Introduction: Immune response against viral infections and tumors not only requires the recruitment of immune cells but also cytokines. Cytokine dysregulation is associated with inflammatory diseases such as cancer, autoimmune diseases, infections and allergy. Intake of fruit and vegetables are known not only to reduce inflammation but may also provide protection against various diseases. Methods: Effects of selected fruits and herbs on cytokines profile of IL-8, IL-1β, IL-6, IL-10, TNF and IL-12p70 were examined using the CBA flow cytometric assay. Peripheral blood mononuclear cells (PBMC) obtained from blood samples of twelve healthy subjects aged 20 to 30 years [males = 6 and females = 6] were treated with papaya, mata kucing, dang shen and pu-erh tea, respectively, for 6 and 48 hours at various concentrations. In vivo effects was further tested on healthy volunteers [males = 2, females = 4] by 2-days consumption of papaya following 2-days washout period without papaya. The diet of volunteers was controlled with fixed meals. Results:In vitro results after 6 hours of culture showed that papaya-treated PBMC significantly increased IL-8, IL-1β and IL-6 but reduced IL-10. Mata kucing-treated PBMC significantly increased IL-8 but reduced IL-6 while pu-erh tea significantly reduced IL-8, IL-1β, IL-6 and TNF. Cytokine analysis for dang shen-treated PBMC was only conducted at 48 hours. After 48 hours, papaya extract significantly reduced IL-8, IL-6 (8000 μg/ml), IL-10 and TNF. Significant increase of IL-6 was observed at 4000 and 16000 μg/ml. Mata kucing extract significantly increased IL-1β, IL-6 but reduced TNF. Significant increase of TNF was observed at 16000 μg/ml. Dang shen and pu-erh tea reduced IL-8, IL-1β, IL-6, IL-10 and TNF. However, in vivo papaya consumption did not show any significant changes and levels were low. Conclusion: This study showed fruits such as papaya and mata kucing had both stimulatory and inhibitory effect on various pro-inflammatory cytokines while effect of herbs such as dang shen and pu-erh tea were inhibitory. Immunomodulatory studies of natural food such as fruits and herbs may provide better understanding and subsequently improve management of inflammatory diseases.
The immune system responds to stimulus by activation/increase or inhibition/decrease in activities. These immu-nomodulatory effects may be triggered by various factors in the environment including cytokines, hormones and growth factors, as well as flavonoids, antioxidants and various antigens in food and the environment. Immunosup-pression has a direct effect on the capacity of the immune system to fight against infection and cancer formation. A pro-inflammatory response, however, may induce further progression of tumours that had formed. Inflammation is also associated with many chronic illnesses including pain. The suppressive effects from phytochemicals have been shown in the potential to reduce T-lymphocyte proliferation in vitro and in vivo. Studies have demonstrated inhibi-tion of pro-inflammatory cytokines from flavonoid such as naringenin, green tea polyphenol extract, encapsulated fruit and vegetable juice powder concentrate. Feijoa sellowiana Berg var. coolidge fruit juice consumption exerted anti-inflammatory activity on edema-induced mice within first hour of treatment while agipenin, a natural flavonoid reduced neuroinflammation by protection against damage from dendritic cells stimulated T cells in experimental autoimmune encephalomyelitis mouse models. Dietary polyphenols were found to exert a regulatory role on den-dritic cell function. Our own study showed immunosuppressive effect from increased T regulatory cells from papaya consumption. Increased regulatory cells are associated with cancer conditions. On the other hand, grape juice con-sumption mobilized gamma–delta T cells. Ginseng berry extract increased pro-inflammatory molecules in dendritic cells in the spleen while polysaccharide fractions from Momorica charantia, an edible medicinal vegetable increased various immune indexes. Fruits may also have endo-immunomodulatory function causing differential effects in male and female. Sex hormones can influence immune changes based on sex as seen in increased NK cells in males and antibodies in females. We observed a population of CD4-CD45RA-CD69+CD25- cells was significantly lower in males. However, none of these studies have been directly conducted on cancers. Investigation into this area may help improve decision making in cancer management.