Antiperoxidative components in Thymus vulgaris

Chromones and biflavonoids from Garcinia pedunculata and Garcinia nujiangensis and their anti-inflammatory activity

Plants of the Garcinia genus were rich in structurally diverse and naturally bioactive components, while limited studies have been reported for Garcinia pedunculata Roxb. and G. nujiangensis C. Y. Wu & Y. H. Li. Four previously undescribed compounds including three chromones, garpedunchromones A-C (1-3), and one biflavonoid, nujiangbiflavone A (14), along with fifteen known analogs (4-13, 15-19) were isolated from G. pedunculata and G. nujiangensis. The structures of the isolated compounds were determined based on their HRESIMS data, extensive NMR spectroscopic analyses, and ECD calculations. The chromone derivatives were isolated from Garcinia for the first time. Compound 14 was a rare biflavonoid with C-3─C-6″ linkage. The biological evaluation of these isolates against NO production was conducted in the LPS-induced RAW 264.7 cells, resulting in the identification of a series of potent NO inhibitors, of which garpedunchromone B (2) was the most active with an IC50 value of 18.11 ± 0.96 μM. In the network pharmacology studies, the potential targets of compounds and inflammation were obtained from PharmMapper and GeneCards database. GO and KEGG enrichment analysis revealed that the overlapped targets were closely related to the major pathogenic processes linked to inflammation. Garpedunchromone B and proteins binding sites were being predicted.

Exploring the Biochemical and Nutra-Pharmaceutical Prospects of Some Thymus Species - A Review

The Thymus genus includes various medicinal and aromatic species, cultivated worldwide for their unique medicinal and economic value. Besides, their conventional use as a culinary flavoring agent, Thymus species are well-known for their diverse biological effects, such as antioxidant, anti-fungal, anti-bacterial, anti-viral, anti-tumor, anti-inflammatory, anti-cancer, and anti-hypertensive properties. Hence, they are used in the treatment of fever, colds, and digestive and cardiovascular diseases. The pharmaceutical significance of Thymus plants is due to their high levels of bioactive components such as natural terpenoid phenol derivatives (p-cymene, carvacrol, thymol, geraniol), flavonoids, alkaloids, and phenolic acids. This review examines the phytochemicals, biological properties, functional food, and nutraceutical attributes of some important Thymus species, with a specific focus on their potential uses in the nutra-pharmaceutical industries. Furthermore, the review provides an insight into the mechanisms of biological activities of key phytochemicals of Thymus species exploring their potential for the development of novel natural drugs.

Kinetics of Flavonoid Degradation and Controlled Release from Functionalized Magnetic Nanoparticles

Flavonoids are naturally occurring antioxidants that have been shown to protect cell membranes from oxidative stress and have a potential use in photodynamic cancer treatment. However, they degrade at physiological pH values, which is often neglected in drug release studies. Kinetic study of flavonoid oxidation can help to understand the mechanism of degradation and to correctly analyze flavonoid release data. Additionally, the incorporation of flavonoids into magnetic nanocarriers can be utilized to mitigate degradation and overcome their low solubility, while the release can be controlled using magnetic fields (MFs). An approach that combines alternating least squares (ALS) and multilinear regression to consider flavonoid autoxidation in release studies is presented. This approach can be used in general cases to account for the degradation of unstable drugs released from nanoparticles. The oxidation of quercetin, myricetin (MCE), and myricitrin (MCI) was studied in PBS buffer (pH = 7.4) using UV-vis spectrophotometry. ALS was used to determine the kinetic profiles and characteristic spectra, which were used to analyze UV-vis data of release from functionalized magnetic nanoparticles (MNPs). MNPs were selected for their unique magnetic properties, which can be exploited for both targeted drug delivery and control over the drug release. MNPs were prepared and characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy, superconducting quantum interference device magnetometer, and electrophoretic mobility measurements. Autoxidation of all three flavonoids follows a two-step first-order kinetic model. MCE showed the fastest degradation, while the oxidation of MCI was the slowest. The flavonoids were successfully loaded into the prepared MNPs, and the drug release was described by the first-order and Korsmeyer-Peppas models. External MFs were utilized to control the release mechanism and the cumulative mass of the flavonoids released.

A new hemiacetal chromone racemate and α-glucosidase inhibitors from Ficus tikoua Bur

From the petroleum ether and ethyl acetate portions of the 95% ethanol extract of Ficus tikoua Bur., a new hemiacetal chromone racemate, named (±)-ficunomone (1), together with twenty-two known flavonoids (2-23) were isolated. The new structure was elucidated by NMR, HRESIMS, and X-ray single-crystal diffraction analysis, and the known structures were determined by comparison of spectroscopic data with those reported from literatures. All the compounds were assayed for their inhibitory activities against yeast α-glucosidase, seven flavonoids could inhibit α-glucosidase, among which compounds 22 and 23 exhibited the highest inhibitory activity, with IC50 values at 5.12 ± 0.10 and 3.43 ± 0.15 μM respectively. Preliminary structure and relationship activity of all the compounds was analysed. Kinetic analysis of compounds 22 and 23 indicated that they are both uncompetitive inhibitors. Molecular docking studies revealed that they bound to amino acid residues of the α-glucosidase activity pocket.

