International Journal of Pharmacology
2005 | 9,241,751 words
The International Journal of Pharmacology (IJP) is a globally peer-reviewed open access journal covering the full spectrum of drug and medicine interactions with biological systems, including chemical, physiological, and behavioral effects across areas such as cardiovascular, neuro-, immuno-, and cellular pharmacology. It features research on drug ...
Antioxidant Activity of Aqueous Methanol and Ethyl Acetate Extract of Leaves...
Y. Potchoo
Faculte Mixte de Medecine et de Pharmacie, Universite de Lome B.P. 1515, Lome, Togo
I.P. Guissou
Departement de Medecine et Pharmacopee Traditionnelle, Institut de Recherche en Science de la Sante (IRSS/CNRST), Ouagadougou (Burkina Faso)
M. Lompo
Departement de Medecine et Pharmacopee Traditionnelle, Institut de Recherche en Science de la Sante (IRSS/CNRST), Ouagadougou (Burkina Faso)
E. Sakie
Faculte Mixte de Medecine et de Pharmacie, Universite de Lome B.P. 1515, Lome, Togo
B. Yaro
Departement de Medecine et Pharmacopee Traditionnelle, Institut de Recherche en Science de la Sante (IRSS/CNRST), Ouagadougou (Burkina Faso)
Read the Summary
Year: 2008 | Doi: 10.3923/ijp.2008.120.124
Copyright (license): Creative Commons Attribution 4.0 International (CC BY 4.0) license.
[Full title: Antioxidant Activity of Aqueous Methanol and Ethyl Acetate Extract of Leaves of Annona senegalensis Pers from Togo Versus the One Originates from Burkina Faso]
[[[ p. 1 (unverified proofreading) ]]]
[Find the meaning and references behind the names: Life, Data]
Life International Journal of Pharmacology ISSN 1811-7775 Life science alert ansinet Asian Network for Scientific Information
[[[ p. 2 (unverified proofreading) ]]]
[Summary: This page introduces a study comparing the antioxidant activity of Annona senegalensis leaf extracts from Togo and Burkina Faso. It mentions the extraction methods used (aqueous methanol and ethyl acetate), determination of total polyphenols and flavonoids, and antioxidant activity assessment using DPPH.]
[Find the meaning and references behind the names: Keys, Ali, Faso, Abdi, Choice, Plant, Aim, Work, Roo, Coudert, Fax, Lom, Present, Development, Togo, Pers, Saki, Part, Micro, Heart, Year, Yao, Yaro, Sant, Chemical, Due, Role, Free, Author, Study, Africa, End]
International Journal of Pharmacology 4 (2): 120-124, 2008 ISSN 1811-7775 2008 Asian Network for Scientific Information Antioxidant Activity of Aqueous Methanol and Ethyl Acetate Extract of Leaves of Annona senegalensis Pers from Togo Versus the One Originates from Burkina Faso 'Y. Potchoo, I.P. Guissou, M. Lompo, 'E. Sakiè and B. Yaro 'Faculté Mixte de Médecine et de Pharmacie, Université de Lomé B.P. 1515, Lomé, Togo Département de Médecine et Pharmacopée Traditionnelle, Institut de Recherche en Science de la Santé (IRSS/CNRST). Ouagadougou (Burkina Faso) Abstract: The aim of the present study is to evaluate and compare the antioxidant potential of the leaves extracts of Annona senegalensis (Ammoniaceae) of Togo versus the one of Burkina Faso. To this end, aqueous methanol and ethyl acetate extracts by splitting and by steeping were achieved and the determination of total polyphenols of which flavonoids was carried out. A survey of the antioxidant activity using the DPPH methods was performed. The content in total polyphenol (3.17 0.03%) and flavonoid (2.33 10.17%) of 70% (v/v) aqueous methanol extract of the specimen from Togo was significantly higher than the one from Burkina (2.66±0.08 and 1.64±0.04%, respectively) (p<0.00001 for total polypheral; p<0.05 for total flavonoid), whereas, the amount of total flavonoid in the ethyl acetate extract of the species from Burkina (10.38%) was triplicated. For the two types of extracts, the species of Burkina Faso showed an improved antioxidant activity than the one of Togo (IC 8.51 and 21.08 µg ml. ' versus 12.46 and 29.22 µg m1, 1, respectively) (p<0.05). These free radicals inhibition activity of the extracts may be due at least to polyphenolic flavonoids identified by means of IIPLC assay performed in the preliminary study. These flavonoids were