Micronutrients as immunomodulatory tools for COVID-19 management.

COVID-19 rapidly turned to a global pandemic posing lethal threats to overwhelming health care capabilities, despite its relatively low mortality rate. The clinical respiratory symptoms include dry cough, fever, anosmia, breathing difficulties, and subsequent respiratory failure. No known cure is available for COVID-19. Apart from the anti-viral strategy, the supports of immune effectors and modulation of immunosuppressive mechanisms is the rationale immunomodulation approach in COVID-19 management. Diet and nutrition are essential for healthy immunity. However, a group of micronutrients plays a dominant role in immunomodulation. The deficiency of most nutrients increases the individual susceptibility to virus infection with a tendency for severe clinical presentation. Despite a shred of evidence, the supplementation of a single nutrient is not promising in the general population. Individuals at high-risk for specific nutrient deficiencies likely benefit from supplementation. The individual dietary and nutritional status assessments are critical for determining the comprehensive actions in COVID-19.

The smell of Tokishakuyaku-san (TJ-23) induces generation of regulatory T cells and prolongation of survival of fully allogeneic cardiac grafts in mice.

Oral administration of Tokishakuyaku-san (TJ-23), a Japanese herbal medicine, induces prolongation of cardiac allograft survival and generates regulatory cells in mice. Because herbal medicines usually have unique odor, and because smell is supposed to modulate the immune system, we examined whether the odor of TJ-23 induced prolonged allograft survival and regulatory cell generation. Naïve CBA mice (H2(k)) and olfactory-dysfunctional CBA mice after a stereotaxic operation underwent transplantation of C57BL/6 (B6, H2(b)) hearts, receiving fumigated water only or TJ-23 until rejection. Untreated or treated with water fumigation CBA mice rejected B6 cardiac grafts acutely (median survival times [MSTs], 7 and 8.5 days). When CBA mice were treated with fumigation of TJ-23, allograft survival was significantly prolonged (MST, 48 days). Olfactory-dysfunctional CBA mice treated with fumigation of TJ-23 rejected grafts acutely (MST, 7 days). Treatment with fumigation of TJ-23 also suppressed splenocytes proliferation and interferon-γ production. Secondary CBA recipients of whole splenocytes or CD4(+) cells from primary TJ-23-treated CBA recipients of B6 cardiac allografts at 30 days after grafting showed prolonged survival of B6 hearts (MST, >60 days). Flow cytometry studies showed increased CD4(+)CD25(+)Foxp3(+) regulatory cells in recipients given fumigation of TJ-23. In conclusion naïve but not olfactory-dysfunctional CBA mice treated with fumigation of TJ-23 displayed prolonged survival of fully allogeneic cardiac allografts and generation of regulatory cells.