Evaluation of the effectiveness and safety of Korean red ginseng extract as immune-enhancer in Vietnamese adults: A randomized placebo-controlled trial

Purpose: To investigate the safety and immune-enhancing effect of Korean red ginseng (KRG) extract in Vietnamese adults. Methods: Participants in this randomized, placebo-controlled double-blinded study were administered either 960 mg of KRG extract (n = 51) or placebo capsules (n = 50) for 12 weeks at Hanoi Medical University, Vietnam. The KRG extract was standardized to contain 5.27 mg of 3 ginsenosides (Rg1, Rb1, and Rg3) per gram. Blood samples for assessment of treatment effectiveness were collected from the subjects on days 21 and 84. Immune cytokines were quantified using enzyme-linked immunosorbent assay (ELISA). Blood samples for safety assessment, hematological and biochemical variables, and urinalysis were performed at the beginning and end of the intervention (days 21 and 84, respectively). Results: The KRG group showed a significant increase in lymph T cell % at the end of the 12-week intervention (p < 0.001). There were significant decreases in numbers of white blood cells (WBC) and natural killer (NK) cells in both groups. However, there were no significant differences in populations of WBC and NK cells between the 2 groups. Serum concentrations of cytokines, i.e., TNF-α, β, γ; IFN-α, γ; IL-1β and 4β were decreased in the KRG group when compared to baseline values. There were no probable or definite adverse events (AEs) related to KRG. A total of 9 participants (4 in KRG group and 5 in placebo group) tested positive for COVID-19 during the trial. Conclusion: The KRG extract-induced increase in population of T-cells and reductions in cytokine levels following a 12-week exposure may be beneficial for COVID-19 patients.