The Application of Citrus folium in Breast Cancer and the Mechanism of Its Main Component Nobiletin: A Systematic Review

Table 3

The antitumor activity of NOB in BC.

Mechanism	Cell lines/animal models	In vitro/in vivo	Assay/treatment	Results	References
Cell viability inhibition	1 MCF-7 cell; 2 Hs578T cells	In vitro	An MTT assay	(i) At 12.5 μM, NOB decreased the cell viability to 85.3 ± 4.5%; At 25 μM, NOB decreased the cell viability to 79.3 ± 7.0%; At 50 μM, NOB decreased the cell viability to 71.2 ± 5.0%; At 100 μM, NOB decreased the cell viability to 60.3 ± 6.0%; At 200 μM, NOB decreased the cell viability to 54.4 ± 4.5%; (ii) At 100 μM, NOB showed greater toxicity toward the more invasive Hs578Ts(i)8 variant cell line, decreasing the cell viability to 51.6% after 72 h	[88]; [89]
Cell growth inhibition	Hs578T cells	In vitro	Cell counting	After 24 h, limited effects were observed; After 48 h, NOB reduced the number of cells by 40%; After 72 h, NOB reduced the number of cells by 50%	[89]
Cell cycle arrest	Hs578T cells	In vitro	Western blot assay	Chk2 phosphorylation at T68 decreased after 10 min in the presence of NOB	[89]
Cell cycle arrest	MCF-7 cells	In vitro	Flow cytometry assay	At 100 μM of NOB, a G1 block occurred in MCF-7 cells that was accompanied	[90]
Proliferation inhibition	MCF-7, T47D, MDA-MB-231c	In vitro	An MTT assay	NOB had a strong inhibitory effect on the proliferation of MDA-MB-231 cells and a weak inhibitory effect on the proliferation of HUVEC cells	[91]
Proliferation inhibition	MDA-MB-435, MCF-7	In vitro	Cell counting	Inhibition rates of NOB on treated cells ranged from 60 to 95%, beginning at 12 h and lasting up to 4 days, in all cell lines	[92]
Proliferation inhibition	Breast cancer model; (i) Adult female Sprague Dawley rats with body weights (BWs) of 180–220 g (6-7 weeks old)	In vivo	DMBA (control rats); NOB (experimental rats)	(i) Compared with normal rats, the expression of proliferation-related proteins was increased in DMBA-treated rats; (ii) NOB-treated rats showed downregulation of cell proliferation protein expression; (iii) No significant changes were observed in the normal control group and rats treated with NOB alone	[93]
Apoptosis promotion	MCF-7 cells	In vitro	Flow cytometry assay	At 50 μM, NOB induced cell apoptosis at the rates of 8.62 ± 3.5%; At 100 μM, NOB induced cell apoptosis at the rates of 11.2 ± 2.0%; At 200 μM, NOB induced cell apoptosis at the rates of 17.1 ± 3.7%; The apoptosis rate of untreated cells was 5.4 ± 0.97%	[88]
Migration inhibition	1 MCF-7 cell; 2 Hs578T cells	In vitro	Wound healing assay	(i) At 200 μM of NOB, the inhibition rates of the migration were 38.2 ± 3.2% after 24 h; At 200 μM of NOB, the inhibition rates of the migration were 44.8 ± 2.5% after 48 h; (ii) At 100 μM of NOB, the migration was reduced by 40% in the Hs578Ts(i)8 cell	[88]; [89]
Migration inhibition	MCF-7 cells	In vitro	Western blot assay	The expression levels of MMP-2 and MMP-9 were decreased in MCF-7 cell lines	[88]
Expression of protein connected with BC	MCF-7 cells	In vitro	Western blot and quantified protein levels of total p65 and nuclear p65; p38 and p-p38; Total Nrf2 and nuclear Nrf2	(i) At 50, 100, and 200 μM, NOB downregulated the translocation of p65 in the MCF-7 cells; (ii) NOB had no significant effect on p65 protein expression at this concentration; (iii) At 100 and 200 μM of NOB, the level of p-p38 was significantly increased; At 50 μM, NOB had no significant effect on p38 phosphorylation; At 100 and 200 μM, NOB significantly affected the expression of p38; (iv) At 100 and 200 μM, NOB significantly reduced the levels of Nrf2; At 50 μM, NOB had no obvious effect	[88]
Angiogenesis inhibition	MCF-7, T47D cells	In vitro	Angiogenesis assay; Western blot assay; RT-PCR analysis; Electrophoretic mobility shift assay (EMSA)	At 200 μM, NOB significantly inhibited tube formation in the extracellular matrix; At 200 μM of NOB, the inhibition of angiogenesis occurred in HUVEC cells; (i) NOB downregulated the expression of phosphorylated EGFR; (ii) NOB reduced the expression levels of phosphorylated Src, FAK, STAT3, and PXN; (iii) After NOB treatment for 24 h, angiogenic factors were inhibited; (iv) NOB downregulated the DNA/STAT3 complex in MCF-7 and T47D cells	[91]