Effects of auxins and different culture systems on the adventitious root development of Passiflora pohlii Mast. and their ability to produce antioxidant compounds

Passiflora pohlii Mast. is a wild species native to Brazil, with potential agronomic interest. Although there are few studies on this particular species, recent works described several biological activities in other species of the genus. The goal of this work was to establish adventitious roots cultures from stem and root segments excised from in vitro-grown plants of P. pohlii, as well as to perform phytochemical analyses and evaluate the antioxidant potential of extracts obtained from the in vitro materials, in comparison with in vivo-grown plants. The influence of different parameters (type of explant, culture systems, light, and type and concentrations of auxins) on the induction of adventitious roots was evaluated. Internodal segments showed the best rhizogenesis induction on solidified medium supplemented with 2.7 µM NAA, whereas root segments showed the highest proliferation rate on liquid medium supplemented with 2.85 µM IAA, both in the absence of light. TLC analysis indicated the presence of saponins in extracts from all in vivo and in vitro-derived materials. The antioxidant potential was determined by DPPH and TLC-DPPH assays. The highest antioxidant activities were observed in extracts from primary and secondary roots of in vivo-grown plants. The characterization of the phytochemical profile of the in vitro and in vivo materials, as well as their pharmacological potential are reported for the first time for this species.

     

Silene vulgaris subsp. macrocarpa leaves and roots from Morocco: assessment of the efficiency of different extraction techniques and solvents on their antioxidant capacity,brine shrimp toxicity and phenolic characterization

Abstract

This study was undertaken to investigate the effect of various solvents and techniques on the extractability of antioxidant compounds, particularly phenolics, from leaves and roots of Silene vulgaris subsp. macrocarpa grown wild in Morocco. Maceration and hot extraction with methanol or water and Soxhlet ethanol extraction were utilized. Aimed at establishing the potential safety of the extracts, Artemia salina lethality bioassay was performed. All the extracts were found to be non-toxic, except for the leaf Soxhlet ethanol. The antioxidant potential of the extracts was evaluated in vitro by DPPH, reducing power, and ferrous ions chelating activity assays. The leaf extracts displayed noticeable radical scavenging and chelating activities, and maceration with methanol (Mac-MeOH) resulted the most suitable extraction method for an effective recovery of antioxidants; further, the root Mac-MeOH extract demonstrated good chelating properties (IC₅₀ = 335.49?±?0.70?µg/mL). Thus, leaf and root Mac-MeOH extracts were subjected to phytochemical investigations. The total phenolic, flavonoid and condensed tannin content was determined spectrophotometrically. Thirteen polyphenolic compounds were positively identified, by HPLC-PDA-ESI-MS, in the leaf extract for the first time, with p-coumaric acid derivatives being the most abundant ones (81%), whereas only catechin and procyanidin B1 were found in the root extract.     

Control of Staphylococcus aureus methicillin resistant isolated from auricular infections using aqueous and methanolic extracts of Ephedra alata

In the current study the potential use of aqueous and methanolic extracts of Ephedra alata aerial parts as biological control agent against pathogenic bacteria and especially Staphylococcus aureus methicillin resistant isolated from auricular infections was evaluated. Chemical tests and spectrophotometric methods were used for screening and quantification of phytochemicals. The assessment of the antioxidant activity was accomplished by DPPH and ABTS radicals scavenging assays. Extracts were evaluated for their antibacterial efficacy by diffusion and microdilution methods. Biofilm inhibition was tested using XTT assay and the cytotoxicity of extracts was carried out on Vero cell line. The GC-FID analysis revealed that E. alata was rich in unsatured fatty acids. In addition, the aqueous extract had the highest flavonoid and protein contents (30.82 mg QE /g dry extract and 98.92 mg BSAE/g dry extract respectively). However, the methanolic extract had the highest phenolic, sugars and tannins. The antioxidant activity demonstrated that the aqueous extract exhibited the strong potency (IC50 ranged between 0.001 and 0.002 mg/mL).Both extracts displayed antimicrobial activity on Gram negative and positive strains. They were effective against S. aureus isolated from auricular infections. The tested extracts were able to inhibit biofilm formation with concentration-dependent manner.Moreover, no cytotoxic effect on Vero cells line was demonstrated for the extracts. Overall, our findings highlight the potential use of E. alata extract as a novel source of bioactive molecules with antioxidant, antibacterial and antiobiofilm effects for the control of infectious disease especially those associated to S. aureus methicillin resistant.     