Extensive analysis of the cultivated medicinal herbal drug Origanum dictamnus L. and antimicrobial activity of its constituents

Phytochemical investigations of the methanol extract from Origanum dictamnus L. (Lamiaceae) resulted in the isolation of forty compounds belonging to the classes of terpenes, resorcinol derivatives, flavonoids, depsides, neolignans and jasmonates. Chromatographic isolations were targeted by using two analytical platforms, NMR and HPLC-PDA-MS. In parallel, HPLC-PDA-MS of individual fractions enabled the unambiguous identification of additionally eight components. In total 48 constituents were isolated/identified. Among the isolated constituents are four undescribed compounds, one resorcinol derivative, one monoterpene, one diterpene and one acylated flavonoid glycoside. The structures of the isolated compounds were elucidated on the basis of spectroscopic analyses, including 1D and 2D NMR, and HPLC-ESI-MS and HRMS experiments. Representative compounds were tested for their antimicrobial activity against Staphylococcus aureus and Pseudomonas aeruginosa. I4-II7-dicarvacrol was the most potent constituent.

Potential use of essential oils in cosmetic and dermatological hair products: A review

BACKGROUND

Essential oils have great interest among the increasing demand for herbal cosmetics in the market. They are natural sources of biologically active ingredients due to the wide application of such compounds as well as their particular chemical composition. Several researches have evaluated the effectiveness of these bioactive ingredients for use in cosmeceuticals, mainly in both hair scalp and shaft hair damage repair. Thus, the amounts and their associations define the properties of these compositions with interest for hair cosmetic use, such as antioxidant, inflammatory, and antimicrobial activities. Because they are complex compounds, their actions on the skin, hair scalp, and shaft are not yet fully understood.

AIMS

The purpose of this review is to highlight the relevant researches and findings on essential oils in hair care.

METHODS

In order to achieve this objective, the present work comprises an updated bibliographic review related to essential oils used in hair care.

RESULTS

It was possible to observe that cosmeceuticals containing essential oils applied to the scalp are preferable for topical activity. Also, it was noticed that there are few reports regarding their use in hair shaft. However, it was found that some oils are used to intensify the brightness and fix the hair color.

CONCLUSIONS

This work demonstrated that the use of essential oils in both cosmetic products (industrial application) and those associated with oils carriers (as individual protocols) may lead to satisfactory results in the treatment of some scalp dysfunctions.

Ethnobotanical Survey of Medicinal Plants Used to Treat Cardiovascular Disorders in Ghasemloo Valley of Urmia City

AIMS

Many pharmacutical plants belonged to this region are used as the traditional drug by traditional physicians of the Urmia city in order to treat signs of disorders and cardiovescular system diseases.

BACKGROUND

The Ghasemloo valley located in the Urmia city is one of the typical areas in the northwestern Iran and includes many pharmacutical and plant species.

OBJECTIVE

Many pharmacutical plants belonged to this region are used as the traditional drug by traditional physicians of the Urmia city in order to treat signs of disorders and cardiovescular system diseases.

METHOD

Study was performed among 35 grocers in the Urmia city to identify effective and famous pharmacutical plants in treatment of cardiovescular and related diseases. Firstly a complete list of Urmia grocers was prepared from the Food and Drug Administrator of the Urmia University of Medical Sciences. The direct observation and interview alongside collecting herbarium samples of usual and effective indigenous medicinal plants were used to identify disorders and different signs of cardiovascular diseases. Questionnaires included personal information of grocers and they completed indigenous plants list containing information including the plant local name, the used organ, method of use, and the traditional therapeutic effect. Herbarium samples mentioned in the questionnaire were collected from the region and sent to the Jahad-e-Keshavarzi Research Centers and the Agriculture Faculty of Urmia university to determine the genus and species. After identifying and confirming the plant species, data related to the plant and results of cardiovascular research conducted on them were collected and recorded with reference to valid scientific sites. Data were enterred into the Excel 2010 program and then analyzed.

RESULT

60 medicinal plants of 26 families in Urmia were identified as effective in treatment of cardiovascular diseases from interviews and questionnaires; some plants mentioned in this study had known traditional therapeutic effects on cardiovascular disorders in the literature and some were identified with new effects. Results showed that the most therapeutic effects in cardiovascular diseases belonged to families Rosaceae (15%), Fabaceae (13%), Asteraceae (13%), and Apiaceae (10%). The most used organs of plants were the leave (23%) and fruit (19%). Plants were used mainly as infusion (68%) in the traditional method. Most plants of this study were used to treat the blood cholesterol (29%), hypertension (9%), the blood coagulation, prevention of bleeding (9%), and decrease in the abdominal fat (9%).

