Β-carotene Linoleic Acid Assay Research Articles

Phytochemical investigation, antioxidant and anticholinesterase activities of Ganoderma adspersum

Ganoderma species are mostly used as therapeutic agents, nowadays. Some are consumed as tea, in coffee as well as dietary supplements even by the healthy people. Bioassay-guided isolation of Ganoderma adspersum (Schulz.) Donk. yielded compounds: applanoxidic acid G (1), applanoxidic acid E (2), applanoxidic acid A (3), and Δ22-stigmastenol (4). Purified compounds were characterized using 1D, 2D NMR, and MS analysis. All extracts and isolated compounds were evaluated for their antioxidant and anticholinesterase activities. The antioxidant activity was performed by six methods and the anticholinesterase activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. Among the extracts, the ethyl acetate extract exhibited the best antioxidant activity in all tests. It also indicated two times better BChE inhibitory activity (IC50: 19.97±1.32μg/mL) than that of galantamine. Among the compounds, compound 4 exhibited higher lipid peroxidation-inhibitory activity in β-carotene linoleic acid assay (IC50: 160.39±2.16μg/mL). Compounds 1 and 4 exhibited a moderate inhibitory activity against the BChE enzyme (IC50: 147.73±2.18 and 116.59±2.11μg/mL, respectively). The phenolic profile was analyzed by HPLC-DAD. Sixteen phenolic and organic acids were studied and seven of them detected. Fumaric and caffeic acids were identified as major phenolic acids. This paper represents the first chemical work on G. adspersum, which is a novel source of pharmaceuticals and preservatives.

Preparation, characterization and antioxidant activities of acetylated polysaccharides from Cyclocarya paliurus leaves

In this study, polysaccharides extracted from Cyclocarya paliurus leaves were modified to obtain its three acetylated derivatives, Ac-CP1, Ac-CP2, and Ac-CP3. The physicochemical characteristics and antioxidant activities of acetylated derivatives were investigated. The results of chemical and FT-IR spectrum analysis showed differences between acetylated derivatives and native C. paliurus polysaccharide, which revealed that the acetylation were successful. Relative to unmodified polysaccharide, the protein contents of acetylated derivatives decreased, while carbohydrate values increased. The molecular weight (Mw) of acetylated derivatives were approximately 1.05–1.09×106Da and were mainly composed of Ara, Gal, Glc, Man, GalA. Ac-CP1 with relatively low degree of substitution (0.13±0.01) exhibited excellent antioxidant activity in DPPH radical assay (95.21±0.89%), and also had strong chelating activity on β-carotene–linoleic acid assay (34.64±2.07%) at 0.5mg/ml. In addition, scanning electron microscope (SEM) observations suggested that acetylation could change the morphology and structure of polysaccharides from C. paliurus leaves.

Potential Antioxidant, Antiproliferative and Hepatoprotective Effects ofCrataegus Meyeri

In this study, the potential antioxidant, antiproliferative and hepatoprotective effects of Crataegus meyeri Pojark. were investigated. The antioxidant activity of the ethanolic flower extracts was evaluated by using DPPH (2,2-diphenyl-1-picrylhydrazyl) and β-carotene–linoleic acid assays. Total phenolic contents were also measured. The results obtained showed that C. meyeri can act as a high radical scavenger reaching 88.67%. In vitro antiproliferative activity for the same extracts was determined by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay against PC3 and PC14 cells. The extracts of the plant at concentrations of 0.5, 1 and 1.25% were administered orally to the three experimental groups, including partially hepatectomized rats for 42 days. At the end of the experimental period, animals were sacrificed, and blood was collected for the assessment of serum levels of ALT (alanine aminotransferase), AST (aspartate aminotransferase) and GGT (gamma-glutamyltransferase). In biochemical assay, a significant decrease in the levels of serum ALT and AST was found in the experimental groups. Practical Applications The antioxidant activity studies on Crataegus species have exhibited that these species possess considerable antioxidant potential because of their polyphenolic compounds such as flavonoids and procyanidines. In this study, the findings are consistent with these observations. However, our results also demonstrated that C. meyeri exerts a protective effect against partial hepatectomy-induced liver injury in rats and could provide a new potential approach to inhibit the proliferation of human non-small cell lung cancer cells.

