Chemical composition,antioxidant and antibacterial activities of two Spondias species from Northeastern Brazil

Context: The leaves of Spondias tuberosa Arr. Cam. (Anacardiaceae) and Spondias mombin L. have been traditionally used for medicinal purposes. Some studies reveal their antibacterial, antimicrobial, and antiviral properties.

Objective: Determine the chemical composition, antioxidant, and antimicrobial activities of Spondias species to justify its ethnopharmacological use.

Materials and methods: Spondias species extracts were prepared with methanol:water 80:20 and analyzed by silica gel column chromatography and reversed phase liquid chromatography (HPLC). The antioxidant activity was evaluated by scavenging the radicals 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS?+) and measuring antimicrobial activity (agar well diffusion method, minimum inhibitory concentration and minimum bactericidal concentrations).

Results: The HPLC analysis of Spondias extracts demonstrated the occurrence of high yield of flavonoids. Found in S. mombin were quercetin (2.36?±?0.01?mg/g) and ellagic acid (41.56?±?0.01?mg/g) and in S. tuberosa species rutin (53.38?±?1.71?mg/g), quercetin (24.46?±?0.87?mg/g), and ellagic acid (169.76?±?0.17?mg/g). The antibacterial activity of the extracts against the various bacteria strains varied from 8.8 to 20.1?mm. MIC values from 62.5 to 125 µg/mL were satisfactory when compared with other plant products. Medium DPPH scavenging activity IC₅₀ for Spondias extracts varied from 0.042 to 0.558?mg/mL and for ABTS from 0.089 to 0.465?mg/mL. DPPH scavenging activity for constituent ellagic acid IC₅₀?=?0.042?mg/mL and for quercetin IC₅₀?=?0.081?mg/mL.

Discussion and conclusion: The chemical study of Spondias leaf extracts showed the occurrence of quercetin, rutin and ellagic acid, substances with relevant antioxidant and antimicrobial activities.     

The mutagenic,antimutagenic and antioxidant properties of Hypericum lydium

Context: There is a growing market demand for Hypericum sp., a pharmacologically active plant that has been traditionally used to treat various ailments. However, there have been limited studies on the extract or essential oil of Hypericum lydium Boiss (Hypericaceae).

Objective: This study investigates for the first time the antioxidant, mutagenic and antimutagenic activity of an ethanol extract of H. lydium.

Material and methods: Ethanol extract from aerial parts of H. lydium harvested from Turkey were tested for this mutagenic and antimutagenic activities (2.0–0.002?mg/plate) using Ames Salmonella/microsome test system. 4-Nitro-o-phenylenediamine (4-NPD) (3?μg/plate) for the Salmonella typhimurium TA98 and sodium azide (NaN₃) (8?μg/plate) for the S. typhimurium TA100 were used as positive controls. The antioxidant activity, total antioxidant activity and phenolic constituent of the extract (2.0–0.002?mg/mL) was determined by the inhibition of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), β-carotene-linoleic acid model and by means of Folin–Ciocalteu reagent, respectively.

Results: The extract showed no sign of mutagenicity at the tested concentrations (0.002–2.0?mg/mL), and showed concentration-dependent antimutagenic activity against NaN₃ and 4-NPD ranging from 26.8 to 81.5%. The extract was found to be an efficient scavenger of DPPH (IC₅₀ 0.165?±?0.23?mg/mL) and to inhibit β-carotene-linoleic acid bleaching (IC₅₀ 0.39?±?0.11?mg/mL).

Discussion and conclusion: These findings indicate ethanol extract of H. lydium to be a safe and effective agent that may be incorporated into new strategies for the prevention of cancer and mutagenesis.     

