Table 2.
Immune activities and content of micronutrients and vitamins in tea infusion.
| Micronutrients and vitamins | Immune activities | Content in tea infusion | Actual body requirement | Reference |
|---|---|---|---|---|
| Selenium | Acts as immunostimulatory; helps in regulating oxidative stress; regulates phagocytic activity of macrophages; enhances T-cell proliferation, NK-cell mediated cytotoxicity; increases NK cell, lymphocytes, and leukocyte counts; modulates antioxidant capacity of lungs | Se-rich green tea (GT) - 1.44 μg Se/g DW; Regular GT - 0.13 μg Se/g DW; Se-rich black tea (BT) - 1.42 μg Se/g DW; Regular-BT - 0.08 μg Se/g DW |
55 ug/day | (50) |
| Iron | Promotes activation of NF-kB cells; enhances host resistance to intracellular pathogens; regulates anti-microbial activity of macrophages | GT: 0.142–0.099 mg/L BT: 0.100–0.084 mg/L |
12–15 mg/day | (51) |
| Zinc | Enhances phagocyte activities and cytokine secretion of macrophages; acts as antioxidant against reactive oxygen and nitrogen species; important for development and function of neutrophils and NK cells; Zn deficiency leads to decreased lymphocyte counts | GT: 0.130–0.588 mg/L BT: 0.113–0.057 mg/L |
10–15 mg/day | (51) |
| Copper | Target invading pathogens in the phagosome with activated macrophages. Neutrophil and monocytes activities impaired with deficiency in Cu. Enhances NK cells | GT: 0.033–0.191 mg/L; BT: 0.072–0.441 mg/L | 900 ug/day | (51) |
| Manganese | Stimulation of interferon production | GT: 0.78–3.94 mg/L; BT: 0.56–7.49 mg/L | 1.8–2.3 mg/day | (51) |
| Vitamin B2 | Essential for proper functioning of macrophages; B2 deficiency leads to decreases pathogen recognition and impaired immune response | GT: 3.26–2.80 µg/gm BT: 3.34–0.58 µg/g; |
1.8–2.5 mg/day | (52) |
| Vitamin B12 | Acts as immunomodulator; enhances NK cell activity; increases lymphocyte count; enhances T-cell proliferation | GT: 0.046–0.263 µg/g DW BT: 0.104–0.859 µg/g DW; |
2.4 ug/day | (53) |
Selenium enriched tea plantation is being practiced particularly in regions with low soil Se content and human Se deficient areas, as part of Se-biofortification. Infusions were prepared with 1 g of each tea incubated for 5 min in 50–100 ml of Milli-Q (MQ), or boiled distilled water.