Lycopene: features and potential significance in the oral cancer and precancerous lesions

Developmental synergism in the management of oral potentially malignant disorders

Oral potentially malignant disorders (OPMDs) are associated with an increased risk of occurrence of cancers of the oral cavity or lips. The unifying theme of OPMDs is their potential risk for cancer development. Therefore, the primary objective of the management should be to prevent carcinogenesis. Beyond diagnosis, current strategies for the management of OPMDs predominantly include non-surgical and surgical interventions and a "watch-and-see" approach, such as disease monitoring or surveillance, and preventive strategies. Though no optimal clinical treatment has gained universal approval for reducing or preventing malignant development of OPMDs. Therefore, an urgent need exits for improved treatment properties and effective predictive markers for OPMDs treatment. This review aims to outline recent synergism regarding to the management of OPMDs. Developing new technologies and improved application parameters to promote the treatment efficacy and a novel management prescription approach to OPMDs are proposed.

Efficacy of lycopene for management of oral potentially malignant disorders: A systematic review and meta-analysis

OBJECTIVE

The aim of this study was to investigate the available evidence on the efficacy of lycopene in the management of oral potentially malignant disorders (OPMDs).

STUDY DESIGN

PubMed, Scopus, Web of Science, Google Scholar, China National Knowledge Infrastructure, and ProQuest databases were searched up to April 20, 2022. All clinical trials that assessed the efficacy of lycopene (I) on the signs/symptoms (O) of patients with OPMDs (P) in comparison to either active control or placebo (C) were included. Meta-analysis was conducted using the RevMan software (Cochrane Collaboration, London, UK).

RESULTS

A total of 27 clinical trials (20 on oral submucosa fibrosis [OSF], 5 on oral lichen planus [OLP], and 2 on leukoplakia) were included. Overall, lycopene was efficacious in reducing signs and symptoms of OSF, OLP, and leukoplakia. The pooled data revealed comparable efficacy of lycopene and prednisolone in reducing pain and promoting clinical resolution of OLP. Additionally, the pooled data reported comparable efficacy of lycopene and conventional controls in improving the mouth opening and tongue protrusion in patients with OSF.

CONCLUSIONS

The results reveal promising effects of lycopene in alleviating signs and symptoms of OSF, OLP, and leukoplakia. However, owing to the observed heterogeneity and short follow-up periods, further well-designed studies with long-term therapy and follow-up are highly recommended.

Tomatoes: An Extensive Review of the Associated Health Impacts of Tomatoes and Factors That Can Affect Their Cultivation

Simple Summary

The research outlined in this review paper discusses potential health benefits associated with a diet enriched with tomatoes and tomato products. This includes details of previous studies investigating the anticancer properties of tomatoes, protection against cardiovascular and neurodegenerative diseases and diabetes, maintenance of a healthy gut microbiome, and improved skin health, fertility, immune response, and exercise recovery. The specific parts of a tomato fruit that contribute these health benefits are also outlined. The potential disadvantages to a tomato-rich diet are detailed, especially the consumption of supplements that contain compounds found in tomatoes, such as lycopene. This review also discusses how the cultivation of tomato plants can affect the nutritional value of the fruit harvested. Different environmental growing conditions such as light intensity, growing media, and temperature are explained in terms of the impact they have on the quality of fruit, its nutrient content, and hence the potential health benefits acquired from eating the fruit.

Abstract

This review outlines the health benefits associated with the regular consumption of tomatoes and tomato products. The first section provides a detailed account of the horticultural techniques that can impact the quality of the fruit and its nutritional properties, including water availability, light intensity, temperature, and growing media. The next section provides information on the components of tomato that are likely to contribute to its health effects. The review then details some of the health benefits associated with tomato consumption, including anticancer properties, cardiovascular and neurodegenerative diseases and skin health. This review also discusses the impact tomatoes can have on the gut microbiome and associated health benefits, including reducing the risk of inflammatory bowel diseases. Other health benefits of eating tomatoes are also discussed in relation to effects on diabetes, the immune response, exercise recovery, and fertility. Finally, this review also addresses the negative effects that can occur as a result of overconsumption of tomato products and lycopene supplements.

