Electrochemical and spectrophotometric assessment of antioxidant properties in Asphodelus tenuifolius Cav. extracts

The objective of the present work was to investigate the anti-oxidative potential of methanolic extract of Carissa opaca roots and its fractions in solvents of different polarities. Total phenolic (TPC) and flavonoid (TFC) contents of methanolic extract were 211.95 ± 0.78 μg/mL gallic acid equivalents (GAE) and 8.35 ± 0.21 μg/mL rutin equivalents (RE), respectively. Ethyl acetate contained the highest amounts of both (TFC, 11.8 ± 0.28 RE; TPC, 342.80 ± 0.42 GAE) followed by chloroform fraction (TFC, 7.50 ± 0.14 RE; TPC, 275.85 ± 0.50 GAE). Extract and fractions displayed remarkable DPPH radical scavenging activity. EC50 values of methanolic extract was 0.88 mg/mL, while that of hexane, chloroform, ethyl acetate, n-butanolic and aqueous fractions were 0.58, 0.38, 0.29, 0.36 and 5.83 mg/mL, respectively, ethyl acetate fraction being most potent. The ethyl acetate fraction also showed the highest activity in terms of reducing power, phosphomolybdate and ABTS assays. All the fractions showed fairly good lipid peroxidation inhibitory activity, which remained almost constant over three days. Based on the results it can be concluded that roots of Carissa opaca contains phytochemicals with exploitable antioxidant, free radical scavenging, and lipid peroxidation inhibitory potential.

Chloris breviseta Benth belongs to the family Poaceae. It is an annual specie that multiplies only by seeds. The plant leaves were cold extracted with ethanol to obtain ethanol extract, which was subsequently fractionated into n-hexane, chloroform and ethyl acetate fractions by maceration method. Three fractions were subjected to phyto-chemical and anti-microbial screening using standard methods. Phyto-chemical analysis showed that both chloroform and ethyl acetate fractions contained flavonoids, saponins steroids, alkaloids, terpenoids and anthraquinones, while only steroids and terpenoids were present in hexane fraction. Results of antibacterial screening of hexane, ethyl acetate and chloroform fractions showed the fractions exhibited various levels of activities against Staphylococcus aureus, Salmonella typhi, Staphylococcus pyogenes, Bacillus subtlis, Escherichia. coli, while antifungal screening of the fractions against various fungal species: Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus, Candida albicans and Rhizopus spp were carried out by agar well diffusion method. Chloroform fraction recorded highest activities against bacterial organisms: S. aureus, B. subtlis and S. typhi with inhibition zones of 20, 23 and 32 mm respectively, with exception of S. pyogenes in which n-hexane fraction recorded the highest inhibition zone of 28 mm. Similarly, the results of anti-fungal screening against A. niger, A. flavus, A. fumigatus, C. albicans and Rhizopus spp showed that chloroform fraction recorded highest activities against, Rhizopus spp, A. flavus and C. albicans 13, 12.9 and 24.9 mm zone of inhibition at 200 mg/ cm3 concentration. Ciprofloxacin and fluconazole were used as positive controls for bacterial and fungal species respectively. Fluconazole exhibited highest activities than all the three fractions against the fungal organisms, with exception of chloroform fraction which recorded higher activity (24.9 mm) against C. albicans than fluconazole (22 mm). The phyto-chemicals contained in the plant leaves extract of Chloris breviseta could be the source of bioactive compounds that can be explored and isolated and to produce novel antimicrobial agents for drug synthesis.

The root bark of Calotropis procera (Family: Asclepiadaceae) was extracted with methanol. The methanolic extract was separated into hexane, chloroform, ethyl acetate, and water soluble fractions. The ethyl acetate fraction was subjected to bioassay-guided fractionation and final purification was achieved by column chromatography. The structure of the compound was elucidated by spectroscopic methods (ESI-MS, 1H and C NMR, COSY, HSQC, and HMBC) and the comparison of the data obtained with that reported in the literature. It was concluded that the compounds isolated was taxifolin 4’-O-β-D-glucopyranoside, a dihydroquercetin glycoside. The crude extracts of hexane, chloroform, ethylacetate, and water soluble fractions of methanol extract and the isolated compound were subjected to antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and brine shrimp lethality bioassay. The result shows that the maximum inhibitions in the DPPH assays were isolated compound (51.7 %), methanol (80.7 %), and water (29.2 %) fractions while ascorbic acid standard was (84.4 %). However, the results for hexane, chloroform and ethyl acetate fractions in the DPPH assays were poor and hence discarded. The results for the in vitro cytotoxicity activity shows that ethyl acetate and hexane fractions showed significant cytotoxicity with LC50 value of 1.0±0.2 and 2.4 ±0.1 respectively.