rutin and isoquerectrin as flavanols (specimen from Togo) of which are added epicatechin and catechin derivatives (flavanols) in the specimen from Burkina. The traditional use of plant leaves may imply in part this activity against the free radicals. Keys words: Annona senegalensis from Togo, Annona senegalensis from Burkina Faso, aqueous methanol extracts, ethyl acetate extracts, total polyphenols, total flavonoids, antioxidant activity INTRODUCTION The free radicals are chemical species (O, OH, RO', ROO, 110, 0,*) (Coudert et al., 1994) produced in the organism during the chemical reactions that contribute to the development and the maintenance of the cellular life. These are very reactive species towards endogenous molecules (DNA, proteins, lipids) having a beneficial role (antimicrobial activity) but implied especially in the pathological physiology of numerous affections: atherosclerosis, heart failure, ageing. neurodegenerative disorders, cancer, diabetes mellitus and a plethora of other diseases (Coudert et al., 1994; Abdi and Ali, 1999). So, one constantly attends nowadays the increasing development of substances having the suitability to stop the initiation and/or the propagation of reactions (oxidization) leading up to the production of these free radicals: These are the free radical scavenging or antioxidant agents which are synthesis substances but more and more the phytochemical principles of medicinal plants. In the preliminary phytochemical study, we have also reported the circumstances of choice of Annona senegalensis as subject of study; we have described its physical characteristics, its ecosystem of growing and its numerous traditional uses not only in Togo but also in many other countries of Africa. A review of the literature showed that the free radical scavenging activity has not yet been evaluated nor in the leaves nor in any other part of the plant. In order to value the antioxidant potential of this plant, our work intends to do this compared to the species originates from Burkina Faso using extracts from the leaves. MATERIALS AND METHODS This study has been carried out during the year 2006 al The Institute of Research in Science of Health (IRSS/CNRST), Department of Medicine and Traditional Pharmacopeia, Ouagadougou, Burkina Faso. Corresponding Author: Potchoo Yao, Faculté Mixte de Médecine et de Pharmacie, Université de Lomé B.P. 1515, Lomé, Togo Tél: (228) 338 60 08/225 47 39/911 34 78 Fax: (228) 221 85 95/250-17-68 120
[[[ p. 3 (unverified proofreading) ]]]
[Summary: This page details the methods used in the study, including plant material collection, extraction, phytochemical screening, determination of total polyphenolic and flavonoid compounds, and evaluation of antioxidant activity (qualitative and quantitative). It mentions spectrophotometry and thin layer chromatography.]
[Find the meaning and references behind the names: Range, Rapid, Class, Deg, Sheet, Blank, Reader, Standard, Plus, Int, Thin, Aluminium, Excel, Grand, Dowd, Give, Tae, Dry, Deep, Under, High, Violet, Cach, Point, Gel, Acid, Purple, Sample, Table, Room, Light, Color, General, Min, Ehm, Positive]
Int. J. Pharmacol., 4 (2): 120-124, 2008 Collection of the plant material, extraction and phytochemical screening of the extracts: To this end, a preliminary study has previously been performed. Determination of total polyphenolic compounds: The concentration of total polyphenol compounds in the 70% (v/v) aqueous methanol extract (Ehm) were determined spectrophotometrically on the basis of a standard curve (R 0.9988) plotted using tannic acid (serial dilutions to give a range of 3.33-23.33 μg mL¹). Briefly, 50 μL of extract and the standard previously dissolved in 60% methanol were diluted (3-fold replicated). The absorbance of the studied extract and the serial concentrations of the standard were measured with an LV-Visible Agilent spectrophotometer 8453 E at 280 nm against a blank. The content in total polyphenolic compounds was calculated using the equation of the standard curve and the results expressed as mg of Tamic Acid Equivalent. (TAE) per 100 mg of