Dietary Carotenoids in Head and Neck Cancer-Molecular and Clinical Implications

Head and neck cancer (HNC) is one of the most common cancers in the world according to GLOBCAN. In 2018, it was reported that HNC accounts for approximately 3% of all human cancers (51,540 new cases) and is the cause of nearly 1.5% of all cancer deaths (10,030 deaths). Despite great advances in treatment, HNC is indicated as a leading cause of death worldwide. In addition to having a positive impact on general health, a diet rich in carotenoids can regulate stages in the course of carcinogenesis; indeed, strong epidemiological associations exist between dietary carotenoids and HNS, and it is presumed that diets with carotenoids can even reduce cancer risk. They have also been proposed as potential chemotherapeutic agents and substances used in chemoprevention of HNC. The present review discusses the links between dietary carotenoids and HNC. It examines the prospective anticancer effect of dietary carotenoids against intracellular cell signalling and mechanisms, oxidative stress regulation, as well as their impact on apoptosis, cell cycle progression, cell proliferation, angiogenesis, metastasis, and chemoprevention; it also provides an overview of the limited preclinical and clinical research published in this arena. Recent epidemiological, key opinion-forming systematic reviews, cross-sectional, longitudinal, prospective, and interventional studies based on in vitro and animal models of HNC also indicate that high carotenoid content obtained from daily supplementation has positive effects on the initiation, promotion, and progression of HNC. This article presents these results according to their increasing clinical credibility.

An overview of effect of lycopene and curcumin in oral leukoplakia and oral submucous fibrosis

The purpose of the current article was to evaluate the recently published researches on the use of lycopene and curcumin in oral leukoplakia (OL) and oral submucous fibrosis (OSF). A comprehensive review of the current researches enveloping PubMed, Ovid, and Cochrane was made using the keywords [(Lycopene) OR (Curcumin) AND (Leukoplakia OR OL OR OSF OR OSMF OR OSF OR Submucous Fibrosis)]. We included only randomized control trials and in the English language. The search covers the data from 1994 to August 2020. Six studies (2 of OL and 4 of OSF) finally qualified are included in the study for the qualitative analysis of the result. Out of these six studies, four were found having high risk, one with unclear risk and one with low risk. Only one study came out as finally suitable for the quantitative analysis of the result. A total of 90 participants were included in this review, with a mean age of 32 with a range of 17–60 years. Out of 90 participants, 70 were male and 20 were female. It is evident from the result of this study that the use of oral curcumin and lycopene has significant improvement in the mouth opening, burning sensation, and cheek flexibility in comparison to the placebo. The use of oral curcumin and lycopene appears to be effective and safe in the treatment of OL and OSF but to read the result of use of oral curcumin and lycopene in OL caution should be taken because of bias.

Association between Oral Cancer and Diet: An Update

Oral cancer, included within head and neck cancer, is the sixth most common malignant neoplasm in the world. The main etiological factors are tobacco and alcohol, although currently, diet is considered an important determinant for its development. Several dietary nutrients have specific mechanisms of action, contributing to both protection against cancer and increasing the risk for development, growth, and spread. Foods such as fruits, vegetables, curcumin, and green tea can reduce the risk of oral cancer, while the so-called pro-inflammatory diet, rich in red meat and fried foods, can enhance the risk of occurrence. Dietary factors with a protective effect show different mechanisms that complement and overlap with antioxidant, anti-inflammatory, anti-angiogenic, and anti-proliferative effects. The main limitation of in vivo studies is the complexity of isolating the effects related to each one of the nutrients and the relationship with other possible etiological mechanisms. On the contrary, in vitro studies allow determining the specific mechanisms of action of some of the dietary compounds. In conclusion, and despite research limitations, the beneficial effects of a diet rich in vegetables and fruits are attributed to different micronutrients that are also found in fish and animal products. These compounds show antioxidant, anti-inflammatory, anti-angiogenic, and anti-proliferative properties that have a preventive role in the development of oral and other types of cancer.

