Purifying activity of free radicals and mutagenic controls of Loranthaceae extracts

SOBERÓN, J.R.; SGARIGLIA, M. A.; SAMPIETRO; QUIROGA, E. N.; VATTUONE, M. A.

Molecular Medicinal Chemistry

IDECEFYN

Lugar: Buenos Aires; Año: 2006 vol. 11 p. 26 - 27

1666-888X

Free radicals are highly reactive species, responsible for diverse health dysfunctions, e.g., heart problems, cell aging processes and carcinogenesis. The demand of antioxidants (free radical purifying substances) of natural origin has been increased, partly owing to the doubts raised regarding the safety in the use of synthetic antioxidants, such as butylated hydroxytoluene (BHT) or butylated hydroxyanisol (BHA). This work studies the antioxidant and antimutagenic activities of plant extracts from Psittacanthus cuneifolius (Ruiz & Pav.) Blume and Tripodanthus acutifolius (Ruiz & Pav.) Van Tieghem. Dry and powdered leaves were separately subjected to three types of extractions: infusions, decoctions and tinctures. Antioxidant activity was evaluated by purifying capacity of DPPH, superoxide anion (O2-) and HO. radical. Mutagenic and antimutagenic activities were evaluated using Escherichia coli WP2 uvrA pKM 101 Trp- strains, susceptible to  mutagen action. The assays with DPPH. showed that the tincture of T. acutifolius and the infusion of P. cuneifolius possessed the highest purifying activity Regarding reference drugs, quercetin was the most active. All extracts of P. cuneifolius and the tincture of T. acutifolius showed higher activity than quercetin, while the tincture and infusion of T. acutifolius exhibited higher activity than rutin. BHT presented smaller purifying activity regarding all tested substances. The superoxide anion scavenging technique demonstrated that the highest activity was that of the infusion of P. cuneifolius and the tincture of T. acutifolius. The purifying capacity of HO. radical showed the highest non-specific and specific purifying activity for the infusion of P. cuneifolius. The prooxidant activity was absent in most cases. All tested extracts had higher activity than mannitol. Plant extracts with outstanding mutagenic activities were the tinctures of T. acutifolius and P. cuneifolius. The tincture of T. acutifolius exhibited higher antimutagenic power than that of P. cuneifolius at high concentrations. Aqueous extracts didn´t show antimutagenic action. The tests of mutagenic activity generated similar growth percentages to those of spontaneous reversion controls, what would imply absence of  mutagenic or promutagenic activity. Our results would indicate that the purifying capacity of free radicals depends on the type of extraction, suggesting the potential use of plant extracts as a source of genomic protective agents or carcinogenesis preventive agents.