analyzed using analysis of covariance at alpha level of 0.05. Results: A significant increase was found in the levels of hypoxanthine (P = 0.001) and xanthine (P = 0.001) while a statistically significant reduction was found in the level of uric acid (P = 0.02). However, after training, the HGPRT serum level did not increase significantly (P = 0.386). Conclusions: The results suggest that this short-term program was able to improve the variables involved in the purine nucleotide recycling pathway, and probably led to maintaining the balance of total nucleotide pool.

Antioxidant and Anticancer Activities of Walnut (Juglans regia L.) Protein Hydrolysates Using Different Proteases

Walnut (Juglans regia L.) contains approximately 20-25% protein with abundant essential amino acids. The enzymatic hydrolysate of Persian walnut (Chandler) seed proteins was prepared by incubation with three different proteases, including pancreatic chymotrypsin and trypsin, and a microbial enzyme proteinase K. The hydrolysates were found to possess excellent antioxidant capacities. The peptide fractions scavenged the 2, 2'-anizo-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radicals and inhibited the activity of reactive oxygen species. Walnut protein hydrolysates were also tested, for the first time, against the viability of human breast (MDA-MB231) and colon (HT-29) cancer cell lines. MTT, [3-(4, 5dimethylthiazolyl)-2,5-diphenyl-tetrazolium bromide], assay was used to assess in vitro cancer cell viability upon treatment with the peptide fractions. The peptide fractions showed cell growth inhibition of 63±1.73% for breast cancer and 51±1.45% for colon cancer cells. Thus, a direct correlation between antioxidant and anticancer activities of walnut peptide fractions exists and supports their potential therapeutic benefit.

Antioxidant and cytotoxic lignans from the roots of Bupleurum chinense

In the search for biologically active compounds from the roots of Bupleurum chinense D C., phytochemical investigation of its ethanol extract led to the isolation and identification of a new 8-O-4′ neolignan glucoside, saikolignanoside A (1), along with eight known lignans (2–9). Their structures were determined on the basis of IR, UV, HRESIMS, and NMR spectroscopic analyses. The antioxidant and cytotoxic effects of isolated compounds were evaluated in vitro. The isolated compounds (IC50 > 200 μM) did not display 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Whereas compounds 1–2, 5, 7, and 9 exhibited potent 2, 2′-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging properties with IC50 values ranging from 8.34 to 15.24 μM, while compounds 3–4, 6, 8 showed moderate properties. In addition, all compounds were evaluated for cytotoxicities against A549, HepG2, U251, Bcap-37, and MCF-7 cell lines. Compounds 5 and 9 (IC50 < 51.62 μM) possessed stronger cytotoxic activities against all the tested tumor cell lines, compared with the positive control 5-Fluorouracil.

Multiple on-line HPLC coupled with biochemical detection methods to evaluate bioactive compounds in Danshen injection.

On-line high performance liquid chromatography (HPLC) coupled with three biochemical detection (BCD) methods was applied to evaluate bioactive components in Danshen injection. On-line HPLC-photo-diode array-fluorescence detection based on the fluorogenic substrate 7-acetoxy-1-methyl quinolinium iodide, was built to search acetylcholinesterase (AChE) inhibitors in Danshen injection. On-line HPLC coupled with the scavenging assay of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals was developed to screen antioxidants. The three active profiles were obviously different. Radical scavenging profiles revealed seven strong peaks in the chromatographic fingerprint possessing obvious free radical inhibition effects, while some minor peaks exhibited stronger AChE inhibition activities. The main radical scavengers and AChE inhibitors were identified by HPLC-MS. Several unknown ingredients showing strong AChE inhibition activities needed further identification except protocatechuic aldehydrate, salvianolic acid H or I and lithospermic acid. The on-line multiple on-line HPLC-BCD methods will provide powerful tools in the field of pharmacognosy for fast-track identification of interesting and/or novel bioactive compounds.

Genetics of seed flavonoid content and antioxidant activity in cowpea (Vigna unguiculata L. Walp.)

Information about the type of gene action governing the inheritance of cowpea seed flavonoid content and antioxidant activity is prerequisite for starting an effective breeding program for developing improved varieties. For this purpose, half-diallel crosses among seven diverse parents were made. The homozygous parents and 21F1 hybrids were evaluated at Maroua in the Sudano-Sahelian zone of Cameroon using a randomized complete block design with three replicates. Flour samples produced from decorticated seeds were used for biochemical analysis. Analysis of variance showed significant differences (P<0.001) among genotypes for the studied traits with ranges of 363.6–453.9mg rutin equivalent per 100g dry weight (DW) for total flavonoids, 13.38–30.73mg ascorbic acid equivalent per 1g DW for ferric iron reducing activity, 70.98–266.93mg trolox equivalent per 100g DW for 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, and 90.93–370.62mg trolox equivalent per 100g DW for 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging activity. Both additive and non-additive gene effects were significant in the genetic control of these traits, but dominance variance was greater than additive variance. The traits were mainly controlled by overdominance model suggesting a selection in the delayed generations. Broad- and narrow-sense heritability estimates varied from 0.90 to 0.99 and from 0.12 to 0.45, respectively. The variances due to both general and specific combining ability were highly significant for all studied traits. Recessive alleles had positive effects on DPPH and ABTS scavenging activities, whereas dominant alleles had positive effects on flavonoid content and ferric iron reducing activity. These results could help cowpea breeders to improve the antioxidant potential of cowpea seeds by appropriate selection.