Effect of Lycopene on Oral Squamous Cell Carcinoma Cell Growth by Inhibiting IGF1 Pathway

Purpose

Lycopene has produced robust clinical effects and shows a promising chemopreventive in the oral cancer and precancerous lesions. However, much is still unknown about its mechanisms of the carotenoid in protecting against oral squamous cell carcinoma (OSCC). Insulin-like growth factor 1 (IGF1) pathway serves as a key regulatory signal pathway in the tumor microenvironment, which may be associated with the angiogenesis, tumorigenicity, and cancer proliferation. The current study was focused on elucidating the potential pathway played for lycopene to exert its function in treating with OSCC.

Materials and Methods

Firstly, we explored the dose- and time-response of CAL-27 and WSU-HN6 cells to lycopene. Both cells were incubated with various concentrations of lycopene (0.25, 0.5, 1, 2 µM). The inhibiting rate of cell proliferation was assessed using MTT assay. To observe the regulating effect of lycopene on OSCC, cell migration, apoptosis and tumor formation were detected in vitro and in vivo. The potential signaling pathways of OSCC cells treated with lycopene were analyzed by Affymetrix microarrays. And then, we investigated the changing of IGF1 signaling pathway, on the protein levels of tumor tissue after lycopene.

Results

Cell proliferation was inhibited by lycopene in a dose- and time-dependent manner. The optimum inhibition efficiencies for OSCC cells were also found. Further, the results also demonstrated that pre-treatment of OSCC with lycopene drastically induced cell apoptosis suppresses cell migration and tumor growth. Mechanistically, ingenuity pathway analysis further revealed that IGF1 pathway participate in killing effects on OSCC after treatment of lycopene. Lycopene may inhibit the pathway by regulating protein expression of IGF1, IGF binding protein (BP) 1, IGFBP3, transcription factor Jun/AP-1 (JUN), and forkhead box O1 (FOXO1).

Conclusion

These observations indicate that lycopene regulates OSCC cell growth by inhibiting IGF1 pathway, which may be a promising agent for the treatment of OSCC.

Efficacy of Lycopene in the Treatment of Oral Submucous Fibrosis: A Meta-analysis of Randomized Controlled Trials

OBJECTIVES

The aim of this meta-analysis was to systematically evaluate the efficacy of lycopene in improving maximum mouth opening and other clinical symptoms in patients with oral submucous fibrosis (OSF).

METHODS

We searched 5 databases: PubMed, Web of Science, Embase, The Cochrane Library, and EBSCO. Randomized controlled trials were collected to evaluate the efficacy of lycopene in the treatment of OSF. Each database was searched from inception to April 30, 2019. The RevMan 5.3 software was used for this meta-analysis.

RESULTS

The included studies were 7 randomized controlled trials involving 758 patients with OSF. The results of this meta-analysis showed that lycopene was significantly more effective in improving maximum mouth opening in OSF patients than placebo treatment (mean difference [MD]: 3.15; 95% confidence interval [CI]: 2.19-4.10, P < .0001, I² = 0%). Compared with control groups, lycopene could significantly increase the maximum mouth opening in patients with OSF after 1 month of treatment (MD, 2.40; 95% CI, 2.22-2.58; P = .91; I² = 0%), 2 months of treatment (MD, 3.19; 95% CI, 2.87-3.51; P = .93; I² = 0%), and 3 months of treatment (MD, 4.89; 95% CI, 4.51-5.28; P = .86; I² = 0%). However, no significant difference was found in alleviation of burning sensation after 1 month (risk ratio [RR], 1.04; 95% CI, 0.89-1.23; P = .73; I² = 0%), 2 months (RR, 0.98; 95% CI, 0.73-1.31; P = .69; I² = 0%), and 3 months of treatment (RR, 0.84; 95% CI, 0.47-1.52; P = .81; I² = 0%); tongue protrusion (MD, -1.59; 95% CI, -4.15 to 0.97; P = .12; I² = 58%); and pain associated with the lesion after 1 month (RR, 1.05; 95% CI, 0.92-1.21; P = .77; I² = 0%), 2 months (RR, 0.95; 95% CI, 0.75-1.19; P = .35; I² = 0%), and 3 months (RR, 0.95; 95% CI, 0.68-1.33; P = .14; I² = 51%) in patients with OSF between lycopene and control groups.

