Ripening-induced chemical modifications of papaya pectin inhibit cancer cell proliferation

Author(s)

Ramos do Prado, Samira Bernardino ^[1] ; Ferreira, Gabrielle Fernandez ^[1] ; Harazono, Yosuke ^{[2, 3, 4, 5]} ; Shiga, Tania Misuzu ^[1] ; Raz, Avraham ^{[2, 3, 4]} ; Carpita, Nicholas C. ^[6] ; Fabi, Joao Paulo ^{[7, 1, 8]}

Affiliation

^[1] Univ Sao Paulo, Dept Food Sci & Expt Nutr, Sch Pharmaceut Sci, Sao Paulo, SP - Brazil

^[2] Wayne State Univ, Sch Med, Dept Oncol, Detroit, MI - USA

^[3] Wayne State Univ, Sch Med, Dept Pathol, Detroit, MI 48201 - USA

^[4] Karmanos Canc Inst, Detroit, MI - USA

^[5] Tokyo Med & Dent Univ, Dept Maxillofacial Surg, Bunkyo Ku, Tokyo 1138510 - Japan

^[6] Purdue Univ, Dept Bot & Plant Pathol, W Lafayette, IN - USA

^[7] Univ Sao Paulo, Food & Nutr Res Ctr NAPAN, Sao Paulo, SP - Brazil

^[8] Sao Paulo Res Fdn, Food Res Ctr FoRC, CEPID FAPESP Res Innovat & Disseminat Ctr, Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: SCIENTIFIC REPORTS; v. 7, NOV 29 2017.
• Web of Science Citations: 10

Abstract

Papaya (Carica papaya L.) is a fleshy fruit with a rapid pulp softening during ripening. Ripening events are accompanied by gradual depolymerization of pectic polysaccharides, including homogalacturonans, rhamnogalacturonans, arabinogalactans, and their modified forms. During intermediate phases of papaya ripening, partial depolymerization of pectin to small size with decreased branching had enhanced pectin anti-cancer properties. These properties were lost with continued decomposition at later phases of ripening. Pectin extracted from intermediate phases of papaya ripening markedly decreased cell viability, induced necroptosis, and delayed culture wound closing in three types of immortalized cancer cell lines. The possible explanation for these observations is that papaya pectins extracted from the third day after harvesting have disrupted interaction between cancer cells and the extracellular matrix proteins, enhancing cell detachment and promoting apoptosis/necroptosis. The anticancer activity of papaya pectin is dependent on the presence and the branch of arabinogalactan type II (AGII) structure. These are first reports of AGII in papaya pulp and the first reports of an in vitro biological activity of papaya pectins that were modified by natural action of ripening-induced pectinolytic enzymes. Identification of the specific pectin branching structures presents a biological route to enhancing anti-cancer properties in papaya and other climacteric fruits. (AU)

• FAPESP's process: 15/15661-8 - Effects of cancer cells treatment with pectins from different plant types
• Grantee: Gabrielle Fernandez Ferreira
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 15/01004-5 - Multi-User Equipment approved in grant 2012/23970-2: QuantStudio 7 flex Real-Time PCR system, 96-well fast, laptop (catalog #: 4485698)
• Grantee: Joao Paulo Fabi
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 13/07914-8 - FoRC - Food Research Center
• Grantee: Bernadette Dora Gombossy de Melo Franco
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 12/23970-2 - Biological changes of papaya pectins with possible benefits to human health
• Grantee: Joao Paulo Fabi
• Support Opportunities: Research Grants - Young Investigators Grants