3Cheeke P R, Piacente S, Oleszek W. Anti-inflammatory and anti-ar- thritic effects of Yucca schidigera: a review [ J ]. Journal of Inflam- mation, 2006: 3-6.
4Wina E, Muetzel S, Becker K. The impact of saponins or saponin containing plant materials on ruminant production-A Review [ J ]. Journal of Agricultural and Food Chemistry, 2005, 53 : 8093-8105.