厚壳贻贝抗氧化肽的分离、鉴定及活性评价

目的：以厚壳贻贝(Mytilus coruscus)为原材料,以抗氧化活性为筛选指标,运用酶解技术和现代分离纯化技术,制备抗氧化多肽。方法：以1,1-二苯基-2-三硝基苯肼自由基(DPPH?)、羟自由基(HO?)及2,2"-联氮-双-3-乙基苯并噻唑啉-6-磺酸自由基(ABTS?)清除率为指标,优化酶解条件。通过超滤、凝胶过滤层析和反向高效液相色谱分离抗氧化肽,并评价其抗氧化活性。结果：最佳酶解条件为：木瓜蛋白酶、酶解时间3 h、加酶量3%、料液比1：50。通过反相高效液相色谱及测序,鉴定4条多肽分别为HK1：Gln-Thr-Asp(362.34 Da);HK2：His-Gln-Glu-Glu(541.52 Da);HK3：Leu-Glu-Gly-Asp-Thr(533.54 Da);HK4：Thr-Gln-Glu(376.37 Da)。其对DPPH?自由基清除率的EC₅₀分别为0.523±0.002 mg/mL,0.419±0.002 mg/mL,0.467±0.007 mg/mL,0.626±0.011 mg/ mL;对HO?自由基清除率的EC₅₀分别为0.587±0.027 mg/mL,0.866±0.034 mg/mL,1.009±0.018 mg/mL,1.014±0.036 mg/mL)、对ABTS?自由基清除率的EC₅₀分别为0.218±0.001 mg/mL,0.117±0.002 mg/mL,0.121±0.001 mg/mL,0.415±0.003 mg/mL。结论：木瓜蛋白酶酶解厚壳贻贝蛋白,可以产生具有显著自由基清除活性的酶解肽,可为厚壳贻贝抗氧化肽的开发利用提供理论依据和参考。     

4-O-Caffeoylquinic acid as an antioxidant marker for mulberry leaves rich in phenolic compounds

Mulberry (Morus alba L.) leaves are widely used as herbal tea to prevent heat stroke. Potential chemical markers of the antioxidant properties and its correlation with harvesting times and leaf location were explored in this study. A 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay guided isolation of mulberry leaves extract provided five phenolic compounds: 5-O-caffeoylquinic acid (1), 4-O-caffeoylquinic acid (2), gastrodin (3), isoquercetin (4) and rutin (5). The 50% radical-scavenging concentrations (SC₅₀) of these compounds were 32.76 ± 0.27, 11.41 ± 0.48, 404.30 ± 4.92, 10.63 ± 0.96, and 10.57 ± 0.61 μg/mL, respectively. Chromatographic fingerprinting allowed content analysis of 1–5 in samples over a 12-month period. Compounds 1–5 were abundance in apical leaves (0–10 cm) in January and February at temperatures < 20 °C. Contents of 2 and 5 were highest in these months and were strongly correlated to the antioxidant property. Therefore, we suggested that the mulberry leaves harvested during January and February have high yield of 4-O-caffeoylquinic acid and this compound can be used as antioxidative marker in mulberry leaves.     

Chemical composition and antioxidant activities of the essential oil and methanol extracts of Psammogeton canescens

This study is outlined to probe the chemical composition of essential oil and in vitro antioxidant activity of the essential oil and methanol extracts of Psammogeton canescens. The chemical composition of the hydrodistilled essential oil of the aerial parts of P. canescens was analyzed by GC and GC/MS. The main constituents of the oil were found to be β-bisabolene (33.35%), apiole (28.34%), α-pinene (11.86%) and dill apiole (8.17%). Antioxidant activities of the samples were determined by three various testing systems namely DPPH, β-carotene/linoleic acid, and reducing power assay. In DPPH system, the highest radical-scavenging activity was seen by the polar subfraction of methanol extract (49.5 ± 1.21 μg/ml). Furthermore, in the second case the inhibition capacity (%) of the polar subfraction (92.40% ± 0.72) found to be the stronger one. However, in the reducing power assay, a reverse activity pattern more than in the first two systems was observed, and the essential oil was stronger radical reducer than was the methanol extract in all of the concentration tested. Our findings demonstrate that the essential oil and methanol extracts of P. canescens possess significant antioxidant activities and may be suggested as a new potential source of natural antioxidant.     