&lt;i&gt;In vitro&lt;/i&gt; Cytotoxic and Antioxidant Activity of Leaf Extracts of Mangrove Plant, &lt;i&gt;Phoenix paludosa&lt;/i&gt; Roxb

Purpose: To investigate the anti-proliferative and antioxidant potentials of four different solvent extracts of Phoenix paludosa Roxb leaves. Methods: Four different solvent (hexane, chloroform, ethyl acetate and methanol) leaf extracts of the plant were tested for cytotoxicity against four cancer cells, viz, MCF-7 (oestrogen positive breast cancer cell line), MDA-MB-231 (triple negative breast cancer cell line), SK-BR-3 (breast adenocarcinoma) and ACHN (renal adenocarcinoma) as well as two normal cell lines, namely, HEK-293 (embryonic kidney cells) and MCF-10A (normal mammary epithelial cells)]. 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) and 2, 29-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) free radical scavenging assays were used to evaluate the antioxidant activity of the crude extracts. Results: The methanol extract showed the highest antioxidant activity (DPPH, half maximal inhibitory concentration (IC50) = 30.17 ± 6.21 µg/mL) and (ABTS, IC50 = 27.91 ± 3.21 µg/mL). Of the four extracts, methanol extract showed the strongest significant (p < 0.05) cytotoxicity to all four cancer cell lines at 24 and 48 h of incubation followed by the chloroform extract (IC50 of methanol extract (24 and 48 h): 36.71 ± 8.72 and 33.19 ± 5.53 µg/mL (MCF-7), 159.7 ± 32.09 and 141.9 ± 26.2 µg/mL (MDA-MB-231), 103.3 ± 18.9 and 75.39 ± 19.39 µg/mL (SKBR-3), 57.21 ± 3.72 and 43.16 ± 10.25 µg/mL (MCF-10A), 37.48 ± 5.75 and 26.99 ± 1.85 (ACHN) and 66.83 ± 14.26 and 60.34 ± 10.66 µg/mL (HEK-293)). Furthermore, the methanol extract was least cytotoxic to normal cell lines. Conclusion: The results obtained indicate that the methanol leaf extract of P. paludosa exhibit potent antioxidant and cytotoxic activities and has the potential of being developed into an anti-cancer agent.

Lignan accumulation in callus and Agrobacterium rhizogenes-mediated hairy root cultures of flax (Linum usitatissimum)

Agrobacterium rhizogenes is gaining intensity in research to develop and produce a large number of commercially important secondary metabolites, such as lignans. Worldwide, lignans are receiving great attention because of their putative beneficial effects on human health. In this study, we investigated the potential of callus and A. rhizogenes, hairy roots, of flax Linum usitatissimum in accumulating lignans, namely, secoisolariciresinol diglucoside (SDG), secoisolariciresinol (SECO) and matairesinol (MAT). Callus cultures were established on Gamborg B5 medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) alone or in combination with 6-benzyladenine or gibberellic acid (GA3). These callus cultures were transformed with A. rhizogenes, which were initiated on 1.0 mg l−1 2,4-D + 0.5 mg l−1 GA3 or 1.0 mg l−1 GA3 media. Both hairy root culture 1 and hairy root culture 2 accumulated SDG, SECO and MAT with a total lignan concentration of 1.227 and 1.057 µmol g−1, respectively. However, non-transformed cultures did not accumulate MAT but accumulated SECO. Determination of total phenolic content by high-performance liquid chromatography revealed higher phenolic acid content in hairy root cultures compared with that in non-transformed cultures. Antioxidant activity, as measured by 2,2-diphenyl-1-picryl-hydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid-free radical scavenging assays, was significantly higher in hairy root cultures than in non-transformed cultures. Furthermore, the extract of hairy root culture showed inhibition of proliferation of human breast cancer cell line (MCF-7).