lyophilised extract. Determination of total flavonoid compounds: The total flavonoids (a class of polyphenols) content of 70% aqueous methanol extract and ethyl acetate extract (Eea) was determined with the help of Dowd method adapted by Arvouet-Grand et al. (1991) using 2% aluminium trichloride in methanol as reagent. The absorbance was measured using an Agilent UV-Visible spectrophotometer 8453 at 415 mm against a blank. The standard curve (R' -0.9986) was plotted using the serial concentrations of quercetin. The content in total flavonoid constituents was calculated using the equation of the standard curve and the results expressed as mg of Quercetin Equivalent (QE) per 100 mg of lyophilised extract. Evaluation of the antioxidant activity Qualitative determination of the antioxidant activity: It is a rapid test in order to evaluate the antioxidant activity on the precipitated fraction of ethyl acetate extracts of both samples. Based on the method previously described (Burils and Bucar, 2002), the solutions of each extrael and quercetin as standard were spotted on the starting point. on silica gel F251 of a thin layer chromatography sheet and developed in an appropriate migration solvent system. After this, the silica gel sheet is allowed to dry and sprayed with 1% 2, 2-diphenyl-1-picryl-hydrazil (DPPH a purple coloured free radical general.or) in methanol. Any bleaching of the purple color background of DPPH reagent to the site of the spots within 30 min was taken as positive result. Quantitative determination of the antioxidant activity: The free radical scavenging potency of 70% aqueous methanol and ethyl acetate extracts was determined using the method of Mensor et al. (2001) with some modifications. Briefly, each extract and quercetin (21 mg ml), as positive control, were diluted to give concentrations ranging 1050-0.5 µg ml. ' with dimethyl sulfoxide (DMSO). The solution of 1% DPPH in methanol was prepared. Two hundred microliter of this solution was added to 10 μL of cach extract or quercetin solutions in various concentrations and allowed to react in the steam room at 37°C for 30 mn. The blank and the negative control were prepared with appropriate solvents. Each assay was 4 fold replicated. The decrease in absorbance. (deep violet to light yellow) of the mixtures of tested extracts or quercetin was measured at 190 mn on a spectrophotometer Biorad Model 680 Microplate Reader. These absorbance values were converted to the percentage of inhibition of free radical scavenging activity (1%) using the formula: 1%Ex100 A.. where, A, was the absorbance of the sample, A. was the absorbance of the control. The TC (concentration causing 50% inhibition of a maximum effect estimate in 100%) value of each extract was calculated using the equation of linear regression of plots (excel software) of concentrations of tested samples (µg m1). The inhibition of DPPH activity of quercetin was also measured under the same condition to serve as standard antioxidant agent. RESULTS of Phytochemical contents the extracts: The phytochemical principles identified in the preliminary study were mainly polyphenols (flavonoids, catechol tannins, anthocyanosides), saponosides and carotenoids for the 70% aqueous methanol extract and anthocyanosides, flavonoids and carotenoids for chyl acetate extract. The High Performance Liquid Chromatography (IIPLC) analysis of the extracts has confumed the presence of flavonoids, especially rutin and isoquercetrin (Plavonols) in the specimen from Togo and the preceding compounds plus epicatechin and catechin derivatives (flavanols) in the specimen from Burkina. Determination of total polyphenolic and flavonoid content: Table 1 shows the content in total polyphenols and flavonoids (a group of polyphenol) of Ehm and Eea from 121
[[[ p. 4 (unverified proofreading) ]]]
[Summary: This page presents a table (Table 1) comparing the total polyphenolic and flavonoid content, along with antioxidant activity (IC50), of extracts from Togo and Burkina Faso. It includes statistical analysis (Student's t-test) comparing the polyphenolic and flavonoid content.]
