NITRIC OXIDE RADICAL SCAVENGING ACTIVITY OF AQUEOUS EXTRACT OF TERMINALIA BELERICA BARK AKHLESH SINGHAI*, GOVIND NAYAK, ASHOK BUDHWANIa and ASHISH SINGHAIb Lakshmi Narain College of Pharmacy, BHOPAL (M.P.) INDIA a Daksh Institute of Pharmacy, CHHATARPUR (M.P.) INDIA b VNS Institute of Pharmacy, BHOPAL (M.P.) INDIA
In the present investigation, am attempt has been made to investigate the in vitro antioxidant potential of aqueous extract of Terminalia belerica bark (TBB). The nitric oxide assay method has been performed at different doses (100-500 mg). The total phenolic contents and total flavonoid contents have also been determined. The results of the present study shows that the aqueous extract of TBB possess antioxidant activity through the DPPH free radical scavenging activity. The preliminary phytochemical investigation indicates the presence of flavonoids and polyphenols. The results are found to be significant when compared with the standard ascorbic acid. Further studies are required to determine the mechanism and isolation of active constituents involved in the antioxidant activity. Key words: Terminalia belerica, DPPH, Flavonoid, Phenolic contents.
Free radicals had been implicated in several human diseases e.g. atherosclerosis, arthritis, ischemia and reperfusion injury of many tissues, central nervous system injury, gastritis, ageing, inflammatory response syndrome, respiratory diseases, liver diseases, cancer and AIDS1-4. Many herbal plants contain antioxidant compounds and these compounds protect cells against the damaging effects of reactive oxygen species (ROS), such as singlet oxygen, superoxide, peroxyl radicals, hydroxyl radicals and peroxynitrite5, 6. Moreover, these synthetic antioxidants also show low solubility and moderate antioxidant activity7. Therefore, many researchers are in search for antioxidants of natural origin. Terminalia belerica is a large deciduous tree with characteristic bark traditionally ________________________________________
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Singhai et al.: Nitric Oxide Radical Scavenging….
called as Baheda or Bibitaki. It is grown throughout India. Its principal constituents are gallic acid, ellagic acid, β-sitosterol and chebulagic acid8. It is astringent, tonic, expectorant and laxative. Its pulp is used in dropsy, piles and diaorrhea. It is also useful in leprosy, fever and hair care. It is also used in oxalic acid and preparation of ink. It is used in case of rheumatism. Seed oil is applied in skin diseases and premature graying of hair9, 10. In the present investigation, we have attempted to investigate the antioxidant potential of the barks of Terminalia belerica.
Material and methods Plant material and extraction
The barks of Terminalia belerica were collected from Bhopal, cut into small pieces and dried in shade for 5 days. The dried barks were then grinded. This material was macerated in water for 72 hours with occasional shaking in dark. Macerate was decanted and filtered. The marc was pressed and filtration was done 2-3 times. The macerates were concentrated to give aqueous extract (22.13% w/w).
Various chemicals used were DPPH (1, 1-diphenyl-2-picryl-hydrazyl) (Sigma Chemicals, USA) and aluminum chloride. Ascorbic acid obtained from Sisco Research Laboratories Pvt. Ltd., India. Folin-Ciocalteus's phenol reagent and sodium carbonate were from Merck Chemical Supplies (Damstadt, Germany). All chemicals and solvents were of analytical grade.
Preliminary phytochemical investigation
The preliminary phytochemical screening of the extract was carried out to know the different constituents present in aqueous fractions of Terminalia belerica as per the standard procedures. The extract were tested for alkaloids11, 12, sterols13, triterpenes14, saponins15, flavonoids16, tannins12,17, carbohydrates12, glycosides and...