CONCLUSIONS

The results of this meta-analysis showed that lycopene is more effective for improving symptoms of maximum mouth opening than placebo groups and control groups, but there were no significant differences in burning sensation, pain associated with lesion, and tongue protrusion in patients with OSF compared with control groups.

Carotenoids in Cancer Metastasis-Status Quo and Outlook

Metastasis represents a major obstacle in cancer treatment and the leading cause of cancer-related deaths. Therefore, the identification of compounds targeting the multi-step and complex process of metastasis could improve outcomes in the management of cancer patients. Carotenoids are naturally occurring pigments with a plethora of biological activities. Carotenoids exert a potent anti-cancer capacity in various cancer models in vitro and in vivo, mediated by the modulation of signaling pathways involved in the migration and invasion of cancer cells and metastatic progression, including key regulators of the epithelial-mesenchymal transition and regulatory molecules, such as matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), urokinase plasminogen activator (uPA) and its receptor (uPAR), hypoxia-inducible factor-1α (HIF-1α), and others. Moreover, carotenoids modulate the expression of genes associated with cancer progression and inflammatory processes as key mediators of the complex process involved in metastasis. Nevertheless, due to the predominantly preclinical nature of the known anti-tumor effects of carotenoids, and unclear results from certain carotenoids in specific cancer types and/or specific parts of the population, a precise analysis of the anti-cancer effects of carotenoids is essential. The identification of carotenoids as effective compounds targeting the complex process of cancer progression could improve the outcomes of advanced cancer patients.

Long-term effectiveness of lycopene in the management of oral submucous fibrosis (OSMF): A 3-years follow-up study

BACKGROUND

Long-term follow-ups after receiving lycopene therapy for management of oral submucous fibrosis (OSMF) are scarce. The study aimed to assess the long-term efficacy of lycopene for management of OSMF symptoms.

METHODS

In this prospective clinical study, 400 clinically diagnosed early OSMF patients were assessed for the efficacy of lycopene in alleviation of burning sensation (BS) and reduced mouth opening (MO) symptoms in comparison to placebo. After 1-year follow-up, group A (lycopene group) was divided equally into group A1 and group A2. group A1 patients were retreated with lycopene and the A2 group was followed without retreatment. After 2-year follow-up, the Group A2 patients were advised retreatment but not followed as most of the patient did not agree for follow-up. However, group A1 patients were continued to follow-up every 6 months for a total three years. Statistical analysis was by independent sample t-test and P-value <.05 were considered as significant.

RESULTS

A statistically significant difference (P < .05) in BS and MO was found between group A and B with lycopene showing better results. At one-year follow-up, a statistically significant recurrence in the symptoms was found (P < .05) in the lycopene group (group A). After the second intervention, there was a statistically significant difference in the improvement of symptoms between the group A1 and A2 at 6 months and 1 year (P < .05) with group A1 (retreatment) showing better results.

CONCLUSIONS

Treatment with lycopene led to improvement in the symptoms of OSMF in the present study. The results highlight the importance of retreatment of lycopene for its long-term effect on alleviation the symptoms of OSMF.

Lycopene Inhibits Epithelial-Mesenchymal Transition and Promotes Apoptosis in Oral Cancer via PI3K/AKT/m-TOR Signal Pathway

Background

Oral cancer (OC) is one of the most common cancers around the world. Despite the progress in treatment, the prognosis of OC remains poor, especially for patients with advanced diseases. It urges the development of novel therapeutic options against OC. Lycopene (LYC) is an antioxidant with chemoprotective properties against cancer. However, little is known about the mechanisms underlying the protective role of LYC in OC tumorigenesis.

Methods

In this study, we investigated the anti-cancer effect of LYC on the progression of OC in vitro and in vivo and explored the underlying mechanisms involved in this process.

Results

LYC inhibited OC cell proliferation, migration, invasion, apoptosis, and xenograft tumor growth in a dose-dependent manner. Furthermore, we found that LYC might inhibit epithelial-mesenchymal transition and induce apoptosis in OC cells by deactivating the PI3K/AKT/m-TOR signaling through increasing the levels of E-cadherin and Bax and downregulating N-cadherin, p-PI3K, p-AKT, p-m-TOR, and bcl-2.

