Carica papaya increases regulatory T cells and reduces IFN-γ+CD4+ T cells in healthy human subjects

Authors

  • Maha Abdullah,

    Corresponding author
    1. Immunology Unit, Department of Pathology, Faculty of Medicine and Health Sciences (FMHS), Universiti Putra Malaysia (UPM), Malaysia
    2. MAKNA-Cancer Research Laboratory, Institute of Biosciences, UPM, Malaysia
    • Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, UPM 43400, Serdang, Selangor, Malaysia Fax: +603-89412787
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  • Pei-Shin Chai,

    1. Immunology Unit, Department of Pathology, Faculty of Medicine and Health Sciences (FMHS), Universiti Putra Malaysia (UPM), Malaysia
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  • Chiew-Yee Loh,

    1. Immunology Unit, Department of Pathology, Faculty of Medicine and Health Sciences (FMHS), Universiti Putra Malaysia (UPM), Malaysia
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  • Mun-Yee Chong,

    1. Immunology Unit, Department of Pathology, Faculty of Medicine and Health Sciences (FMHS), Universiti Putra Malaysia (UPM), Malaysia
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  • Huai-Wei Quay,

    1. Immunology Unit, Department of Pathology, Faculty of Medicine and Health Sciences (FMHS), Universiti Putra Malaysia (UPM), Malaysia
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  • Sharmili Vidyadaran,

    1. Immunology Unit, Department of Pathology, Faculty of Medicine and Health Sciences (FMHS), Universiti Putra Malaysia (UPM), Malaysia
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  • Zainina Seman,

    1. Hematology Unit, Department of Pathology, FMHS, UPM, Malaysia
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  • Mirnalini Kandiah,

    1. Department of Nutrition and Dietetics, FMHS, UPM, Malaysia
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  • Heng-Fong Seow

    1. Immunology Unit, Department of Pathology, Faculty of Medicine and Health Sciences (FMHS), Universiti Putra Malaysia (UPM), Malaysia
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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 (R2=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.

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