A comparative exploration of the phytochemical profiles and bio-pharmaceutical potential of Helichrysum stoechas subsp. barrelieri extracts obtained via five extraction techniques

We endeavoured to probe into and compare the possible effect(s) of different extraction techniques (accelerated solvent extraction (ASE), microwave-assisted extraction (MAE), ultrasonication-assisted extraction (UAE), maceration, and Soxhlet extraction (SE)) on the bioactivity (antioxidant and enzyme inhibitory activities) of the aerial parts of Helichrysum stoechas subsp. barrelieri (Ten.) Nyman. Total phenolic and flavonoid contents of the extracts obtained by different extraction methods followed the order of ASE > MAE > UAE > maceration > SE. Extract obtained by ASE was the most potent radical scavenger (219.92 and 313.12 mg Trolox equivalent [TE]/g, against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), respectively) and reducing agent (927.39 and 662.87 mg TE/g, for cupric reducing antioxidant capacity (CUPRAC) and ferric reducing antioxidant power (FRAP), respectively). Helichrysum stoechas extract obtained by UAE (18.67 mg ethylenediaminetetraacetic equivalent [EDTAE]/g) was the most active metal chelator and inhibitor of acetylcholinesterase (4.23 mg galantamine equivalent [GALAE]/g) and butyrylcholinesterase (6.05 mg GALAE/g) cholinesterase. Extract from maceration (183.32 mg kojic acid equivalent [KAE]/g) was most active against tyrosinase while ASE extract (1.66 mmol acarbose equivalent [ACAE]/g) effectively inhibited α-glucosidase. In conclusion, data amassed herein tend to advocate for the use of non-conventional extraction techniques, namely ASE and UAE, for the extraction of bioactive secondary metabolites from H. stoechas aerial parts.     

Phytochemical analysis,antioxidant and antimicrobial activity of wild and in vitro derived plants of Ceropegia thwaitesii Hook – An endemic species from Western Ghats,India

Ceropegia thwaitesii Hook (Asclepiadaceae), an endemic plant species, due to habitat destruction and over exploitation has a very restricted distribution in the Western Ghats of Tamil Nadu, India. The present wrok aimed to determine the chemical composition, the total phenolic (TPC), flavonoid (TFC) and tannin content (TEC), and to assess the antioxidant properties of various extracts of in vivo plants (IVP) and in vitro regenerated plants (IRP) of C. thwaitesii. Some phenolic compounds like gallic acid, cathechol, vanillin and salicylic acid were identified and quantified by HPLC. All the extracts possessed relevant radical scavenging activity on DPPH, Superoxide radical scavenging activity, and Nitric oxide radicals as well as total antioxidant ability. DPPH assay of in vitro methanol stems extracts and ethanol leaves extracts revealed the best antioxidant properties with important IC₅₀ values of 0.248?±?0.45?µg/mL and 0.397?±?0.67?µg/mL, respectively, whereas in vivo chloroform stems extracts showed a lower antioxidant activity (IC₅₀ of 10.99?±?0.24?µg/mL). The IRP methanol extracts of stem and leaves had good inhibitory activity against all tested microorganisms in a dose-dependent manner. These results suggested that in vitro raised plants of C. thwaitesii are an excellent source of antioxidant compounds to be exploited on an industrial level as food additive.     

