Antioxidant Activities of Plants Used in Traditional Medicine in Turkey

Ethanol extracts from 6 species representing six different families, used in traditional medicine in Turkey were evaluated for their antioxidant activities. The inhibition of superoxide anion formation and lipid peroxidation levels of Ononis spinosa, Centranthus longiflorus, Lythrum salicaria, Plantago major, Juglans regia and Teucrium polium extracts were tested using in vitro standard procedures and IC₅₀ values were determined. In vitro tests included superoxide anion radical scavenging activity and lipid peroxidation. All ethanol extracts of plants showed concentration-dependent superoxide anion radical scavenging activity. The results of the superoxide anion formation assay showed that the ethanol extract of Centranthus longiflorus was found to be most potent inhibitor (IC₅₀ 0.77?mg/ml) and followed by Plantago major (IC₅₀ 1.21?mg/ml), Juglans regia (IC₅₀ 1.39?mg/ml), Ononis spinosa (IC₅₀ 1.35?mg/ml), Teucrium polium (IC₅₀ 3.10?mg/ml) and Lythrum salicaria (IC₅₀ 5.00?mg/ml). All the extracts, excluding Ononis spinosa and Teucrium polium, showed concentration-dependent inhibitory effect on lipid peroxidation. IC₅₀ values of the effective ethanol extracts of plants on lipid peroxidation were as follows: Juglans regia (IC₅₀ 3.3?mg/ml), Plantago major (IC₅₀ 3.4?mg/ml), Centranthus longiflorus (IC₅₀ 3.9?mg/ml) and Lythrum salicaria (IC50 5.3?mg/ml). The results showed that Centranthus longiflorus, Plantago major and Juglans regia extracts had the highest antioxidant capacities among the six species examined.     

Screening of Spanish Medicinal Plants for Antioxidant and Antifungal Activities

Abstract

Dichloromethane, ethyl acetate, methanol, and aqueous extracts obtained from 16 Spanish medicinal plants were screened for their antioxidant and antifungal activities. The radical scavenging capacity was evaluated by the DPPH method using a rapid screening by TLC and a spectrophotometric assay. Polar extracts obtained from Jasonia glutinosa L. (Lamiaceae), Tanacetum parthenium (L.) Schultz (Lamiaceae), Equisetum telmateia Ehrh. (Equisetaceae), Verbena officinalis L. (Verbenaceae), and Lythrum salicaria L. (Lythraceae) showed high antioxidant properties. Among them, the methanol extract of Lythrum salicaria showed the strongest antiradical capacity with an IC₅₀ value similar to the positive control ascorbic acid. On the contrary, the best antifungal properties against Rhizopus stolonifer were produced by ethyl acetate or dichloromethane extracts from Anthemis arvensis L. subsp. arvensis (Asteraceae), Tanacetum parthenium, Santolina chamaecyparissus L. subsp. squarrosa Nyman (Asteraceae), Anagallis arvensis L. (Primulaceae) and the methanol extract of Anagallis foemina Miller (Primulaceae). The dichloromethane extract of Anthemis arvensis subsp. arvensis was the best inhibitor of fungus growth.     

Antioxidant,anticholinesterase and antibacterial activities of Stachys guyoniana and Mentha aquatica

Context: Stachys guyoniana Noë ex. Batt. and Mentha aquatica L. are two Algerian Lamiaceae used in folk medicine.

Objective: To investigate their antioxidant, anticholinesterase and antibacterial activities.

Material and methods: n-Butanol (BESG), ethyl acetate (EESG) and chloroform (CESG) extracts of S. guyoniana and methanol (MEMA) and chloroform (CEMA) aerial part extracts of M. aquatica and methanol (MERMA) and acetone (AERMA) roots extracts of M. aquatica were evaluated for their antioxidant activity by the β-carotene-linoleic acid, DPPH^? and ABTS^?+?scavenging, CUPRAC and metal chelating assays. The anticholinesterase activity was tested against AChE and BChE. The antibacterial activity was assessed by MICs determination against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella heidelberg, Klebsiella pneumoniae, Enterobacter aerogenes and Morganella morganii strains.

