tannins and 2-aminofluorene

A fraction isolated from Terminalia arjuna was studied for its antimutagenic effect against 4-nitro-o-phenylenediamine (NPD) in TA98, sodium azide in TA100 and 2-aminofluorene (2AF, S9-dependent), a promutagen, in both TA98 and TA 100 tester strains of Salmonella typhimurium using the Ames assay. The fraction inhibited the mutagenicity of 2AF very significantly in both strains while the revertant colonies induced by NPD and sodium azide were reduced moderately. 1H-NMR, 13C-NMR, IR and UV-spectroscopic data of the fraction revealed it to be tannin in nature.

Topics: Antimutagenic Agents; Chromatography, Thin Layer; Fluorenes; Magnetic Resonance Spectroscopy; Medicine, Ayurvedic; Mutagenicity Tests; Mutagens; Mutation; Phenylenediamines; Phytotherapy; Plants, Medicinal; Rosales; Salmonella typhimurium; Sodium Azide; Spectrophotometry, Infrared; Spectrophotometry, Ultraviolet; Tannins

A tannin fraction (TC-E) from the dried fruit pulp of Terminalia chebula was obtained by successfully extracting with 95% ethyl alcohol and ethyl acetate. TC-E was subjected to silica gel chromatography which yielded four fractions, viz., TC-EI, TC-EII, TC-EIII and TC-EIV. Thin layer chromatography (TLC) and 13C-NMR revealed that TC-EI was gallic acid (GA) derivative while the other fractions were tannin in nature. TC-E and its fractions were evaluated for their antimutagenic potential against two direct-acting mutagens, 4-nitro-o-phenylenediamine (NPD) and 4-nitroquinoline-N-oxide (4NQNO), and S9-dependent mutagen, 2-aminofluorene (2AF) in TA98 and TA100 strains of Salmonella typhimurium. The study revealed that the extract (TC-E) and its fractions were highly significant against S9-dependent mutagen, 2AF. The effect was found to be more or less corresponding with the nature of the fractions, as the monomeric TC-EI (a GA derivative) was least effective as compared to other fractions which were oligomeric, and the order of their effectiveness as per their IbD50 value being TC-EIV (8.9 micrograms)>TC-EIII (17.8 micrograms)>TC-EII (45 micrograms)>TC-EI (320 micrograms) in TA98; TC-EIV being 40 times more effective than TC-EI in inhibiting his+ revertants. A similar effect was noticed in TA100 too, where TC-EI was the least effective and TC-EII had the maximum effect. A similar result was noticed when the antimutagenicity of GA (a monomeric) was compared with tannic acid (TA, an oligomeric). However, chebula tannins were found to be partly effective against NPD but not at all effective against 4NQNO.

Topics: Antimutagenic Agents; Fluorenes; Plants, Medicinal; Salmonella typhimurium; Tannins