Panico AM, Cardile V, Garufi F, Puglia C, Bonina F, Ronsisvalle S. Effect of hyaluronic acid and polysaccharides from Opuntia ficus indica (L.) cladodes on the metabolism of human chondrocyte cultures. J Ethnopharmacol. 2007 May 04;111(2):315–21. doi: 10.1016/j.jep.2006.11.020. PMID: 17196777.