Results: In the β-carotene test, the CESG (IC₅₀: 2.3?±?1.27?μg/mL) exhibited the highest activity. The BESG was the best scavenger of DPPH^? (IC₅₀: 2.91?±?0.14?μg/mL). In the ABTS test, AERMA was the most active (IC₅₀: 4.21?±?0.28?μg/mL). However, with the CUPRAC, the BESG exhibited the best activity (A_0.50: 0.15?±?0.05?μg/mL) and was active in metal chelating assay with 48% inhibition at 100?μg/mL. The BESG was the best AChE inhibitor (IC₅₀: 5.78?±?0.01?μg/mL) however, the AERMA showed the highest BChE inhibitory activity (IC₅₀: 19.23?±?1.42?μg/mL). The tested extracts exhibited a good antibacterial activity.

Conclusion: This study demonstrated good antioxidant, anticholinesterase and antibacterial potential of S. guyoniana and M. aquatica, which fits in well with their use in folk medicine.     

Antibacterial,antioxidant and anti-proliferative properties and zinc content of five south Portugal herbs

Context: Crataegus monogyna L. (Rosaceae) (CM), Equisetum telmateia L. (Equisataceae) (ET), Geranium purpureum Vil. (Geraniaceae) (GP), Mentha suaveolens Ehrh. (Lamiaceae) (MS), and Lavandula stoechas L. spp. luisieri (Lamiaceae) (LS) are all medicinal.

Objective: To evaluate the antioxidant, antiproliferative and antimicrobial activities of plant extracts and quantify individual phenolics and zinc.

Material and methods: Aerial part extracts were prepared with water (W), ethanol (E) and an 80% mixture (80EW). Antioxidant activity was measured with TAA, FRAP and RP methods. Phenolics were quantified with a HPLC. Zinc was quantified using voltammetry. Antibacterial activity (after 48?h) was tested using Enterococcus faecalis, Bacillus cereus, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Listeria monocytogenes. Antiproliferative activity (after 24?h) was tested using HEP G2 cells and fibroblasts.

Results: Solvents influenced results; the best were E and 80EW. GP had the highest antioxidant activity (TAA and FRAP of 536.90?mg AAE/g dw and 783.48?mg TE/g dw, respectively). CM had the highest zinc concentration (37.21?mg/kg) and phenolic variety, with neochlorogenic acid as the most abundant (92.91?mg/100?g dw). LS was rich in rosmarinic acid (301.71?mg/100?g dw). GP and LS inhibited the most microorganisms: B. cereus, E. coli and S. aureus. GP also inhibited E. faecalis. CM had the lowest MIC: 5830?μg/mL. The antibacterial activity is explained by the phenolics present. LS and CM showed the most significant anti-proliferative activity, which is explained by their zinc content.

Conclusion: The most promising plants for further studies are CM, LS and GP.     

Evaluation of the acute antihyperglycemic effects of four selected indigenous plants from Jordan used in traditional medicine

Context:?Eryngium creticum Lam. (Umbelliferae), Geranium graveolens L.Her.exn Ait (Geraniaceae), Paronychia argentea Lam. (Caryophyllaceae), and Varthemia iphionoides Boiss (Compositae) have traditionally been used as antidiabetic phytomedicines. However, their alleged benefits and mechanisms remain elusive.

Objectives:?To evaluate the effect of these plants on in vitro and in vivo enzymatic starch digestion.

Materials and methods:?In vitro enzymatic starch digestion with acarbose or (1–50 or 100?mg/ml) plants aqueous extracts was assayed using α-amylase and α-amyloglucosidase. Oral starch tolerance tests and oral glucose tolerance tests were determined for the plant extracts at concentrations 125, 250, and 500?mg/kg body weight. Blood glucose levels in rats treated with plant extracts or drugs (acarbose or metformin and glipizide) were measured at ?30, 0, 45, 90, and 135?min.

Results and discussion:?In vitro, acarbose, and water extracts of G. graveolens and V. iphionoides exerted significant dose-dependent dual inhibition of α-amylase and α-glucosidase, with respective IC₅₀s of 1.2?μg/ml, 84.7, and 65.2?mg/ml. Comparable in vivo acute postprandial antihyperglycemic efficacies were obtained for G. graveolens and V. iphionoides in starch-fed rats. E. creticum exhibited substantial acute antihyperglycemic activities in starch-treated rats, despite lacking any favorable in vitro effectiveness. However, P. argentea lacked any inhibitory efficacy. None of the plant extracts qualified for improving the glucose tolerance in fasted rats on glucose loading.

Conclusion:?G. graveolens and V. iphionoides can be considered as potential candidates for therapeutic modulation of impaired fasting glycemia, impaired glucose tolerance, and type 2 diabetes.     

Cytotoxic,antioxidant and antimicrobial effects of nine species of woundwort (Stachys) plants

Context: Woundwort (Stachys) plants from the Lamiaceae family have been used in folk medicine for various purposes.

