Table 1.

Anti-cancer activities of commonly studied herbs.

Herbs	Main Active Chemical Constituents	Animal Model/Tumor Cell Line	Anti-Cancer Activities/Outcome	Molecular Mechanisms/Outcome	References
Ginseng	Ginsenoside Rh2	MDA-MB-231 and MCF-7 breast cancer cell lines	Anti-proliferative and apoptosis	(i) Induce changes in hypo-methylated genes (ii) Mediate G(0)/G(1) phase cell cycle arrest (iii) inhibit the production of inflammatory cytokines (iv) Obstruct nuclear factor (NF)-κB signaling and mitogen-activated protein kinase pathways	[30,32,34,35]
Ginseng	Ginsenoside Rg3	MDA-MB-231 and MCF-7 breast cancer cell lines	Anti-proliferative	(i) Decrease expression of cyclin D1 and cyclin A (ii) Arrest cells in the G-1 phase	[36]
Garlic	Diallyl disulfide	MDA-MB-468 cancer cell line and female Swiss albino mice with EAC tumor	Decrease tumor growth and apoptosis	(i) Induce apoptosis by promoting caspase-3 expression (ii) Prevent oxidative degradation of anti-tumor protein, p53	[37]
Curcuma longa	Curcumin	MDA-MB-231 and BT-483 breast cancer cells	Anti-proliferative effect in a dose-dependent manner	(i) Downregulation of NFkappaB inducing genes (ii) Decrease transcription of matrix metalloproteinases (MMPs)-1 and cyclin D	[38]
Curcuma longa	Curcumin	MCF-7 and MDA-MB-231 breast cancer cells	Inhibition of cell proliferation and induction of apoptosis	Down-regulation of the beta-catenin pathway	[39]
Echinacea	Extracts of Echinacea purpurea	BT-549 mammalian breast cancer cell	Inhibition of cell proliferation	Mechanism not given	[40]
Arctium lappa (greater burdock)	Arctigenin	MDA-MB-231 breast cancer cells	Induce apoptosis	(i) Activation of the ROS/p38 MAPK pathway (ii) Induction of mitochondrial caspase-independent pathways with increased Bax/Bcl-2 ratio	[41]
Arctium lappa (greater burdock)	Arctigenin	MCF-7 and MDA-MB-231 human breast cancer cell lines	Anti-metastatic effect	Inhibiting the NF-κB, Akt/MAPK signaling pathways, and MMP-9	[42]
Flaxseed (dietary)	Lignans	Athymic mice inoculated with human MCF-7 cancer cells	Inhibition of cell proliferation and induced apoptosis	Reduced mRNA expressions of cyclin D1, epidermal growth factor receptor and Bcl2	[43]
Nigella sativa	Thymoquinone	T-47D and MDA-MB-468 breast cancer cells	Induced apoptosis	(i) Promote G (1) phase arrest via translation upregulation of procaspase-3 and Bax (ii) Inhibition of cyclin D1 and cyclin E, and PARP cleavage alongside downregulation of the gene expression of survivin, Bcl-2 and Bcl-xL	[44]
Nigella sativa	Thymoquinone	MCF-7 breast cancer cell line	Induced apoptosis	Upregulation of the expression of tumor suppressor gene p53 in a time-dependent manner	[45]
Nigella sativa	Thymoquinone	MDA-MB-231 triple-negative breast cancer cells	Anti-metastatic effect	Downregulate the expressions of CXCR4 in breast cancer cells in a time- and dose-dependent manner	[46]