Radical scavenging activity pdf merge
In the present study, antioxidant activities of the phenolic extracts from H. The extracts of C.
All the extracts showed dose dependent reducing power activity and moreover, they were well correlated with the total phenolic substances. The potential of multiple antioxidant activity of samples can be further evidenced by inhibition of reactive oxygen mediated erythrocyte cell lysis and metal ion chelating activity. Natural phenolic phytochemicals in plants have been receiving increased interest from consumers and researchers for their beneficial health effects on coronary heart diseases and cancers mainly due their antioxidant activity.
Free radicals and other reactive oxygen species generated in living organisms leads to many diseases including cancer, cardiovascular diseases, cataracts, asthma, hepatitis, liver injury and immunodeficiency diseases Lee et al.
The use of synthetic antioxidants is an old practice and their safety could be questioned by the consumers.
The alternative natural compounds with efficient antioxidant activity have been paid increasing attention. Helicteres isora L. Sterculiaceae and Ceiba pentandra L. Bombacaceae are two important, traditionally used medicinal plants in India.
The former is a shrub or small tree available in forests throughout the central and western India. In tradition, the root juice is claimed to be useful in diabetes, empyema and a favorite cure for snakebite.
The root and the bark are expectorant, demulcent, astringent, anti-galactagogue, and useful in constipation, colic, scabies, gastropathy, diabetes, diarrhea and dysentery. The extract from the root and bark possess insulin-sensitizing, hypolipidemic activity and has the potential for use in the treatment of typediabetes Kumar et al. Moreover, the root extracts exhibited significant antihyperglycemic activity and the effect was comparable with that of glibenclamide Venkadesh et al.
Further, the aqueous extract of the bark showed potential hypoglycaemic and hypolipidaemic effects in streptozotocin induced diabetic rats Kumar and Murugesan ; Kumar et al.
The fruits are astringent, refrigerant, stomachic, vermifuge, vulnerary and useful in griping of bowels, flatulence of children and also possess antispasmodic effect. The dried fruit is demulcent and mildly astringent.
Among the Bhils of Rajasthan, an extract of the fruit is given orally to children to relieve diarrhea. The powdered fruits mixed with neem oil are used for treatment of paralysis among the tribal inhabitants of eastern Bihar Satake et al.
From the fruits, three new compounds O - b-D-glucopyranosyl rosmarinic acid 2 , 4, O -di- b-D-glucopyranosyl rosmarinic acid 3 and 2 R - O - O - b-D-glucopyranosyl caffeoyl 4-hydroxyphenyl lactic acid named as O - b-D glucopyranosyl isorinic acid 4 were isolated together with rosmarinic acid 1. Among these, compound 3 had greater scavenging activity against superoxide anion produced with xanthine and xanthine oxidase XOD than rosamarinic acid Khare The fruit extract has also been reported to be a potent inhibitor of human immunodeficiency virus type-1 HIV-1 Otake et al.
In Asia, Oceania, Africa and Central America this species is used to treat various disorders, including diarrhea, fever, gonorrhea and parasitic infections and as a diuretic and emollient. The gum and unripe fruits were considered as astringent; root used as antidiabetic and antispasmodic Noreen et al.
Extract from bark showed anti-inflammatory properties both in in vivo and in vitro, which can be related to several reports of traditional use in the treatment of ailments of an inflammatory nature such as asthma and cough Ladeji et al. The bark extract of C. A new naphthoquinone, 2,7-dihydroxyformylisopropylmethyl-1,4-naphthoquinone 1 together with a known naphthoquinone, 8-formylhydroxyisopropylmethoxymethyl-1,4-naphthoquinone 2 , sesquiterpenoids and isoflavones have been isolated from the heartwood of this plant and particularly the naphthoquinones exhibited antimicrobial activity.
Similarly, two new isoflavones, pentandrin and pentandrin glucoside and, vavain and its glucoside were isolated from the stem barks of C. From the above account, it is evident that the plant samples have high level of biologically active components which exhibited most of the medicinal properties. Therefore, the present work aims at further investigating their antioxidant activity through the use of several in vitro assay systems and this will provide insight information with reference to their medicinal value.
All other reagents used were of analytical grade. Fresh dried fruits of H. The dried seeds of C. Then, the samples were ground into fine powder and stored in separate screw cap bottles before analysis. The freeze-dried extracts thus obtained were used directly for assessment of antioxidant capacity through various chemical assays.
How to Combine Multiple PDF's into One on a Mac
Then 0. The amount of total phenolics was calculated as tannic acid equivalents from the calibration curve Siddhuraju and Becker The total flavonoid content of sample extracts were determined by the use of a slightly modified colorimetric method described previously Zhishen et al.
