Turmeric, one of the oldest cultivated spices with a long history of medical use, has caught the interest of both medical and scientific sectors because it is the main source of polyphenol curcumin. Turmeric’s most active component is curcumin. Turmeric’s brilliant yellow colour comes from curcumin, a non-obtrusive bioactive component. By the twentieth century, scientists all around the world had identified it, and its antibacterial qualities had been shown for the first time in 1949. As a result of the research, researchers were able to discover curcumin’s antibacterial, anti-inflammatory, antioxidant, and other significant properties. Curcumin has several health advantages and healing capabilities. It was largely in practice to treat skin problems, upper respiratory problems, joint pain, gastrointestinal problems, and other diseases.
Modern research has confirmed some of these long-known therapeutic effects and has helped to explain the underlying molecular pathways.
Curcumin, known for its antioxidant properties, helps to decrease swelling and inflammation in cancer patients. As inflammation appears to play a severe role in cancer, oncologists around the world advise curcumin supplements to help the patients with side effects of chemotherapy and radiotherapy. Curcumin’s anti-cancer potential comes from its immunomodulatory ability to interact with multiple immunological mediators. Curcumin has anti-cancer properties in laboratory studies on cancer cells. It appears to be capable of killing cancer cells and also preventing the growth of new ones.
Curcumin has an anti-tumour effect that includes reducing proliferation, cell survival, triggering apoptosis, death receptor pathway, and protein kinase pathway suppression, which inhibits tumour growth and invasion by suppressing many types of cellular signalling pathways. Curcumin is also effective at various stages of cancer growth. It stops normal cells from forming tumours (tumour start), metastasis, angiogenesis, and invasion by blocking cancer cells’ transition. Curcumin’s anticancer effect in vivo and in vitro demonstrated that it can inhibit carcinogenesis and tumour cell proliferation in a variety of tumour cell types.
Researchers have established curcumin’s anticarcinogenic capabilities in animals by its ability to prevent tumour development and progression. Curcumin also alters structurally unrelated membrane proteins across many signalling pathways in studies. It infiltrates deep into the cellular membrane in a trans-bilayer orientation, anchored by hydrogen bonding to the phosphate group of lipids, causing negative curvature in the bilayer, according to a recent study. Curcumin may directly influence apoptosis by boosting the permeabilizing activity of the apoptotic protein by promoting negative curvature. Curcumin reduces cell proliferation, invasion, metastasis, and angiogenesis by suppressing numerous signalling pathways. Curcumin’s chemopreventive effect could be related to its capacity to trigger apoptosis through many routes. It regulates various genes or gene products involved in cell death pathways, either directly or indirectly, as mentioned above.
Curcumin has a wide spectrum of molecular targets, implying that it affects a variety of biochemical and molecular pathways. It binds to a total of 33 proteins, including thioredoxin reductase, cyclooxygenase-2, tubulin, and others. Transcription factors, growth factors and their receptors, cytokines, enzymes, and genes affecting cell proliferation and death are among the molecular targets regulated by this drug. Curcumin suppresses practically all types of tumour cell proliferation and survival. Curcumin-induced cell death mediates by both activation of cell death pathways and inhibition of growth/proliferation pathways, according to growing evidence.
According to growing evidence, curcumin-induced cell death mediates by both activation of cell death pathways and inhibition of growth/proliferation pathways. Many studies show that curcumin plays a different effect on cancer cells than on normal cells. In curcumin-induced cell death, there were more than 40 biomolecules involved. Researchers have discussed the molecular link between different signal transduction pathways that cause apoptosis, whether operating alone or collectively. Curcumin’s action mediates by several cell signalling channels. Therefore developing resistance to it is unlikely.
Curcumin’s impact on cell proliferation and signal transduction pathway activation has been studied in both androgen-dependent and independent prostate cancer cell lines. Curcumin inhibited AR, AP-1, NF-B, and CBP transactivation and expression, according to the findings. It offers a lot of potential as an anticancer drug for prostate cancer, according to these researchers. Curcumin increased the ability of TRAIL to induce apoptosis in androgen-insensitive PC-3 cells while sensitising androgen-responsive TRAIL-resistant LNCaP cells.
It disrupts microtubule assembly dynamics, which may decrease cancer cell proliferation. Curcumin caused considerable depolymerization of interphase microtubules and mitotic spindle microtubules in HeLa and MCF-7 cells at higher inhibitory doses. The effects on cellular microtubules were negligible at low inhibitory doses. Microtubule assembly was disturbed in vitro, GTPase activity was decreased, and tubulin aggregation was stimulated. Curcumin-down-regulated Taxol induced phosphorylation of the serine/threonine kinase Akt, a survival signal that is often regulated by NF-kappaB, in one study, while curcumin had no effect on tubulin polymerization or cyclin-dependent kinase Cdc2 activation induced by Taxol.
To summarise, curcumin has the ability to kill a wide range of tumour cell types in a variety of ways. Curcumin uses a variety of cell death methods, thus, it’s feasible that cells won’t develop resistance to curcumin-induced cell death. Curcumin is also a promising medication candidate because of its ability to kill tumour cells but not normal cells. Despite multiple animal studies and clinical trials, we need more research to fully understand the benefits of curcumin.