Conclusion

We reported for the first time that LYC exhibited anti-cancer effects on OC development both in vitro and in vivo via regulating EMT process and apoptosis. These findings provide support for the potential clinical use of LYC in OC treatment.

Oral submucous fibrosis: A global challenge. Rising incidence, risk factors, management, and research priorities

Oral submucous fibrosis is a potentially malignant disorder of the oral cavity, with a high rate of malignant transformation. It is very common among habitual areca nut chewers. The pathogenesis of oral submucous fibrosis is not well established, but it is believed to be a disease of multifactorial origin, including areca nut chewing, ingestion of chilies, genetic factors, immunologic processes and nutritional deficiencies. Genetically susceptible individuals when exposed to areca nut chewing develop this disease over a variable period of time. Oral submucous fibrosis is considered to be a disease of collagen metabolism. Several genetic factors are reported but there is no consensus about the exact mechanism of disease initiation. Variations in histopathological presentation are noted among oral submucous fibrosis patients with habitual areca nut chewing in different forms and other additive agents, eg betel quid, pan masala and gutkha, together with a variety of tobacco habits. The role of epigenetic modifications, such as miRNA regulation, and DNA methylation is also being reported as part of the pathogenesis of oral submucous fibrosis. A combined approach, including analysis of genetic and epigenetic regulations with different habits, might be helpful to better understand the contributory factors and pathogenesis of this serious disorder.

Plant-Derived Bioactives in Oral Mucosal Lesions: A Key Emphasis to Curcumin, Lycopene, Chamomile, Aloe vera, Green Tea and Coffee Properties

Oral mucosal lesions have many etiologies, including viral or bacterial infections, local trauma or irritation, systemic disorders, and even excessive alcohol and tobacco consumption. Folk knowledge on medicinal plants and phytochemicals in the treatment of oral mucosal lesions has gained special attention among the scientific community. Thus, this review aims to provide a brief overview on the traditional knowledge of plants in the treatment of oral mucosal lesions. This review was carried out consulting reports between 2008 and 2018 of PubMed (Medline), Web of Science, Embase, Scopus, Cochrane Database, Science Direct, and Google Scholar. The chosen keywords were plant, phytochemical, oral mucosa, leukoplakia, oral lichen planus and oral health. A special emphasis was given to certain plants (e.g., chamomile, Aloe vera, green tea, and coffea) and plant-derived bioactives (e.g., curcumin, lycopene) with anti-oral mucosal lesion activity. Finally, preclinical (in vitro and in vivo) and clinical studies examining both the safety and efficacy of medicinal plants and their derived phytochemicals were also carefully addressed.

Evaluation of Conditions Affecting Properties of Gac (Momordica Cocochinensis Spreng) Oil-Loaded Solid Lipid Nanoparticles (SLNs) Synthesized Using High-Speed Homogenization Process

In this study, we attempted the preparation of gac oil-loaded solid lipid nanoparticles (SLNs) by the high-speed homogenization method using Naterol SE solid lipid, a cosmetic self-emulsifying base, and surfactant and investigated the effects of different conditions on the characteristics of the resulting nanoparticles. The suspensions containing 5% active agents (gac-oil, w/w) were dispersed in a surfactant concentration of 5% (w/w) (Span 80:Tween 80 ratio of 28:72 w/w) and 2.5% (w/w) of solid lipid (Naterol SE) concentration. Suitable conditions for hot homogenization were 13,000 rpm, 60 min and 60 °C for speed, time and temperature, respectively. The suitable conditions for the subsequent cold homogenization were 25 min of homogenization time and 5 °C of temperature. The results showed that the mean size of SLNs-gac oil was 107 nm (measured by laser diffraction spectrometry, LDS), and dried size of SLNs-gac oil ranged from 50 to 80 nm (measured by transmission electron microscope, TEM). In addition, the study investigated the impact of gac oil content on the particle size of SLNs-gac oil and its stability under different storage conditions of UV radiation and storage temperature. At high storage temperatures, the color changes (ΔE) of the samples were more profound in comparison to that at the low storage temperature. The ΔE value of the blank sample (SLN-FREE gac-oil) was higher than that of the Gac oil-loaded SLNs samples (SLN-gac oil).

