A new study published in the Nutrients Journal highlights the impact of curcumin supplementation on the immune response following the immunization of Coronavirus disease 2019 (COVID-19) survivors with a primary series of monovalent COVID-19 vaccines.
Study: Curcumin Confers Anti-Inflammatory Effects in Adults Who Recovered from COVID-19 and Were Subsequently Vaccinated: A Randomized Controlled Trial. Image Credit: Microgen / Shutterstock
Introduction
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the COVID-19 pandemic that overwhelmed healthcare systems and national economies, bringing international trade and travel to historic lows. Vaccines to counter the virus were released by the start of 2021 and proved effective in reducing the severity and fatality of the infection.
However, the effect was typically transient, and repeated boosters were eventually mandated. Vaccine breakthrough infections and reinfections are being reported at increasing rates globally, and these subsets of patients continue to spread the virus, allowing the pandemic to continue.
Inflammatory phenomena have been reported to affect the outcomes of COVID-19, with severe and prolonged COVID-19 symptoms associated with hyper-inflammation and immune dysregulation. An effective and regulated immune response is thus essential to protect against severe illness.
Curcumin is a polyphenol obtained from the rhizomes of the turmeric plant Curcuma longa, with supposed anti-inflammatory, antiviral, and antioxidant activity. It targets multiple pro-inflammatory pathways like the nuclear factor-kappa B (NF-kB), resulting in reduced levels of a host of inflammatory cytokines and chemokines such as interleukin (IL)-6, interferon (IFN) γ, monocyte chemoattractant protein (MCP)-1, and tumor necrosis factor (TNF)-α.
Curcumin is safe even at relatively high doses and is well tolerated by the body. However, it is poorly bioavailable and is rapidly broken down in the liver in humans. Therefore, better formulations should be used to test their immunomodulatory and anti-inflammatory activities.
The level of immunity achieved following COVID-19 is typically different from that attained by immunization, whether against reinfection or breakthrough infection.
The current study was carried out between June 2021 and May 2022. The novel curcumin formulation HydroCurc (CURC) was tested for its effects on circulating inflammatory biomarkers in adults who had recovered from COVID-19. This was compared with the effects of a placebo.
"HyrdoCurc is complexed with Lipisperse technology and is suggested to enhance bioavailability via its ability to reduce curcumin agglomeration and increase curcumin absorption."
The study comprised 31 participants, all of whom had received similar vaccine types. The mean interval from the COVID-19 diagnosis to their participation in the trial was ~280 days. Almost three-quarters of the participants were female, with a mean age of ~28 years.
All participants were given a 500 mg tablet, either of CURC or placebo, twice a day for four weeks.
What did the study show?
The scientists found that the levels of certain inflammatory biomarkers dropped significantly in the CURC group relative to the placebo group. IL-6, and MCP-1 both showed a decline. Others did not show a significant difference.
These two biomarkers have been considered to point to increased odds for acute and persistent dysregulation of inflammation, whether in COVID-19 or chronic inflammatory conditions. This is the first time the benefits of curcumin have been explored in people with previous COVID-19, followed by vaccination.
These findings indicate that curcumin supplementation reduced the increases in these two markers compared to the placebo group.
What are the implications?
Curcumin has the potential to antagonize the entry of SARS-CoV-2 into the cell, as shown by in silico studies. This corroborates reports of its antiviral activity in earlier mechanistic studies involving other enveloped viruses. It is also a potent anti-inflammatory molecule, which lends additional strength to strategies to alleviate the severity of COVID-19 outcomes using curcumin.
"Aberrant and persistent elevations in IL-6 and MCP-1 may be associated with the risk for acute and chronic inflammatory conditions."
IL-6 is a key component in the cytokine storm linked to an adverse prognosis in COVID-19. It is a positive feedback molecule that initiates and propagates inflammation. MCP-1 is produced as an inflammatory response and promotes the movement of monocytes and other white cells between the circulation and the site of inflammation.
Clinical trials support the anti-inflammatory activity of curcumin and its promising role in various conditions linked to inflammation. The current study adds the strength of evidence to existing research, using a novel form of curcumin with increased bioavailability.
Conclusion
The results suggest that curcumin supplementation could improve the inflammatory-immune response (specifically IL-6 and MCP-1) in adults who have recovered from COVID-19 and later received a primary course of vaccines.
"These findings indicate that curcumin supplementation may help to control inflammation and support resilience."
Studies could show if curcumin is also useful in strengthening immunity following COVID-19 immunization to prevent breakthrough infections.
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