Chemical composition, antioxidant and antimicrobial activity of the essential oil from the leaves of Macleaya cordata (Willd) R. Br.

The essential oil from the leaves of Macleaya cordata R.Br. obtained by hydrodistillation was analysed by gas chromatography/mass spectrometry. Sixty-eight compounds consisting of up to 92.53% of the essential oil were identified. Antioxidant activities of the essential oil were evaluated by using DPPH radical scavenging and β-carotene–linoleic acid assays. The essential oil showed moderate antioxidant activity. In addition, the essential oil exhibited potential antimicrobial activity against all tested microorganisms, with diameters of inhibition zones ranging from 8.7 ± 0.5 to 17.2 ± 1.2 mm and minimum inhibitory concentration values from 125 to 500 μg/mL. We selected the most sensitive bacterium Staphylococcus aureus as model to observe of the action of essential oils of M. cordata on the membrane structure by scanning electron microscopy. The treated cell membranes were damaged severely. The results presented here indicate that the essential oil of M. cordata may be potential sources of antioxidant and antimicrobial agents in the future.

Sulfated modification, characterization and antioxidant activities of polysaccharide from Cyclocarya paliurus

In this study, polysaccharide extracted from Cyclocarya paliurus was chemically modified to obtain its sulfated derivatives. The physicochemical characterizations and antioxidant properties of these sulfated polysaccharide derivatives were comparatively investigated by chemical methods, circular dichroism spectra, high-performance anion exchange chromatography, high-performance gel permeation chromatography, fourier transform infrared spectrometry, and hydroxyl radical assay, DPPH radical assay, superoxide radical assay and β-carotene–linoleic acid assay, respectively. Results showed that these modifications were successful, and the physicochemical and antioxidant properties of polysaccharides were changed after sulfation. Among these sulfated polysaccharides, the S-CP1–8 with relatively the lowest degree of substitution (DS), molecular weight (Mw) and the highest protein content exhibited excellent antioxidant activities in hydroxyl, superoxide, DPPH radical assay and β-carotene–linoleic acid assay. These results indicated that the in vitro antioxidant activities of the sulfated polysaccharides from Cyclocarya paliuru may be related to combined effects of DS, Mw, sulfate content, protein and uronic acid content.

Sulfated modification of the polysaccharides from Ganoderma atrum and their antioxidant and immunomodulating activities

In this study, three chemically sulfated polysaccharides (S-PSG) with different degree of sulfate substitution (DS) were derived from Ganoderma atrum. FT-IR and 13C NMR spectra indicated that the substitution was predominantly on C-6 position compared with the C-2 position. The antioxidant and immunomodulatory activities of S-PSG were further examined to determine the relationship between its structure and bioactivity. The results showed that compared with the native polysaccharide, the S-PSG-2 with moderate DS and molecular weight exhibited the highest immunomodulatory activity by increasing the macrophage phagocytosis capacity and TNF-α production. The DPPH radical scavenging activity was also greatly enhanced by S-PSG in all the groups compared with PSG. However, the reducing power and the antioxidant activities in β-carotene–linoleic acid assay were decreased. These results indicated that except for the DS, some other structural characteristics such as molecular weight, substitution position and chain conformation were also important factors affecting their bioactivities. And the S-PSG-2 we derived could be served as immunomodulator and free-radical inhibitors.