CONCLUSION

Some herbs introduced in this study have new therapeutic effects introduced for the first time. It is necessary to study therapeutic effects of indigenous plants presented in this research in order to prove studied and mentioned therapeutic effects and to provide study field for researchers in relation to identifying effective substances and studying claimed clinical effects of these plants on different cardiovascular diseases.

Interactive Impact of Arbuscular Mycorrhizal Fungi and Elevated CO2 on Growth and Functional Food Value of Thymus vulgare

Arbuscular mycorrhizal fungi (AMF) and elevated CO₂ (eCO₂) have been effectively integrated to the agricultural procedures as an ecofriendly approach to support the production and quality of plants. However, less attention has been given to the synchronous application of AMF and eCO₂ and how that could affect the global plant metabolism. This study was conducted to investigate the effects of AMF and eCO₂, individually or in combination, on growth, photosynthesis, metabolism and the functional food value of Thymus vulgare. Results revealed that both AMF and eCO₂ treatments improved the photosynthesis and biomass production, however much more positive impact was obtained by their synchronous application. Moreover, the levels of the majority of the detected sugars, organic acids, amino acids, unsaturated fatty acids, volatile compounds, phenolic acids and flavonoids were further improved as a result of the synergistic action of AMF and eCO₂, as compared to the individual treatments. Overall, this study clearly shows that co-application of AMF and eCO₂ induces a synergistic biofertilization impact and enhances the functional food value of T. vulgare by affecting its global metabolism.

A Review on Applications and Uses of Thymus in the Food Industry

Thyme is one of the most important medicinal plants because of its ethnopharmacological relevance and high content of bioactive compounds. This review focuses particularly on thyme as an alternative natural antioxidant and antimicrobial with potential use in the food industry. This is in line with the preferences of the current consumer, who demands healthier and more natural products. Different studies have concluded that the use of thyme increases stability and reduces lipid oxidation during the shelf-life period of foods (meat, meat products, milk, fish or fish products), which makes thyme a promising source of natural additives. Despite these findings, the use of Thymus extracts or essential oils as natural additives in foods is reduced in comparison with other natural preservative extracts. This review provides an overview of the most important information on the positive effect of the bioactive compounds of thyme and its uses as a preservative in foods, taking into account its origin (from plants, plant extracts or essential oils).

Facile synthesis and characterizations of antibacterial and antioxidant of chitosan monoterpene nanoparticles and their applications in preserving minced meat

Chitosan nanoparticles loaded monoterpenes (ChMNPs) were prepared for preservation of minced meat from oxidative changes and growth of microorganisms. Four monoterpenes (limonene, linalool, menthol and thymol) were used to synthesis of four different types of ChMNPs. The physicochemical characteristics of nanoparticles were analyzed using Scanning electron microscopy (SEM) and Zeta potential. SEM showed that the nanoparticles were nearly uniformly shape and size and the zeta potential values ranged between 0.0346 and -0.1690 mV. In vitro antimicrobial activity of Ch, monoterpenes (M) and ChMNPs against Gram (-) bacteria Escherichia coli (ATCC 8739) and Salmonella typhimurium (ATCC 1402) was analyzed using serial dilution test. E. coli was more susceptible than S. typhimurium to these products. ChMNPs exhibited good in vivo antimicrobial and antioxidant property for the minced meat samples during refrigerated storage. Verification of testing hypothesis was performed by assessing a DPPH radical scavenging activity, peroxide value and E. coli reduction of experimental nanoparticles. Significant effects of ChMNPs were observed at 1000 and 2500 mg/kg on the total number of E. coli in meat samples during storage time. The results indicate that ChMNPs can be used to preserve food as antimicrobial agents and to extend shelf life.

A Phytopharmacological review of a Mediterranean plant: Lavandula stoechas L

The Mediterranean region is characterized by a diverse vegetation cover, and the Lavandula genus is one of the most important medicinal and aromatic plants in this region. It has been used in traditional medicine as a treatment for anxiety and insomnia and to improve sleep quality for a long history. Lavender is commonly used in perfumes, soaps, bath powders, and scented sachets. It can flavor teas or food even at low concentrations. Several ethnopharmacological studies have demonstrated its use in treating several diseases; it has anti-inflammatory, antioxidant, antispasmodic, sedative, insecticidal, antimicrobial and antifungal activities. This paper reviews the geographical distribution, traditional uses, chemical composition, and pharmacological activities of the Lavandula stoechas.