A Review of Promising Natural Chemopreventive Agents for Head and Neck Cancer

Head and neck squamous cell carcinoma (HNSCC) accounts for 300,000 deaths per year worldwide, and overall survival rates have shown little improvement over the past three decades. Current treatment methods including surgery, chemotherapy, and radiotherapy leave patients with secondary morbidities. Thus, treatment of HNSCC may benefit from exploration of natural compounds as chemopreventive agents. With excellent safety profiles, reduced toxicities, antioxidant properties, and general acceptance for use as dietary supplements, natural compounds are viewed as a desirable area of investigation for chemoprevention. Though most of the field is early in development, numerous studies display the potential utility of natural compounds against HNSCC. These compounds face additional challenges such as low bioavailability for systemic delivery, potential toxicities when consumed in pharmacologic doses, and acquired resistance. However, novel delivery vehicles and synthetic analogues have shown to overcome some of these challenges. This review covers 11 promising natural compounds in the chemoprevention of HNSCC including vitamin A, curcumin, isothiocyanate, green tea, luteolin, resveratrol, genistein, lycopene, bitter melon, withaferin A, and guggulsterone. The review discusses the therapeutic potential and associated challenges of these agents in the chemopreventive efforts against HNSCC. Cancer Prev Res; 11(8); 441-50. ©2018 AACR.

The Health Potential of Fruits and Vegetables Phytochemicals: Notable Examples

Fruit and vegetables are essential components of a healthy diet. The World Health Organization (WHO) recommends an intake of five to eight portions (400-600 g) daily of fruits and vegetables to reduce risk of cardiovascular disease, cancer, poor cognitive performance, and other diet-related diseases, as well as for the prevention of micronutrient deficiencies. Much of their potential for disease prevention is thought to be provided by phytochemicals, among which the preventive activity of antioxidants is most well documented. Since numerous meta-studies published indicate variable and often contradictory results about the impact of isolated phytochemicals on health, their consumption as supplements must be carried out with care, because doses may exceed the recommended nutritional intake. Nonetheless, there is a general consensus that whole fruit and vegetable intake is more important in providing health benefits than that of only one of their constituent, because of additive and synergistic effects. This review describes the most recent literature regarding the health benefits of some selected fruits and vegetables. Importantly, since some phytochemicals regulate the same genes and pathways targeted by drugs, diets rich in fruits and vegetables in combination with medical therapies are being considered as novel approaches to treatment. Therefore, phytochemicals in fruits and vegetable might be a promising tool for the prevention and/or amelioration of a wide range of diseases.

Anti-carcinogenic and Anti-bacterial Properties of Selected Spices: Implications in Oral Health

"Let food be thy medicine and medicine be thy food", as said by the father of medicine, Hippocrates in 431 B.C. Nature has provided us with a variety of treatment modalities in the form of food. For the first 5,000 years of civilization, humans relied on herbs and foods for medicine. Only in the past 60 years have we forgotten our medicinal "roots" in favor of patented medicines. While pharmaceutical ingredients have their value, we should not overlook the well-documented, non-toxic and inexpensive healing properties of food. As an individual we consume food several times a day without a complete understanding of its innate qualities. As part of a daily diet, food plays a significant role in helping our bodies function at their best. There are hundreds of extremely nutritious foods, but the items in this article do more than providing healthy nutrients. Many of them consist of ingredients with hidden pharmaceutical qualities ranging from anti-inflammatory to anti-carcinogenic agent. They not only boost our innate immunity but also act as an adjunct to medicines for specific treatment. Prevention and management of symptoms can often be improved significantly through the foods we consume regularly. This paper overviews these beneficial traits of food ingredients, consumed on a daily basis, in various oral diseases.