Antioxidant and Anti-proliferative Activities of Flavonoids from &lt;i&gt;Bidens pilosa&lt;/i&gt; L var &lt;i&gt;radiata&lt;/i&gt; Sch Bip

Purpose: To investigate the chemical composition of Bidens pilosa L. var. radiata . Sch Bip. (BP), as well as its antioxidant and anti-proliferative activities. Methods: The whole herb of BP was extracted with 95 % ethanol, which was then partitioned sequentially with petroleum ether, ethyl acetate and n-butyl alcohol to obtain petroleum ether, ethyl acetate (EE-BP), n-BuOH and water fractions. EE-BP was further isolated and purified by repeated column chromatography. The obtained compounds were identified by comparing 1H and 13C nuclear magnetic resonance (NMR) spectra with published data for the compounds. Flavonoids were evaluated for 1,1-diphenyl-2-picrylhydrazy (DPPH) and 2, 2 -azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radical scavenging activity by colorimetric methods, while their anti-proliferative effect against human colon cancer RKO cells was determined by 3-(4,5) dimethylthiahiazo (-z-y1)-3,5-diphenytetrazoliumromide (MTT) method. Results: A total of 6 compounds were isolated from BP, including flavonoids or flavonoid glycosides, among which were isoquercitrin (1), vitexin (2), astragalin (3), 5,6,7,4'-tetramethoxylflavone (4), 5,3',4'- trihydroxy-3,7-dimethoxylflavone (5) and quercetin (6). The results indicate that compound 6 was the most effective in both DPPH and ABTS free radical-scavenging assays, with half maximal inhibitory concentration (IC50) of 10.7 μmol/L and 17.5 μmol/L, respectively. Both compounds 4 and 5 exhibited significant growth inhibitory effect on RKO cells with IC50 of 39.08 μmol/L and 17.68 μmol/L, respectively (p < 0.01). Conclusion: BP contains a series of flavonoid compounds, possessing significant antioxidant activity and antiproliferative effect in RKO cells, thus suggesting that it is a potential health supplement and an easily available resource of natural antioxidants for use in colon cancer prevention. Keywords: Bidens pilosa , Flavonoid, Antioxidant, Anti-proliferation, Colon cancer

Chemical composition, antioxidant and antimicrobial activities of essential oils from leaves, aerial stems, basal stems, and rhizomes of Etlingera fimbriobracteata (K.Schum.) R.M.Sm.

Essential oils from the leaves, aerial stems, basal stems, and rhizomes of Etlingera fimbriobracteata (K.Schum.) R.M.Sm. were analyzed using a gas chromatography-flame ionization detector (GC-FID) and by gas chromatography-mass spectrometry (GC–MS). β-Pinene (67.8%) and 1,8-cineole (37.2%) were the main components of the oils from leaves and aerial stems, respectively, whereas decanal was the main component of basal stems and rhizomes (27.5% and 34.4%, respectively). The antioxidant activities of the oils were evaluated using several in vitro assays; the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging assays, the reducing power ability (RPA) assay, and the ferric reducing antioxidant power (FRAP) assay. In all the tests, essential oils from different plant parts showed very poor antioxidant activity compared with those of the reference standards, ascorbic acid (AA) and butylated hydroxytoluene (BHT). However, all the oils exhibited moderate to potent broad-spectrum antimicrobial activity against all tested strains except for Pseudomonas aeruginosa. In disc diffusion and broth microdilution assays, the inhibition zones and MIC values of the essential oils were in the range of 8–87.7mm and 2.4–625μg/mL, respectively. Because of their strong antimicrobial activity, the essential oils of E. fimbriobracteata could be a potential alternative to conventional antimicrobials in food, cosmetics, and pharmaceutical industries.

Antioxidant activity of camel and bovine milk fermented by lactic acid bacteria isolated from traditional fermented camel milk (Chal)

Chal is a traditional fermented product produced from spontaneously fermented camel milk which contains several bacterial species with potential usage in producing traditional dairy products and functional foods. The aims of this study were to isolate and identify predominant lactic acid bacteria (LAB) from Chal and investigate antioxidant activity of camel and bovine milk fermented by these isolates. Chal samples were collected from Turkman Sahra, Golestan Province, Iran. The protein hydrolysis was determined by o-phthaldialdehyde (OPA) method, and antioxidant activities of whey fractions were evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals scavenging methods. Nine catalase-negative bacteria including Lactobacillus (L.) plantarum, L. paraplantarum, L. kefiri, L. gasseri, L. paracasei, Leuconostoc (Leu.) lactis, Weissella (W.) cibaria, and Enterococcus (E.) faecium were isolated and identified by conventional and molecular methods. Both camel and bovine milk were fermented by the strains for 24 h. Fermented camel milk showed significantly (P < 0.05) higher antioxidant activity than bovine milk. Camel milk fermented by Leu. lactis showed significantly (P < 0.05) higher DPPH (57.90 ± 4.59 μM) and ABTS (1484.35 ± 128.20 μM; P < 0.05) radical scavenging activity compared to samples fermented by other strains. According to sensory evaluation of fermented camel and bovine milks, camel milk fermented by Leu. lactis SM10 had the highest overall acceptance values. Our findings suggest that camel and bovine milk fermented by LAB isolated from Chal could potentially be used for producing novel functional foods.