A Study on Phytochemical Constituents and In Vitro Antioxidant Activity of Carica papaya
Kanagavalli M. and Anuradha R.*
PG Department of Biochemistry, S.T.E.T Women’s College, Mannargudi, Tamilnadu, India- 614016.
Corresponding author: anu_ra09@yahoo.in
ABSTRACT:
Antioxidant activity of methanolic extract of seeds of Carica papaya was investigated for its free radical scavenging activity by adapting in vitro models of free radical production. Phytochemical screening revealed that the extract possess tannins, pseudotannin, flavonoids, glycosides,alkaloids. The extract was investigated for its antioxidant activity using 1,1-Diphenyl 2-picrylhydrazyl(DPPH).The extracts showed good antioxidant activity that was better than ascorbic acid. It has been concluded that the derivatives of Carica papaya has significant antioxidant activity.
KEYWORDS: In vitro antioxidant activity, phytochemical analysis, Carica papaya.
INTRODUCTION:
Antioxidant means “against oxidation” and the work to protect lipid from peroxidation by radicals. The human body as an elaborate antioxidant defense system1. The main characteristic of an antioxidant is its ability to trap free radicals. Highly reactive free radicals and oxygen species are present in biological systems from a wide variety of sources. These free radicals may oxidize nucleic acids, proteins, lipids or DNA and can initiate degenerative disease. Antioxidant compounds like Phenolic acids, polyphenols and flavonoids scavenge free radicals such as peroxide, hydro peroxide or lipid peroxyl and thus inhibit the oxidative mechanisms that lead to degenerative diseases There are a number of clinical studies suggesting that the antioxidants in fruits, vegetables, tea and red wine are the main factors for the observed efficacy of these foods in reducing the incidence of chronic diseases including heart disease and some cancers 2.
Papaya is one of the few rapidly growing and heavily yielding fruit trees. Fruiting in papaya is so abundant that thinning become necessary to avoid deformation due to crowding and for optimum number of fruits develop fully3.It is tonic, stimulant, laxative, digestive and rejuvenate. The unripe fruit is prescribed for stomach troubles, jaundice and gastritis and liver disorders. The juice of papaya contains pepsin, a protein splitting enzyme used as a meat tenderizer. Papaya aid in digesting the proteins of eggs, milk, meat, beans and similar food products.
Decoction of inner stem – bark ids taken orally twice daily for dental carries4. Powered seeds is taken orally as an anthelmintic5. Hot water extract of seeds is taken orally as an anti inflammatory and analgesic6. Fresh fruit is eaten as an abortifacient. Tender fruits are used in different forms. To expel intestinal worms, ripe fruit are eaten7. Hot water extract of flower is taken orally as a heart tonic. Hot water extract of leaves is taken orally has a febrifuge and heart tonic8. Hot water extract of ripe – dried fruit is taken orally as an emmenagogue9. Hot water extract of ripe fresh fruit is said to be astringent to the bowels, an aphrodisiac, and is used for biliousness. Unripe fresh fruit is taken orally as a diuretic and to treat flatulence10.
MATERIALS AND METHODS:
Collection of plant:
The healthy plant of Carica papaya Seed were colleted from Edaiyarnatham Village, Mannargudi Taluk, Thiruvarur District, Tamilnadu, India. It was collected in early morning and was washed in tap water and shade-dried for 10 days.
Preparation of plant extracts:
The shade dried plant material was powdered using kitchen blender and that powder was subjected to soxhlet extraction with methanol (60°C) for 24hrs.Each solvent extract was distilled and condensed at 40°C.The condensed extract was stored at room temperature in air tight bottles and uses for further studies.
Qualitative analysis of secondary metabolites:
The dried plant material was powdered and subjected to the following systematic chemical test in order to identify the nature of chemical constituents present.
Antioxidant Assay:
The antioxidant activity of Plant extracts were determined by in vitro methods such as, the DPPH free radical scavenging assay of Benzie and Strain,(1996)11.
RESULTS AND DISCUSSION:
Phytochemical Studies:
The present study described the preliminary phytochemical test of the seed extract of Carica papaya revealed the presence of various bioactive components of which flavonoids, alkaloids, glycosides, carbohydrate, tannins and pseudo tannins were the most prominant ones and shown in Table 1. All the phytochemical possess various medicinal property viz; phytochemical such as phenolic compounds, flavonoids have been reported to be associated with antioxidative action in biological system, acting as scavengers of singlet oxygen free radicals 12.
Antioxidant Activity by DPPH method:
Table 2 represent in percentage of free radical scavenging effect of methanolic extract of Carica papaya. The antioxidant potential of seed extract of Carica papaya may be due to the presence of poly-phenolic compounds,which needs further analysis. The methanolic extract (70%) showed good antioxidant activity in all in vitro free radical scavenging models when compared to extract of Carica papaya (50%).The percentage of inhibition was 10% and 22% respectively. Ramadan et al. (2003) reported that strong scavenging activity of Carica papaya seed against a spectrum of ROS, may contributed by cumulative effect of various anti-oxidants.
Table 2: Antioxidant activity of plant extract as measured by DPPH Method
|
Sample Concentration |
Free radical scavenging Activity (%) |
|
Ascorbic acid Carica papaya (50%) Carica papaya (70%) |
12 % 10% 22% |
From the study, it was concluded that the methanolic extract of seed of Carica papaya scavenged DPPH and inhibited the lipid peroxidation in vitro. Carica papaya significantly enchances the antioxidant enzyme system. Further attempts are being made to isolate chemical compounds and this evaluation for the assessment of the antioxidant activity.
ACKNOWLEDGEMENTS:
The authors are grateful to the management of STET Women’s college, Mannargudi for their encouragement and support.
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Received on 05.11.2011 Modified on 25.11.2011
Accepted on 05.12.2011 © RJPT All right reserved
Research J. Pharm. and Tech. 5(1): Jan. 2012; Page 119-120