Optimization of Ultrasonic-Assisted Extraction and Radical-Scavenging Capacity of Phenols and Flavonoids from Clerodendrum cyrtophyllum Turcz Leaves

Ultrasonic-assisted extraction (UAE) was developed to extract phenolic and flavonoid antioxidants from Clerodendrum cyrtophyllum Turcz leaves. The optimal experimental parameters for antioxidant extraction from C. cyrtophyllum leaves were measured using single-factor experimentation combined with response surface methodology (RSM). Total phenolic content (TPC) and total flavonoid content (TFC) assays were used to quantify antioxidant compounds. Next, antioxidant radical scavenging capacity was measured using 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′ -azino-bis(3-ethylbenzothiazoline-6-sulphonicacid) (ABTS) radicals. Optimized extraction conditions for UAE from C. cyrtophyllum leaves were as follows: 60.9% ethanol, 85.4 min, and 63.3°C for maximal TPC extraction (16.8±0.2 mg GAE/g DW); 67.7% ethanol, 82.9 min, and 63.0°C for maximal TFC extraction (49.3±0.4 mg RT/g DW); 48.8% ethanol, 85.1 min, and 63.9°C for maximal DPPH radical-scavenging capacity (86.8±0.2%); and 50.6% ethanol, 81.3 min, and 63.4°C for maximal ABTS radical-scavenging capacity (92.9±0.5%). Ethanol concentration was the most important factor in the extraction process. Our work offers optimal extraction conditions for C. cyrtophyllum as a potential source of natural antioxidants.     

蓝莓果渣提取物总酚含量及抗氧化活性研究

研究了蓝莓果渣提取物总酚含量及其抗氧化活性。分别采用水、40%乙醇及纤维素酶辅助乙醇超声提取蓝莓果渣,并用Folin-Ciocalteu试剂对3种提取物的总酚含量进行评估;并采用DPPH清除实验及O2—.清除实验对3种提取物的抗氧化活性进行研究。实验结果表明,纤维素酶辅助超声提取蓝莓果渣的总酚含量最高,可达425.36±15.21 mg GAE.100 g-1DW,远远高于水提物(169.46±9.75 mg GAE.100 g-1DW)及醇提物(218.39±12.54mg GAE.100 g-1DW)中的总酚含量。且纤维素酶辅助乙醇超声提取物对DPPH的清除能力为2.67±0.13 gVc.100 g-1DW,对O—.2的清除能力2.48±0.14 g Vc.100 g-1DW,明显好于醇提物及水提物抗氧化活性。     

Variation in antioxidant properties and phenolics concentration in different organs of wild growing and greenhouse cultivated Castilleja tenuiflora Benth.

The content of total phenolic compounds and flavonoids was determined in methanol extracts of root, stem, leaves, and inflorescences from wild growing and greenhouse cultivated plants of Castilleja tenuiflora. The antioxidant activity in each extract was evaluated using three in vitro models: scavenging of free radicals with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), and reducing power by the phosphomolybdenum assay. Both, antioxidant activity and phytochemicals content were influenced significantly (P < 0.05) by the source of the plant material and the organ. Cultivated plants had the highest content of phenolic compounds (37.95 mg gallic acid equiv. g^?1 dry weight, P < 0.05) and the strongest antioxidant activity. Total phenolic compounds content correlated significantly with the antioxidant activity for all studied plant material and organs (P < 0.05). TLC profile using DPPH as a detection reagent indicated that the phenylethanoids verbascoside and isoverbascoside are the main contributors to the free-radical scavenging of C. tenuiflora. Cultivated plants of C. tenuiflora are an alternative source of natural antioxidants to wild growing plants. The antioxidant properties of C. tenuiflora may be associated with its traditional use to treat conditions consistent with radical-related diseases (e.g. inflammation, tumors).     