The ethanolic extract derived from aerial parts of an indigenous medicinal plant Paeonia emodi was screened for enzyme inhibition activities against Urease (jack bean and Bacillus pasteurii) and α-Chymotrypsin. The extract was also investigated for its radical scavenging activity using DPPH assay. The crude extract was found to possess significant enzyme inhibition activities against jack bean (74%) and Bacillus pasteurii (80%) urease and a moderate activity (54%) against α-Chymotrypsin. The extract also displayed excellent (83%) radical scavenging activity. On the basis of these results, the crude extract was subsequently fractionated into n-hexane, chloroform, ethyl acetate, n-butanol and water fractions and tested independently for the aforesaid activities. Significant inhibitory activity against urease enzyme was observed for the ethyl acetate, n-butanol and water fractions while the n-hexane and chloroform fractions were devoid of any such activity. In the α-Chymotrypsin enzyme inhibition studies the activity was concentrated into the ethyl acetate fraction. All the fractions displayed potent radical scavenging activity. The crude extract and fractions thereof were also subjected to total phenolic content determination. A correlation between radical scavenging capacities of extracts and total phenolic content was observed in the majority of cases.

Evaluation of the toxicity and molluscicidal and larvicidal activities of Schinopsis brasiliensis stem bark extract and its fractions

BACKGROUND: Antioxidant capacity of the chloroform, ethyl acetate, n‐butanol and water fractions of the aerial parts of Calluna vulgaris (L.) Hull (Ericaceae) has been assessed in this study. Antioxidant capacity of the plant was screened by assays of 2,2‐diphenyl‐β‐picrylhydrazyl, superoxide anion and hydrogen peroxide scavenging, metal‐chelating activity and reducing power. Butylated hydroxyanisole was used as reference in all assays; ethylene diamine tetraacetic acid was also used as reference in the assay of metal‐chelating activity. Total phenolic contents of the fractions were determined by the Folin–Ciocalteu method.RESULTS: Liquid chromatography/diode array detection/mass spectrometry was used for phytochemical identification of the fractions. Kaempferol‐3‐O‐β‐D‐galactoside was found to be the major constituent in the ethyl acetate fraction (37.1 ± 0.9%), followed by the n‐butanol fraction (4.6 ± 0.1%). High occurrence of antioxidant capacity, with the exception of metal‐chelating activity, was observed in the ethyl acetate and chloroform fractions as well as in kaempferol‐3‐O‐β‐D‐galactoside.CONCLUSION: Calluna vulgaris and its major flavonoid, kaempferol‐3‐O‐β‐D‐galactoside, show high antioxidant capacity in various assays. As far as is known, this is the first report on antioxidant capacity of C. vulgaris and its major flavonoid. Copyright © 2009 Society of Chemical Industry

Corncobs (Zea mays) are beneficial to human health as they contain tyrosinase inhibitors and natural antioxidants, but they are not used as they are considered as waste. This research evaluated the inhibition test towards tyrosinase enzyme and antioxidant activity of corncob fraction using in-vitro DPPH method and its correlation to phenolic and flavonoids. Corncob fraction was extracted using the maceration method applying 70% ethanol solvent. The ethanol extract of corncob was suspended by water and then partitioned with chloroform, ethyl acetate, and aquadest to produce three fractions (chloroform, ethyl acetate, and aquadest fractions). These fractions were analyzed through the tyrosinase inhibition test, applying in vitro tyrosinase enzyme inhibition and antioxidant activity using radical scavenging test DPPH (2 2,2-diphenyl-1-picrylhydrazyl). Meanwhile, the total phenolic and flavonoids content tests were determined spectroscopically. The results showed ethyl acetate fraction had the highest tyrosinase activity with IC50 values of 185.76 µg/mL, followed by the aquadest fraction (IC50 676.44µg/ml) and the chloroform fraction (IC50 709.26 µg/mL). The antioxidant activity using DPPH radical scavenging method exhibited that ethyl acetate fraction had the highest antioxidant activity with IC50 of 25.79 µg/mL followed by the chloroform fraction (IC50 of 29.15 µg/mL) and the aquadest fraction (IC50 of 32.41 µg/mL). The total phenolic content of the corncob fraction ranged between 1.73 to 7.43% (w/w) gallic acid equivalents (GAE), while the entire flavonoid content ranged between 0.01 to 1.34% (w/ w) quercetin equivalent (QE). The tyrosinase activity and antioxidants of the corncob fractions correlated with the total phenolic and flavonoid contents.