In vitro antioxidant and antitumor activities of six selected plants used in the Traditional Arabic Palestinian herbal medicine

Context: Despite several pharmacological applications of the medicinal plants in the Traditional Arabic Palestinian Herbal Medicine in Palestine (TAPHM), studies on their antioxidant properties are still scarce.Objective: This work evaluates the antioxidant and antitumor activities of the ethanol extracts from different parts of six plants: [Arum palaestinum Boiss (Araceae), Urtica pilulifera L. (Urticaceae), Coridothymus capitatus (L.) Reichb (Lamiaceae), Majorana syriaca (L.) Rafin. (Lamiaceae), Teucrium creticum L. (Lamiaceae), and Teucrium capitatum L. (Lamiaceae)] used in the TAPHM.Materials and methods: The antioxidant activity was evaluated for the ethanol extracts by DPPH and β-carotene–linoleic acid assays together with total contents of phenols and flavonoids. For the anti-carcinogenic evaluation, the extracts were tested for the ability to inhibit the proliferation of breast cancer cells (MCF-7) using the MTT reduction assay.Results: Among the extracts, the U. pilulifera had the highest amount of total phenolics, possessing the second highest total flavonoids. It also showed a maximum cytotoxic activity (IC50 = 63 µg/ml), followed by C. capitatus, and A. palaestinum. Otherwise, the extract of T. creticum was demonstrated to be an efficient scavenger of O2 (IC50 = 83 µg/ml), followed by M. syriaca, C. capitatus, T. capitatum, A. palaestinum, and U. pilulifera.Discussion and conclusion: The results suggest that the investigated plants have shown varied antioxidant capacities which were strongly correlated with their contents of phenolics. Accordingly, this study proposes that the therapeutic benefit of these plants can be, at least in part, attributed to its potential inhibition of oxidative processes.

Antioxidant Properties and Glucan Compositions of Various Crude Extract from <i>Lentinus squarrosulus</i> Mycelial Culture

Various crude extracts of Lentinus squarrosulus mushroom mycelium and culture broth were prepared for antioxidant studies, glucan and carbohydrate compound analysis. Crude extract from ethanol, cold and hot water extraction was tested on several complementary test systems namely DPPH free radical scavenging, β-carotene linoleic acid oxidation, total phenolic compound, total flavonoid compound, total carbohydrate content and total glucan compositions. The antioxidant activity of the crude extracts of Lentinus squarrosulus mushroom mycelium and culture broth was determined by 2,2’ diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method and β-carotene linoleic acid assay. Crude extracted from culture broth EPS EE recorded the highest radical scavenging effects at 20 mg/mL (85%) which is closer to the control antioxidants (ascorbic acid 97%; BHT 92.4%; BHA 93.6%). Both the ethanol extract (IPS EE and EPS EE) exhibited the highest β-carotene linoleic acid oxidation by recording IC50 values of 0.6 and 0.65 mg/mL respectively. IPS EE (0.59 mg/g) and EPS WE (0.58 mg/g) showed high flavonoid content whereas total phenol content was high in EPS WE (0.85 mg/g) and IPS EE (0.84 mg/g). Total carbohydrate concentrations were high in IPS HWE and IPS CWE with 19.1 and 16.3 mg/mL respectively and these data correlate with the β-glucan content in both extracts. The highest β-glucan content found in IPS CWE and IPS HWE were 12.2 and 11.4% w/w respectively.

Chemical Composition and Biological Properties of Essential Oils of Two Mint Species

Purpose: To analyze the composition of essential oils of two types of mint as well as compare the antimicrobial, antioxidant and anti-inflammatory activities of the two oils. Methods: Peppermint (M. piperita L.) and chocolate mint (M. piperita L.) oils were obtained by steam distillation in a Clevenger-type apparatus. The chemical composition of the essential oils was determined by gas chromatography-mass spectrometry (GC/MS). The minimal inhibitory concentration (MIC) of the essential oils were determined by broth dilution method. The antioxidant activities of the oils were determined by 2, 2-diphenyl-1-picrylhydrazyl (DPPH)DPPH radical scavenging assay, β-Carotene-linoleic acid assay, andnitric oxide (NO) radical scavenging assay. Results: The two essential oils contain high levels of alcohol (43.47-50.10%) and terpene (18.55-21.07%) with the major compound being menthol (28.19-30.35%). The antimicrobial activity (minimum inhibitory concentration, MIC) of peppermint oil against E. coli, S. aureus and P. aeruginosa (0.15, 0.08, 0.92 %v/v, respectively) was stronger than that of chocolate mint (0.23, 0.09, 1.22 %v/v, respectively). In the anti-oxidant test including DPPH and β-Carotenelinoleic acid assays, peppermint oil showed superior antioxidant properties to chocolate mint oil (4.45 - 19.86 μl/mL). However, with regard to scavenging NO radical activity, chocolate mint oil exhibited higher activity than peppermint (0.31 and 0.42 μl/mL, respectively). Chocolate mint oil also exhibited higher anti-inflammatory activity than peppermint oil (0.03 and 0.08 μl/mL, respectively). Conclusion: The results obtained should help to clarify the functional applications of these folk herbs and their essential oils for aromatherapeutic healing and other folkloric uses.