Evaluation of antioxidant and anticancer activities of chemical constituents of the Saururus chinensis root extracts

Evaluation of antioxidant and anticancer activities were screened by various Saururus chinensis root extracts. Four solvents (ethyl acetate, methanol, ethanol, and water) extracts were investigated for their total flavonoids, phenol contents and their antioxidant activity of DPPH (2,2-diphenyl-1-picrylhydrazyl), NO (nitric oxide), H₂O₂ (hydrogen peroxide), ABTS 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonicacid)diammonium assays, FRAP (ferric reducing ability of plasma) assays and anticancer activity. The total phenolic and flavonoid content of extracts were determined by using FC (Folin–Ciocalteu) and AlCl₃ colorimetric assay method. Total flavonoid content in these plants ranged from 24.7 to 72.1 mg g^?1 and amount of free phenolic compounds was between 11.2 and 67.1 mg g^?1 extract. The all extracts have significant levels of phenolics and flavonoids content. Anticancer activity was screened for MCF-7 breast cancer cell line. Ethanol extract shows significant of antioxidant activity and water extract shows significant of anticancer activity compared with standard (BHT) butylated hydroxy toluene. These ethanol and water extracts could be considered as a natural source for using antioxidant, and anticancer agents compared to commercial available synthetic drugs.     

Antioxidant activity and protective effects of Uncaria rhynchophylla extracts on t-BHP-induced oxidative stress in Chang cells

Uncaria rhynchophylla (UR) is widely used as a traditional Chinese herbal medicine. However, there are few studies on antioxidant activity of UR extracts. The study was aimed at determining the antioxidant activity, the contents of polyphenol and flavonoid of UR extracts. Various assays were employed to evaluate the antioxidant property of water and ethanol extracts from the UR, compared to those of the other natural and synthetic antioxidants. UR extracts had high total phenolic contents in both the water (160 ± 2.32 mg GAE/g extracts) and ethanol extracts (190.2 ± 3.16 mg GAE/g extracts). In addition, total flavonoid contents were high in both the water extracts (154 ± 1.47 mg CE/g extracts) and ethanol extracts (184.2 ± 2.41 CE/g extracts). Specially, DPPH radical scavenging activity of ethanol extracts from UR were similar with vitamin C as a positive control. In addition, antioxidant capacity in ferric reducing antioxidant power (FRAP) were higher than that for BHT, which was used as a positive control. The antioxidant activity of extracts from UR showed stronger activity than those of vitamin C and α-tocopherol in ferric thiocyanate (FTC) and thiobarbituric acid (TBA) methods. The ethanol extracts of UR protected on H₂O₂-induced DNA damage. In addition, cytoprotective and anti-apoptotic effect of ethanol extracts from UR was also investigated in t-BHP-induced hepatotoxicity. Therefore, these results indicate that UR extracts have antioxidant properties through its ability to enhance the cell viability, mediation of production of ROS. The UR extracts could be suitable as an antioxidant in the food industry.     

Preliminary investigation on chemical composition and bioactivity of differently obtained extracts from Symphytum aintabicum Hub.- Mor. &Wickens

Symphytum species, commonly known as comfrey, hold a long history of folk medicinal uses for healing wounds, bone fractures and other pain resulting from inflammation. However, many species belonging to this genus have not yet been scientifically investigated and hence investigation in this regard is warranted. In the present research, S. aintabicum extracts prepared by different extraction techniques (homogenizer assisted extraction, infusion and maceration) were assayed for their chemosystematic attributes (total phenolic, flavonoid) as well as bioactive compound contents, antioxidant and enzyme inhibition potentials. For instance, the extracts were found to possess phenolic and flavonoid levels ranging from 35.50 to 112.25 mg GAE/g and 2.54–25.12 mg RE/g, respectively. In general, the extracts displayed significant antioxidant activity. However, methanolic and infusion extracts were observed as the most potent radical scavengers and reducing agents, most likely related to their phenolic content. The extracts also showed metal chelating power and total antioxidant capacity in phosphomolybdenum assay. Moreover, while all extracts showed inhibition on amylase, only the methanolic extracts acted as inhibitors of cholinesterases and tyrosinase, most probably due to their relatively higher flavonoid content. The findings also indicated that the extraction method as well as the solvent type used to more or less affect the yield of the bioactive compounds and extracts’ bioactivity reported herein. Hence, as a first report highlighting the in vitro pharmacological properties of S. aintabicum, promising results were revealed from the quantitative chemosystematic analysis of bioactive components present and as sources of antioxidants and enzyme inhibitors against key human illnesses, thus providing scope for potential applications in phytomedicine development.     

