Antimutagenic Agents: Agents that reduce the frequency or rate of spontaneous or induced mutations independently of the mechanism involved.Mutagenicity Tests: Tests of chemical substances and physical agents for mutagenic potential. They include microbial, insect, mammalian cell, and whole animal tests.Furylfuramide: Used formerly as antimicrobial food additive. It causes mutations in many cell cultures and may be carcinogenic.Mahonia: A plant genus in the family BERBERIDACEAE. Oregon Grape was discovered in North America and classified by Pursh as a BERBERIS but Nuttall claimed it is different enough to call it a new genus, MAHONIA. Now botanists insist on Berberis while horticulturists stay with this genus. It is a source of BERBERINE.Mutagens: Chemical agents that increase the rate of genetic mutation by interfering with the function of nucleic acids. A clastogen is a specific mutagen that causes breaks in chromosomes.Plant Extracts: Concentrated pharmaceutical preparations of plants obtained by removing active constituents with a suitable solvent, which is evaporated away, and adjusting the residue to a prescribed standard.Butea: A plant genus of the family FABACEAE that contains butrin and isobutrin.N-Nitrosopyrrolidine: Carcinogenic nitrosamine that may be formed from preservatives in meats during their preparation or in the liver during metabolism.