C3 Reduct®-Reductive, Bioavailable Curcuminoid Metabolites

C3 Reduct®-Reductive, Bioavailable Curcuminoid Metabolites

Press release by N. Kalyanam, Ph.D. | Mar 31, 2022

Curcuminoids are among the most useful nutritional ingredients for the maintenance of health. It is known that curcuminoids are metabolized extensively. But some of the major metabolites such as the glucuronides have been shown to be pharmacologically inactive since they are not good antioxidants or address inflammation or other health issues in contrast to their parent curcumin(oids) (Choudhury et al., 2015). On the contrary, the reductive metabolites of curcuminoids retain essentially all the useful health-promoting activities of curcuminoids. Sabinsa’s C3 Reduct® is composed of the most prominent reduced metabolites of curcuminoids, namely tetrahydrocurcuminoids (THCs).

THCs are found in the plant kingdom, and arise from human metabolism of curcuminoids, but also result from gut microbiota transformation of curcumin (Hassaninasab et al., 2011).

Japanese researchers have shown that these reductive metabolites such as THCs are more bioavailable than parent curcuminoids (Okada et al., 2001).

C3 Reduct®: An outstanding antioxidant

C3 Reduct, an off-white material stable over a wide pH range, is also an outstanding antioxidant. THCs, the main actives in C3 Reduct®, in fact excel their parent curcuminoids in this aspect. THCs not only suppress lipid peroxidation but in preclinical studies show an increase in the levels of various antioxidant enzymes, thus being useful under conditions of oxidative stress.

Approved ‘Novel Food’ with numerous health benefits

Sabinsa conducted numerous preclinical studies to establish the safety of C3 Reduct®, culminating in a human clinical study that showed 300mg/day was safe. The safety details formed part of the successful submission of C3 Reduct® as a Novel Food in the European Union, presumably the first-ever metabolites of a nutrient accorded this coveted Novel Food Status (EFSA, 2021).

A series of papers on THCs showed in preclinical diabetic models a reduction in sugar and lipid levels, but also an increase in insulin levels (Murugan and Pari, 2006).

In another aspect, THC was more effective than curcumin itself in protecting intestinal cells from mutant transformations showing the chemoprotective ability of THCs  in maintaining colon health. Under inflammatory colon conditions, THC could inhibit the expression of inflammatory enzymes such as iNOS, COX-2 and NF-kB (Lai et al., 2011; Zhang et al., 2018).

THCs have beneficial effects on the profiles of gut microbiota compositions, positively influencing conditions such as healthy sugar levels and airway inflammation (Yuan et al., 2020; Wu et al., 2021).

The health of organs such as the lung, liver and kidney are important, but their functions degrade under various noxious stimuli. Fibrotic status in these organs prevent their optimum function while THCs may help them reverse back to their healthy functional status (Lau et al., 2018).

THC, the active ingredient in C3 Reduct®, is also neuroprotective (Gao et al., 2016; Maiti et al., 2021).

THC significantly reduced adipocyte size and decreased HOMA-IR index in high-fat diet (HDF)-diet induced obese mice (Fig)  (Pan et al., 2018).

Clinical trials

In addition to establishing safety through a human clinical trial, Sabinsa has conducted a trial wherein C3 Reduct® was shown effective in restoring oral health in subjects through a 21-day trial (Majeed et al., 2020).  Similar observations in oral health were supported by yet another clinical trial by independent researchers, again using C3 Reduct® (Chhaparwal et al., 2018).

An ongoing human trial to show the effectiveness of C3 Reduct® on lung fibrosis is based on positive preclinical findings.

C3 Reduct®: Complete nutritional ingredient

C3 Reduct®, with its pleiotropic pharmacological activities mirroring curcuminoids, is a restorative functional ingredient for various human organs when adversely affected through external stimuli. They are summarized in a recent monograph published by Sabinsa Corporation (Majeed et al., 2019).