Table 1.

Immune-modulating effects of natural compounds in human studies

Compound	Doses	Human participants	Effects	Refs
β-carotene	50 mg on alternate days for 10–12 years or placebo	38 middle-aged men 51–64 y, 21 elderly men 65–86 y	Increased NK cell activities in elderly men to levels similar to those in younger men	Santos, 1996
β-carotene	15 mg daily for 26 days or placebo	25 healthy nonsmoking men	Increased the percentages of monocytes expressing antigen-presenting molecules	Hughes, 2000
β-carotene	90 mg daily for 21 days or placebo	25 healthy elderly women 60–80 y	No differences in the profiles of lymphocyte subsets (CD3+, CD4+, CD8+ T cells, and CD19+ B cells)	Santos, 1997
	50 mg on alternate days for 10–12 years or placebo	50 healthy elderly men 50–86 y
Lycopene	13.3 mg daily for 12 weeks or placebo	58 healthy volunteers >65 years	No differences in T cell subsets and their expression of functional surface molecules	Corridan, 2001
β-carotene	8.2 mg daily for 12 weeks or placebo
Curcumin	3 g daily for 2 weeks	30 non-small-cell lung cancer patients	Increased Th1 cells, decreased Treg cells in peripheral blood	Zou, 2018
Curcumin	3 g daily for 1 month	40 advanced colon cancer patients	Increased Th1 cells, decreased Treg cells in peripheral blood	Xu, 2017
Resveratrol	1 g daily for 28 days	9 healthy volunteers	Increased the number of circulating Treg cells (CD3+CD4+CD25+CD127-) and CD3+NKG2D+ T cells	Espinoza, 2017
			Decreased levels of proinflammatory cytokines in plasma, such as TNF-α and MCP-1
Polyphenon E	400–2000 mg daily for up to 6 months	33 Rai stage 0-II CLL patients	Decreased absolute lymphocyte count (ALC)	Shanafelt, 2009
Polyphenon E	2000 mg daily for up to 6 months	42 Rai stage 0-II CLL patients	Decreased absolute lymphocyte count (ALC)	Shanafelt, 2013
Green tea extract	4 capsules daily for 1 month + 6 capsules for 5 months	12 Rai stage 0 CLL patients	Decreased lymphocytosis and circulating Treg cells	D’Arena, 2013
	6 capsules contain 4602 mg of green tea leaves, 189 mg of EGCG, and 97.5 mg of caffeine		Decreased IL-10 and TGF-β serum levels
Agaricus blazei Murill Kyowa (ABMK)	9 packs daily for 9 weeks	100 gynecological cancer patients	Increased NK cell activity	Ahn, 2004
Ganoderma lucidum polysaccharide (GLPS)	1800 mg daily for 12 weeks	34 advanced-stage cancer patients	Increased the absolute number of CD56+ NK cells	Gao, 2003
			Increased levels of IL-2, IL-6, and IFN-γ in plasma
			Decreased levels of IL-1 and TNF-α in plasma
Ganoderma lucidum polysaccharide extract	1800 mg daily for 12 weeks	47 advanced colorectal cancer patients	Increased the number of CD3+, CD4+, CD8+, and CD56+ lymphocytes	Chen, 2006
			Increased NK cell activities
			Increased levels of IL-2, IL6, and IFN-γ in plasma
			Decreased levels of IL-1 and TNF-α in plasma
Lentinula edodes mycelia extract (LEM)	1800 mg daily for 3 weeks	10 breast cancer patients with nodal metastases	Prevented chemotherapy-induced decline in cytotoxic activities of NK and LAK cells	Nagashima, 2013
			Prevented chemotherapy-induced decline in the proportion of activated NK and NK T cells in lymphocytes
Lentinula edodes mycelia extract (LEM)	1800 mg daily for 4 weeks	1 gastric and 7 colorectal cancer patients	Increased IFN-γ production by CD4+ T, CD8+ T, and CD56+ NK/NKT cells	Okuno, 2011
Protein-bound polysaccharide K (PSK)	3 g daily for 2 years	139 stage III colorectal cancer patients	Increased the number of NK cells	Ohwada, 2006
Sizofiran (SPG)	20 mg injected intramuscularly at 5 and 2 days before surgery	40 stage III–IV head and neck cancer patients	Increased cytotoxic activities of NK cells and LAK cells	Kano, 1996
			Increased CD4+ T cells in lymph nodes
			Increased IL-2 production
Sizofiran (SPG)	0.2 mg or 20 mg injected intramuscularly 7 and 3 days before radiation therapy	45 stage II–III invasive cervical cancer patients	Increased tumor-infiltrating T cells	Nakano, 1996