An aliquot of 0. Rutin was used as a standard compound for the quantification of total flavonoid. The scavenging activity of sample extracts on hydroxyl radical was measured according to the method of Klein et al. The reaction was initiated by adding 0. After incubation the reaction was terminated by the addition of 1.
The reaction mixture without sample was used as control. A control without sample extract was used. The antioxidant activity AA was calculated as percentage of inhibition relative to the control using the following equation:. Different concentrations of the extracts were taken in separate test tubes. Five mL of 0. The control was prepared as above without any extract, and methanol was used for the baseline correction.
Radical scavenging activity was expressed as the inhibition concentration IC 50 , i. Metal chelating property of the sample was assessed by bipyridyl assay Yamaguchi et al.
The chelating activity of the samples was evaluated using EDTA as standard. The erythrocytes from cow blood were separated by centrifugation and washed with saline phosphate buffer pH 7. The extract yield percentage, total phenolics and flavonoid contents of the extracts obtained from H. Among the different extracts, the maximum yield was obtained for the methanol extracts of C. Isora However, acetone being a successive solvent, the extract yield percentage of both the samples was found to be much lower Isora registered higher level of extract recovery percentage, the total phenolic content of the respective extract was found to be lower 3.
Extarct yield percentage, total phenolics and total flavonoid content in C. CPMe C. However, in H. In previous studies, the presence of phenolic substances including flavonoids and tannins were reported in H. Furthermore, Ueda et al. The results of the present study strongly suggest that phenolics are important components of these plants and some of their pharmacological effects could be attributed to the presence of these constituents. The reducing property is generally associated with the presence of reductants.
The antioxidant action of reductants is based on the breaking of free radical chain by donation of a hydrogen atom.
Reductants also react with certain precursors of peroxide, thus preventing peroxide formation. The data presented here indicated that the marked reducing activity of the extracts seems to be due to the presence of polyphenols, which may act as reductants by donating the electrons and reacting with free radicals to convert them to more stable products and terminate radical chain reaction.
A strong reducing power was noted for methanol and acetone extracts of C. Much lower reducing power was assisted to methanol and acetone extracts of H. Similar relationship between the polyphenolic constituents and reducing power activity has been reported for several plant extracts Amarowicz et al. The results elucidate that polyphenolic contents of the sample extracts appear to function as good electron and hydrogen donors and therefore should be able to terminate radical chain reaction by converting free radicals to more stable products.
Reducing power activity of methanol and acetone extract of H. Hydroxyl radical is an extremely reactive free radical formed in biological systems and has been implicated as a highly damaging species in free radical pathology, capable of damaging almost every molecule found in living cells. This radical has the capacity to join nucleotides in DNA and cause strand breakage, which contributes to carcinogenesis, mutagenesis and cytotoxicity.
In addition, this species is considered to be one of the quick initiators of lipid peroxidation process, abstracting hydrogen atoms from unsaturated fatty acids.
Hydroxyl radical scavenging activity was estimated by generating the hydroxyl radicals using ascorbic acid-iron EDTA. The hydroxyl radical is formed by the oxidation reaction with dimethyl sulfoxide DMSO to yield formaldehyde, which provides a convenient method to detect hydroxyl radicals by treatment with Nash reagent Singh et al.
The scavenging abilities of extracts on hydroxyl radical are shown in Fig. Among the sample extracts, acetone extract of C. This was closely followed by the methanol extract of C. A linear relationship was observed between hydroxyl radical scavenging activity and total phenolic content. These results indicate that the potential scavenging abilities of phenolic substances might be due to the active hydrogen donor ability of hydroxyl substitution.
Hagerman et al. In similar lines, methanol extract of pomegranate peel and grape fruit have also been reported to contain sustainable hydroxyl radical scavenging activity and which might be attributed to the presence of phenolic substances Singh et al. The investigation reveals that both the sample extracts had good hydroxyl scavenging activity and can be used as a good hydroxyl radical scavenger. Hydroxyl radical scavengign activity of methanol and acetone extract of H.
The inhibition of lipid peroxidation might be due to the hydrogen donating ability of phenolic derivatives and subsequent radical stabilization. Many investigations that focused on fruits, vegetables and plant extracts found positive and highly significant relationship between total phenolic content and antioxidant activity Velioglu et al.
Peroxidation inhibiting property of methanol and acetone extract of H. The degree of discolouration indicates the scavenging potentials of the antioxidant extract. In the present study, the free radical scavenging potentials of the extracts at different concentrations were tested. Among the extracts, C. In fact, the activity shown by the methanol extract of C.
Presences of flavonoids generally possess higher antioxidant activity because of double bonds existing in C-ring. Generally the radical scavenging activity of flavonoids depends on their structure and hydroxyl group arrangement.