Essential oil composition and antioxidant and antimicrobial properties of the aerial parts of Salvia eremophila Boiss. from Iran

The essential oil composition and in vitro antioxidant and antimicrobial activity of the essential oil and methanol extract of Salvia eremophila were evaluated in this research. GC and GC/MS analysis of the plant essential oil resulted in the identification of 28 compounds representing 99.24% of the oil. Borneol (21.83%), α-pinene (18.80%), bornyl acetate (18.68%) and camphene (6.54%) were detected as the major components consisting 65.85% of the oil. The plant essential oil and methanol extract were also subjected to screenings for the evaluation of their antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene–linoleic acid tests. While the plant essential oil showed only weak antioxidant activities, its methanol extract was considerably active in both DPPH (IC₅₀ = 35.19 μg/ml) and β-carotene–linoleic acid (inhibition percentage: 72.42%) tests. Appreciable total phenolic content (101.25 μg/mg) was also detected for the plant methanol extract as gallic acid equivalent in the Folin–Ciocalteu test. The plant was also screened for its antimicrobial activity and good to moderate inhibitions were recorded for its essential oil and methanol extract against most of the tested microorganisms.     

Chemical composition and biological activities of essential oil of Beilschmiedia pulverulenta

Context: The ethnopharmacological study of Beilschmiedia indicates that several species are used for the treatment of various ailments.

Objective: This is the first study of the chemical composition of Beilschmiedia pulverulenta Kosterm (Lauraceae) essential oil and its antioxidant, antimicrobial, antityrosinase, anti-inflammatory, and anticholinesterase activities.

Materials and methods: The antioxidant activities were evaluated by β-carotene, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, ferric-reducing antioxidant power (FRAP), and phenolic content at different concentrations. The antimicrobial activities against Gram-positive and Gram-negative bacteria and fungi were revealed by disk diffusion and microdilution. The antityrosinase and anti-inflammatory activities were assayed against mushroom tyrosinase and lipoxygenase enzymes. The anticholinesterase activity was analyzed using acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes.

Results: Forty-two components were detected in B. pulverulenta oil with eugenol (45.3%) being the major component. The oil phenolic content and the FRAP were 660.1?mg gallic acid/g and 604.0?mg ascorbic acid/g, respectively. The oil gave an IC₅₀ value of 94.5?µg/mL and an inhibition of 93.9% in DPPH and β-carotene, respectively. The antimicrobial activity showed that the oil had strong activity against all Gram-positive bacteria with an minimum inhibitory concentration (MIC) value each of 62.5?µg/mL and moderate against all fungi with MIC and minimum bactericidal concentration (MBC) values each of 125?µg/mL. The oil showed significant antityrosinase and anti-inflammatory activities with 67.6 and 62.5% inhibition, respectively. In addition, the oil had moderate AChE (56.5%) and BChE (48.2%) activities.

Discussion and conclusion: The results show that the oil could potentially be used for nutraceutical industries, food manufactures, and therapeutic agents against various diseases such as inflammation and rheumatism.     

Antioxidant activities of the essential oils and methanol extracts from myrtle (Myrtus communis var. italica L.) leaf,stem and flower

This study was designed to examine the chemical composition and antioxidant activity of the essential oils and methanol extracts of Myrtus communis var. italica L. leaf, stem and flower. Myrtle leaf and flower were the valuable organs for the essential oil production representing a yield of 0.61% and 0.30% (w/w), respectively. The essential oil composition of myrtle leaf and flower was characterized by high proportions of α-pinene, the main compound of monoterpene hydrocarbon class, with 58.05% for leaf and 17.53% for flower. Stem was rich in oxygenated monoterpenes, largely due to 1,8-cineole with 32.84%. The total phenol contents varied between different myrtle parts; leaf extract had higher total phenol content (33.67 mg GAE/g) than flower (15.70 mg GAE/g) and stem (11.11 mg GAE/g) extracts. Significant differences were also found in total tannin contents among different myrtle parts, representing 26.55 mg GAE/g in leaf, 11.95 mg GAE/g in flower, 3.33 mg GAE/g in stem. The highest contents of total flavonoids and condensed tannins were observed in stem (5.17 and 1.99 mg CE/g, respectively) and leaf (3 and 1.22 mg CE/g, respectively) extracts. The HPLC analysis indicated that the main phenolic class was hydrolysable tannins (gallotannins) in leaf (79.39%, 8.90 mg/g) and flower (60.00%, 3.50 mg/g) while the stem was characterized by the predominance of flavonoid class (61.38%, 1.86 mg/g) due to the high presence of catechin (36.91%, 1.12 mg/g). Antioxidant activities of the essential oil and the methanolic extract from different myrtle parts were evaluated by using DPPH radical scavenging, β-carotene-linoleic acid bleaching, reducing power and metal chelating activity assays. In all tests, methanolic extracts of different myrtle parts showed better antioxidant activity than essential oils.     