Total phenolic content and antioxidant activity of three Iranian endemic Achillea species

Bioactive compounds such as phenolics and essential oils involved in medicinal plants are beneficial for human health. Medicinal plants are potential sources of natural antioxidants. The genus of Achillea is comprised of more than 100 species worldwide with different medicinal applications. Nineteen species of Achillea have been recognized in Iran. Since the endemic medicinal species are considered as new natural sources of bioactive compounds, in this study, total phenolics and antioxidant activity of three endemic Achillea species (A. pachycephalla, A. aucherii and A. kellalensis) were compared with a synthetic antioxidant butylated hydroxytoluene (BHT). Total phenolic content was determined according to the Folin–Ciocalteu method and varied from 15.55mg in A. aucherii to 60.65mg tannic acid/1g of dry product in A. pachycephalla. Antioxidant activity of methanolic extract evaluated according to 1,1-diphenyl-2-picryl-hydrazyl (DPPH), ferric thiocyanate (FTC) and β-carotene–linoleic acid assay. In DPPH assay, A. aucherii showed the highest IC50 (844μg/ml), while A. kellalensis and A. pachycephalla possessed 518μg/ml and 248μg/ml, respectively. For reducing power, A. pachycephalla had the highest absorbance in 700nm (2.601), while A. aucherii possessed the lowest one (0.236). The results showed that three studied endemic species had acceptable antioxidant activity and can be introduced as important sources of natural antioxidants for pharmaceutical and medical purposes.

Evaluation of phenolic compounds, antioxidant activities and fatty acid composition of Amanita ovoidea (Bull.) Link. in Turkey

Antioxidant capacity of Amanita ovoidea (Bull.) Link. was studied by using the methods of scavenging effect on DPPH radicals, β-carotene–linoleic acid assay, reducing power and estimation of phenolics. Seven phenolics of A. ovoidea methanolic extract were analysed by high performance liquid chromatography (HPLC), and 3 of them were determined as p-coumaric acid, cinnamic acid and ferulic acid. Additionally, the total phenolic content of A. ovoidea was estimated at 0.53mg/g concentration. The scavenging effect of A. ovoidea on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals was measured as 36.4% at 0.5mg/mL, and its reducing power was 0.36mg/mL at 1.2mg/mL. IC50 values were determined as 0.79mg/mL for A. ovoidea, 0.36mg/mL for BHA and 0.41mg/mL for BHT. The fatty acids were estimated via the method of gas chromatography analysis; 37 different fatty acids were found in A. ovoidea. Oleic acid (58.8%) was the dominant component, and the other major components were linoleic acid (18%), palmitic acid (15.8%) and stearic acid (5.4%). The results demonstrated that A. ovoidea shows antioxidant activity and contains a number of fatty acids important for human health. A. ovoidea can thus be recommended as a source of natural antioxidants and fatty acids.