Zataria multiflora extract and carvacrol affect cardiotoxicity induced by Adriamycin in rat

Background Because of the antioxidant effects of Zataria multiflora (ZM) and carvacrol (CAR) and also the role of oxidative stress in the induction of cardiotoxicity induced by Adriamycin (ADR), the aim of this study was to investigate the improvement effects of ZM extract and CAR on cardiotoxicity induced by ADR in rats. Methods Twenty-eight male rats were randomly assigned to four groups including (1) the control group; (2) the ADR group, which received ADR intravenously at the beginning of the study and the (3) ZM+ADR and (4) CAR+ADR groups, which received ZM and CAR by gavage for 28 consecutive days and ADR as single dose. Blood samples were collected on days 0 and 28 to determine serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT) and lactate dehydrogenase (LDH). Also, cardiac tissue was removed for redox marker evaluation. Results In the ADR group, malondialdehyde (MDA) significantly increased and superoxide dismutase (SOD) activity and total thiol contents significantly reduced, as compared with the control group, while CAR administration significantly improved this condition. Treatment with ZM significantly increased the SOD activity and total thiol content, as compared with the ADR group. The level of LDH significantly increased on day 28 in the ADR group compared to the control group, and administration of ZM and CAR significantly decreased it. The SGPT and SGOT levels in the ADR group significantly increased, and CAR administration significantly reduced them. Conclusion The results indicate that the administration of ZM hydroalcoholic extracts and its active ingredient, CAR, could reduce the oxidative stress damage through promotion of the cardiac and systemic antioxidant system. Also, CAR administration demonstrated better improvement in cardiotoxicity with ADR in rats.

Flavonoid biosynthetic pathways in plants: Versatile targets for metabolic engineering

Plants, fungi, and microorganisms are equipped with biosynthesis machinery for producing thousands of secondary metabolites. These compounds have important functions in nature as a defence against predators or competitors as well as other ecological significances. The full utilization of these compounds for food, medicine, and other purposes requires a thorough understanding of their structures and the distinct biochemical pathways of their production in cellular systems. In this review, flavonoids as classical examples of secondary metabolites are employed to highlight recent advances in understanding how valuable compounds can be regulated at various levels. With extensive diversity in their chemistry and pharmacology, understanding the metabolic engineering of flavonoids now allows us to fine-tune the eliciting of their production, accumulation, and extraction from living systems. More specifically, recent advances in the shikimic acid and acetate biosynthetic pathways of flavonoids production from metabolic engineering point of view, from genes expression to multiple principles of regulation, are addressed. Specific examples of plants and microorganisms as the sources of flavonoids-based compounds with particular emphasis on therapeutic applications are also discussed.

Flavonoids: an overview

Flavonoids, a group of natural substances with variable phenolic structures, are found in fruits, vegetables, grains, bark, roots, stems, flowers, tea and wine. These natural products are well known for their beneficial effects on health and efforts are being made to isolate the ingredients so called flavonoids. Flavonoids are now considered as an indispensable component in a variety of nutraceutical, pharmaceutical, medicinal and cosmetic applications. This is attributed to their anti-oxidative, anti-inflammatory, anti-mutagenic and anti-carcinogenic properties coupled with their capacity to modulate key cellular enzyme function. Research on flavonoids received an added impulse with the discovery of the low cardiovascular mortality rate and also prevention of CHD. Information on the working mechanisms of flavonoids is still not understood properly. However, it has widely been known for centuries that derivatives of plant origin possess a broad spectrum of biological activity. Current trends of research and development activities on flavonoids relate to isolation, identification, characterisation and functions of flavonoids and finally their applications on health benefits. Molecular docking and knowledge of bioinformatics are also being used to predict potential applications and manufacturing by industry. In the present review, attempts have been made to discuss the current trends of research and development on flavonoids, working mechanisms of flavonoids, flavonoid functions and applications, prediction of flavonoids as potential drugs in preventing chronic diseases and future research directions.

Polyphenols Isolated from Xanthoceras sorbifolia Husks and Their Anti-Tumor and Radical-Scavenging Activities

Xanthoceras sorbifolia Bunge. is used in traditional medicine in North China. To evaluate the anti-tumor and radical-scavenging activities of X. sorbifolia husks polyphenols and determine their structure-activity relationships, 37 polyphenols 1–37 were obtained by bioassay-guided fractionation. Two new compounds 1–2, and compounds 5, 6, 8, 9, 11, 14–17, 21–25, 27–29, 31, 33, 34, 36, and 37 were isolated from the genus Xanthoceras for the first time. Compounds 1–37 did not show strong cytotoxicity against the four tested tumor cell lines (A549, HepG2, MGC-803, and MFC) compared to paclitaxel and under the conditions tested in the anti-tumor assay, but compounds 3, 4, 7, 8, 10, 18–20, 25, 26, 29, 30, 32, and 35 exhibited stronger radical-scavenging activity than ascorbic acid in a 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt assay. This was the first report on the anti-tumor and radical-scavenging activities of the polyphenols isolated from X. sorbifolia husks. Overall, the present study contributed valuable information concerning X. sorbifolia husks use in medicine and pharmacology.