Influence of the extraction solvent on antioxidant activity of Althaea officinalis L. root extracts

Althaea officinalis (Malvaceae) is a well-known plant that is widely distributed throughout the world. Aqueous and hydroalcoholic extracts from A. officinalis root are used mainly because of their antitussive and expectorant activity. It is well known that these activities are based on the polysaccharide composition, but little is known about the possible antioxidant activity of root extract. The present study evaluated antioxidant activity of root extracts prepared with different extraction solvents applying ABTS^·+ (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), hypochlorous acid scavenging assay and iron-induced lipid peroxidation. The results showed that the extract prepared with water as extraction solvent did not possess antioxidant activity, whereas the extracts obtained using ethanol:water as extraction agent showed well pronounced antioxidant activity. In particular, the extracts obtained at low concentration of ethanol in the mixed solvent (50:50 and 70:30, v/v) showed higher scavenging activity for ABTS^·+ radicals and hypochlorite ions than the extract obtained with the higher ethanol concentration (90:10, v/v). These results correlated very well with phenolic and flavonoid content of the extracts. The extracts did not show cytotoxic effect on human BV-173 leukemic cells but may have immunomodulating effects due to their antioxidant properties.     

Chemical composition and biological properties of Synedrella nodiflora (L.) Gaertn: A comparative investigation of different extraction methods

Synedrella nodiflora (L.) Gaertn. (Asteraceae), is a weed with ethnomedicinal uses. To extend scientific information on this species, we evaluated the effects of different extraction procedures (maceration, Soxhlet, sonication and homogenizer-assisted extraction (HAE)) using methanol as solvent, on the chemical composition and biological potential. The chemical profiles of the extracts were identified using a chromatographic (UHPLC-HRMS) technique. The antioxidant and enzyme inhibitory activities of the studied extracts were determined. The extract obtained by Soxhlet technique showed a higher level of total phenolic (TPC) and flavonoid content (TFC) and was a superior source of antioxidant compounds. The macerated extract was the most potent inhibitor of cholinesterases and α-glucosidase, whereas the highest activity against tyrosinase was observed in the order of sonication > Soxhlet > HAE > maceration. A modest activity was observed against α-amylase for all the extracts. Multivariate analysis showed that the bioactive compounds recovery and the biological activities of S. nodiflora were mostly dependent on the nature of the extraction technique used. In conclusion, S. nodiflora extracts showed good biological potential and data massed from this study could serve as a scientific baseline for further investigation in order to exploit its potential for designing novel bio-products with therapeutic applications.     

Studies on the antioxidant activity and phenolic compounds of enzyme-assisted water extracts from Du-zhong (Eucommia ulmoides Oliv.) leaves

Enzyme-assisted water extracts (EWEDL) and ethanol extracts of Du-zhong leaves (EEDL) were evaluated for their antioxidant activities using the DPPH radical-scavenging assay, Fe²⁺-chelating assay, and inhibition ability of the linoleic acid peroxidation assay. In general, the antioxidant activity of Du-zhong leaf extracts increased with increasing concentration. Based on the two extracting methods with different antioxidative reactions, it was shown that the enzyme-assisted water extracting method was more effective for antioxidant extraction from Du-zhong leaves. By HPLC-MS analysis, the main phenolic compounds (geniposidic acid, epicatechin, and chlorogenic acid) identified in EWEDL and EEDL were similar. EWEDL and EEDL had total phenolic contents of 13.84?±?0.11 and 14.72?±?0.14?mg chlorogenic acid equivalents (CAE) in each gram of extract, respectively. However, there was no positive correlation between total phenolic content and antioxidant activities of EWEDL and EEDL measured by the three different assays.     