Objective: This study was designed to analyze cytotoxic, antioxidant and antimicrobial activities of Stachys plants, because these fields have extensively benefited of drug discovery from natural sources.

Materials and methods: Nine Stachys plants were collected from different regions of Iran. Cytotoxic activities of methanol, 80% methanol and dichloromethane (DCM) extracts of these plants were assessed on three human cancer cell lines (HL-60, K562 and MCF-7 cells) with the MTT assay, while antioxidant and antimicrobial activities were determined on methanol extracts by DPPH and nutrient broth micro-dilution assays, respectively.

Results: DCM extract of St. pilifera Benth. had the lowest IC₅₀ in three cancer cell lines ranging from 33.1 to 48.2?µg/ml, followed by the 80% methanol extract of St. persica S.G.Gmel. ex C.A.Mey. (IC₅₀ range: 62.1–104.1?µg/ml) and DCM extract of St. byzantina C. Koch (IC₅₀ range: 62.7–131.0?µg/ml). St. byzantina. St. lavandulifolia Vahl., St. acerosa Boiss., St. obtusicrena Boiss. and St. persica showed lowest IC₅₀ values in the DPPH scavenging assay (135.1, 162.6, 164.7, 169.4 and 172.4?µg/ml, respectively), while their total phenolic contents were 23.9, 18.2, 18.6, 20.4, 27.8?mg equivalent of gallic acid in 1?g dry plant, respectively. The methanol extracts of St. byzantina and St. persica inhibited all six tested Gram-negative and Gram-positive bacterial strains.

Conclusion: Various Stachys species (especially St. byzantina and St. persica) are valuable sources of natural compounds with important biological properties.     

Biological activities of ethyl acetate extract of different parts of Hyssopus angustifolius

Context: Hyssopus angustifolius M. Bieb. (Lamiaceae) is one of the most important medicinal plants in Iranian traditional medicine for the treatment of lung inflammation, laryngitis and cough relief. Much attention has been paid to this medicinal plant because of its traditional uses.

Objective: The present study examined the antioxidant and antihemolytic activities of ethyl acetate extract of stems, leaf and flowers of Hyssopus angustifolius.

Materials and methods: Antioxidant activity of extracts was evaluated by employing six different models, i.e., DPPH, nitric oxide and hydrogen peroxide scavenging, metal chelating and reducing power activities and hemoglobin-induced linoleic acid system. Also, antihemolytic activity was evaluated against hydrogen peroxide-induced hemolysis.

Results: Flowers extract showed the better activity than leaf and stems extracts in DPPH radical scavenging activity (IC₅₀ was 275.4?±?7.6 μg mL^?1). Leaf, stems and flowers extracts showed good nitric oxide scavenging activity (IC₅₀ were 376.6?±?11.4 µg mL^?1 for flowers, 297.6?±?9.6 μg mL^?1 µg mL^?1 for leaves and 837.8?±?19.2 µg mL^?1 for stems). The leaf extract exhibited better hydrogen peroxide scavenging and Fe²⁺ chelating activity than stems and flowers extracts. In hemoglobin-induced linoleic acid system, all of the extracts exhibited very good activity. Also, extracts show weak reducing power activity. The ethyl acetate extract of leaf showed better antihemolytic activity than the flower and stems (IC₅₀ was 94.0?±?2.4 μg mL^?1).

Discussion and conclusion: These findings give a scientific basis to the traditional usage of Hyssopus angustifolius, also showing its potential as rich sources of natural antioxidant compounds.     

Antitumor activities of extracts from selected desert plants against HepG2 human hepatocellular carcinoma cells

Abstract

Context: Phytochemicals are produced by desert plants to protect themselves against stressful environments. They have been shown to be useful in preventing and fighting adverse pathophysiological conditions and complex diseases, including cancer. Although many desert plants have been investigated for their antitumor properties, a large number of them still remain to be explored for possible therapeutic applications in oncologic diseases.

Objective: To screen the antitumor effects of selected desert plants, namely Achillea fragrantissima (Forssk.) Sch. Bip. (Compositae), Ochradenus baccatus Delile (Resedaceae), Origanum dayi Post (Lamiaceae), Phlomis platystegia Post (Lamiaceae) and Varthemia iphionoides Boiss (Compositae), against an in vitro tumor model utilizing HepG2 human hepatocellular carcinoma cells.