Study of the antioxidant activity of Thymus sibthorpii Bentham (Lamiaceae)

From the aerial parts of Thymus sibthorpii Bentham (Lamiaceae), five flavonoids apigenin (1), 7-methoxy-apigenin (2), naringenin (3), eriodictyol (4) and eriodictyol-7-glucoside (5), have been isolated together with caffeic acid methyl ester (6), rosmarinic acid (7) and rosmarinic acid methyl ester (8). The structures of the isolated compounds were established by spectroscopic methods. The extracts and the isolated compounds were tested for their free radical scavenging activity using the following in vitro assays: (i) interaction with the free stable radical of DPPH (1,1-diphenyl-2-picrylhydrazyl), (ii) inhibition of linoleic acid lipid peroxidation induced by the dihydrochloric acid of 2,2-azobis-2-amidinepropane (AAPH) and (iii) the scavenging activity of enzymatically produced superoxide anion. Their inhibitory activity toward soybean lipoxygenase was evaluated in vitro, using linoleic acid as a substrate. The antioxidant results of the extracts are discussed in terms of their constitution in phenolic compounds, which were determined following the Folin-Ciocalteu method.

Identification and characterization of dimeric oxidation products of p-cymene-2,3-diol isolated from Thymus vulgaris L

The aim of this study was to investigate the oxidation products of p-cymene-2,3-diol, a major antioxidative constituent of thyme (Thymus vulgaris L.). Although a dimeric form of p-cymene-2,3-diol and some derivative substances exhibiting valuable food technological and health-promoting properties have been reported in earlier publications, no obvious correlation has been shown between these substances. A modified HPLC-ESI-MS method made it possible to prove that two dimers, 3,4,3',4'-tetrahydroxy-5,5'-diisopropyl-2,2'-dimethylbiphenyl (1) and the newly identified 3',4'-dihydroxy-5,5'-diisopropyl-2,2'-dimethylbiphenyl-3,4-dione (2), are oxidation products of p-cymene-2,3-diol. 2 was characterized by the fragmentation pattern determined by multiple mass spectrometry, (1)H NMR, (13)C NMR, H-H COSY, HSQC, and HMBC. Both biphenyls were also quantitated in freeze-dried thyme as well as in a food matrix spiked with thyme extract. Model experiments using raw and cooked minced pork meat as matrix and sodium nitrite as oxidizing and reduction agent with and without ascorbic acid as protective reagent showed the correlation between food processing and dimer generation.

Effects of thymol on B16-F10 melanoma cells

Aromatic monoterpene, thymol, shows several beneficial activities, such as an antioxidative effect. However, the mechanism of its toxicity remains to be fully defined. In preliminary studies, thymol was characterized as a melanin formation inhibitor in an enzymatic system; however, thymol showed moderate cytotoxicity but not an antimelanogenic effect on B16-F10 melanoma cells. Thymol exhibited cytotoxicity, with an IC(50) value of 400 μM (60.09 μg/mL). This moderate toxic effect was suppressed with the addition of vitamin C and vitamin D, and 20 and 40% of cell viability was increased, respectively. Subsequently, the treatment of L-cysteine on thymol-treated melanoma cells reversed the toxic effect of thymol. Moreover, a significant oxidative stress condition was observed when B16 melanoma cells were cultured with thymol. In conclusion, the antioxidant actions of thymol generate a stable phenoxy radical intermediate, which generates reactive oxygen species and quinone oxide derivatives. Thus, it is proposed that the primary mechanism of thymol toxicity at high doses is due to the formation of antioxidant-related radicals.

Antioxidant potential of thyme extract: alleviation of N-nitrosodiethylamine-induced oxidative stress

Protective role of thyme extract against N-nitrosodiethylamine (NDEA)-induced oxidative stress has been evaluated in albino rats. For this, one group of rats were fed diet supplemented with thyme extract (0.5%) and served as the test group, whereas animals of the other group fed on normal diet served as the control group. The rats were fed on respective diets for a period of 2 weeks after which stress was induced to half the animals of each group by i.p. administration of NDEA at 200 mg/kg body weight. Animals were killed 48 h post stress-induction period. Feed intake and body weight decreased significantly in both test and control groups, the effect being less in test group. Increase in osmotic fragility and in-vitro lipid peroxidation (LPO) on stress induction was of lower degree in the test group. NDEA toxicity was mainly reflected in liver as evidenced by increased activities of plasma aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase. The effect was of lower degree in test group as compared with that in the control group. Increase in urea levels observed following NDEA administration was also of lower degree in test groups. Blood glutathione (GSH) levels increased more so in test group compared with control group on stress induction. The activities of superoxide dismutase (SOD), peroxidase (Px), and catalase (CAT) activities decreased significantly on stress induction in erythrocytes. LPO increased in all the tissues through varying degree, and the increase was appreciably of lower degree in test group. The activity of SOD increased significantly in both test and control group on stress induction, whereas activities of Px and CAT decreased following NDEA treatment, and the effects were of lower degree in test group. Thus, supplementation of diet with thyme extract can improve antioxygenic potential and hence help to prevent oxidative stress.