Crude methanolic extract as well as subsequent solvent fractions of Viola betonicifolia (VB) whole plant were tested for various in-vitro biological activities, including nematicidal, antioxidant, larvecidal, phytotoxic and cytotoxic. All extracts were also tested for their total flavonoid and phenolic contents. A dose dependent effect was observed against both nematodes. Ethyl acetate fraction was highly effective against Meloidogyne incognita , followed by chloroform and methanolic extract while the highest mortality of Meloidogyne javanica was observed against ethyl acetate followed by chloroform and methanolic extract with 45, 43 and 31% mortality, respectively. The antioxidant activity was tested using 1, 1-diphenyl 1-2-picryl-hydrazyl (DPPH) scavenging and reducing power assay for all extracts. The chloroform fraction showed highly significant antioxidant activity followed by ethyl acetate and methanolic extract. The maximum larvecidal effect against Aedes aegypti was observed for chloroform fraction followed by ethyl acetate fraction. In case of phytotoxic activity, butanol fraction was most effective followed by ethyl acetate fraction. Significant results were found by aqueous fraction with LC 50 46 µg/ml and chloroform with LC 50 56 µg/m against brine shrimp. Phytochemical studies indicated that ethyl acetate fraction was rich of flavonoid and phenolic contents followed by chloroform and methanolic extract. It was concluded that the ethyl acetate and chloroform fractions are the most significant sources of antihelmintic, antioxidant, larvecidal, phytotoxic and cytotoxic compounds.

Comparative evaluation of antimicrobial and antioxidant potential of ethanolic extract and its fractions of bark and leaves of Terminalia arjuna from north-western Himalayas, India

The continuous search for novel compounds against microbial infections and oxidative stress-induced debilitating diseases like diabetes has intensified in recent years. This study evaluated the phytochemical constituents, time-kill antimicrobial, antioxidant, and antidiabetic potentials of whole fruit extracts of Nauclea latifolia Smith. The antibacterial potential was evaluated using micro-broth dilution method and the degree of mortality was examined at different concentrations over a period of 2 h against Staphylococcus aureus and Shigella sonnei as representative organisms. The antioxidant activity of the extracts was determined using 1, 1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide (NO), hydrogen peroxide (H2O2) and iron chelating assays. The antidiabetic potential was determined by evaluating the inhibitory effects of the extracts on the activities of α-amylase and α-glucosidase, while the modes of the enzymes inhibition were assessed using Lineweaver-Burk kinetics.The crude extract displayed minimum inhibitory concentration (MIC) ranging between 0.19 and 1.56 mg/mL. The lowest MIC value displayed by the n-hexane, ethylacetate and n-butanol fraction was 0.19, and 0.39 mg/mL by the chloroform fraction. Total mortality was recorded by n-butanol fraction at 3xMIC (0.57 mg/mL) after 15 min of contact time and ethylacetate fraction after 60 min of contact time against Stapylococcus aureus at the same concentration. Also total mortality was recorded after 60 min of contact time at 3xMIC by n-butanol fraction against Shigella sonnei. The ethyl acetate fraction has the highest total phenol (413.4 mg/g) and total flavonol (8.3 mg/g) contents which is significantly different (p < .05) from all other extracts. For the flavonoid content, the n-butanol fraction had the highest content (35.6 mg/g) followed by n-hexane, ethylacetate and chloroform fraction, respectively. N-butanol fraction showed the highest radical scavenging activities while chloroform and n-butanol fraction showed strong inhibitory potentials against α-amylase and α-glucosidase, respectively. The results obtained showed that whole fruit of Nauclea latifolia elicited noteworthy antimicrobial, antioxidant and antidiabetic activities which are attributed to the presence of its phytoconstituents and thus support its folkloric uses in the treatment of microbial infections and oxidative stress-mediated diseases like hyperglycemia.