In vitro propagation of Caralluma tuberculata and evaluation of antioxidant potential

Present study describes rapid in vitro propagation of Caralluma tuberculata, a traditional medicinal plant, and antioxidant potential of calli and plants extracts. The highest callus induction rate (93.3%) with maximum weight of calli 5.2 g was achieved from shoot tip explants on MS medium supplemented with 9.04 μM 2,4-D and 4.44 μM BA. The maximum shoot induction rate (71.1%) with mean number of shoots 3.66 ± 1.53 and 4.6 cm average shoot length was observed on 13.32 μM BA, 4.52 μM 2,4-D and 2.89 μM GA3 appended in MS medium. The developed shoots were best rooted in the presence of 5.07 μM IAA with 3.0 ± 0.15 roots per plantlet. The plants were successfully acclimatized under in vivo conditions. The plants and calli extracts exhibited good antioxidant activities, however, plant extract activities were more pronounced. The phenolic compounds in plant and calli extracts were 0.16% and 0.057%, respectively. While the flavonoids were 0.092% in plant and 0.039% in calli extract. Total Phenolics, flavonoids; DPPH radical scavenging activity and reducing power potential distributed among different fractions depending upon polarity of the solvent. The highest DPPH scavenging activity and reducing power was exhibited by water fractions; 4.95 mg/mL and 0.729 OD at 10 mg/mL, respectively. The micropropagation protocol can be successfully used for large-scale multiplication and conservation of germplasm of this threatened plant. Furthermore, antioxidant value describes importance of this valuable plant as food and medicine.     

Free radical scavenging of grape pomace extracts from Cabernet sauvingnon (Vitis vinifera)

Pressed grape pomace obtained from the wine production of Cabernet sauvignon (Vitis vinifera) vintage was dried until 9.8% moisture content, ground and submitted to extraction of soluble components from different extraction techniques. Low pressure extractions were performed with ethanol maceration followed by fractionation with n-hexane, dichloromethane, butanol and ethyl acetate. These solvents were furthermore applied for soxhlet extraction. Supercritical fluid extraction (SFE) was also performed to obtain grape pomace extracts by using pure CO(2) and CO(2) with ethanol as co-solvent in concentrations of 10, 15 and 20%w/w. The operating condition used in high pressure extractions was 150bar and 40 degrees C. The antioxidant activity of the grape pomace extracts was determined considering the free radical scavenging assay using 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and was correlated with the total phenol content determined according to the Folin-Ciocalteu method. The results obtained in DPPH tests indicate the highest antioxidant activity of 96.6+/-0.3%AA, with an IC(50) value of 13+/-1, for the extracts obtained with ethyl acetate in solid-liquid extraction. The highest yield values were achieved in soxhlet extraction with ethanol (13.2%w/w) and with butanol (12.2%w/w), and also by SFE with 15% ethanol (9.2%w/w). The lipophilic composition of grape pomace extracts was evaluated by gas chromatography-mass spectrometry with the identification of components like linoleic acid and ethyl linoleate, with important therapeutic activities.     

Protective effects of Cornus walteri W. extracts on t-BHP-induced cell damage through antioxidant activity

This study evaluated the antioxidant potential of extracts from Cornus walteri W. (CW) using various assays for natural antioxidants. We determined the polyphenol and flavonoid contents, as well as the antioxidant properties of water and ethanol extracts from the CW compared with those of other natural and synthetic antioxidants. CW extracts had high total phenolic and flavonoid contents in both the water and ethanol extracts. Various radical (DPPH, hydroxyl, and alkyl) scavenging activities of extracts from CW were higher than that of vitamin C. In addition, the antioxidant capacity measured as ferric reducing antioxidant power (FRAP), and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) as diammonium salt (ABTS) radical scavenging were higher than that of 2,6-di-tert-butyl-4-methylphenol (BHT), used as a positive control. The cytoprotective effect of CW extracts was also observed in tert-butyl hydroperoxide (t-BHP)-induced oxidative damage in Chang cells. These results showed that CW extracts have antioxidant properties through their ability to enhance cell viability, prevent reactive oxygen species (ROS) generation, and inhibit mitochondrial membrane depolarization. The antioxidant potency of the CW extracts could be exploited for their health promoting potential.     