Biological activity and fatty acid composition of Caesar's mushroom

Context: Due to its pleasant aroma and flavor, Amanita caesarea (Scop.) Pers. (Amanitaceae) has been a famous macrofungus since ancient times. This species is also well known in Turkey where people consume it extensively.Objective: Evaluation of the medicinal importance of A. caesarea for human health.Materials and methods: Antioxidant capacity of A. caesarea was studied using the methods of a scavenging effect on 2,2-diphenyl-1-picrylhydrazyl radicals, β-carotene–linoleic acid assay, reducing power and estimation of phenolics. Chloroform, acetone and methanol extracts of A. caesarea were tested for their antimicrobial activity against four Gram-positive bacteria, five Gram-negative bacteria and one yeast by applying a micro dilution method. The fatty acids were estimated via the method of gas chromatography analysis.Results: The scavenging effect of A. caesarea on DPPH radicals was measured as 40.91% at 0.5 mg/mL concentration, and its reducing power was 0.451 mg/mL at 1.2 mg/mL concentration. The phenolics found were catechin (32.5 mg/g), ferulic acid (7 mg/g), p-coumaric acid (6 mg/g) and cinnamic acid (6.2 mg/g). The highest minimum inhibitory concentration observed against the test microorganisms were with the acetone extract (4.8 µg/mL concentration) against Candida albicans. Thirty-seven different fatty acids were determined from A. caesarea, and oleic acid (58%) was the dominant component.Discussion and conclusion: Amanita caesarea had a high-antioxidant and -antimicrobial activity, and it also had important essential fatty acids required for human health. According to the results, this mushroom can be recommended as a major source of natural food.

Antioxidative effect of Iranian Pulicaria gnaphalodes L. extracts in soybean oil

This study was aimed to evaluate antioxidative activities of the ethanol, methanol and water extracts of Pulicaria gnaphalodes in vegetable oil during the storage period. Different concentrations (0, 200, 400 and 800ppm) of ethanol, methanol and water extracts and beta-hydroxy toluene (BHT; 100, 200ppm) were added to soybean oil and incubated for 35days at 65°C. Peroxide values (PVs) and thiobarbituric acid-reactive substance (TBARS) levels were measured every week during the period of the study. Moreover, antioxidant capacities of the extracts were determined using DPPH and β-carotene–linoleic acid methods. Values were compared among groups in each incubation time points using ANOVA. Results showed that DPPH and β-carotene–linoleic acid assay findings on the P. gnaphalodes extracts were comparable to those found on BHT. Moreover, during incubation time, P. gnaphalodes extracts lowered PVs and TBARS levels when compared to the control (p<0.001). In this respect, water extract was more potent than the ethanol and methanol extracts. It seems that water extract of P. gnaphalodes is a potent antioxidant which makes it as a potential antioxidant for oil and oily products during storage.

Preparation and evaluation of antioxidant peptide from papain hydrolysate of Sphyrna lewini muscle protein

Inspired by DPPH radical scavenging assay, an efficient method had been developed to acquire the hydrolysate from Sphyrna lewini muscle protein (SPH) by an orthogonal L9(3)4 test. Under optimal proteolysis parameters (proteolysis time 2 h, total enzyme dose 1.2%, proteolysis temperature 60 °C and pH 6), DPPH radical scavenging rate of SPH reached to 91.27 ± 2.69% at the concentration of 25 mg/mL. Proteolysis time showed significant effects on hydrolysate preparation (p < 0.05). One peptide (SAP) was isolated from SPH by using ultrafiltration, anion-exchange chromatography, gel filtration chromatography and Reversed Phase High Performance Liquid Chromatography (RP-HPLC). The primary structure of SAP was identified as Leu–Asp–Lys with molecular weight of 374.44 Da. SAP exhibited good scavenging activity on hydroxyl radical (EC50 0.17 mg/mL), ABTS radical (EC50 0.19 mg/mL), and superoxide anion radical (EC50 0.12 mg/mL), but moderate DPPH radical (EC50 3.06 mg/mL). SAP was also effective against lipid peroxidation in the model system and peroxyl free radical scavenging in β-carotene linoleic acid assay. These results suggested that SAP could be used as natural antioxidant in enhancing antioxidant properties of functional foods and in preventing oxidation reactions in food processing.

