*2.3.1.1 Anticancer activity*

Thymoquinone, the active compound of the black seed helps to train T cells *in vitro* for adoptive T-cell therapy against cancer and infectious diseases. The cytotoxic effects of different Black seed extracts as an adjuvant therapy to doxorubicin on human MCF-7 breast cancer cells was reported. The lipid extract of black seed was found to be cytotoxic against MCF-7 cells, with a lethal concentration 50 (LC50) of 2.720 ± 0.232 mg/mL, while the aqueous extract was found to be cytotoxic at concentrations as high as 50 mg/mL. *In vitro* and *in vivo* studies showed the

**Figure 3.**

*Chemical structure of principal bioactive components found in black cumin (*Nigella sativa*) seed.*

antitumor and anti-angiogenic effects of thymoquinone on osteosarcoma [63]. Thymoquinone induced a higher percentage of growth inhibition and apoptosis in the human osteosarcoma cell line sarcoma osteogenic-2 (SaOS-2) and inhibits tumor angiogenesis and tumor growth through suppressing nuclear factor kappa light chain enhancer of activated B cells (NF-κB) and its regulated molecules. Thymoquinone cytotoxicity was also studied in human cervical squamous carcinoma cells (SiHa). Thymoquinone's anticancer effects on breast cancer cells, as well as its potential effect on the peroxisome proliferator-activated receptors (PPAR) activation pathway, were investigated [64]. It was discovered that thymoquinone had a strong antiproliferative effect in breast cancer cells, and cytotoxicity was increased when thymoquinone was combined with doxorubicin and 5-fluorouracil. Migration and invasive properties of MDA-MB-231 cells were also reduced in the presence of thymoquinone. *N. sativa* volatile oil in the diet of male Wister rats for 30 weeks significantly reduced malignant and benign colon tumor sizes, incidences and multiplicities.
