Role of Curcumin on Inflammation

There has recently been a craze about using turmeric for a number of health-related issues. Are these claims valid? What is turmeric anyway? I mean, where did it come from and what is the mechanism of action if this root does indeed work for improving health? I intend to reveal here whether jumping on yellow wagon is worth the hype.

Being a rhizomatous, herbaceous perennial from the ginger family, this plant is native to the Indian subcontinent and Southeast Asia. To preserve these roots after harvest, the rhizomes are boiled, dried and ground into powder that can be used for cooking, coloring, and flavoring in many dishes such as curries. It is often used in Ayurvedic medicine because of the curcumin constituents that are thought to be therapeutic. However, curcumin makes up approximately 3% (with an average of 1.5%) of turmeric powder commercially sold including curcumin, demethoxycurcumin, and bisdemethoxycurcumin. Interesting!!! What about the essential oils, you may ask? There are about 34 oils, including tumerone, germacrone (antiviral isolate), atlantone, and zingiberene (the monocyclic sesquiterpene component of ginger comprising ~30% of the essential oils).

Traditionally, turmeric was used in traditional Siddha or Ayurveda medicine, generally place on the skin or adorned the body. For example, during the Haldi ceremony, Gaye holud (yellow on the body), turmeric is used in weddings. In Tamil Nadu and Andhra Pradesh, it is strung into a necklace, or in Marathi the tubers are tied by the couples to their wrists. However, because it is sold by weight, it is commonly adulterated by the addition of toxic powders such as lead oxide, changing the color from its native golden yellow to an orange-red color. Additionally, a compound known as acid yellow 36 is added for use in food products but is deemed illegal in some countries. Does this now make you want to read the label of the turmeric in your spice cabinet? However, in traditional medicine, curcumin has been used to alleviate respiratory conditions, anorexia, coryza, cough, and hepatic diseases.

Research is now supporting the medicinal uses for turmeric’s active ingredient, curcumin, because it has been demonstrated to reduce pro-inflammatory-induced chronic illnesses including cardiovascular, metabolic, pulmonary, auto immune and malignant diseases (Prasad et al). This group went on to suggest that inhibition of transcription factors nuclear factor-kappaB (NF-κB), Wnt/beta-catenin, and activates peroxisome proliferator-activated receptor-gamma and Nrf2 cell signaling pathways. Modulating these activities can potentially lead to downregulation of adipokines and upregulation of adiponectin and other gene products. Curcumin has also been shown to modulate not only cell survival proteins and inflammatory components on a biological level, but it has also been linked to histone acetylase, deacetylase, protein kinases and reductases, and glyoxalase I, as well as DNA, RNA, and metal ions. Needless to say, these are a vast number of pathways being acted upon by this compound.

A recent article by Dai et al suggest curcumin plays a role in alleviating collagen-induced inflammation by targeting the mTOR pathway. Although this study is focused on rheumatoid arthritis, the inflammatory markers that were explored play a vital role in vascular inflammation such as chemokines, cathepsin, matrix matalloproteinases, TNF-α, and IL-1 to breakdown the extracellular matrix and ultimately lead to vascular remodeling. Curcumin is considerably cheap and easily available, making it attractive to use in inflammation studies. Rapamycin (mTOR) role in cellular proliferation, differentiation, and apoptosis makes it an important player in cellular regulation. Using Wistar rats as their model, Dai et al suggest curcumin can potentially inhibit the mTOR pathway under collagen-induced inflammatory conditions when compared to the control group. Additionally, this group demonstrated a reduction in inflammatory cell infiltration in the treatment group alleviating the hyperplasia with curcumin therapy.

Promising results were demonstrated by Xiao et al with hemeoxygenase-1 (HO-1) with cytoprotective effects under some pathological conditions. This group used New Zealand white rabbits that were fed curcumin for four weeks. Once the acute vascular inflammation was induced, there was an increase in serum bilirubin and vascular, liver, and spleen HO-1 mRNA levels with curcumin treatment compared to control, as well as a decrease in vascular inflammation. Furthermore, with HO inhibition or HO-1 siRNA knock down, there was an amelioration of carotid artery HO-1, impeding vascular inflammation. Xiao et al went on to report treatment of human artery endothelial cells with curcumin lead to the activation of the Nrf2 and p38 MAPK signaling pathways.

Ultimately, the active compound in turmeric, curcumin, has been shown to contribute to the reduction of vascular inflammation in addition to rheumatoid arthritis-induced inflammation by decreasing the proinflammatory cytokines and chemokines. Additionally, antioxidant response elements are responsive in the presence of curcumin. The thing to remember here is, with all the positive results, curcumin is not readily bioavailable. To get a therapeutic amount, it should be formulated with delivery compounds such as capsaicin or hyaluronic acid (see image). Furthermore, the dose that is necessary to have an effect may be higher than the amount delivered if it is not correctly monitored. For example, it takes up to 90 mg orally to attenuate oxidative stress following a downhill run according to Kawanishi et al. This reduction was observed due to the increase in the blood’s antioxidant capabilities that utilize the TNF, cyclooxygenase-2, and iNOS to initiate anti-inflammatory mechanisms.

So the question, is it a good idea to jump on the yellow band wagon? Yes. However, some things to keep in mind is to read the labels to be sure the turmeric is pure or try to purchase the root in its native form and dry it to the powder at home. Do your research to make sure you are consuming enough to get the benefits from the product. Make sure you are mixing it with the right compounds. I have been utilizing turmeric for years before this band wagon came along, and I will continue to purchase turmeric roots from the farmer’s market and make powder by drying it out in a low temperature oven overnight (get to the powder by blending in the Ninja Blender). I do not think I will use the diatomaceous earth (silica) that was suggested in one of the recipes I saw online.


If you are interested in recipes using turmeric, there are a lot on @dashdiet1 I also post on my twitter.

Remember to follow me on Twitter @AnberithaT where I will keep you posted on #AHAMeetingsReports @AHA_Meetings and #VascularScience. See you in Hawaii for #ISC2019!


Leave a Comment