[Find the meaning and references behind the names: Less, Bae, Arrow, Eca, Fig, Aderogba, Dose, Low, Cases, Main, Toa, Gss, Burk, Rig, Mean, Taf, Strong, Sem, Good]
Int. J. Pharmacol., 4 (2): 120-124, 2008 Table 1. Toa¨ polyphenolic and Cavonoid condend, and the antioxidant. activity (Co) of 70% aqueous methanol and ethyl acetale extrad. of plant material from Togo versus the one originates from Burk.na Faso Extracts Etm Ig Ehm. Bf Eea Ig Eea Bf Quercelir Total polyphenolic condend. ( g±SEM TAF/100 g dry extrac 3.47±0.03° 2.66+C. 08 Total flaveno:d content. (rig±SEM QE/00ing dry extract) 2.33±0.179 1.64+0.044 13.27+0.20 40.38+1.08 Cso±SEM Qugn 12.46±1.056 8.51+0.66 29.22+2.03* 21.08+0.31j 2 99±0 215 Comparison of total polyphenclic and flavonoic content (Student's t-test): a vs b (p<0.0001), c vs d (p<0.05), e vs f(p<0.0001), Comparison of IC50 values (Student's t-test): gss p<0.00.), h vs s p<0.001), i vs s (p<0.0001). j vss (p<10), gvsh (p<0.05), i vs j (p<0.05) both plants. The quantitative composition of Ehm was 3.47±0.03% of total polyphenols and 2.33±0.17% of total flavonoids for Annona senegalensis of Togo (AsTg) versus, respectively 2.66-0.08% and 1.64±0.04% for Annona senegalensis from Burkina Faso (AsBf). For Eae, the content in total polyphenols of which mainly flavonoids was 13.27±0.20% in Togolese sample versus 10.38 1.08% in the plant originates from Burkina Faso. Comparative antioxidant activity of the extracts Qualitative determination of the antioxidant activity: This chromatogram photography (Fig. 1) shows the positive test of DPPH bleaching to the site of spots issued from ethyl acetate extract of sample originates from Togo (Eea Tg) versus the one from Burkina Faso (Eea Bf) and Quercetin (Q) as standard. Quantitative determination of the antioxidant activity: Table 1 shows the antioxidant potential of Ehm and Eea expressed as the IC value in comparison to the positive control (quercetin). For both plants, 70% aqueous methanol extract. exhibited a highest. antioxidant activity (IC = 8.5110.66 µg ml. for AsBf versus 12.46 1.05 μg mL for As Tg) than cthyl acetate extract (IC) 21.08.31 μg mL-1 for AsBf versus 29.22±2.03 μg mL for AsTg). The two extracts from Annona senegalensis of Burkina Faso showed a potent antioxidant activity 8.51-0.66 (IC5) for Ehm versus μg mL 21.08±0.31 μg mL for Eea) compared to those from Togo (IC50 = 12.16-1.05 μg mL for Ehm versus 29.22±2.03 μg mL for Eea). -1 Statistical analysis: The results of total polyphenolic and flavonoid content, the ICs values of the antioxidan activity are expressed as mean±SEM of three or five determinations. The determination of total polyphenolic and flavonoid content were issued from the Eea Bf Q Eea Tg Fig. 1: Chromatogram of ethyl acetate extracts of Bae Tg versus Eae Bf and quercetin (Q) as standard. The arrow indicates the migration steering of the solvent concentration-absorbance curves. The ICC values were obtained from the dose-response regression plots. In the two cases, good coefficients of correlation R² were observed: 0.9986 and 0.9643 to 0.9842, respectively. A low IC30 value is an indication of a strong antioxidant activity. The two samples were compared in regard to the quantitative determination and the antioxidant activity using the Student's t-test. A probability P of 0.05 or less was considered significant. DISCUSSION The determination of total polyphenols and its related group flavonoids showed that the content of these constituents is significantly higher in Ehm Tg (3.47=0.03 and 2.33±0.17%, respectively) than in Ehm Bf (2.66=0.08 and 1.64±0.04%, respectively) (p<0.00001 for total polyphenol; p<0.05 for total flavonoid). Concerning Eca, as reported by Ibcwuike et al. (1997) and Aderogba et al. (2003, 2004, 2005), the main polyphenolic group that have been isolated in ethyl acetate extract of leaves were flavonoids. In this study, the highest amount (40.38 1.08%) of flavonoids were found in ethyl acetate extract of the specimen collected at Burkina Faso (p<0.0001) (Table 1). These flavonoids are represented at least by mitin, isoquercetrin, epicatechin and catechin derivatives as has detected IIPLC assay. These quantitative and qualitative differences noted in the extract content of phytochemical principles of both species may be explained, as we have discussed in a previous phytochemical screening study, by the climatic 122
[[[ p. 5 (unverified proofreading) ]]]
[Summary: This page discusses factors influencing the observed differences in antioxidant activity, such as environmental conditions, geological environment, harvest period, enzymatic content, and gene expression regulation. It also compares the antioxidant activity of the extracts to that of quercetin.]