Antioxidant activity, acetylcholinesterase inhibition, iridoid content and mutagenic evaluation of Leucosideasericea

Leucosidea sericea is an important medicinal plant widely used in traditional medicine in southern Africa. Leaf and stem petroleum ether (PE), dichloromethane (DCM) and 50% aqueous methanol (MeOH) extracts were investigated for antioxidant and acetylcholinesterase inhibitory activities. The safety of the extracts was evaluated using the Ames test. In addition, the iridoid content of L. sericea stems and leaves were quantified. For DPPH radical-scavenging activity, the stem MeOH extract (EC₅₀ value: 1.6 μg/ml) was more potent than ascorbic acid (EC₅₀ value: 1.7 μg/ml). In the β-carotene-linoleic acid model system, antioxidant activity of the leaf DCM extract (89.8%) was not significantly different to that of butylated hydroxytoluene (BHT) (98.9%). All extracts showed a dose-dependent acetylcholinesterase inhibition; in terms of the IC₅₀ value, the leaf DCM extract (0.14 mg/ml) was the most potent sample. Total iridoid content was 35% higher in the stem extract than in the leaf extract. Based on the Ames test, L. sericea extracts were not mutagenic, either with or without S9 metabolic activation. These findings suggest the safety as well as the potential of L. sericea as a possible source of novel/alternative antioxidant and acetylcholinesterase inhibitory compounds.     

Antioxidant activity and total phenolic content of methanol extracts of Ixora coccinea

Objective: To investigate the in vitro antioxidant activity of methanol extracts of Ixora coccinea L. (Rubiaceae) flower, leaf and stem.

Materials and methods: The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, total antioxidant capacity (TAC) and xanthine oxidase inhibition assay were carried out to evaluate the antioxidant potential of the extract. The IC₅₀ values were calculated for the DPPH and xanthine oxidase assays in order to evaluate the antioxidant efficiency of each of the I. coccinea extracts. The phenol contents were also determined.

Results: I. coccinea flowers revealed the best antioxidant property, presenting much lower IC₅₀ value (6.6?mg/mL for DPPH assay). The flower extract showed a significantly higher antioxidant capacity compared to the other extracts. Furthermore, the highest phenolic content (polyphenols) was found in the flower extract (210.55?±?6.31 µg GAE/mg extract). Moreover, I. coccinea extracts scavenged the superoxide radical generated by the xanthine/xanthine oxidase system. The xanthine oxidase inhibition activity was in the order of allopurinol > leaf > flower > stem with the percentage of inhibition ranged from 39.7% to 77.3% for the plant parts investigated. The highest phenolic contents (polyphenols) were found in the flower extracts (210.55?±?6.31 µg GAE/mg extract).

Conclusions: I. coccinea could be considered as a potential source of natural antioxidant.     

Phytochemical profile,antioxidant and cytotoxic potential of Parkinsonia aculeata L. growing in Saudi Arabia