Antioxidative properties of Thymus vulgaris leaves: comparison of different extracts and essential oil chemotypes

Thyme (Thymus vulgaris L., Lamiaceae) is a subshrub from the Lamiaceae family with plants that are rich in essential oils and antioxidative phenolic substances. Twelve accessions originating from southern France and the variety 'Deutscher Winter' were grown in an experimental field in eastern Austria. Leaf samples from these plants as well as from a commercial thyme rich in thymol were analyzed for their essential oil and the antioxidative potential in various extracts. The assays for antioxidative activity were the total phenolics according to the Folin-Ciocalteu method, DPPH decoloration, and Fe(3+) reduction (FRAP). Both extraction techniques used, in the water bath at 40 degrees C and in the ultrasonic bath at room temperature, proved to be efficient. The best results were obtained with 60% ethanol as extractant. In the comparison of the different accessions the less active and the most active of these extracts differed by factors of 2.1 and 2.6 in the total phenolics and FRAP assay, respectively, and by factors 1.5-2.0 in the DPPH assay. Rosmarinic acid accounted for 22-55% of the antioxidant activity in the ethanolic extracts. Essential oils with high proportions of the phenolic components thymol and/or carvacrol showed the highest antioxidant activity. Ethanolic extracts from the residues after distillation were considerably lower in antioxidant activity than the respective extracts from the dried leaves. Extracts with CH2Cl2 in the ultrasonic bath contained volatiles in proportions close to the essential oil but displayed very low antioxidant activity.

Relaxant effect ofThymus vulgaris on guinea-pig tracheal chains and its possible mechanism(s)

Thymus vulgaris for the treatment of respiratory diseases is indicated widely, and relaxant effects on smooth muscle have been shown previously. In the present study, the relaxant effects of macerated and aqueous extracts of Thymus vulgaris on tracheal chains of guinea-pigs were examined using cumulative concentrations of macerated and aqueous extracts in comparison with saline (as the negative control) and theophylline (as the positive control). The relaxant effects of four cumulative concentrations of macerated and aqueous extracts (0.25, 0.5, 0.75 and 1.0 g %) in comparison with saline (as the negative control) and four cumulative concentrations of theophylline (0.25, 0.5, 0.75 and 1.0 mm; as the positive control) were examined for their relaxant effects on precontracted tracheal chains of guinea-pig by 60 mm KCl and 10 microm methacholine in two different conditions: non-incubated tissues and incubated tissues with 1 microm propranolol and 1 microm chlorphenamine. There were significant correlations between the relaxant effects and the concentrations for both extracts and theophylline in all experimental groups (p < 0.01 to p < 0.001). These results demonstrated a potent relaxant effect of Thymus vulgaris on guinea-pig tracheal chains that was comparable to theophylline at the concentrations used.

In-vitro anti-inflammatory effect of Eucalyptus globulus and Thymus vulgaris: nitric oxide inhibition in J774A.1 murine macrophages

It is well known that nitric oxide (NO) plays an important role in the pathogenesis of inflammatory diseases. Eucalyptus globulus Labill. and Thymus vulgaris L. have been used in traditional medicine in the treatment of bronchitis, asthma and other respiratory diseases. The present study focuses on the effects of these two extracts on NO production induced by lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma) in the murine macrophage cell line J774A.1. In addition, cell viability, scavenging activity and inducible nitric oxide synthase (iNOS) mRNA expression were evaluated. E. globulus and T. vulgaris extracts significantly inhibited the enhanced production of NO induced by LPS and IFN-gamma in a dose-dependent manner. Treatment with these two extracts did not reduce cell viability at any dose used. Both plant extracts showed significant scavenging of NO radicals released by an NO donor, PAPA-NONOate. Results also show that pre-treatment with E. globulus and T. vulgaris extracts significantly inhibits iNOS mRNA expression. This study thus suggests that the inhibition of net NO production by these two extracts may be due to their NO scavenging activity and/or their inhibitory effects on iNOS gene expression.

In vivo topical anti-inflammatory and in vitro antioxidant activities of two extracts of Thymus satureioides leaves

Four extracts at increasing polarity were prepared from the leaves of Thymus satureioides Coss. (Labiatae) and assayed for the in vivo topical anti-inflammatory effect using the croton oil ear test in mice, and for in vitro both antioxidant (DPPH degrees test) and anti-bacterial (broth microdilution method) activities. The chloroform extract showed a topical anti-inflammatory activity (ID50=282 microg cm(-2)), only three times lower than that of the reference drug indomethacin (ID50=93 microg cm(-2)) and its active components were identified as ursolic and oleanolic acids. The methanol extract, showing a significant radical-scavenging effect (SC50=14.54 microg), was characterized by the isolation and identification of some flavonoids. On the contrary, the extracts did not show any anti-bacterial effect against four standard aerobial bacteria strains.