Dysphania ambrosioides (L.) Mosyakin and Clemants is an annual or ephemeral perennial herb used traditionally in the Mediterranean region in folk medicine to treat various illnesses, including those related to the digestive system. This study aims to assess the antispasmodic, myorelaxant, and antioxidant effects of D. ambrosioides flower hydroethanolic extract and its chloroform and ethyl acetate fractions in a comparative study to evaluate the result of the extraction type on the potential activity of the extract. Both rat and rabbit jejunum were used to evaluate the antispasmodic and myorelaxant effect, while the antioxidant effect was evaluated using DPPH, a ferric reducing power assay, and a beta-carotene bleaching test. LC/MS-MS analysis was carried out to reveal the composition of the different types of extract. Following the results, the hydroethanolic extract showed a significant myorelaxant effect (IC50 = 0.39 ± 0.01 mg/mL). Moreover, it was shown that the hydroethanolic extract demonstrated the best antispasmodic activity (IC50 = 0.51 ± 0.05 mg/mL), followed by the ethyl acetate (IC50 = 4.05 ± 0.32 mg/mL) and chloroform (IC50 = 4.34 ± 0.45 mg/mL) fractions. The antioxidant tests showed that the hydroethanolic extract demonstrated high antioxidant activity, followed by the ethyl acetate and chloroform fractions. The LC/MS-MS analysis indicates that the plant extract was rich in flavonoids, to which the extract activity has been attributed. This study supports the traditional use of this plant to treat digestive problems, especially those with spasms.

Bioactive components and properties of ethanolic extract and its fractions from Gynura procumbens leaves

A comparative study was conducted among the flesh (SOF) and pericarp (SOP) of Stauntonia obovatifoliola, a wild edible fruit in China. The nutrient composition of both these tissues was firstly quantified, and liquid-liquid extraction was then used to separate their methanolic extracts to get petroleum ether, chloroform, ethyl acetate, n-butanol, and residual aqueous fractions, which were evaluated for their total phenol content (TPC), total flavonoid content (TFC), antioxidant capacities, and α-glucosidase and acetylcholinesterase inhibition abilities. Finally, high-performance liquid chromatography (HPLC) was used to analyze their phytochemical composition. The results revealed the excellent nutritional properties of both SOF and SOP, especially SOP (total dietary fiber, 15.50 g/100 g; total amino acids, 0.80 g/100 g; vitamin C, 18.00 mg/100 g; Ca, 272.00 mg/kg; K, 402.00 mg/100 g). For both tissues, their ethyl acetate fractions showed the highest TPC (355.12 and 390.99 mg GAE/g DE) and TFC (306.58 and 298.48 mg RE/g DE). Surprisingly, the ethyl acetate fraction of SOP exhibited the strongest DPPH and ABTS radical scavenging capacity with 1046.94 and 1298.64 mg Trolox/g, respectively, which were higher than that of controls Vc and BHT. In contrast, their chloroform fractions exhibited the strongest ferric reducing antioxidant power (1903.05 and 1407.11 mg FeSO4/g DE) and oxygen radical absorbance capacity (951.12 and 1510.21 mg Trolox/g DE). In addition, the ethyl acetate fraction of SOF displayed superior α-glucosidase inhibition ability with the IC50 value of 0.19 mg/mL, which was comparable to control acarbose. In comparison, the ethyl acetate fraction of SOP had the best acetylcholinesterase inhibition ability with the IC50 value of 0.47 mg/mL. The HPLC analysis results demonstrated that the ethyl acetate fraction of SOP showed significantly higher phenolic content, particularly for phenolic acids (p-hydroxybenzoic acid, 8.00 ± 0.65 mg/g) and flavonoids (epicatechin, 28.63 ± 1.26 mg/g), as compared to other samples. The above results suggest that Stauntonia obovatifoliola, especially its pericarp, had excellent nutrient compositions, bioactive properties and phytochemical characteristics, and had the potential to be developed as natural functional food.