Parkinsonia aculeata L. growing in Saudi Arabia was investigated for its phytochemical profile, antioxidant, and cytotoxic properties. UPLC-ESI-MS/MS was employed as a powerful technique for the characterization of secondary metabolites from a hydroalcoholic extract, dichloromethane, and ethyl acetate fractions of P. aculeata L. aerial parts. Sixty-nine compounds (flavonoids, anthocyanins, phenolics and fatty acids) were detected and characterized; flavonoids were the abundant components in the analyzed samples. The dichloromethane fraction was rich in phenolics as vanillic acid hexoside, flavonols as 3,7-dimthylquercetin, and flavones as 3′-hydroxymelanettin. However, the ethyl acetate fraction was rich in flavonoid-C-glycosides as luteolin-8-C-β-D-glucoside (orientin) and apigenin-8-C-glucoside (vitexin), flavonoid- O, C-diglycosides such as luteolin 7-O-[6′'-dihydrogalloyl]-glucosyl-8-C-pentosyl-(1 → 2)-glucoside and 2′'-O-rhamnosyl isoorientin. These compounds were identified for the first time in dichloromethane and ethyl acetate fractions of Saudi P. aculeata L.Additionally, all the samples were assessed for antioxidant activity using DPPH radical scavenging method and for cytotoxic activity through MTT assay. Accordingly, the most active fraction was the ethyl acetate which showed the highest antioxidant activity (SC₅₀ = 57.4 ± 1.2 μg/mL) compared with the positive control, ascorbic acid (SC₅₀ = 12.4 ± 0.5 μg/mL) and moderate cytotoxicity against HepG-2 (hepatocellular carcinoma) and MCF-7 (breast carcinoma) cell lines with IC₅₀ = 56.9 ± 3.1 and 95.8 ± 3.8 μg/mL, respectively compared with cisplatin (IC₅₀ = 3.67 ± 0.22 and 5.71 ± 0.57 μg/mL, respectively for both cell lines). The antioxidant and cytotoxic activities may be attributed to the presence of high percentage of phenolic compounds and hydroxylated flavonoids detected in ethyl acetate fraction using UPLS-ESI-MS/MS.     

Antioxidant activities and molecular mechanisms of the ethanol extracts of Baccharis propolis and Eucalyptus propolis in RAW64.7 cells

Context Numerous studies have reported that propolis possesses strong antioxidant activities. However, their antioxidant molecular mechanisms are unclear.

Objective We utilize ethanol extracts of Chinese propolis (EECP) as a reference to compare ethanol extracts of Eucalyptus propolis (EEEP) with ethanol extracts of Baccharis propolis (EEBGP) based on their antioxidant capacities and underlying molecular mechanisms.

Materials and methods HPLC and chemical analysis are utilized to evaluate compositions and antioxidant activities. ROS-eliminating effects of EEBGP (20–75?μg/mL), EEEP (1.25–3.75?μg/mL) and EECP (1.25–5?μg/mL) are also determined by flow cytometry analysis. Moreover, we compared antioxidant capacities by determining their effects on expressions of antioxidant genes in RAW264.7 cells with qRT-PCR, western blot and confocal microscopy analysis.

Results EEBGP mainly contains chlorogenic acid (8.98?±?0.86?mg/g), kaempferide (11.18?±?8.31?mg/g) and artepillin C (107.70?±?10.86?mg/g), but EEEP contains 10 compositions, whereas EECP contains 17 compositions. Meantime, although EEEP shows DPPH (IC₅₀ 19.55?±?1.28), ABTS (IC₅₀ 20.0?±?0.31) and reducing power (2.70?±?0.08?mmol TE/g) better than EEBGP’s DPPH (IC₅₀ 43.85?±?0.54), ABTS (IC₅₀ 38.2?±?0.33) and reducing power (1.53?±?0.05?mmol TE/g), EEBGP exerts much higher ROS inhibition rate (40%) than EEEP (under 20%). Moreover, EEBGP strengthen antioxidant system by activating p38/p-p38 and Erk/p-Erk kinase via accelerating nucleus translocation of Nrf2. EEEP and EECP improve antioxidant gene expression only via Erk/p-Erk kinase-Nrf2 signalling pathway.

Discussion and conclusion EEBGP and EEEP exert antioxidant activities via different molecular mechanisms, which may depend on chemical compositions.     

Antioxidant,antimicrobial and wound healing properties of Struthanthus vulgaris

Context: Struthanthus vulgaris (Vell.) Mart. (Loranthaceae) has been widely used in traditional medicine in Brazil to bathe wounds.

Objective: The objective of this study is to investigate the in vitro wound healing effects, together with the antioxidant and antimicrobial activities of S. vulgaris leaf and branch extracts.

Material and methods: Ethanol leaf and branch extracts of S. vulgaris were investigated at 1–100?µg/ml concentrations in the scratch assay after 14?h. Antioxidant activity was investigated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay, and the antibacterial activity was tested at concentrations up to 1000?µg/ml against Gram-positive and Gram-negative bacteria by the microdilution test after 24?h. The total phenolic and flavonoid contents were determined by colorimetric methods.