Role of Thymus Oil in Burn Wound Healing

Thymus oil and its components are becoming increasingly popular as naturally occurring antimicrobial and antioxidant agents. The real importance of thymus on nitric oxide (NO) is unknown. NO is an important mediator in numerous physiologic and pathophysiologic events. Stasis and thrombosis in burn wound can progress as a result of the release of local mediators. The implication of NO in burn injury is not well studied. In this study, we tried to determine the role of burn-induced NO and whether thymus oil plays a protective role after a thermal injury. Rats were divided into five groups. We topically applied thymus oil, olive oil, and silverdin and sulfadiazine on the rats, respectively, during a period of 21 days after they were burned while under anesthesia. The burned control group and nonburned control group did not receive any treatment. The results of this study show that NO was overproduced by thermal injury and decreased during the days after burn injury. The decrease in rats treated with thymus and sulfadiazine was higher than the others. These data indicate that thymus oil may serve as a protective agent to the damaged tissues by decreasing the NO level. Histologic examination results show that the formation of new tissue in rats receiving thymus oil was more than other burned groups, and this finding supports our hypothesis.

Studies on the Antioxidant Activities of Desmodium gangeticum

Desmodium gangeticum is herbal species which is widely used in the indigenous system of medicine and is reported to contain flavone and isoflavanoid glycosides. In view of its wide use and it's chemical composition, this study was aimed at examining the antioxidant activity of the extract of D. gangeticum. The extract was studied for diphenyl picryl hydrazyl (DPPH), nitric oxide, ferryl-bipyridyl and hypochlorous acid scavenging activity along with lipid peroxidation. Nitric oxide was generated using sodium nitroprusside and was studied using Griess reagent. In order to study the iron chelating capacity of the extract, the percentage ferryl-bipyridyl inhibition was studied. Hypochlorous acid scavenging activity was tested by measuring the inhibition of 5-thio-2-nitrobenzoic acid oxidation. The extract was also studied for lipid peroxidation assay by thiobarbituric acid-reactive substances (TBARS) method using rat brain homogenate. The results indicate that D. gangeticum extract has potent antioxidant activity.

Studies on the antioxidant activity of Lippia citriodora infusion: scavenging effect on superoxide radical, hydroxyl radical and hypochlorous acid

Lippia citriodora is an herbal species which contains several flavonoids and phenolic acids. In view of the pharmacological interest in natural phenolic compounds as antioxidants, this study examined the superoxide radical, hydroxyl radical and hypochlorous acid scavenging activities of L. citriodora infusion. Superoxide radical was generated either in an enzymatic or in a chemical system, and scavenging ability was assessed by the inhibition of nitroblue tetrazolium reduction. Hydroxyl radical was generated by the reaction of an iron-EDTA complex with H2O2 in the presence of ascorbic acid, and was assayed by evaluating deoxyribose degradation. Hypochlorous acid scavenging activity was tested by measuring the inhibition of 5-thio-2-nitrobenzoic acid oxidation. The results demonstrate that this infusion has a potent superoxide radical scavenging activity and a moderate scavenging activity of hydroxyl radical and hypochlorous acid. The chemical composition of the lyophilized infusion was also determined in an attempt to establish its relationship with the antioxidant activity found in the present study.

GC/MS evaluation of thyme (Thymus vulgaris L.) oil composition and variations during the vegetative cycle

Capillary GC/MS analysis based on polar and non-polar columns has been applied to evaluation of the volatile oils hydrodistilled from thyme (Thymus vulgaris L.) plants. The adopted methodology has been used to monitor seasonal variations in the composition of the oil obtained from thyme herbs harvested at different periods during the plant vegetative and life cycles. Oils from thyme plants of young (2 years) and old (5 years) cultivations have been evaluated from four and two collections, respectively, effected throughout May/December growth period. Generally, the oil was found to be rich in the active monoterpene phenols (thymol and carvacrol) and their corresponding monoterpene hydrocarbon (HC) precursors (p-cymene and gamma-terpinene), which collectively showed synchronized patterns of variation during the different collection periods and in different seasons. The oil from old plant collected in May/June period (0.15% v/w) was characterized by significantly lower levels of monoterpene HCs (mainly gamma-terpinene) and the highest levels of the oxygenated monoterpenes (linalool and borneol), monoterpene phenols (mainly thymol) and their derivatives (mainly carvacrol methyl ether), sesquiterpenes (mainly beta-caryophyllene) and their oxygenated derivatives (e.g. caryophyllene oxide) in comparison with all other samples. A characteristic presence of camphor and thymodihydroquinone was also observed in the old plant oils. On the other hand, the young plant, collected in June/July just before the end of the vegetative cycle, provided the best oil yield (1.2%) with also the highest % content of the monoterpene phenols (thymol: 51.2% and carvacrol: 4%). This latter growth period can represent the best harvest time of young thyme plants in order to obtain an essential oil with better quality and quantity.