[Find the meaning and references behind the names: Stage, Natural, Bugs, Mccune, Purity, Hea, Human, Silva, Gene, Wang, Ring, Saskia, Active, Saharan, Lae, Sci, Thal, Nig, Beck, Reynolds, Comes, Sawadogo, Idowu, Big, Prod, Pieters, Lett, Okoh, Lea, Med, Ros, Case, Arid, Nat, Pyne, Elm, Alaoui, Johns, Galvez]
Int. J. Pharmacol., 4 (2): 120-124, 2008 conditions (Pieters and Vlietinck, 2005, Reynolds, 2002; Metting and Pyne, 2007), the geological environment (Comes and Silva, 2007) of the sites of harvest, the period of the collect, the enzymatic content responsible for the biosynthesis pathways (Pieters and Vlietinck, 2005) and the regulation of gene expression by environmental factors (Boudel, 2007). Indeed, if one considers that the substances elaborated by the plant allow it to adapt to its environment (role of signal, defense against the predators and the parasites, resistance against the harmful bugs and the diseases) (Pieters and Vlietinck, 2005), the one of Burkina being more arid (Sub-Saharan climate), this difference can be explained. The two extracts of both samples belonging to two different ecosystems exhibited a substantial but a least. antioxidant activity (IC = 8.51-29.22 μg mL) in relation to the quercetin (IC = 2.99 μg mL¹) (p<0.001). The DPPH inhibition activity of aqueous methanol extracts (IC;: = 8.51 μg mL for AsBf versus 12.16 μg mL for AsTg) was more polent compared to the one of the ethyl acetate extracts (IC = 21.08 μg mL for AsBf versus 29.22 μg mL for AsTg) (p<0.0001). Indeed, the antioxidant activity of the plant extracts depends on: the type and the polarity of the extracting solvent, the extracting technique, the purity of the active principle, the antioxidant test, the substrate used (Tsuda et al., 1991) and the structural requirements (a number of phenolic hydroxyl groups on ring structures) (Harbome, 1986; Saskia et al., 1996; de Beck et al., 2003). Although the content in total polyphenols and their related flavonoids was higher in Ehm Tg (p<0.00001 for total polyphenol; p<0.05 for total flavonoid), the Ehm Bf has showed the best scavenging activity with IC, valuc of 8.51 μg mL versus ICs, value of 12.16 μg mL for Ehm Tg (p<0.05). Relating to the ethyl acetate extracts, the total flavonoids content of Eea Bl was 3-fold higher than Eae Tg (10.3811.08% versus 13.27 0.20%) (p<0.0001). However, this Hea Bf exhibited a weak scavenging potential compared to the one of Elm Bl (21.08 versus 8.51 μg mL) but more potent than the one of Lae Tg (IC,, – 21.08 µg ml. versus 29.22 µg ml.¯¹) (p<0.05). The effectiveness of the antioxidant activity of the extracts of innona senegalensis from Burkina may be explained by the environmental factors such as the climatic conditions, the stage of plant maturation, the Temperature (Gazzani et al, 1998). McCune and Johns (2005) reported that this antioxidant activity was increased under growing conditions of decreased water and fertility. what is the case of the Sub-saharan climate like the growing ecosystem of Annona senegalensis originates from Burkina. Besides, a big diversity exists in the efficiency of the antioxidant activity of different phenolie compounds (Montalleb et al., 2005). The antioxidant 123 activity reported in this study is related in part to the previous flavonoids (rutin, isoquercetrin, epicatechin and catechin derivatives) which involve at least a catechol group necessary to radical scavenging in any flavonoid thal possesses this activity (Saskia et al., 1996; de Beck et al., 2003). Despite the highest amount of total flavonoids of Lea Bf (10.38±1.08%), this one didn't exhibited a highest scavenging activity than Ehm Bf which contained only 1.6410.04%. This finding confirms the data of the literature according to which no any relationship exist between the antioxidant activity and the content of total flavonoids (Galvez et al., 2005; Sawadogo et al., 2006), even though their free radical scavenging activity is not anymore to demonstrate. The free radical scavenging activity of the 70% aqueous methanol and the ethyl acetate extracts of Annona senegalensis leaves is due in part to their phytochemical constituents of polyphenols of which the flavonoids as reported numerous authors (Pieters and Vlietinck, 2005; Galvez et al., 2005; Aderogba et al., 2004, 2005); other polyphenols like the tannins (Pieters and Vlietinck, 2005), the anthocyanins (Wang et al., 1999) and the saponins (Alaoui et al., 1998) as terpenoid identified in the extracts could also participate to this antioxidant activity. Indeed, these chemical principles have been reported to be involved in the antioxidant activity of various medicinal plants. The present study showed that the leaves extracts of Annona senegalensis from the two ecosystems, especially the one of Burkina Faso constitutes a potent natural source of antioxidant agents. This antioxidant activity could justify in part, the use of this medicinal plant. in traditional practice. REFERENCES Abdi, S. and A. Ali, 1999. Role of ROS modified human DNA in the pathogenesis and aetiology of cancer. Cancer Lett., 142 (1): 1-9. Aderogba, M.A. E.K. Okoh, A.O. Ogunlaini anl B.M. Abegaz, 2003. 6-C-Methylquercetine-3,3',4'trimethyl ether from the leave extract of Poliostigma reticulatum (DC) Hochst. Nig. J. Nat. Prod. Med., 7: 37-38. Aderogba, M.A., E.K. Okoh, T.A. Adelanwa and EM. Obuotor, 2001. Antioxidant properties of the Nigerian Piliostigma species. J. Biol. Sci., 4(4): 501-503 Aderogba, MA, EK. Okoh and TO. Idowu, 2005. Evaluation of antioxidant activity of the secondary metabolites from Poliostigma reticulatum (DC) Ilochst. J. Biol. Sci., 5 (2): 239-242.