Results: Struthanthus vulgaris leaf and branch extracts at 100?µg/ml concentration stimulated migration and proliferation of fibroblasts and enhanced cell numbers by 56.2% and 18.6%, respectively. Antioxidant activity exhibited IC₅₀ values of 24.3 and 18.9?µg/ml for the leaf and branch extracts, respectively. The ethanol leaf extract showed antimicrobial activity against the Gram-positive Staphylococcus mutans and Staphylococcus aureus bacteria, exhibiting minimum inhibitory concentration values of 125 and 500?µg/ml, respectively. An appreciable total phenolic content in the leaves (813.6?±?2.7?mg/g) and branches (462.8?±?9.6?mg/g), and relatively low concentration of flavonoids in the leaves (13.3?±?4.3?mg/g) and branches (1.9?±?0.2?mg/g), was detected.

Discussion and conclusion: The antioxidant and antibacterial activities, together with the strong ability to stimulate proliferation and migration of fibroblasts, provide some support for the traditional use of S. vulgaris.     

Assessment of antinociceptive,anti-inflammatory and antioxidant properties of Cymbopogon winterianus leaf essential oil

The present study investigated the antinociceptive, anti-inflammatory and antioxidant effects of the leaf essential oil (LEO) of Cymbopogon winterianus Jowitt (Poaceae). In the acetic acid-induced writhing and formalin tests, the LEO (50, 100, and 200?mg/kg, p.o.) significantly reduced (p?<?0.05) the number of writhings and paw licking times in the first (0-5?min) and second (15-30?min) phases, respectively. In contrast, the LEO did not alter the latency time for mice licking the rear paws in hot-plate test. The LEO inhibited the carrageenan-induced neutrophil migration to the peritoneal cavity in a dose-dependent manner (35.5%, 42.8%, and 66.1% at doses of 50, 100, and 200?mg/kg, respectively, p?<?0.001). Moreover, LEO exhibited higher scavenging activity toward 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals with an IC₅₀ (12.66?±?0.56 μg/mL). Our present results demonstrated that the LEO has antinociceptive, anti-inflammatory, and antioxidant properties.     

Anti-diabetic Effect of <Emphasis Type="Italic">Boerhavia diffusa</Emphasis> L. Root Extract via Free Radical Scavenging and Antioxidant Mechanism

Objective

The present study was proposed to assess the in vitro free radical-scavenging activity of B. diffusa methanolic extract (BDME) and its modulatory effect against streptozotocin (STZ) induced diabetes in male Wistar rats.

Methods

Experimental diabetes was induced in Wistar albino rats by administering single dose of STZ 40 mg/kg. One week later rats with blood glucose level >200 mg/dL were segregated as diabetes in three groups each containing 6 rats in number.

Results

Total phenolic content in B. diffusa methanol extract (BDME) was found to be 87 mg of gallic acid equivalents/g extract and total flavonoid content found to be 54.1 mg of quercetin equivalents/g extract. Its extract also exhibited DPPH (IC₅₀, 163.1±6.7 μg/mL), nitric oxide (295 μg/mL) and H₂O₂ (159±5.25 μg/mL) radical scavenging activity. Pre-treatment with BDME (100 and 200 mg/kg b.w.) in streptozotocin-induced diabetic rats resulted in significant improvement in blood glucose, blood plasma enzymes SGOT, SGPT and ALP, weight loss, total protein, serum insulin and liver glycogen levels. Furthermore, it restores the activity of antioxidant enzymes viz. SOD, CAT and GPx.

Conclusion

Thus, the result suggests that BDME employed significant anti-diabetic effect in Wistar rats which is associated with its free radical scavenging and antioxidant activity.