Functional Polymorphisms in COX-2 Gene Are Correlated with the Risk of Oral Cancer

Background. This meta-analysis investigated the association between functional COX-2 gene polymorphisms and the risk of oral cancer. Methods. Several electronic databases were searched for published studies using combinations of keywords related to COX-2 gene polymorphisms and oral cancer. After selection of relevant studies, following strict inclusion and exclusion criteria, data was performed using STATA 12.0 software. Results. We retrieved 83 studies from database search using specific search terms. After multiple rounds of selection and elimination, 7 studies were finally identified as suitable to be included in our present meta-analysis, based on their relevance and data integrity. These 7 studies contained a combined total of 2,296 oral cancer patients and 3,647 healthy controls. Our findings demonstrated that +837 T > C (rs5275) polymorphism in COX-2 showed statistically significant differences in gene frequencies in case and control groups in allele model and dominant model. Similar results were obtained with COX-2 gene polymorphism 765 G > C (rs20417). On the other hand, 1195 A > G (rs689466) polymorphism in COX-2 did not confer susceptibility to oral cancers. Conclusion. Based on our results, COX-2 gene polymorphisms, +837 T > C (rs5275) and −765G > C (rs20417), showed clear links with oral cancer susceptibility, and the 1195A > G (rs689466) polymorphism did not show such a correlation.

‘Cell junctions of oral mucosa’- in a nutshell

Junctional complexes are specialized contacts between neighboring cells and between cells and the extracellular matrix. They play an important role in embryogenesis, growth and development, as well as being the cause of pathologies. These contacts lead to a number of different interactions that have a profound effect on cellular biology. Cell junctions are best visualized using conventional or freeze-fracture electron microscopy, which reveals the interacting plasma membranes are highly specialized in these regions.

Cell adhesion molecules (CAMs) are proteins responsible for homophillic and heterophillic adhesions. They consist of various groups, including cadherins, selectins and intergrins and they facilitate cell adhesion, cell signaling, and motility. Dysregulation of these molecules can lead to various pathologies, for example mucocutaneous diseases and invasion of cancer. This review focuses on the pathophysiology of cell junctions and related diseases.

Effects of resveratrol and irradiation upon oral squamous cell carcinoma cells

OBJECTIVE

To evaluate the effects of resveratrol and irradiation on oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

Resveratrol was administered at doses of 5, 10, 25, 50 and 100 µM to PE/CA-PJ15 (OSCC) cultures irradiated with different doses (1, 2.5 and 5 Gy). Effects upon cell viability, apoptosis and migration were evaluated after 24, 48 and 72 h incubation.

RESULTS

After 72 h of incubation, the 100 µM dose of resveratrol induced the greatest decrease in cell viability at all irradiation doses. After 24, 48 and 72 h of incubation, 100 µM of resveratrol induced the greatest cell apoptosis at all irradiation doses. The greatest alterations in the distribution of the G0-G1, G2-M and S phases of the cell cycle were recorded with 50 and 100 µM of resveratrol; after 24, 48 and 72 h of incubation, both these doses resulted in an increase in the S phase, at the expense of the G0-G1 and G2-M phases.

CONCLUSIONS

Resveratrol increases cytotoxic activity in the PE/CA-PJ15 cell line and reduces cell migration capacity, while the combination of resveratrol and irradiation exerts a synergic effect.

Effect of various antioxidants on the shear bond strength of composite resin to bleached enamel: An in vitro study

OBJECTIVE

The aim of this in vitro study was to evaluate and compare the effect of 10% sodium ascorbate, 6.5% proanthocyanidin, and 5% lycopene on the bond strength of composite resin to bleached enamel.

MATERIALS AND METHODS

Labial enamel surfaces of 100 extracted human maxillary central incisors were used in this study. Twenty teeth served as group I (control) and received no bleaching treatment. The remaining 80 teeth were randomly divided into four groups of 20 teeth each, based on the antioxidant used as follows: group II- bleaching with 35% carbamide peroxide gel for 30 min without the use of an antioxidant, group III- bleaching followed by use of 10% sodium ascorbate solution, group IV- bleaching followed by use of 6.5% proanthocyanidin, and group V- bleaching followed by use of 5% lycopene. These groups were further subdivided into two subgroups of 10 teeth each, based on whether composite buildup was done immediately (subgroup A) or after a delay of 2 weeks (subgroup B) post bleaching. Shear bond strength of the specimens was tested under universal testing machine. The data were tabulated and statistically analyzed.