[[[ p. 6 (unverified proofreading) ]]]
[Summary: This page provides a list of references cited in the study, including publications on related topics such as analgesic and anti-inflammatory activity, antioxidant activity of various plants, and the role of phenolic compounds. It lists authors, titles, and publication details.]
[Find the meaning and references behind the names: Van Den Berg, Van Bennekom, Gomes, New, Santos, Pharm, Belg, Griffioen, Franca, Boudet, Watanabe, Eds, Nair, Seed, David, Meda, Alan, Martin, Acker, Cartier, York, Radic, Chem, Fruit, Socrates, Cordero, Gray, Hassar, Diet, Six, Berg, Bastide, Dewitt, Leitao, Cody, Fauziah, Ayuso, Yamamoto, Phan, Reis, Tromp, Papetti, Okeke, Dijoux, Bohlin, Don, Menezes, Evolution, Chang, Asmah, Liss, Houghton, Spinoza, Middleton, Rubal, Clay, Still, Kua, Oil, Hanachi, Lagorce, Bast, Common]
Int. J. Pharmacol., 4 (2): 120-124, 2008 Alaoui, K., J.F. Lagorce, Y. Cherrah, M. Hassar, H. Amarouch and J. Roquebert, 1998. Analgesic and anti-inflammatory activity of saponins of Argania spinoza. Am. Pharm. Fr., 56 (5): 220-228. Arvouel-Grand, A., B. Vemal, A. Pourra and P. Legret 1994. Standardisation d'un extrait de propolis et identification des principaux constituants. J. Phan. Belg., 19 (6): 162-168. Boudet, A.M., 2007. Evolution and current status of research in phenolic compounds. Phytochemistry, 68 (22-24): 2722-2735. Burits, M. and F. Bucar, 2002. Antioxidant activity of Nigella sativa essential oil. Phytother. Res., 14 (5): 323-328. Coudert, P., C. Rubal, V. Saulou, M. Bastide and J. Chopineau, 1994. The free radicals. Actualités Pharmaceutiques, 321: 37-46. de Beck, P.O., G. Cartier, B. David, MG. Dijoux-Franca and A.M. Mariotte, 2003. Antioxidant flavonoids and phenolic acids from leaves of Leed guineense G. Don (Leeaceae). Phytother. Res., 17 (1): 315-3417. Galvez, M., C. Martin-Cordero, P.J. Houghton and M.J. Ayuso, 2005. Antioxidant activity of methanol extracts obtained from Plantago species. J. Agric. Food Chem., 53 (6): 1927-1933. Gazzani, G., A. Papetti, G. Massolini and M. Daglia, 1998. Anti and prooxidant activity of water soluble components of some common diet vegetables and the effect of thermal treatment. J. Agric. Food Chem., 46 (10) 4118-4122. Gomes, C.S.F. and I.B.P. Silva, 2007. Minerals and clay minerals in medical geology. Applied Clay Sci., 36 (1-3): 4-21. Harborne, J.B., 1986. Nature, Distribution and Function of Plants Flavonoids. In: Plants Flavonoids in Biology and Medicine, Cody, B., E. Middleton and J.B. Harbome (Eds.). Alan Liss, New York, pp: 15-21. Ibewnike, J.C., F.O. Ogungbamila, A.O. Ogundaini, IN. Okeke and L. Bohlin, 1997. Anti-inflammatory and antibacterial activities of C-methyl flavonols from Poliostigma thonning ii. Phytother. Res., 11 (1): 281-281. McCune, L.M. and T. Johns, 2005. Antioxidant activity relates to plant part, life form and growing condition some diabetes remedies. Phytochemistry, in 66 (12): 1399-1406. Mensor, L.L., F.S. Menezes, A.S. Leitao, A.S. Reis, T.C. Santos, C.S. Coube and S.G. Leilao, 