Essential oils composition and antioxidant properties of three thymus species.

The essential oils of three wild-growing Thymus species, collected from west of Iran during the flowering stage, were obtained by hydrodistillation and analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS). Under the optimum extraction and analysis conditions, 44, 38, and 38 constituents (mainly monoterpenes compounds) were identified in T. kotschyanus Boiss. and Hohen, T. eriocalyx (Ronniger) Jalas, and T. daenensis subsp lancifolius (Celak) Jalas which represented 89.9%, 99.7%, and 95.8% of the oils, respectively. The main constituents were thymol (16.4-42.6%), carvacrol (7.6-52.3%), and γ-terpinene (3-11.4%). Antioxidant activity was employed by two complementary test systems, namely, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging and ß-carotene/linoleic acid systems. Antioxidant activity of polar subfraction of T. daenensis subsp lancifolius (Celak) Jalas was found to be higher than those of the others in DPPH assay, while nonpolar subfraction of T. eriocalyx (Ronniger) Jalas has most antioxidant activity in ß-carotene/linoleic acid test (19.1 ± 0.1 µg/mL and 96.1 ± 0.8% inhibition rate, resp.).

Effects of probiotic supplementation on abdominal pain severity in pediatric patients with irritable bowel syndrome: a systematic review and meta-analysis of randomized clinical trials.

BACKGROUND: Probiotic supplementation has been used to alleviate abdominal pain in children and adolescents with irritable bowel syndrome (IBS), but the evidence is not compelling. Thus, a systematic review and meta-analysis of randomized clinical trials (RCTs) were performed to investigate the effects of probiotic supplementation on abdominal pain in pediatric patients with IBS. METHODS: PubMed/MEDLINE, Web of Science, Scopus, Cochrane Library, and Embase were the available databases searched to find relevant randomized clinical trials up to April 2021. The effect size was expressed as weighted mean difference (WMD) and 95% confidence interval (CI). RESULTS: Seven RCTs with 441 participants were included, from which the meta-analysis demonstrated that probiotic supplementation has a significant effect on reducing abdominal pain in pediatric patients with IBS (WMD = - 2.36; 95% CI - 4.12 to - 0.60; P = 0.009). Although our study involved children and adolescents (≤ 18 years), the effects of probiotic supplementation seem to be more potent in patients under 10 years old (WMD = - 2.55; 95% CI - 2.84 to - 2.27) compared to patients aged 10-18 years (WMD = - 1.70; 95% CI - 2.18 to - 1.22). The length of supplementation longer than four weeks was more effective (WMD = - 2.43; 95% CI - 2.76 to - 2.09). CONCLUSION: Probiotic supplementation can reduce abdominal pain in pediatric patients with IBS.

Green synthesis of Ag-ZnO nanocomposites using Trigonella foenum-graecum leaf extract and their antibacterial, antifungal, antioxidant and photocatalytic properties.

In the present study, biological synthesis of Ag-ZnO nanocomposites was performed using hydroalcoholic extract of fenugreek leaves. Metal/semiconductor oxide nanocomposites are excellent owing to their optical, electrical, magnetic, and chemical properties that are not detected in single individual constituents. The synthesized Ag-ZnO nanocomposites were investigated through the use of methods such as FTIR, UV vis DRS, SEM-EDX, TEM, XRD, zeta potential analysis, and DLS. The synthesized Ag-ZnO nanocomposites had an average particle size of about 75 nm and a zeta potential of -37.5 mV. The XRD results confirmed that Ag was successfully introduced into the Ag-ZnO nanocomposites via a hydrothermal method. The antimicrobial and antifungal activities of Ag-ZnO nanocomposites were evaluated by agar well diffusion method against three microbial and fungal strains; it was found that the Ag-ZnO nanocomposites were toxic against all the tested microbial and fungal strains. Ag-ZnO nanocomposites was observed to have significant antioxidant activity against DPPH (2,2-diphenyl-1-picrylhydrazyl) free radicals. The Ag-ZnO nanocomposites exhibited excellent photocatalytic activity and stability against the degradation of malachite green under visible light irradiation. The study successfully applied a simple and eco-friendly method for synthesizing efficient multifunctional Ag-ZnO nanocomposites using green synthetic approach.

Chemical composition and antibacterial activity of essential oils from leaves, stems and flowers of Salvia reuterana Boiss. grown in Iran.

The essential oils obtained by hydrodistillation of the leaves, stems and flowers of Salvia reuterana (Lamiaceae) were analysed by GC and GC/MS. Germacrene D and beta-caryophyllene were the major constituents in all the three oils: (28.5, 27.7 and 32.5%) and (15.5, 11.4 and 16.6%), respectively. Bicyclogermacrene (10.2 and 13.2%) was also prodominated in the stem and flower oils. The composition of the oils was mostly quantitativel rather than qualitatively different. All the oils consisted mainly of sesquiterpenes and a small percentage of non-terpenoid compounds. In all the three oils, monoterpenes were in a concentration less than 0.5%. Antibacterial activity was determined by the measurement of growth inhibitory zones.

Interaction of Methanol Spray and Water-Deficit Stress on Photosynthesis and Biochemical Characteristics of Phaseolus vulgaris L. cv. Sadry.