Materials and methods: The aqueous extracts of aerial parts of the aforementioned plants were prepared and used for the in vitro experiments. The HepG2 cells were exposed to varying concentrations (0–4?mg/mL) of each plant extract for 24 or 48?h and the cytotoxicity was measured by the MTT assay.

Results: Following 24?h exposure, O. dayi extract exhibited a substantial antiproliferative effect in HepG2 cells (IC₅₀?=?1.0?mg/mL) followed by O. baccatus (IC₅₀?=?1.5?mg/mL). All plant extracts displayed cytotoxicity following 48?h exposure. Nevertheless, a substantial effect was observed with O. dayi (IC₅₀?=?0.35?mg/mL) or O. baccatus (IC₅₀?=?0.83?mg/mL).

Conclusion: The aqueous extracts from aerial parts of O. dayi and O. baccatus possess antitumor effects against human liver cancer cells. These desert plants represent valuable resources for the development of potential anticancer agents.     

Iron(III) reducing and antiradical activities of three Sideritis from Turkey

Context: Sideritis species (Lamiaceae) are widely used as herbal tea and have been used in folk medicine for their anti-inflammatory, anti-rheumatic, digestive, and antimicrobial activities in Turkey. Sideritis dichotoma Huter., Sideritis erythrantha Boiss. var. cedrotorum, and Sideritis vuralii H. Duman et Ba?er are available as commercial products in Turkey.

Objective: The antiradical activities of the various solvent extracts of Sideritis species are investigated here for the first time.

Materials and methods: Plant samples were sequentially extracted with n-hexane, dichloromethane, methanol, and aqueous methanol (50%, v/v) in Soxhlet apparatus. The extracts of Camellia sinensis (L.) Kuntze (Theaceae) were also prepared for use as a positive control. Total phenolics, iron(III) reductive effects, and 1,1-diphenyl-2-picrylhydrazyl (DPPH^?) radical scavenging activities of the all extracts were measured colorimetrically.

Results: The aqueous MeOH and MeOH extracts contained the highest amount of total phenols, whereas the n-hexane extract contained the lowest amounts. The polar extracts of C. sinensis showed higher antiradical activity and also iron(III) reductive effects than the Sideritis species; however, the non-polar extracts of Sideritis species were found to be more active than those from C. sinensis in the iron(III) reductive assay and in the DPPH^? assay as well. But none of the extracts was found to be as active as with positive controls, viz., ascorbic acid, butylated hydroxyanisole (BHA), and Trolox.

Discussion and conclusion: These results can be shown to have antioxidant activities of these Sideritis species and support the ethnopharmacological use of these Sideritis plants.     

Anti-Helicobactor pylori activity of some Jordanian medicinal plants

Context: Natural flora are considered a major source of new agents for the treatment of Helicobactor pylori. The plants used in this study were selected based on previous traditional use.

Objective: In this study, we evaluated the effect of extracts of 16 medicinal plants grown in Jordan against clinical isolates of H. pylori.

Materials and methods: Tested plant extracts included Aloysia triphylla (L'Her.) Britton (Verbenaceae), Anethum graveolens L. (Apiaceae), Artemisia inculata Delile (Asteraceae), Capparis spinosa L. (Capparaceae), Crataegus aronia (L.) Bosc ex. DC. (Rosaceae), Inula viscose (L.) Ait (Asteraceae), Lavandula officinalis Chaix. (Lamiaceae), Lepidium sativum L. (Cruciferae), Origanum syriaca L. (Lamiaceae), Paronychia argentea Lam. (Caryophyllaceae), Passiflora incarnate L. (Passifloraceae), Psidium guajava L. (Myrtaceae), Sarcopoterium spinosum (L.) Spach (Rosaceae), Sesamum indicum L. (Pedaliaceae), Urtica urens L. (Urticaceae) and Varthemia iphionoids Boiss (Asteraceae). Clinical isolates of H. pylori were tested in vitro for susceptibility to each of the above plant crude extracts using disk diffusion method, and the MIC value was determined for each plant extract using the serial dilution method.

Results: Results showed that ethanol extracts of most medicinal plants exerted cytotoxiciy against H. pylori isolates. Among the tested plant extracts, A. triphylla (MIC: 90?µg/mL, MBC: 125?µg/mL) and I. viscosa (MIC: 83?µg/mL, MBC: 104?µg/mL) showed the strongest activity against both isolates of H. pylori.

Discussion and conclusion: Jordanian medicinal plants might be valuable sources of starting materials for the synthesis of new antibacterial agents against H. pylori.     

