*Corresponding Author:
J. M. Sasikumar
Department of biotechnology, Karpagam arts and science college, Coimbatore - 641 021, India
E-mail: [email protected]
Date of Submission 16 May 2006
Date of Revision 1 March 2007
Date of Acceptance 5 August 2007
Indian J Pharm Sci, 2007, 69 (4): 581-582  

Abstract

Antioxidant activity of the crude methanol extract of Pseudarthria viscida (L) Wight and Arn. stem and root was performed by1,1-diphenyl-2-picrylhydrozyl (DPPH) radical quenching assay and reducing power test models. Both stem and root extracts exhibited potential antioxidant activity in both the assays.

Keywords

Antioxidant activity, Pseudarthria viscida, DPPH radical, Reducing power

Pseudarthria viscida (L) Wight and Arn. (Fabaceae) is a shrub. The roots are stringent, thermogenic, digestive, anthelmintic, antiinflammatory, diuretic, aphrodisiac, nervine, cardio and rejuvenating tonic. They are useful in vitiated conditions of cough, bronchitis, asthma, tuberculosis, helminthiasis, diarrhoea, inflammation, cardiopathy, fever, hemorrhoids, gout, diabetes, hyperthermia and general debility [1]. The extracts of leaf, root, stem and callus obtained from P. viscida showed significant inhibitory activity against some fungal pathogens causing major diseases in crop plants and stored food grains [2]. The present investigation was undertaken to evaluate the antioxidant activity of stem and root extracts of P. viscida.

The plant material was collected from Kerala and authenticated by the Botanical Survey of India (Southern Circle) Government of India, Coimbatore. The stem and roots were shade dried and powdered. They were exhaustively extracted in Soxhlet apparatus with methanol. Phytochemical analysis of methanol extracts of stem and root was done [3]. Antioxidant activity of the plant extracts was studied by 1,1- diphenyl-2-picrylhydrozyl (DPPH) radical quenching assay and reducing power test models. In vitro DPPH radical scavenging activity was carried out by adopting the method of Blois [4]. Different concentrations of the extracts (1000, 500, 250, 125, 50, 25, 10 µg/ml) were prepared and subjected to antioxidant tests. To 500 µl of each of the extracts, 5 ml of 0.1mM methanol solution of DPPH was added, vortexed, followed by incubation at 27° for 20 min. The control was prepared without any extract and absorbance of the sample was measured at 517nm using UV/ VIS Spectrophotometer (ELICO SL-177, Elico ltd, Hyderabad). Radical scavenging activity was expressed as % inhibition of DPPH radicals. IC50 value was also calculated. The reducing power of the extracts was carried out by using the method of Oyaizu [5]. Different concentrations of the extracts (1000, 500, 250 and125 µg/ml) were prepared. To all the test tubes 2.5 ml of Sodium phosphate buffer followed by 2.5 ml of 1% Potassium ferrocyanide solution was added. The contents were vortexed well and then incubated at 50° for 20 min After incubation, 2.5 ml of 10% trichloroacetic acid was added to all the tubes and centrifugation was carried out at 3000 rpm for 10 min. To 5 ml of the supernatant, 5 ml of distilled water was added. To this about 1 ml of 1% ferric chloride was added to each test tube and incubated at 35° for 10 min. The absorbance was read at 700 nm .The reducing power of the methanol extract was linearly proportional to the concentration of the sample. Ascorbic acid was taken as reference standard. The result of phytochemical analysis was recorded in Table 1. Both the stem and root extracts of P. viscida exhibited potential antioxidant activity in the both the assay models (Tables 2 and 3). The methanol extracts from stem and root of P. viscida showed potent antioxidant activity based on the DPPH and reducing power tests in dose dependent manner. The stem and root extracts strongly scavenged DPPH radicals with the IC50 being 31.01±0.091 and 23.78±0.098 µg/ml, respectively. It also caused significant elevation of reducing power. The higher absorbancy at high concentration indicates the strong reducing power potential. The presence of phenolic compounds might be responsible for the antioxidant activity.

Chemical components Stem Root
Alkaloids + +
Steroids and Sterols - -
Flavonoids + +
Tannins and Phenolic compounds + +
Carotenoids - -
Glycosides - -
Saponins + +

Table 1: Phytochemical analysis of P. Viscida

Concentration (µg/ml) Stem IC50 (µg/ml) Root IC50 (µg/ml)
  Inhibition (%) Mean±Stda Inhibition (%) Mean±Stda
  Mean±Stda   Mean±Stda  
1000 94.54±0.432   86.20±0.094  
500 94.1±0.163   85.13±0.817  
250 75.03±0.368   82.8±0.496  
125 68.63±1.59   69.76±0.786  
50 56.9±0.409 31.01±0.091 59.2±0.432 23.78±0.098
25 48.36±0.459   51.32±0.093  
10 40.32±0.356   41.65±0.612  
Ascorbic acid (IC50)     11.24±0.022  

Table 2: Free radical scavenging activity of P. viscida by dpph radical inhibition

Concentration
(µg/ml)
Absorbance at 700 nm inhibition (Mean±Stda)
Stem Root
1000 0.929±0.0301 0.713±0.0387
500 0.571±0.0443 0.488±0.0602
250 0.382±0.0946 0.382±0.0946
125 0.388±0.0602 0.118±0.0602
Control 0.094±0.001   0.082±0.4066
Ascorbic acid {1000 (µg/ml)} 1.634±0.045

Table 3: Reducing power activity of P. viscida

Acknowledgements

The authors express their sincere gratitude to the management of Karpagam Arts and Science College, Coimbatore.

References