Preparation and evaluation of antioxidant peptides from ethanol-soluble proteins hydrolysate of Sphyrna lewini muscle

To get high yield of ethanol-soluble proteins (EP) and the antioxidant peptides from Sphyrna lewini muscle, orthogonal experiments (L9(3)4) were applied to optimize the best extraction conditions and enzyme hydrolysis conditions. The yield of EP reached 5.903±0.053% under the optimum conditions of ethanol concentration 90%, solvent to material ratio 20:1, extraction temperature of 40°C and extraction time of 80min. The antioxidant SEPH (EP hydrolysate of S. lewini muscle) was prepared by using papain under the optimum conditions of enzymolysis time 2h, total enzyme dose 1.2%, enzymolysis temperature 50°C and pH 6, and its DPPH radical scavenging activity reached 21.76±0.42% at the concentration of 10mg/ml. Two peptides (F42-3 and F42-5) were isolated from SEPH by using ultrafiltration, anion-exchange chromatography, gel filtration chromatography and RP-HPLC. The structures of F42-3 and F42-5 were identified as Trp-Asp-Arg and Pro-Tyr-Phe-Asn-Lys with molecular weights of 475.50Da and 667.77Da, respectively. F42-3 and F42-5 exhibited good scavenging activity on hydroxyl radical (EC50 0.15mg/ml and 0.24mg/ml), ABTS radical (EC50 0.34mg/ml and 0.12mg/ml), and superoxide anion radical (EC50 0.09mg/ml and 0.11mg/ml), but moderate DPPH radical (EC50 3.63mg/ml and 4.11mg/ml). F42-3 and F42-5 were also effectively against lipid peroxidation in the model system and peroxyl free radical scavenging in β-carotene linoleic acid assay. Their high activities were due to the smaller size and the presence of antioxidative amino acids within the peptide sequences.

Total Phenolic Content, Antioxidant and Antimicrobial Activity of Sambacus nigra L

Sambacus nigra or elder berry is a plant from Caprifoliaceae family. The total phenolic content (TPC), total flavonoid content (TFC), antioxidant and antimicrobial activity of methanolic, ethanolic and aqueous extract from aerial parts, berries and flowers were evaluated. TPC and TFC was assessed by spectrophotometrical method, the antioxidant activity was evaluated by DPPH and β-carotene linoleic acid assays, micro broth dilution assay were used for antimicrobial screenings. The TPC and TFC were in the ranges 43.7–86.3 mg gallic acid and 8.6–38.9 mg quercetin per g dry weight. The antioxidant activity of methanolic extract from aerial parts, flowers and berries with IC50 20, 30 and 35 μg/ml and inhibition percent (IP) 68, 69 and 61 % was higher than that of other extracts. The TPC and TFC content of above extract were 78.5, 20; 73.3, 38.9; 86.3, 24.6 mg/g; respectively. The methanolic extract from flowers is more effective against different kind of microorganisms especially against Streptococcus pyogenes, Escherichia coli, Salmonella typhimurium and Candida albicans. S. pyogenes is the most sensitive Gram positive bacteria to methanolic, ethanolic and aqueous extract of S. nigra. S. nigra methanolic extract had a good potential as antimicrobial and antioxidant agents for further studies.

Anthraquinone Profile, Antioxidant and Antimicrobial Properties of Bark Extracts of Rhamnus catharticus and R. orbiculatus

The anthraquinone profile, antioxidant and antimicrobial activities as well as the total phenol and total flavonoid contents were determined in methanol extracts of the barks of Rhamnus catharticus L. and R. orbiculatus Bornm. The most abundant anthraquinone derivatives in R. catharticus were physcion (67.8%) and emodin (26.2%), while R. orbiculatus contained mostly physcion (81.3%) and chrysophanol (14.6%). R. catharticus displayed better activity in the beta-carotene-linoleic acid assay, as well as chelating activity, whereas its activity in the reducing power assay was significantly lower than that of R. orbiculatus. Both methanol extracts showed antimicrobial activity against all microbial species tested (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans, Aspergillus niger, Microsporum gypseum) with MIC values either equal to or lower than 2.50 mg/mL. R. catharticus and R. orbiculatus contained several anthranoid aglycones and their bark extracts demonstrated notable antioxidant and antimicrobial properties. The results obtained indicate the medicinal potential of these two species.