2001. Screening of Brazilian plant extracts for antioxidant activity by the use of DPPH free radical method. Phytother. Res., 15 (2): 127-130. Metting, B. and J.W. Pyne, 2007. Biologically active compounds from microalgae. J. Ethnopharmacol., 112 (3): 161-169. Montalleb, G., P. Hanachi, S.H. Kua, O. Fauziah and R. Asmah, 2005. Evaluation of phenolic content and total antioxidant activity in Berberis vulgaris fruit extract. J. Biol. Sci., 5 (5): 618-653. Pieters, L. and A.J. Vlietinck, 2005. Bioguided isolation of pharmacologically active plant components. still a valuable strategy for the finding of new lead compounds? 100th Volume Special Section: Perspectives of Ethnopharmacology. J. Ethnopharmacol., 100 (1-2): 57-60. Reynolds, T., 2002. IIemlock alkaloids from Socrates to poison aloes. Life Sci., 70 (9): 1035-1040. Saskia, A.B.E. V. Acker, D.J. Van Den Berg M.N.J.L. Tromp. D.H. Griffioen, W.P. Van Bennekom. W.L.F. Van Der Vijgh and A. Bast, 1996. Structural aspects of antioxidant activity of flavonoids. Free Radic. Biol. Med., 20 (3): 331-342. Sawadogo, W.R., A. Meda, C.E. Lamien M. Kiendrebeogo, I. P. Guissou and O. G. Nacoulma, 2006. Phenolic content and antioxidant activity of six Acanthiaceae from Burkina Faso. J. Biol. Sci., 6(2): 249-252. Tsuda, T., M. Watanabe, K. Ohshima, A. Yamamoto S. Kawakishi and T. Osawa, 1994. Antioxidative components isolated from the seed of tamarind (Tamarindus indica L.) J. Agric. Food Chem., 42 (12): 2671-2674. Wang, H., M.G. Nair, G.M. Strasburg, Y.C. Chang: A.M. Booren, J.I. Gray and D.L. DeWitt, 1999. Antioxidant and anti-inflammatory activities of anthocyanins and their aglycon, cyanidin, from lart. cherries. J. Nat. Prod. 62 (2): 294-296. Erratum In: J. Nat. Prod., 62 (5): 802. 124
Other Health Sciences Concepts:
Discover the significance of concepts within the article: ‘Antioxidant Activity of Aqueous Methanol and Ethyl Acetate Extract of Leaves...’. Further sources in the context of Health Sciences might help you critically compare this page with similair documents:
Annona senegalensis, Medicinal plant, Flavonoid, Traditional practice, Environmental factor, Qualitative determination, Temperature, Antioxidant activity, HPLC analysis, High performance liquid chromatography, Phytochemical screening, Thin Layer Chromatography, Free radical scavenging, Climatic condition, Rutin, Quercetin, Student's t test, Tannic acid, IC50 value, Ethyl acetate extract, Antioxidant potential, Tannin, DPPH, Phytochemical principles, Percentage of inhibition, Ethyl Acetate, Natural source, Free Radical, Saponin, Spectrophotometer, Quantitative determination, Chlorogenic acid, Absorbance, Carotenoid, Phenolic compound, Aqueous methanol extract, Antioxidant agent, Burkina Faso, Polarity, Total flavonoid compounds, Anthocyanin, Ecosystem, Extracting solvent, Structural requirements, Antioxidant test, Aqueous methanol, Total polyphenolic compounds, Polyphenol, Togo, Epicatechin, Catechin derivatives, Phenolic hydroxyl group, Geological environment, Decreased fertility, Quantitative composition.
