title: Carica papaya increases regulatory T cells and reduces IFN-γ+ CD4+ T cells in healthy human subjects.
abstract: Fruit and vegetables have therapeutic potential as they dampen inflammation, have no known side-effects and as whole foods have prospective additive and synergistic benefits. Th1 (IFN-γ(+) CD4(+))/Th2 (IL-4(+)CD4(+)) T cells play a vital role in mediating inflammatory responses and may be regulated by regulatory T cells (Tregs). Effects of Carica papaya on cells of healthy individuals were determined using flow cytometry methods. Significant down-regulation of IFN-γ(+) CD4(+) (p=0.03, n=13), up-regulation of IL-4(+) CD4(+) (p=0.04, n=13) T cells and up-regulation of CD3(+) CD4(+) CD25(+) CD127(-) (p=0.001, n=15) Tregs were observed after papaya consumption. In vitro cultures showed up-regulation of Tregs in male subjects and was significantly associated with levels of IL-1β in culture supernatants (R(2) =0.608, p=0.04, n=12). Other inflammatory cytokines were significantly suppressed. Papaya consumption may exert an anti-inflammatory response mediated through Tregs and have potential in alleviating inflammatory conditions.
authors.affiliation: Immunology Unit, Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Malaysia. maha@medic.upm.edu.my
authors.forename: Maha
authors.initials: M
authors.lastname: Abdullah
authors.forename: Pei-Shin
authors.initials: PS
authors.lastname: Chai
authors.forename: Chiew-Yee
authors.initials: CY
authors.lastname: Loh
authors.forename: Mun-Yee
authors.initials: MY
authors.lastname: Chong
authors.forename: Huai-Wei
authors.initials: HW
authors.lastname: Quay
authors.forename: Sharmili
authors.initials: S
authors.lastname: Vidyadaran
authors.forename: Zainina
authors.initials: Z
authors.lastname: Seman
authors.forename: Mirnalini
authors.initials: M
authors.lastname: Kandiah
authors.forename: Heng-Fong
authors.initials: HF
authors.lastname: Seow
mesh_terms: D000328:Adult; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D029441:Carica; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000032:analysis*; D053583:Interleukin-1beta / Q000032:analysis; D008297:Male; D010936:Plant Extracts / Q000494:pharmacology*; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects* / Q000276:immunology
chemical_list: D000893:Anti-Inflammatory Agents; D053583:Interleukin-1beta; D010936:Plant Extracts; D007371:Interferon-gamma