Antioxidant activity of organic and aqueous leaf extracts of Cassia occidentalis L. in relation to their phenolic content

In this study, the antioxidant potency of sequential organic and aqueous leaf extracts of Cassia occidentalis was investigated, employing various established in vitro systems such as nitric oxide scavenging (NOS) activity, β-carotene–linoleic acid model system, hydroxyl radical scavenging (HRS) activity, reducing power, metal chelating activity (MCA) and superoxide radical scavenging (SRS) activity. The aqueous extract of the leaves of C. occidentalis was found to be most effective against free radicals, followed by the methanolic, chloroform, petroleum ether and benzene extracts, respectively. A preliminary study of qualitative and quantitative estimations of phenolics was performed, and the results were correlated with different antioxidant tests. A positive and significant (p < 0.05) correlation was observed (R 2 = 0.42 to 0.96) between various test systems, and the results on total phenolics showed that the phenolic compounds were responsible for the antioxidant capacity of the extracts. This study also showed that phenolics may contribute maximally to HRS (R 2 = 0.9236) and MCA (R 2 = 0.9396) and to a lesser extent to NOS activity (R 2 = 0.5819) and the β-carotene–linoleic acid assay (R 2 = 0.8213). The data obtained in the in vitro models clearly establish the antioxidant potency of leaf extracts of C. occidentalis.

Anti-inflammatory, antinociceptive and antioxidant activities of the endemic Soqotraen Boswellia elongata Balf. f. and Jatropha unicostata Balf. f. in different experimental models

In the present study, the two endemic Soqotraen plants Boswellia elongata and Jatropha unicostata were investigated for their anti-inflammatory, antinociceptive and antioxidant potential. To assess the anti-inflammatory and antinociceptive activities, two concentrations of each extract (200 and 400mg/kg, p.o.) were tested in carrageenan-induced rat paw edema, cotton pellet granuloma in rats, acetic acid-induced abdominal writhing and hot-plate test model in mice. Moreover, the antioxidant activity was determined in vitro, using scavenging activity of DPPH radical and β-carotene–linoleic acid assays. Both plants produced significant (P<0.05–0.01) anti-inflammatory and antinociceptive effects; however the results suggest that B. elongata possesses the highest activities. B. elongata and J. unicostata at (400mg/kg) reduced the paw edema considerably (82% and 53%) and the weight of cotton pellet granuloma (51% and 32%), respectively. Furthermore, they diminished the abdominal constriction induced by acetic acid with a 67% and 41% inhibition respectively, and prolonged significantly the reaction time of animal with relatively extended duration of stimulation. In addition, both plants showed considerable antioxidant activity in both assays. These results clearly confirmed the traditional anti-inflammatory indication of B. elongata and suggest that B. elongata could be a potential source for anti-inflammatory, antinociceptive and antioxidant agents.

Chemical composition and antioxidant activity of the essential oil of endemic Viola tianshanica

The composition and in vitro antioxidant activities of the essential oil and methanol extract of the aerial parts of Viola tianshanica were evaluated in this research. GC–MS analysis of the essential oil resulted in the identification of 15 constituents, representing 89.67% of the oil. The major compounds detected in the essential oil were dibutyl phthalate (15.19%), hexadecanoate methyl (8.65%), n-hexadecanoic acid (3.07%) and 2,3-pentanedione (2.62%). Essential oil and methanol extract were tested for their antioxidant activities using 1,1-diphenyl-2-picryl-hydrazyl free radical scavenging and β-carotene linoleic acid assay. In addition, the total phenol of essential oil, polar subfraction and non-polar subfraction were determined.