Crude extract, chloroform fraction and water fraction. Phenolic compounds have been known to possess high antioxidant properties due to their free radical scavenging properties [25]. The calculation of phenolic content helps to predict the antioxidant potential of the extracts. It has been reported that extract containing large amount of polyphenol content possesses a greater antioxidant activity [26]. The polyphenol content of methanol extract of CA was found two times greater than that of other ferns like Cyathea latebrosa, Cibotium barometez, Drynaria quercifolia, Blechum orientale, Dicranopreris linearis, Diaplazium esculentum, Lygodium circinnatum, Nephrolepsis biserrata, and Pyrossia munulariofolia [27]. So, CA can be considered as a higher polyphenolic compounds containing fern.Determination of DPPH radical scavenging activityfoods and single compounds. This assay is based on the measurement of the reducing ability of antioxidants toward DPPH radical, and the decrease of its absorbance [28]. DPPH radical is stable and commercially available organic nitrogen radical, which reacts with hydrogen/ electron donor compounds and has a maximum UV is absorption within the range of 515?20 nm. Upon reduction, the radical solution becomes discolored. Table 2 gives the result from the DPPH radical assay in IC50. In our study, the PNPPMedChemExpress PNPP highest scavenging effect was observed in the ethyl acetate fraction with an IC50 of 16.33 ?0.48 g/ml. This was followed by crude methanol extract, butanol, water and chloroform fractions. The ascorbic acid being a single compound showed a greater antioxidant activity. The highest antioxidant activity of ethyl acetate fraction is due to the presence of greatest amount of polyphenolic compounds in this fraction compared to others.Hydrogen peroxide scavenging activityHydrogen peroxide is an intermediate during endogenous oxidative metabolism and mediates radical oxygen formation such as O, which may be used to predict the scavenging capability of antioxidants in biological systems [29]. Although hydrogen peroxide itself is not very reactive, it can sometimes cause cytotoxicity by giving rise to hydroxyl radicals in the cell. Thus, removing H2O2 is very important throughout food systems [30]. The extracts of CA were capable of scavenging hydrogen peroxide in a concentration dependent manner. IC50 for scavenging of H2O2 was 3.41 ?0.21 for ethyl acetate fraction which was the highest among the fractions. The scavenging of other fractions is given in Table 3. The IC50 value for standard butyl hydroxyanisole (BHA) was 1.32 ?0.07.Nitric oxide (NO) scavenging assayDPPH radical assay is one of the most extensively used methods to evaluate antioxidant activity of plant extracts,6.25 g /ml 12.5 g /mlNO is a potent pleiotropic inhibitor of physiological process, such as smooth muscle relaxation, neural signaling, inhibition of platelet aggregation and regulation25 g /ml 50 g /ml 100 g /ml80 70 60 50 40 30 20 10Nitrate Scavenging percentageAscorbic acidMeOHCHCl3 Extract of CAEtOAcBuOHWaterFigure 1 NO scavenging activity of crude methanol extract and fractions of CA. Data are expressed as mean ?S.D.Lamichhane PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/27362935 et al. BMC Complementary and Alternative N-hexanoic-Try-Ile-(6)-amino hexanoic amide biological activity Medicine 2014, 14:342 http://www.biomedcentral.com/1472-6882/14/Page 6 of5 g/ml 100 80 60 40 20 0 MeOH10 g/ml20 g/ml40 g/ml80 g/ml100 g/mlViability of RAW 264.7 cells ( )CHClEtOAc Extracts of CABuOHWaterFigure 2 Cell viability assay of the crude methanol extract and other fractions of.Crude extract, chloroform fraction and water fraction. Phenolic compounds have been known to possess high antioxidant properties due to their free radical scavenging properties [25]. The calculation of phenolic content helps to predict the antioxidant potential of the extracts. It has been reported that extract containing large amount of polyphenol content possesses a greater antioxidant activity [26]. The polyphenol content of methanol extract of CA was found two times greater than that of other ferns like Cyathea latebrosa, Cibotium barometez, Drynaria quercifolia, Blechum orientale, Dicranopreris linearis, Diaplazium esculentum, Lygodium circinnatum, Nephrolepsis biserrata, and Pyrossia munulariofolia [27]. So, CA can be considered as a higher polyphenolic compounds containing fern.Determination of DPPH radical scavenging activityfoods and single compounds. This assay is based on the measurement of the reducing ability of antioxidants toward DPPH radical, and the decrease of its absorbance [28]. DPPH radical is stable and commercially available organic nitrogen radical, which reacts with hydrogen/ electron donor compounds and has a maximum UV is absorption within the range of 515?20 nm. Upon reduction, the radical solution becomes discolored. Table 2 gives the result from the DPPH radical assay in IC50. In our study, the highest scavenging effect was observed in the ethyl acetate fraction with an IC50 of 16.33 ?0.48 g/ml. This was followed by crude methanol extract, butanol, water and chloroform fractions. The ascorbic acid being a single compound showed a greater antioxidant activity. The highest antioxidant activity of ethyl acetate fraction is due to the presence of greatest amount of polyphenolic compounds in this fraction compared to others.Hydrogen peroxide scavenging activityHydrogen peroxide is an intermediate during endogenous oxidative metabolism and mediates radical oxygen formation such as O, which may be used to predict the scavenging capability of antioxidants in biological systems [29]. Although hydrogen peroxide itself is not very reactive, it can sometimes cause cytotoxicity by giving rise to hydroxyl radicals in the cell. Thus, removing H2O2 is very important throughout food systems [30]. The extracts of CA were capable of scavenging hydrogen peroxide in a concentration dependent manner. IC50 for scavenging of H2O2 was 3.41 ?0.21 for ethyl acetate fraction which was the highest among the fractions. The scavenging of other fractions is given in Table 3. The IC50 value for standard butyl hydroxyanisole (BHA) was 1.32 ?0.07.Nitric oxide (NO) scavenging assayDPPH radical assay is one of the most extensively used methods to evaluate antioxidant activity of plant extracts,6.25 g /ml 12.5 g /mlNO is a potent pleiotropic inhibitor of physiological process, such as smooth muscle relaxation, neural signaling, inhibition of platelet aggregation and regulation25 g /ml 50 g /ml 100 g /ml80 70 60 50 40 30 20 10Nitrate Scavenging percentageAscorbic acidMeOHCHCl3 Extract of CAEtOAcBuOHWaterFigure 1 NO scavenging activity of crude methanol extract and fractions of CA. Data are expressed as mean ?S.D.Lamichhane PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/27362935 et al. BMC Complementary and Alternative Medicine 2014, 14:342 http://www.biomedcentral.com/1472-6882/14/Page 6 of5 g/ml 100 80 60 40 20 0 MeOH10 g/ml20 g/ml40 g/ml80 g/ml100 g/mlViability of RAW 264.7 cells ( )CHClEtOAc Extracts of CABuOHWaterFigure 2 Cell viability assay of the crude methanol extract and other fractions of.