In vitro assessment of selected Korean plants for antioxidant and antiacetylcholinesterase activities

Context: Antiacetylcholinesterase (AChE) drugs have been a main therapeutic treatment for Alzheimer’s disease because increased AChE levels play a key role in reducing neurotransmission.

Objectives: Extracts from 35 Korean plants were selected and screened for antioxidant and anti-cholinesterase activity to explore new sources derived from Korean natural resources that could be used as AD therapeutic agents.

Materials and methods: The antioxidant effect of extracts from 35 selected Korean plants was determined using two most common free radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS). Additionally, the effect of extracts, identified as antioxidants, on acetylcholinesterase inhibition was assessed by an acetylcholinesterase assay kit.

Results: Out of 36 extracts of 35 plants tested, Oenothera biennis L. (9.09?μg/mL), Saururus chinensis (Lour.) Baill. (9.52?μg/mL) and Betula platyphylla var. japonica (9.85?μg/mL) showed strong DPPH scavenging activity. Twelve other extracts also exerted moderate free radical scavenging activities with IC₅₀ values ranging from 10 to 50?μg/mL. Antioxidant capacity detected by ABTS assay was only significant in O. biennis (23.40?μg/mL), while the other extracts were weak or unable to reduce the production of ABTS. Based on the antioxidant activities of these plant extracts, 19 extracts with IC₅₀ values less than 100?μg/mL in DPPH assay were selected for further AChE inhibition assay. Among the extracts tested, the IC₅₀ value for Prunella vulgaris var. lilacina NAKAI (18.83?μg/mL) in AChE inhibitory activity was the lowest, followed by O. biennis (20.09?μg/mL) and Pharbitis nil Chosy (22.79?μg/mL).

Conclusions: Considering complex multifactorial etiology of AD, the extracts of P. vulgaris var. lilacina (aerial part), O. biennis (seed) and P. nil (seed) may be safe and ideal candidates for future AD modifying therapies.     

Antioxidant Activity Studies on Selected Sideritis. Species Native to Turkey

ABSTRACT

Sideritis. L. species are widely used as medicinal plants and as herbal teas in Turkey, in which 45 species of the genus are naturally found. The aim of this study was to determine the antioxidant activity of Sideritis. species found in the Mediterranean region. In this study, the antioxidant activities of the lyophilized extracts obtained from aerial parts of 17 species (18 taxa) of Sideritis. were compared, of which 15 taxa were endemic. The antioxidant activities of aqueous extracts were studied by two different techniques: qualitative DPPH (1,1-diphenyl-2-picrylhydrazyl radical) assay to detect the free radical scavenging activity and the TBA assay to detect liposome lipid peroxidation. All the extracts (except S. erithrantha. subsp. erithrantha., S. dichotoma., S. syriaca. subsp. nusariensis., S. tmolea.) showed a strong antioxidant activity with the DPPH test. High activity was observed in the S. brevibracteata. (IC₅₀ mg/ml = 0.16), S. condensata. (IC₅₀ mg/ml = 0.33), S. serratifolia. (IC₅₀ mg/ml = 0.31) extracts with the lipid peroxidation assay method.     

Phytochemical analysis,antiproliferative and antioxidant activities of Chrozophora tinctoria: a natural dye plant

Context: Chrozophora tinctoria (L.) A. Juss. (Euphorbiaceae) is known as ‘dyer’s-croton’ and used to obtain dye substances. Recently, natural antioxidants and colorants have been of interest because of their safety and therapeutic effects.

Objective: This study investigates the antiproliferative and antioxidant activities of the various extracts and fractions from C. tinctoria and analyzes their phytochemical contents.

Materials and methods: The aerial parts of C. tinctoria were extracted with water, ethyl acetate, n-butanol, and methanol/chloroform. Phenolic compounds and other constituents of the extracts were analyzed by HPLC/TOF-MS. The ethyl acetate extract (EA) was fractionated by flash chromatography. The extracts, fractions, and major phenolic compounds were investigated for their antiproliferative activities on human cervical adenocarcinoma (HeLa) cell line at the concentrations of 5–100?μg/mL by using BrdU ELISA assay during 24?h of incubation. DPPH radical scavenging activities (5–150?μg/mL) and total phenolic contents of the samples were also evaluated.