Antioxidant effect of flavonoids after ascorbate/Fe2+-induced oxidative stress in cultured retinal cells11Abbreviations: BME, basal medium of Eagle; DCFH2, 2′,7′-dichlorodihydrofluorescein; LDH, lactate dehydrogenase; PC, partition coefficient; Rf, retardation factor; ROS, reactive oxygen species; TBA, thiobarbituric acid; and TBARS, thiobarbituric acid-reactive substances

In this study, we investigated the structure-activity relationship of four flavonoids, i.e. eriodictyol, luteolin, quercetin, and taxifolin, in cultured retinal cells after ascorbate/Fe(2+)-induced oxidative stress. The relative order of antioxidant efficacy, determined by the thiobarbituric acid method, was the following: eriodictyol > quercetin > luteolin > taxifolin. Upon preincubation, the flavonoids were also effective in reducing the extent of lipid peroxidation. Oxidative stress, determined by the changes in fluorescence of 2',7'-dichlorodihydrofluorescein, was also decreased in the presence of the flavonoids, showing the following order of antioxidant efficacy: eriodictyol > taxifolin approximately quercetin > luteolin. Ascorbate/Fe(2+)-induced oxidative stress or incubation in the presence of the flavonoids did not significantly affect the viability of retinal cells. We also evaluated the degree of membrane partition of the flavonoids. In this system, the results strongly suggest that the higher antioxidant activity of the flavonoids is not correlated with the presence of a double bond at C(2)-C(3) and/or a hydroxyl group at C(3) on the C ring, but rather may depend on the capacity to inhibit the production of reactive oxygen species to interact hydrophobically with membranes. Eriodictyol was shown to be the most efficient antioxidant in protecting against oxidative stress induced by ascorbate/Fe(2+) in the retinal cells.

Negative atmospheric pressure chemical ionisation low-energy collision activation mass spectrometry for the characterisation of flavonoids in extracts of fresh herbs

The flavonoid composition of commonly eaten fresh herbs such as dill, oregano and parsley was analysed by combined LC, MS and low-energy collision induced dissociation (CID) MS-MS. Negative atmospheric pressure chemical ionisation (APCI) MS and MS-MS were used to provide molecular mass information and product-ion spectra of the glycosyl compounds. The most prominent fragment was found to arise from the aglycone ion, which provides molecular mass information about the glycosyl substituent and the aglycone. Product-ion spectra of the aglycone verified the identity by comparison with product-ion spectra of authentic standards. Methoxylated flavonoids provide characteristic fragmentation, i.e., loss of *CH3, which add to the usefulness of the method for identifying unknown flavonoids. Negative-mode APCI-MS is thus demonstrated to be a good alternative to the commonly employed positive mode operation.

Protection of mitochondrial functions against oxidative stresses by isoflavans from Glycyrrhiza glabra

Isoflavan derivatives, glabridin (1), hispaglabridin A (2), hispaglabridin B (3), 4'-Omethylglabridin (4) and 3'-hydroxy-4'-O-methylglabridin (5), isolated from Glycyrrhiza glabra, were investigated for their ability to protect liver mitochondria against oxidative stresses. Mitochondrial lipid peroxidation linked to respiratory electron transport and that induced non-enzymatically were inhibited by these isoflavans. Hispaglabridin A (2) strongly inhibited both peroxidations and 3'-hydroxy-4'-O-methylglabridin (5) was the most effective at preventing NADH-dependent peroxidation. 3'-Hydroxy-4'-O-methylglabridin (5) protected mitochondrial respiratory enzyme activities against NADPH-dependent peroxidation injury. Dihydroxyfumarate-induced mitochondrial peroxidation was also prevented by this isoflavan. Isoflavans from G. glabra were shown to be effective in protecting mitochondrial function against oxidative stresses.

Elevated, sustained peroxynitrite levels as the cause of chronic fatigue syndrome

The etiology of chronic fatigue syndrome (CFS) has been both obscure and highly contentious, leading to substantial barriers to both clear diagnosis and effective treatment. I propose here a novel hypothesis of CFS in which either viral or bacterial infection induces one or more cytokines, IL-1beta IL-6, TNF-alpha and IFN-gamma. These induce nitric oxide synthase (iNOS), leading to increased nitric oxide levels. Nitric oxide, in turn, reacts with superoxide radical to generate the potent oxidant peroxynitrite. Multiple amplification and positive feedback mechanisms are proposed by which once peroxynitrite levels are elevated, they tend to be sustained at a high level. This proposed mechanism may lower the HPA axis activity and be maintained by consequent lowered glucocorticoid levels. Similarities are discussed among CFS and autoimmune and other diseases previously shown to be associated with elevated peroxynitrite. Multiple pharmacological approaches to the treatment of CFS are suggested by this hypothesis.