Review on Molecular and Therapeutic Potential of Thymoquinone in Cancer

Abstract

Thymoquinone (TQ) is the predominant bioactive constituent present in black seed oil (Nigella sativa) and has been tested for its efficacy against cancer. Here, we summarize the literature about TQ’s molecular mechanism of action and its ability to induce apoptosis and inhibit tumor growth in preclinical models. TQ has anti-inflammatory effects, and it inhibits tumor cell proliferation through modulation of apoptosis signaling, inhibition of angiogenesis, and cell cycle arrest. Chemosensitization by TQ is mostly limited to in vitro studies, and it has potential in therapeutic strategy for cancer. The results favor efficacy and enhancement of therapeutic benefit against tumor cells resistant to therapy based on cellular targets that are molecular determinants for cancer cell survival and progression. There have been attempts to synthesize novel analogs of TQ directed toward superior effects in killing tumor cells with more enhanced chemosensitizing potential than parent TQ compound. Based on published reports, we believe that further in-depth studies are warranted including investigation of its bioavailability and Phase I toxicity profiling in human subjects. The results from such studies will be instrumental in advancing this field in support of initiating clinical trials for testing the effects of this ancient agent in cancer therapy.

Thymoquinone induces apoptosis in human colon cancer HCT116 cells through inactivation of STAT3 by blocking JAK2- and Src-mediated phosphorylation of EGF receptor tyrosine kinase

“…1A), a dietary phytochemical, is the major bioactive constituent present in black seed oil (Nigella sativa), which is widely consumed as a condiment and has long been used in Ayurvedic medicine. TQ has been reported to exert antioxidative, anti-inflammatory and anticancer effects (5)(6)(7). Several studies have reported that TQ inhibits cell proliferation, induces apoptosis and impedes the in vivo growth of xenograft tumors of various human cancer cells including those of the stomach (8,9), colorectal (10,11), lungs (12), breast (5) and prostate (13).…”

Basic Studies on Chemopreventive Properties of Quercetin and Curcumin and Other Plant-origin Compounds in Ovarian Cancer Cells – A Mini-review

“…Similar effects were observed in the case of curcumin. The role of NF-κB as a potential molecular target in the action of studied plant-origin compounds was strongly postulated by authors and others [105]. The enhanced cell kill resulting from treatment of cancer cells with these two phytochemicals (applied 2/0 sequence of administration) may be related to the reduced expression of NF-κB and down-regulation of AKT kinase and cyclooxygenase-2 (COX2) protein pathways.…”

Mechanism of Action of Nigella sativa on Human Colon Cancer Cells: the Suppression of AP-1 and NF-κB Transcription Factors and the Induction of Cytoprotective Genes

“…Several classes of compounds have been isolated from the seeds of N. sativa, such as alkaloids, flavonol triglycosides, saponins and an isobenzofuranone derivative (Ahmad et al, 2013). Among these active compounds, much of the biological activities of the seeds have been attributed to thymoquinone, the major component of the essential oil (Banerjee et al, 2010). Accordingly, most researchers have dealt with thymoquinone and its derivatives, as the anticancer bioactive compounds in N. sativa and have paid little attention, if any, to other ingredients, such as saponins, present in the herb.…”