     

Antimicrobial and antioxidant properties of the essential oil of Salvia lanigera from Cyprus

The essential oil of aerial parts of Salvia lanigera Poir. (Lamiaceae) growing wild in Cyprus was obtained by hydrodistillation and was analysed by GC and GC-MS. A total of 67 compounds, representing 93.6% of the oil, were identified, and the major components were showed to be thymol (12.1%), hexadecanoic acid (6.0%), carvacrol and α-thujone (5.7%). The essential oil was assayed for its antioxidant and antimicrobial activities. Antimicrobial activity of the oil, evaluated using the broth dilution method, resulted higher against Gram-positive bacteria than the other referenced strains tested. Antioxidant activity of the oil was evaluated by using DPPH and FRAP methods together with three antioxidant standards, l-ascorbic acid, tert-butyl-4-hydroxy toluene (BHT) and gallic acid. The activity of the sample in both methods was higher than that of all of standards used at the same dose.     

Antidiabetic,antioxidant, molecular docking and HPTLC analysis of miquelianin isolated from Euphorbia schimperi C. Presl

The present study demonstrates the miquelianin or quercetin 3-O-glucuronide (compound 1) isolated from aerial parts of Euphorbia schimperi exhibited significant results for antioxidant and antidiabetic potential. The compound 1 along with kaempferol 3-O-glucuronide (compound 2) and quercetin 3-O-rhamnoside (compound 3) isolated from the same source were quantified by validated HPTLC method. Antioxidant activity was determined by chemical means in terms of ABTS radical cation and DPPH radical scavenging activity. Compound 1 showed significant scavenging activity in both ABTS and DPPH assays as compared to standard BHA. In ABTS method IC₅₀ values of compound 1 and standard BHA is found to be 58.90 ± 3.40 µg/mL and 28.70 ± 5.20 µg/mL respectively while in DPPH assay IC₅₀ values of Compound 1 and standard BHA is 47.20 ± 4.90 µg/mL and 34.50 ± 6.20 µg/mL respectively. Antidiabetic effect was studied through α-amylase and α-glucosidase inhibitory activity. The mechanistic approach through molecular modelling also support the strong binding sites of compound 1 which showed significant α-amylase and α-glucosidase inhibitory activities with IC₅₀ values 128.34 ± 12.30 and 89.20 ± 9.20 µg/mL respectively as compared to acarbose 64.20 ± 5.60 and 52.40 ± 4.60 µg/mL respectively. The results of validated RP-HPTLC analyses revealed the concentration of compound 1 found to be 16.39 µg/mg and for compound 2 and compound 3 as 3.92 and 14.98 µg/mg of dried extract, respectively.     

Anti-oxidant activity and major chemical component analyses of twenty-six commercially available essential oils

This study analyzed 26 commercially available essential oils and their major chemical components to determine their antioxidant activity levels by measuring their total phenolic content (TPC), reducing power (RP), β-carotene bleaching (BCB) activity, trolox equivalent antioxidant capacity (TEAC), and 1,1-diphenyl-2-picrylhydrazyl free radical scavenging (DFRS) ability. The clove bud and thyme borneol essential oils had the highest RP, BCB activity levels, and TPC values among the 26 commercial essential oils. Furthermore, of the 26 essential oils, the clove bud and ylang ylang complete essential oils had the highest TEAC values, and the clove bud and jasmine absolute essential oils had the highest DFRS ability. At a concentration of 2.5 mg/mL, the clove bud and thyme borneol essential oils had RP and BCB activity levels of 94.56% ± 0.06% and 24.64% ± 0.03% and 94.58% ± 0.01% and 89.33% ± 0.09%, respectively. At a concentration of 1 mg/mL, the clove bud and thyme borneol essential oils showed TPC values of 220.00 ± 0.01 and 69.05 ± 0.01 mg/g relative to gallic acid equivalents, respectively, and the clove bud and ylang ylang complete essential oils had TEAC values of 809.00 ± 0.01 and 432.33 ± 0.01 μM, respectively. The clove bud and jasmine absolute essential oils showed DFRS abilities of 94.13% ± 0.01% and 78.62% ± 0.01%, respectively. Phenolic compounds of the clove bud, thyme borneol and jasmine absolute essential oils were eugenol (76.08%), thymol (14.36%) and carvacrol (12.33%), and eugenol (0.87%), respectively. The phenolic compounds in essential oils were positively correlated with the RP, BCB activity, TPC, TEAC, and DFRS ability.     