超声法提取山里红叶总黄酮及其抗氧化活性研究

采用超声辅助提取法从山里红叶中提取总黄酮。通过Box Behnken实验设计(BBD)结合响应面法(RSM)来优化超声提取的条件。影响山里红叶总黄酮提取效率的4个主要变量为液固比,温度,乙醇浓度和时间,得到的最佳值分别为15,40℃,40%,32 min。在此条件下,总黄酮的产率为15.50 mg·g^-1。体外抗氧化实验表明,山里红叶提取物的DPPH自由基清除能力为0.69 mg·mL^-1(以IC₅₀值表示) ,与传统的浸渍提取和热回流提取方法相比,超声提取的方法具有更好的抗氧化活性。实验结果表明超声提取法适用于提取山里红叶中的总黄酮,并且其提取物具有较好的抗氧化活性。     

Antioxidant potential of microalgae in relation to their phenolic and carotenoid content

In the past decades, food scientists have been searching for natural alternatives to replace synthetic antioxidants. In order to evaluate the potential of microalgae as new source of safe antioxidants, 32 microalgal biomass samples were screened for their antioxidant capacity using three antioxidant assays, and both total phenolic content and carotenoid content were measured. Microalgae were extracted using a one-step extraction with ethanol/water, and alternatively, a three-step fractionation procedure using successively hexane, ethyl acetate, and water. Antioxidant activity of the extracts varied strongly between species and further depended on growth conditions and the solvent used for extraction. It was found that industrially cultivated samples of Tetraselmis suecica, Botryococcus braunii, Neochloris oleoabundans, Isochrysis sp., Chlorella vulgaris, and Phaeodactylum tricornutum possessed the highest antioxidant capacities in this study and thus could be a potential new source of natural antioxidants. The results from the different types of extracts clearly indicated that next to the well-studied carotenoids, phenolic compounds also contribute significantly to the antioxidant capacity of microalgae.     

In vitro antioxidant,antimicrobial and antiproliferative studies of four different extracts of Orthosiphon stamineus,Gynura procumbens and Ficus deltoidea

BackgroundMedicinal plants are important source of drugs with pharmacological activities. Therefore, there is always rising demands to discover more therapeutic agents from various species. Orthosiphon stamineus, Gynura procumbens and Ficus deltoidea are high valued medicinal plants of Malaysia contain rich source of phenolic and flavonoid compounds. The aims of the present study were to evaluate anti-oxidant, antimicrobial and anti-proliferative effects on A549, HePG2 and MCF7 cell lines of four different extracts of Orthosiphon stamineus, Gynura procumbens and Ficus deltoidea.MethodologyThe leaves of all selected plants were extracted with methanol, chloroform, ethyl acetate and butanol separately with simple cold maceration. Antioxidant activity of all crude extracts were quantitatively measured against DPPH and Ferric Reducing Assay. Antimicrobial evaluation was done by Microdilution and MTT assay and antipoliferative activity of all extracts of selected plant were evaluated against A549, HePG2 and MCF7 cell lines.ResultsResults showed that methanol extract exhibited highest percentage free radical scavenging activity of almost all extracts of selected plants. Antimicrobials results showed chloroform and methanol extracts of O. stamineus extract were the two most active extracts against resistant MRSA but not S. aureus. Only methanol extract of G. procumbens showed antimicrobial activity against the tested pathogens. Chloroform and methanol extracts of F. deltoidea elicited antimicrobial activity against S. aureus but not MRSA. Antiproliferative activity against three tested cell lines results showed that ethyl acetate extract of O. stamineus showed good effect whereas methanol extract of F. deltoidea and G. procumbens exhibited good antiproliferative activity.ConclusionsThe results of the present investigation demonstrated significant variations in the antioxidant, antimicrobial and antiproliferative effects of different solvent extracts. These data could be helpful in isolation of pure potent compounds with good biological activities from the extracts of plants.