Results: 4-Hydroxybenzoic acid (268.20?mg/kg), apigenin-7-glucoside (133.34?mg/kg), and gallic acid (68.92?mg/kg) were the major components of EA. CT/E-F6 (IC₅₀?=?64.59?±?0.01?μg/mL) exhibited the highest antiproliferative activity. CT/E-F2 (IC₅₀=?14.0?±?0.0?μg/mL) and some fractions displayed higher radical scavenging activity compared to synthetic antioxidant BHT (IC_50?=_?23.1?±?0.0?μg/mL). Among the main phenolics, gallic acid exhibited the highest antiproliferative and radical scavenging abilities (IC_50?<_?5?μg/mL).

Conclusion: In this study, we have determined the biologically active fractions and their high effects may be attributed to the presence of gallic acid.     

Assessment of in vitro antipsoriatic activity of selected Indian medicinal plants

Abstract

Context: Phyllanthus simplex Retz. (Phyllanthaceae), Crotolaria juncea Linn. (Leguminosae), Leucas aspera Linn. (Lamiaceae), and Vitex glabrata R.Br. (Verbenaceae) are well-known Indian medicinal plants. Different parts of these plants are used for healing purposes traditionally in the treatment of psoriasis and various other disorders. This prompted us to assess the antipsoriatic activities of these plants.

Objectives: Petroleum ether and ethanol extracts of the selected plants, i.e., P. simplex (whole plant), C. juncea (seeds), L. aspera (aerial parts), and V. glabrata (leaves) were investigated for their in vitro antipsoriatic activity.

Materials and methods: Antipsoriatic activity of the extracts was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, using HaCaT cells. About 200?µl of different concentrations (25, 50, 100, 200, and 400?µg/ml) of test samples were prepared in the cell culture medium and incubated for 24?h before MTT assay to determine the viable cells. The effect of these extracts on nitric oxide (NO) production and lipid peroxidation was also evaluated.

Results: Our findings revealed that these plants showed promising skin keratinocyte antiproliferative activity. However, the petroleum ether extract of C. juncea (CJPE) and ethanol extract of L. aspera (LAEE) were found to exhibit significant activity (IC₅₀ value?=?45.45 and 55.36?µg/ml, respectively).

Discussion and conclusions: The inhibitory action against NO production and lipid peroxidation in HaCaT cells suggested that the antipsoriatic activity of the extracts was mediated by an antioxidant mechanism. These findings validate the claims of the use of these plants in the treatment of psoriasis.     

Phytochemical screening and evaluation of in vitro antioxidant and antimicrobial activities of the indigenous medicinal plant Albizia odoratissima

Context: Albizia odoratissima (L. f.) Benth has been used in Indian folk medicine to treat numerous inflammatory pathologies, such as leprosy, ulcers, burns and asthma.

Objective: To evaluate the antioxidant and antimicrobial properties of A. odoratissima.

Materials and methods: Dried leaves of A. odoratissima were extracted in organic solvents (hexane, chloroform, ethyl acetate, and methanol). The total phenolic content (TPC) and total flavonoid content (TFC) were determined using the Folin-Ciocalteu and aluminum chloride colorimetric methods, respectively. The antioxidant activity was examined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide (H₂O₂), 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), and ferric reducing antioxidant power (FRAP) assays. The antibacterial activity was examined using minimum inhibitory concentration (MIC) and the minimum bacterial concentration (MBC), determined by broth microdilution method against Gram-negative bacteria (Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Proteus vulgaris) and Gram-positive bacterium (Staphylococcus aureus).

Results: The TPC ranged from 4.40?±?1.06 to 1166.66?±?31.85?mg GAE/g of dry weight (DW), and the TFC ranged from 48.35?±?3.62 to 109.74?±?1.84?mg QE/g of DW. The IC₅₀ values of the ethyl acetate extract for DPPH, ABTS, and H₂O₂ were 10.96?±?0.40, 4.35?±?0.07, and 163.82?±?1.52?μg/mL, respectively. Both methanol and ethyl acetate extracts demonstrated effective antibacterial activity with MICs and MBCs values ranging 136–546?μg/mL and 273–1093?μg/mL, respectively, against the tested pathogenic species.

Conclusions: The leaves of A. odoratissima showed potent free radical scavenging property and antimicrobial activity.     

Antioxidant activity and chemical composition of essential oils of three aromatic plants from La Rioja province

Context: The use of many traditional medicinal plants is often hampered by the absence of a proper biochemical characterization, which is essential to identify the bioactive compounds present in it. The essential oils (EOs) of three native species from the La Rioja province were analyzed: Lippia turbinata Griseb and Lippia integrifolia (Griseb.) Hieron (Verbenaceae), and Clinopodium gilliesii (Benth.) Kuntze (Lamiaceae).