Extraction and quantification of polyphenols from kinnow (Citrus reticulate L.) peel using ultrasound and maceration techniques

An investigation was carried out to extract polyphenols from the peel of kinnow (Citrus reticulate L.) by maceration and ultrasound-assisted extraction (UAE) techniques. The antioxidant potential of these polyphenols was evaluated using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and superoxide radical scavenging assays; and their antimicrobial activity was assessed against bacterial strains Staphyloccoccus aureus, Bacillus cereus, and Salmonella typhimurium. The highest extraction yield was obtained through the solvent ethanol at 80% concentration level, whereas UAE was a more efficient technique and yielded comparatively higher polyphenol contents than maceration. Maximum polyphenols were extracted with 80% methanol [32.48 mg gallic acid equivalent (GAE)/g extract] using UAE, whereas minimum phenolics (8.64 mg GAE/g extract) were obtained with 80% ethyl acetate through the maceration technique. Elevated antioxidant activity of kinnow peel extracts was exhibited in three antioxidant assays, where 80% methanolic extracts showed the highest antioxidant activity (27.67 ± 1.11mM/100 g for FRAP) and the highest scavenging activity, 72.83 ± 0.65% and 64.80 ± 0.91% for DPPH and superoxide anion radical assays, respectively. Strong correlations between total polyphenols and antioxidant activity were recorded. Eleven phenolic compounds—including five phenolic acids and six flavonoids—were identified and quantified by high performance liquid chromatography. Ferulic acid and hesperidin were the most abundant compounds whereas caffeic acid was the least abundant phenolic compound in kinnow peel extracts. Maximum inhibition zone was recorded against S. aureus (16.00 ± 0.58 mm) whereas minimum inhibition zone was noted against S. typhimurium (9.00 ± 1.16 mm). It was concluded that kinnow mandarin peels, being a potential source of phenolic compounds with antioxidant and antimicrobial properties, may be used as an ingredient for the preparation of functional foods.     

Chemical composition and bioactivities of the essential oil from different organs of <Emphasis Type="Italic">Ferula communis</Emphasis> L. growing in Tunisia

The essential oils obtained by the hydrodistillation from the fresh flowers, leaves, stems, and roots of Ferula communis L., growing in Tunisia were analyzed by GC and GC/MS. Thirty-two components were identified in the oil of flowers with camphor (18.3 %), α-pinene (15.3 %), and β-eudesmol (9.3 %) as the main constituents. Twenty-nine compounds were identified in the oil of stems with β-eudesmol (28.1 %), δ-eudesmol (11.1 %), and α-eudesmol (9.6 %) as the main compounds. Twenty compounds were characterized in the oil of roots with dillapiole (7.9 %), guaiol (7.3 %), and spathulenol (6.8 %). In the oil of leaves, α-eudesmol (25.2 %), β-eudesmol (20.7 %), δ-eudesmol (10.1 %), and caryophyllene oxide (7.2 %) were found as the main constituents. This study was undertaken to evaluate the antioxidant activity using DPPH (2,2′-diphenyl-1-picrylhydrazyl), ABTS (2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid), reducing power, and catalase activity. We tested also the antibacterial, cytotoxic, and cholinesterase inhibition properties of the essential oil of different organs of F. communis. The essential oil of the stems showed the highest antioxidant activity (IC₅₀ = 0.03 ± 0.001 mg mL^?1), in DPPH assay and the important result of catalase (303.03 µmol H₂O₂ degraded/min/protein) of F. communis. The antibacterial activity of the oil was determined by micro-well dilution assay. The best results (MIC = 0.156 ± 0.02 mg mL^?1) were exhibited by the essential oil of the leaves of F. Communis against Pseudomonas aeruginosa. Besides, the strongest cytotoxic activity against Hela cells was shown with essential oils’ leaves with an inhibition percentage of 79.05 % at the concentration of 500 µg mL^?1. However, the best inhibition percentage of A 549 cells was detected for essential oils’ leaves with an inhibition percentage of 54.56 % at 250 µg mL^?1. Our finding showed that the essential oil of the flowers was the most active, with 64.623 % of inhibition against butyrylcholinesterase at 10 mg mL^?1 from the incubation time of 30 min.