Chainey root (Smilax spinosa Mill.) is popularly used in Nicaragua’s traditional medicine for its believed anti-bacterial, anti-toxin and antioxidant properties. Despite the widespread use of this plant in Nicaragua, especially on the Atlantic coast, literature contains few reports on the antioxidant activity and chemical composition of S. spinosa. Scientific evidence is required to verify its medicinal effects. Therefore, the aims of this study were to investigate the antioxidant properties of S. spinosa’s root methanolic (ME) extract and its ethyl acetate (EA), n-butanol and water soluble fractions. The total phenolic and flavonoid content, 1,1-Diphenyl-2-Picrylhydrazyl (DPPH) free radical scavenging capacity and Iron (II) chelating activity were investigated. The cytotoxic effect of the EA fraction on human liver hepatoma (HepG2) cells and its cytoprotective properties against H2O2 induced oxidative stress on healthy human liver (FL83B) cells were established. Results demonstrated the antioxidant activity of S. spinosa root to be concentration dependant. Phenolics and flavonoids were found in the ME extract as well as in the EA, n-butanol and water soluble fractions. EA fraction revealed the highest gallic acid equivalence (GAE) of 71.81± 0.36 mg/g DW. Quercetin equivalent was also highest for the EA fraction (45.27± 31.27 mg/g). On the other hand, lowest phenolics and flavonoids were observed in the water soluble fraction. The DPPH scavenging capacity and Iron (II) chelating activity of all four fractions were above 70% at 0.1 mg/ mL. However, none of the fractions were better iron chelators than positive control EDTA. EA showed the highest DPPH scavenging percentage (93%) at 0.2 mg/mL. Among all test samples, the EC50 value of EA soluble fraction was the lowest (0.033 ± 0.002 mg/mL), indicating stronger antioxidant activity than those of positive controls ascorbic acid (0.067 ± 0.0002 mg/mL) and gallic acid (0.068 ± 0.0004 mg/mL). Because of its outstanding antioxidant activity, the EA fraction was selected for further assessment of cytotoxic and cytoprotective effects on the viability of human liver cells. Cytotoxic effect of S. spinosa root EA fraction on the proliferation of human liver hepatoma (HepG2) cells was assessed with the 2-(4-Iodophenyl)-3 - (4-nitrophenyl-5 (2, 4-disulfophenyl) - 2H-tetrazolium (WST-1) assay. S. spinosa EA fraction was capable of interrupting the development and proliferation of HepG2 cells at a concentration dependant manner. At 1500 µg/mL the scavenging of 100% cancerous cells was accomplish by the EA fraction. The Protective effect of the EA fraction on healthy human liver (FL83B) cells viability was assessed by treating the cells with EA for 1 hr prior to the addition of H2O2. The relative cell survival was determined by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. At a concentration of 12.5 µg/mL, the EA fraction enhanced a protective effect on the cells viability allowing 77% cells survival. Results provided a scientific support to the antioxidant properties of S. spinosa Mill. root extract in vitro. Further evaluation of its antioxidative properties in vivo is needed to ensure functionality and long term safety.

The effects of Curcuma mangga ethanolic extract (CME) and its fractions, e.g., aqueous, chloroform, ethyl acetate, and hexane fractions, from C. mangga rhizome were investigated on nociceptive responses using writhing, hot plate, and formalin tests in mice and inflammatory models using carrageenan-induced rat paw edema and croton oil-induced mouse ear edema. The results showed that CME and all fractions (200 mg/kg, p.o.) significantly reduced the number of writhings. Oral administration (p.o.) of CME, chloroform, and hexane fractions (200 mg/kg) significantly prolonged the latency time, whereas aqueous and ethyl acetate fractions were inactive. The activities of CME, chloroform, and hexane fractions were abolished by naloxone (2 mg/kg, intraperitoneal (i.p.)). CME and all fractions at the dose of 200 mg/kg significantly produced antinociception in both early and late phases of the formalin test. CME, chloroform, and hexane fractions were more prominent in licking inhibition than those of the aqueous and ethyl acetate fractions. CME and all fractions (150 mg/kg, p.o.) showed significant reduction of rat paw edema. The order of activity on inhibition of paw edema at 4 h was chloroform fraction > hexane fraction > ethyl acetate fraction > CME > aqueous fraction. When topically applied at 0.5 mg/ear, CME and all fractions suppressed ear edema induced by croton oil. CME and chloroform fraction showed a greater inhibition by 53.97 and 50.29%, respectively. These results suggested that CME and its fractions, especially chloroform and hexane fractions from C. mangga rhizome, possessed centrally acting analgesic as well as anti-inflammatory activities.