Objective: The aim of this study was to evaluate their EOs antioxidant activity (AA) and their chemical composition.

Materials and methods: EOs were analyzed by gas chromatography-mass spectrometry (GC-MS). To enhance the aqueous solubilization of the EOs, EO–water emulsions were prepared (concentration range of 0.1–6?mg?mL^?1). AA was determined using ABTS, DPPH, and peroxyl radical scavenging assays, as well as by the β-carotene bleaching test.

Results: Piperitenone oxide was a major constituent in L. turbinata, pulegone and piperitenone oxide in C. gilliesii, and β-caryophyllene in L. integrifolia. Lippia turbinata EO was the most active ABTS and DPPH radical scavenger (SC₅₀ values of 0.40?±?0.14 and 0.74?±?0.08?mg?mL^?1, respectively). Clinopodium gilliesii EO exhibited the highest hydrogen peroxide scavenging activity (SC₂₅ value?=?1.52?±?0.27?mg?mL^?1). In the β-carotene assay, L. turbinata EO was more effective at inhibiting lipid peroxidation than the other two oils (IC₂₅ value?=?0.15?±?0.04?mg?mL^?1).

Conclusion: Our results suggest that the AA observed can be justified by the presence of oxygenated monoterpenes, mainly piperitenone oxide. Finally, L. turbinata EO might be used as a safe natural antioxidant and food preservative in the food and cosmetic industries.     

Essential oil composition and antinociceptive activity of Thymus capitatus

Context: The essential oil (EO) from Thymus capitatus Hoff. et Link. (Lamiaceae) has been traditionally used for its medicinal properties, such as anti-inflammatory, analgesic, antioxidant and antimicrobial properties.

Objective: Characterize the constituents from T. capitatus EO and further evaluate the antinociceptive activity by in vivo and in vitro procedures.

Materials and methods: Gas chromatography–mass spectrometry was used to identify and quantify the constituents of the T. capitatus EO. The antinociceptive activity was evaluated in vivo by the glutamate-induced nociception model in male Swiss mice (25?g), at doses of 3, 6 and 12?mg/kg, 1?h before evaluation of the licking time response (0–15?min). The mechanism of T. capitatus EO (1–500?μg/mL) on the isolated nerve excitability of Wistar rat (300?g) was assessed by the single sucrose technique.

Results and discussion: The EO of T. capitatus presented 33 components, mainly monoterpenes and sesquiterpenes, carvacrol (ca. 80%) was its major constituent. T. capitatus EO induced antinociception in orally treated mice (3, 6, and 12?mg/kg) reducing the licking time from control (100.3?±?11.9?s) to 84.8?±?12.2, 62.7.6?±?9.9, and 41.5?±?12.7?s, respectively (n?=?8; p?T. capitatus EO (500?μg/mL) decreased the compound action potential amplitude (V_CAP) of about 80.0?±?4.3% from control recordings (n?=?4; p?+?channels.

Conclusions: The present study demonstrated the antinociceptive activity of Thymus capitatus essential oil, which acts via peripheral nervous excitability blockade.     

Antioxidant and antimicrobial activities of branches extracts of five Juniperus species from Turkey

Context: Several Juniperus species (Cupressaceae) are utilized in folk medicine in the treatment of infections and skin diseases.

Objective: This work was designed to evaluate the antioxidant and antimicrobial potential of methanol and water branches extracts of Juniperus species from Turkey: Juniperus communis L. var. communis (Jcc), Juniperus communis L. var. saxatilis Pall. (Jcs), Juniperus drupacea Labill. (Jd), Juniperus oxycedrus L. subsp. oxycedrus (Joo), Juniperus oxycedrus L. subsp. macrocarpa (Sibth. & Sm.) Ball. (Jom).

Materials and methods: Total phenolics, total flavonoids and condensed tannins were spectrophotometrically determined. The antioxidant properties were examined using different in vitro systems. The toxicity was assayed by Artemia salina lethality test. The antimicrobial potential against bacteria and yeasts was evaluated using minimum inhibitory concentration and minimum bactericidal concentration (MIC/MBC) measurements. The effect on bacteria biofilms was tested by microtiter plate assay.