This study was a factorial experiment with a completely randomized design and three replications. The four levels of methanol spraying were used. Spraying was carried out three times during the growing season at 10-day intervals beginning at 4 weeks after sowing. The spraying of solution continued until saturation of droplets on the leaves was achieved. The levels of water-deficit stress applied were nonstress, moderate water stress and severe water stress. The results showed that there was a significant difference (P ≤ 0.05) between the methanol and water-deficit stress treatments for chlorophyll (Chl) a and Chl b, carotenoid, total chlorophyll, net photosynthesis (PN ), intercellular CO2 (Ci ), maximal quantum yield of photosystem II photochemistry (Fv /Fm ), leaf moisture, water use efficiency and relative water content. The application of foliar methanol at all levels of water-deficit stress significantly decreased the catalase activity of the roots. Under all levels of water-deficit stress, the 30% (v/v) methanol treatment significantly decreased peroxidase activity in the roots over that for the control. The results suggest that foliar application of methanol can decrease the negative effects of water-deficit stress on Phaseolus vulgaris L. cv. Sadry.

Volatile constituents and antioxidant activity of flowers, stems and leaves of Nasturtium officinale R. Br.

GC-MS analyses of the essential oils of leaves, stems and flower of Nasturtium officinale resulted in the identification of 9, 8 and 15 compounds, representing 97%, 100% and 94.7% of the oils, respectively. The main compounds of the oil of leaves were myristicin (57.6%), α-terpinolene (8.9%) and limonene (6.7%). Caryophyllene oxide (37.2%), p-cymene-8-ol (17.6%), α-terpinolene (15.2%) and limonene (11.8%) were the main components in stems, whereas limonene (43.6%), α-terpinolene (19.7%), p-cymene-8-ol (7.6%) and caryophyllene oxide (6.7%) were the major constituents in the oil of flowers. All the samples were subjected to a screening for their possible antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ß-carotene-linoleic acid assays. In the above tests, methanol extracts of leaves showed higher antioxidant activity than the oils and methanol extracts of stems and flowers.

The in vitro antioxidative properties of the essential oils and methanol extracts of Satureja macrosiphonia Bornm.

This study was designed to examine the in vitro antioxidant activities of the essential oil and methanol extracts of Satureja macrosiphonia in pre-flowering and flowering stages. GC and GC-MS analyses of the essential oils resulted in the identification of 35 and 24 compounds, representing the 95.1% and 92.6% of the oils, respectively. Major constituents of the oil of the pre-flowering stage were terpinene-4-ol (20.8%) and α-terpineol (14.7%), while in the oil of the flowering stage α-terpineol (26.7%) and borneol (16.6%) were found to be the main components. The samples were subjected to screening for their possible antioxidant activity by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ß-carotene-linoleic acid assay. In general, the polar subfraction of methanol extract in the flowering stage exhibited the greatest antioxidant activity in the DPPH test. In the ß-carotene-linoleic acid test, the essential oil of the flowering stage had the highest antioxidant activities.

Antioxidant Activity of the Essential Oil and Methanolic Extract of Teucrium orientale (L.) subsp. taylori (Boiss.) Rech. f.

This study was designed to examine the chemical composition and in-vitro antioxidant activity of the essential oil and methanolic extract of Teucrium orientale subsp. taylori. The GC and GC-MS analysis of the essential oil resulted in determination of 40 components representing 96.4% of the oil. The major constituents of the oil were linalool (28.6%), caryophyllene oxide (15.6%), 1,8-cineol (4.5%), ß-pinene (8.7%), 3-octanol (9.5%), ß-caryophyllene (7.3%), and germacrene-D (4.1%). Antioxidant activities of the samples were determined by two different tests, namely DPPH and ß-carotene- linoleic acid assay. In DPPH system, the weakest radical scavenging activity was exhibited by the non-polar sub fraction of methanolic extract (237.40 ± 2.1 µg/mL). Antioxidant activity of the polar sub fraction of methanolic extract was superior to all samples tested, showing an EC50 value of 61.45 ± 0.5 µg/ mL. The inhibition capacity (%) of the polar sub fraction of methanolic extract (95.21% ± 1.3) was found to be the strongest and almost equal to the inhibition capacity of the positive control BHT (94.9% ± 1.1). The amount of the total phenolics was the highest in the polar subfraction, i.e. 370 µg/mg of the dry extract (37%). A positive correlation was observed between the antioxidant activity and the total phenolics of the extracts.

Influence of growth phase on the essential oil composition of Ziziphora clinopodioides Lam.

Ziziphora clinopodioides belongs to the Lamiaceae family, that are widespread all over Iran. The leaves, flowers and stems of the plant are frequently used as wild vegetables or additives in food to offer aroma and flavour. The chemical composition of the essential oils obtained from the aerial parts of Z. clinopodioides Lam. in different growth stages were analysed by GC and GC-MS, and 29 components were identified. Pulegone (30.1%), thymol (21.3%), p-mentha-3-en-8-ol (12.9%) and piperitenone (9.3%) were the main components in the pre-flowering stage. In the flowering stage, pulegone (44.6%), p-mentha-3-en-8-ol (10.5%), 1,8-cineoil (10.4%), piperitenone (8.7%) and thymol (6.7%) were identified as the main constituents and in the post-flowering stage, pulegone (41.3%), isomenthone (11.6%), p-mentha-3-en-8-ol (11%), p-mentha-3,8-diene (7.2%) and thymol (5.8%) were identified as the major components.

Chemical constituents of the essential oils of different stages of the growth of Stachys lavandulifolia Vahl. from Iran.

The essential oil of the aerial parts of different stages of growth as pre-flowering, flowering and post flowering of Stachys lavandulifolia Vahl (Lamiaceae) were isolated by hydro distillation. The chemical composition of volatile oil was analyzed by capillary GC and GC/MS. The main components were found to be: alpha-pinene) 27.25, 25.66, 8.52%), myrcene (17.33, 9.33, 23.85%), beta-phellandrene (21.96, 37.49, 12.58%), beta-caryophylene (14.3, 8.38, 16.86%).