Ability of Curcumin to Decrease Cytokines Involved in Mucositis in the Autologous Transplant

Overview

Mucositis is a very common complication in bone marrow transplant setting. It is a result of injury to the gut caused by high dose chemotherapy. Currently there are no universal protocols that have been accepted as a standard to prevent and treat mucositis in the transplant setting. Post transplant upto 80% of patients suffer from a severe mucositis. Proinflammatory cytokines play a major role in the development of mucositis. Interventions that decrease the levels of these cytokines may be beneficial in preventing mucositis. This study is aimed at evaluating the role of curcumin in reducing cytokine levels and the incidence and duration of mucositis in patients undergoing autologous stem cell transplantation.

Mucositis is an inevitable side-effect of intensive conditioning therapy used for hematopoietic stem cell transplantation and usually refers to the mucosal ulceration of mouth and throat. However, it is generally accepted that oral mucositis (OM) is in reality the most obvious manifestation of damage or injury elsewhere particularly that of the gut. The incidence of oral mucositis (WHO grades I-IV ) with certain myeloablative conditioning regimens has been reported in up to 90% with range of severe mucositis (WHO grade III/IV) from 10 to 78%. Mucositis is a complex biological process which occurs in four phases - 1. inflammatory/vascular phase; 2. epithelial phase; 3. ulcerative/bacteriological phase; 4. healing phase. Each phase is interdependent and is the consequence of a series of actions mediated by cytokines, the direct effect of the chemotherapeutic drug on the epithelium, the oral bacterial flora and the status of the patient's bone marrow. Pro-inflammatory cytokines such as interleukin -1 (IL-1), interleukin -6 (IL-6),interleukin-8 (IL-8), interleukin-17 (IL-17), Tumour Necrosis Factor-alpha (TNF-α), Transforming Growth Factor-B (TGF-B),Interferon gamma (IFN-γ) and certain prostaglandins play a central role in its pathogenesis. Chemotherapy, in particular, affects the release of both interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-α)from the epithelium. TNF-α is capable of causing tissue damage and may be an accelerating and initiating event in the mucositis process. IL-1 incites an inflammatory response resulting in increased sub-epithelial vascularity with a potential consequent increase in the local levels of cytotoxic agent. On the other hand, cytokines like TGF-β are known inhibitors of epithelial cell proliferation by preventing cell cycle progression and accumulating cells in G1 or G0. For clonogenic stem cells in the intestine, this might render them more resistant to the cytotoxic damage, leaving more clonogenic stem cells to start the regeneration process. Cytokine modulation is the primary mechanism of action of several agents experimented in the recent past to reduce mucositis. For example, Triclosan oral rinse and interleukin-11 (IL-11) therapy reduce ulceration and duration of mucositis by downregulation of PGE2, TNF-α, IL-12 and IFN-γ. It is quite possible that a role exists for transcription factors which modify the genetic expression of cytokines and enzymes which are critical in producing tissue damage. Such factors, such as NF-kappa B, increase the rate of gene transcription and thereby the rate of messenger RNA and protein production. Therefore inhibition of NF-kB could be beneficial in the reduction of mucosal injury. Currently there are no universal protocols that have been accepted as a standard to prevent and treat OM in the transplant setting. Research is proceeding on several new fronts. Palifermin, recombinant human - keratinocyte growth factor-1, has been shown to the most effective agent so far in few phase II studies. Accumulating evidence suggests that curcumin inhibits various inflammatory cytokines through inhibition of Nuclear Factor Kappa- β. Curcumin, polyphenol derivative with low toxicity profile, is commonly used in India for its anti-inflammatory actions. It is derived from the plant Curcuma longa. In vitro studies have shown potent anti-inflammatory activity at concentrations of 1 umol/L. Though oral bioavailability of curcumin is poor, in vivo sepsis models in mice have shown good anti-inflammatory activity despite poor plasma levels. Similarly significant decrease of ex vivo production of LPS induced PGE2 levels have been seen in patients treated with curcumin. Phase I studies in cancer patients have shown that curcumin can be given at doses ranging from 440 mg to 12 grams daily without any toxicity. There was no dose-limiting toxicity; dosing was limited by the number of pills that patients could or would swallow daily. Curcumin used for cancer prevention is seldom administered in a pure chemical form. Rather, it typically consists of three separate curcuminoids consisting of curcumin itself as well as demethoxycurcumin and bisdesmethoxycurcumin. Plasma levels of curcumin and its metabolites such as curcumin glucuronide and curcumin sulphate have been shown to be in the range of 10- 50 ng/ml in patients receiving doses greater than 3.6 gms daily. This peak concentration is seen 1 hour after a given dose. In a recently published study of curcumin in pancreatic cancer little, if any, free or unconjugated curcumin was detected in the plasma of 19 subjects who received a daily dose of 8 g curcumin. An apparent steady-state level of conjugated curcumin in plasma that was achieved by day 3; this level was 22 to 41 ng/mL. Though the peak plasma concentration of curcumin detected is low, at these doses, biological activity demonstrated by either reduction of cytokine levels or decrease in the activity of NK-kB has been seen in all patients. There are no studies exploring the role of curcumin in mucositis in patients undergoing high dose chemotherapy .The Investigators aim to study the pharmacokinetics and pharmacodynamics of curcumin in the above setting. Patients with mucositis may have difficulty in swallowing tablets. Therefore a lozenge formulation of curcumin will be employed in this study. Lozenges will be manufactured by Pharmanza Herbal Pvt. Ltd (PH). Each lozenge of 1g contains 100mg of curcumin. A capsule formulation of curcumin manufactured by PH containing 27% of curcuminoids was employed in an earlier study in osteogenic sarcoma patients at this centre. Single dose pharmacokinetics with 4g of the formulation yielded peak curcumin concentration of 37.69 ng/ml and half-life of about 2.5 hours - (unpublished data). The time to peak concentration was around 3 hours. Based on this data, a dose of four lozenges (4 gm) twice a day (BID) was deemed necessary and sufficient to achieve the desired inhibition of NF-kB.