Results: Both in the DPPH (1,1-diphenyl-2-picrylhydrazyl) and TBA (thiobarbituric acid) test Jom resulted the most active (IC₅₀?=?0.034?±?0.002?mg/mL and 0.287?±?0.166 µg/mL). Joo exhibited the highest reducing power (1.78?±?0.04 ASE/mL) and Fe²⁺ chelating activity (IC₅₀?=?0.537?±?0.006?mg/mL). A positive correlation between primary antioxidant activity and phenolic content was found. The extracts were potentially non-toxic against Artemia salina. They showed the best antimicrobial (MIC?=?4.88-30.10 µg/mL) and anti-biofilm activity (60–84%) against S. aureus.

Discussion and conclusion: The results give a scientific basis to the traditional utilization of these Juniperus species, also demonstrating their potential as sources of natural antioxidant and antimicrobial compounds.     

Carthamus,Salvia and Stachys species protect neuronal cells against oxidative stress-induced apoptosis

Context: Finding effective therapies for neurodegenerative diseases is of utmost importance for the aging population. Plants growing in Iran are rich sources of antioxidants and active phytochemicals.

Objective: The protective capacity of plants, with a special focus on those with reported antioxidant or neuroprotective potential or nervous system-related applications in folk medicine, was tested against oxidative stress-induced apoptosis.

Materials and methods: Aerial parts of 20 plants including Carthamus, Salvia, and Stachys species were extracted with 80% methanol and dichloromethane and preincubated with neuronal PC12 cells for 3?h. Oxidative stress and apoptosis were induced by hydrogen peroxide (75?µM, 1?h exposure). Cell viability and intracellular reactive oxygen species (ROS) were measured by MTT and 2′,7′-dichlorofluorescein-diacetate (DCFH-DA) assays, respectively, while apoptosis was determined by annexin V-FITC/propidium iodide staining by a flow cytometer.

Results: Eighty percent methanol extracts of Carthamus oxyacantha Bieb. (Asteraceae), Salvia santolinifolia Boiss. (Lamiaceae), and Salvia sclarea L. (Lamiaceae) at the concentration of 100?μg/ml showed significant neuroprotection in the MTT assay by 38.7, 34.7, and 39.5%, respectively, and inhibited intracellular ROS by 48.6, 61.9, and 61.4%, respectively. The first two extracts also significantly inhibited apoptosis. Dichloromethane extracts of C. oxyacantha and Stachys pilifera Benth. (Lamiaceae) at the concentration of 25?μg/ml showed neuroprotection by 27.5 and 26.5%, respectively, and inhibited ROS by 44.5 and 39.4%, respectively.

Conclusion: The above-mentioned plants seem to have important biological activities and their further study may lead to the discovery of new natural therapeutics useful against disorders such as Alzheimer and Parkinson diseases.     

Chemical composition and biological activities of extracts and essential oil of Boswellia dalzielii leaves

Context: Boswellia dalzielii Hutch. (Burseraceae) is an aromatic plant. The leaves are used for beverage flavouring.

Objective: This study investigates the chemical composition and biological activities of various extracts.

Materials and methods: The essential oil was prepared via hydrodistillation. Identification and quantification were realized via GC-MS and GC-FID. Consecutive extractions (cyclohexane, dichloromethane, ethyl acetate and methanol) were carried out and various chemical groups (phenolics, flavonoids, tannins, antocyanins and sugar) were quantified. The volatile compounds of organic extracts were identified before and after derivatization. Antioxidant, antihyperuricemia, anti-Alzheimer, anti-inflammatory and anticancer activities were evaluated.

Results: In the essential oil, 50 compounds were identified, including 3-carene (27.72%) and α-pinene (15.18%). 2,5-Dihydroxy acetophenone and β-d-xylopyranose were identified in the methanol extract. Higher phenolic (315.97?g GAE/kg dry mass) and flavonoid (37.19?g QE/kg dry mass) contents were observed in the methanol extract. The methanol extract has presented remarkable IC_50?=_?6.10?mg/L for antiDPPH, 35.10?mg/L for antixanthine oxidase and 28.01?mg/L for anti-5-lipoxygenase. For acetylcholinesterase inhibition, the best IC₅₀ (76.20 and 67.10?mg/L) were observed, respectively, with an ethyl acetate extract and the essential oil. At 50?mg/L, the dichloromethane extract inhibited OVCAR-3 cell lines by 65.10%, while cyclohexane extract inhibited IGROV-1 cell lines by 92.60%.

Discussion and conclusion: Biological activities were fully correlated with the chemical groups of the extracts. The ethyl acetate and methanol extracts could be considered as potential alternatives for use in dietary supplements for the prevention or treatment of diseases because of these extracts natural antioxidant, antihyperuricemic and anti-inflammatory activities.