A Systematic Review Assessing Clinical Utility of Curcumin with a Focus on Cancer Prevention

Abstract

Scope: There is extensive pre-clinical evidence for utility of curcuminoids across many diseases with a particular focus on cancer prevention, yet there remains a paucity of clinical evidence for its approved use. To assess current knowledge on the broader potential for clinical efficacy of curcumin and in particular, in cancer prevention strategies, this study undertook a systematic review determining the number and quality of randomized controlled trials (RCTs) undertaken across any pathology. Methods and Results: Search strategies for RCTs using a quantifiable amount of curcuminoids, are applied across Medline (Medical Literature Analysis and Retrieval System Online), Embase (Excerpta Medica dataBASE), Cochrane and clinicaltrials.gov. There are 314 curcuminoid-based RCTs, with 100 of these revealing significant within-and between-group changes relating to the primary outcome. Twenty three studies are conducted in a setting where there is an increased risk of cancer. Fifteen of these meet all prescribed quality criteria, and 10 reveal positive outcomes. Conclusions: A substantial number of studies reveal positive outcomes following curcumin use. However, despite the vast array of preclinical data, there are relatively few RCTs conducted in the prevention setting. Future approaches to trials must deliver improved robustness and credibility of curcumin-related research to facilitate approvals for use in clinical settings.

A Presurgical Study of Curcumin Combined with Anthocyanin Supplements in Patients with Colorectal Adenomatous Polyps

“…Curcumin and anthocyanin extracts have been demonstrated to be phytochemicals with potential antitumor activity in CRC [8,9,[16][17][18][19]. A recent systematic review shows a significant number of clinical trials conducted with curcumin formulations in a cancerpreventive setting with positive outcomes, but only 30% include putative biomarkers of efficacy as clinical endpoints [9]. Conversely, data relating to the CRC-preventive activity of anthocyanins are mainly based on observational studies [19].…”

“…This natural polyphenol shows antioxidant and anti-inflammatory effects through the regulation of numerous intracellular targets that control CRC cell growth in in vitro and in vivo studies [8]. On the other hand, clinical studies in humans are very few and have shown conflicting results [8,9]. A wide range of curcumin formulations have been explored during recent years in order to improve its curcumin poor bioavailability and low oral absorption.…”

Counteracting Action of Curcumin on High Glucose-Induced Chemoresistance in Hepatic Carcinoma Cells

“…Curcumin has a proven ability to counter chemoresistance in cancer cells (14,19,20). The ability of curcumin to modulate the regulatory networks governing the balance of cell survival and induction of cell death is well established (20,21). Curcumin has been demonstrated to amend the expression of molecules central to chemoresistance including members of the ABC drug efflux transporter family (14,17,22).…”

“…In renal tubular epithelial cells, curcumin was also shown to obviate high glucose-induced epithelial-to-mesenchymal transition (EMT) (23). High glucose conditions can aggravate the invasion and migration (24), while curcumin can impede the metastatic events in a variety of malignancies (18,21). Antineoplastic potential, metabolic modulatory ability, and chemosensitizing property along with safety investigations (15,16,20,21,25,26) provide an edge to curcumin over other phytochemicals.…”

“…High glucose conditions can aggravate the invasion and migration (24), while curcumin can impede the metastatic events in a variety of malignancies (18,21). Antineoplastic potential, metabolic modulatory ability, and chemosensitizing property along with safety investigations (15,16,20,21,25,26) provide an edge to curcumin over other phytochemicals. However, the potential of curcumin against high glucose-induced chemoresistance remains undefined.…”