Interventions for the Prevention of Oral Mucositis in Patients Receiving Cancer Treatment: Evidence from Randomised Controlled Trials.

Oral mucositis is a common and most debilitating complication associated with cancer therapy. Despite the significant clinical and economic impact of this condition, there is little to offer to patients with oral mucositis, and the medications used in its management are generally only palliative. Given that mucositis is ultimately a predictable and, therefore, potentially preventable condition, in this study we appraised the scientific literature to evaluate effective methods of prevention that have been tested in randomised controlled trials (RCTs). Published high-level evidence shows that multiple preventative methods are potentially effective in the prevention of oral mucositis induced by radiotherapy, chemotherapy, or both. Anti-inflammatory medications (including benzydamine), growth factors and cytokines (including palifermin), cryotherapy, laser-and-light therapy, herbal medicines and supplements, and mucoprotective agents (including oral pilocarpine) showed some degree of efficacy in preventing/reducing the severity of mucositis with most anticancer treatments. Allopurinol was potentially effective in the prevention of radiotherapy-induced oral mucositis; antimicrobial mouthwash and erythropoietin mouthwash were associated with a lower risk of development of severe oral mucositis induced by chemotherapy. The results of our review may assist in highlighting the efficacy and testing the effectiveness of low-cost, safe preventative measures for oral mucositis in cancer patients.

Molecular Mechanisms of Malignant Transformation of Oral Submucous Fibrosis by Different Betel Quid Constituents-Does Fibroblast Senescence Play a Role?

Betel quid (BQ) is a package of mixed constituents that is chewed by more than 600 million people worldwide, particularly in Asia. The formulation of BQ depends on a variety of factors but typically includes areca nut, betel leaf, and slaked lime and may or may not contain tobacco. BQ chewing is strongly associated with the development of potentially malignant and malignant diseases of the mouth such as oral submucous fibrosis (OSMF) and oral squamous cell carcinoma (OSCC), respectively. We have shown recently that the constituents of BQ vary geographically and that the capacity to induce disease reflects the distinct chemical composition of the BQ. In this review, we examined the diverse chemical constituents of BQ and their putative role in oral carcinogenesis. Four major areca alkaloids-arecoline, arecaidine, guvacoline and guvacine-together with the polyphenols, were identified as being potentially involved in oral carcinogenesis. Further, we propose that fibroblast senescence, which is induced by certain BQ components, may be a key driver of tumour progression in OSMF and OSCC. Our study emphasizes that the characterization of the detrimental or protective effects of specific BQ ingredients may facilitate the development of targeted BQ formulations to prevent and/or treat potentially malignant oral disorders and oral cancer in BQ users.

Kava constituents exert selective anticancer effects in oral squamous cell carcinoma cells in vitro.

Kava is a beverage made from the ground roots of the plant Piper Methysticum. Active compounds of Kava have previously been demonstrated to exert an antiproliferative effect through cell cycle arrest and promotion of apoptosis. Our aim was to investigate the in vitro effects of the main constituents derived from Kava on oral squamous cell carcinoma (OSCC) activity. Gas chromatography mass spectrometry (GCMS) was used to characterise the main constituents of two Kava preparations. Cell proliferation was assessed in two human OSCC cell lines (H400 and BICR56) and in normal oral keratinocytes (OKF6) treated with the identified Kava constituents, namely Flavokawain A (FKA), Flavokawain B (FKB), yangonin, kavain and methysticin using an MTS in vitro assay. Cell migration at 16 h was assessed using a Transwell migration assay. Cell invasion was measured at 22 h using a Matrigel assay. Cell adhesion was assessed at 90 min with a Cytoselect Adhesion assay. The two Kava preparations contained substantially different concentrations of the main chemical constituents. Treatment of malignant and normal oral keratinocyte cell lines with three of the identified constituents, 10 µg/ml FKA, 2.5 µg/ml FKB and 10 µg/ml yangonin, showed a significant reduction in cell proliferation in both H400 and BICR56 cancer cell lines but not in normal OKF6 cells. Remarkably, the same Kava constituents induced a significant reduction of OSCC cell migration and invasion. We have demonstrated, for the first time, that Kava constituents, FKA, FKB and yangonin have potential anticancer effects on OSCC. This highlights an avenue for further research of Kava constituents in the development of future cancer therapies to prevent and treat OSCC.

Protective effect of kava constituents in an in vitro model of oral mucositis.

PURPOSE: Oral mucositis is a debilitating inflammatory disorder observed in patients undergoing active cancer treatment, particularly cancer of the head and neck region. A key pathway believed to be involved in the pathogenesis of oral mucositis is the formation of reactive oxygen species (ROS). The identification of compounds that can inhibit this pathway may therefore be of benefit in treating this disorder. The kava plant (Piper methysticum) contains various constituents, including flavokawain A (FKA), flavokawain B (FKB), yangonin, methysticin and kavain. These constituents are known to be biologically active and possess anti-oxidative properties. This study therefore focused on examining these constituents for their effect on ROS formation in an in vitro oral mucositis model. METHODS: Cell proliferation was assessed in normal oral keratinocytes (OKF6) treated with and without kava constituents, namely FKA, FKB, yangonin, methysticin and kavain using an MTS in vitro assay. Oxidative stress was assessed by co-treating and pre-treating OKF6 cells with H2O2. The effects were quantified by analysis of ROS production, using a CM-H2DCFDA assay. RESULTS: Pre-treatment of cells for 24 h with 2.5 µg/ml kavain and 5 µg/ml FKA demonstrated a significant protective anti-oxidative effect. Similarly, FKB at a concentration of 2.5 µg/ml, demonstrated a trend of ROS reduction but was observed to be cytotoxic at concentrations greater than 5 µg/ml. Reduction in ROS production by methysticin and yangonin was compromised by their cell cytotoxicity. CONCLUSION: This was the first study to identify the anti-oxidative effects and safety of FKA and kavain with regard to oral keratinocytes, highlighting their potential use in the development of a preventative treatment for oral mucositis.

Functional and molecular effects of a green tea constituent on oral cancer cells.

BACKGROUND: Green tea is heavily consumed on a global basis for its health benefits. The active ingredient, (-)-epigallocatechin gallate (EGCG), is a major polyphenol demonstrated to inhibit the growth of various non-oral cancer cell lines and interfere with the carcinogenic process, including downregulation of the epidermal growth factor receptor (EGFR). Our aim was to determine the phenotypic changes of oral cancer cells treated with EGCG and concurrently assess the effect on EGFR expression and activation. METHODS: Oral cancer cells (H400 and H357) were treated with 10 µg/mL and 20 µg/mL of EGCG for up to 72 hours. Phenotypic changes were assessed by performing cell proliferation analysis and cell migration (Transwell) assays. Expression of EGFR and its phosphorylated form (p-EGFR) was determined by Western blotting. RESULTS: Cell proliferation of both cell lines was significantly reduced at 48hrs when treated with 20 µg/mL EGCG. However, after 72 hours of treatment the effect of EGCG on cell proliferation ceased. Treatment of both cell lines with 10 µg/mL and 20 µg/mL of EGCG resulted in significant reduction in cell migration. Mechanistically, EGFR expression did not change significantly after treatment with EGCG; however, there was a reduction in its phosphorylated form. CONCLUSION: EGCG transiently inhibits both cell proliferation and migration of oral cavity cancer cells. This effect is associated with a decrease in the expression of phosphorylated EGFR. It is possible that more frequent bursts of EGCG could result in a persistent and sustained cancer inhibition, but this requires further research for clarification.