Table 2.

List of natural products that improve cancer immunotherapy, including cancer vaccines, immune-check points inhibitors and adoptive cell transfer therapy.

Category	Source	Natural product	Key points of sensitizing immunotherapy	Ref.
Saponins	Ginseng	Ginsenoside Rg3	•Trigger “ICD” effect •Down-regulate the expression of PD-L1	74,141,142
		Ginsenoside Rg1	•Enhance the anti-cancer effect of cancer DC-based vaccines through NF-κB pathway	97
		Ginsenoside Rk1	•Down-regulate the expression of PD-L1 through NF-κB pathway	140
	Astragalus	Astragalus saponins	•Enhance the anti-cancer effect of cancer protein-based vaccines	96
	Quillaja saponaria Molina	QS-21	•Enhance the anti-cancer effect of cancer vaccines	165
	Crocus sativus corme	CS5	•Enhance the anti-cancer effect of cancer protein-based vaccines	95
	Anemone flaccida	Anemone flaccida saponins	•Down-regulate the expression of PD-1 and PD-L1 through STAT3 pathway	125
	Panax ginseng	Sapogenin	•Down-regulate the expression of PD-1 and PD-L1 through STAT3 pathway	136
	Acacia concinna	Diosgenin	•Enhance the anti-cancer effect of anti-PD-1 antibody (CD279, BP0146)	151
Polysaccharides	Dioscorea	Dioscrorea polysaccharides	•Enhance the anti-cancer effect of cancer DNA vaccines	104
	Astragalus membranaceus	Astragalus polysaccharides	•Enhance the anti-cancer effect of cancer DC-based vaccines with Codonopsis polysaccharide	106
	Codonopsis pilosulae	Codonopsis polysaccharides	•Enhance the anti-cancer effect of cancer DC-based vaccines with Astragalus polysaccharide	106
	Basil	Basil polysaccharides	•Enhance the anti-cancer effect of cancer DC-based vaccines	108
	Ganodema	Ganodema polysaccharides	•Enhance the anti-cancer effect of cancer vaccines •Down-regulate the expression of PD-1 and PD-L1 through STAT3 pathway	109
	Dendrobium officinale	Dendrobium officinale polysaccharides	•Down-regulate the expression of PD-1 and PD-L1 through STAT3 pathway	126
	Cordyceps militaris	CMPB90-1	•Down-regulate the expression of PD-L1 through NF-κB pathway	143
	Hedyotis diffusa	Hedyotis diffusa polysaccharides	•Enhance the anti-cancer effect of adoptive CIK cells immunotherapy	157
Flavonoids	Onion	Quercetin	•Trigger “ICD” effect (with alantolactone at 1:4 ratio)	76
	H. Diffusa Wild	Rutin	•Enhance the anti-cancer effect of cancer peptide-based vaccines	114
	Fruits	Procyanidin	•Enhance the anti-cancer effect of cancer peptide-based vaccines	115
	Pomelo	Naringenin	•Enhance the anti-cancer effect of cancer vaccines	116
	Silybum marianum (L.) Gaertn.	Silibinin	•Down-regulate the expression of PD-L1 through JAK-STAT pathway	134
	Scutellaria baicalensis	Baicalein Baicalin	•Down-regulate the expression of PD-L1 through JAK-STAT pathway	135
	Celery	Apigenin	•Down-regulate the expression of PD-L1 through JAK‒STAT pathway	138
	Orange peel	Hesperidin	•Down-regulate the expression of PD-L1 through NF-κB pathway	145
	Kudzu root	Puerarin	•Enhance the therapeutic outcome of anti-PD-L1 antibody through regulation of CAFs	165
Others	Chili pepper	Capsaicin	•Trigger “ICD” effect	68
	Grapes	Resveratrol	•Trigger “ICD” effect	75
	Ginger	Curcumin	•Enhance the anti-cancer effect of cancer peptide-based vaccines •Enhance the anti-cancer effect of adoptive T cells immunotherapy	101,158
		6-Gingerol	•Enhance the anti-cancer effect of adoptive T cells immunotherapy	161
	Inula racemosa	Alantolactone	•Trigger “ICD” effect (with quercetin at 1:4 ratio)	76
	Lithospermum erythrothizon	Shikonin	•Trigger “ICD” effect	79
	Marine red algae	λ-Carrageenan	•Enhance the anti-cancer effect of cancer peptide-based vaccines	166
	Anthocyanin	Dephinidin-3-O-glucoside (D3G) Cyanidin-3-O-glucoside (C3G)	•Down-regulate the expression of PD-1 and PD-L1 through STAT3 pathway	128
	Coptidis rhizomes	Berberine	•Down-regulate the expression of PD-L1 through JAK‒STAT pathway	133
	Salvia miltiorrhiza	Tanshinone	•Down-regulate the expression of PD-L1 through JAK‒STAT pathway	152
		Crytotanshinone	•Enhance the anti-cancer effect of anti-PD-L1 antibody (clone 10F.9G2)	152
	Sophora alopecuroides L.	SA-49	•Down-regulate the expression of PD-L1	147
	Andrographis paniculata	Andrographolide	•Enhance the anti-cancer effect of anti-PD-1 antibody (CD279, BP0146)	149
	Seaweed	Fucose	•Enhance the effect of adoptive T cells immunotherapy	159
	Neem leaf	Neem leaf glycoprotein	•Enhance the anti-cancer effect of adoptive cells immunotherapy	160