RESULTS

Significantly higher shear bond strength values were observed in teeth treated with control group prior to bonding, followed by sodium ascorbate group.

CONCLUSION

Within the limitations of this study, it can be concluded all the antioxidants used in this study increased the bond strength of bleached enamel. Among the antioxidant groups, sodium ascorbate showed significantly higher bond strength compared to proanthocyanidin and lycopene.

Dietary intake of lycopene by the Belgian adult population

OBJECTIVE

Lycopene is a potent antioxidant, and it has been suggested that intake of tomatoes and tomato products containing lycopene is associated with a decreased risk of various chronic diseases. The aim of the present study was to evaluate the distribution of dietary lycopene intake in the Belgian population and to determine the most important contributors to lycopene intake.

DESIGN

Cross-sectional study.

SETTING

National food consumption data from the Belgian Food Consumption Survey (BFCS) 2004 were used for the intake assessment. Determination of the lycopene content in foods was performed with HPLC-UV. Individual food consumption data were multiplied by the actual mean concentrations of lycopene per food.

SUBJECTS

Individuals (n 3083) aged 15 years and older participated in the study and provided two 24 h recalls.

RESULTS

The mean lycopene intake among Belgian adults was 4·1 (sd 2·3) mg/d or 0·059 (sd 0·033) mg/kg body weight per d. Lycopene intake among men (4·6 (sd 2·6) mg/d) was higher than among women (3·6 (sd 2·1) mg/d), and was higher in the younger compared with the older age groups. Cis-lycopene intake represented about one-third of the total lycopene intake. Tomatoes and tomato products (43%) and sauces and ready-to-eat meals containing tomato sauces (41%) were the main contributors to lycopene intake in Belgium.

CONCLUSIONS

The lycopene intake of the Belgian adult population was comparable to intakes reported in neighbouring countries and was below the acceptable daily intake.

The Efficacy of ErCr:YSGG Laser Fibrotomy in Management of Moderate Oral Submucous Fibrosis: A Preliminary Study

INTRODUCTION

Oral submucous fibrosis (OSMF) is a chronic insidious disease mainly associated with fibroelastic change of the oral mucous membrane, leading to progressive trismus and oral burning sensation. The management of OSMF is empirical, depends on staging of the condition and is combination of conservative/medical/surgical interventions. Management of moderate OSMF is more challenging as conservative and medical treatments are not effective while surgical techniques involving fibrotomy and reconstruction of resultant defect are excessive. Lasers can provide an alternative and better means for surgical fibrotomy in moderate OSMF as they are minimally invasive and have the advantage of short operating time, less hemorrhage, faster healing, less morbidity, less surgical-site scarring and relapse. Laser fibrotomy in moderate OSMF have been done under general anesthesia.

MATERIALS AND METHODS

A case series of 16 cases of moderate OSMF treated with Erbium Chromium Yttrium Scandium Gallium Garnet (ErCr:YSGG) laser fibrotomy under local anesthesia in combination with cessation of habits, topical steroids, lycopene and oral physiotherapy is presented.

RESULTS

The mean increase in mouth opening achieved at 1 year was 17.5 mm. The mean difference in the preoperative and 1 year mouth opening was found to be statistically significant. The mean difference in the preoperative and six-month Visual Analogue Scale scores for oral burning sensation and Oral Health Impact Profile-14 scores for assessment of oral health-related quality of life was statistically significant implying improvement.

CONCLUSIONS

ErCr:YSGG laser fibrotomy under local anesthesia is a minimally invasive, cost effective, chair-side procedure and an useful adjunct in management of moderate OSMF.

Synergic effect of curcumin or lycopene with irradiation upon oral squamous cell carcinoma cells

OBJECTIVE

An in vitro study was carried out to evaluate the effect of curcumin, lycopene, and irradiation upon oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

Curcumin and lycopene were administrated at doses of 3, 4.25, 5.50, and 6.75 μM in PE/CA-PJ15 OSCC cultures irradiated with different doses (1, 2.5, and 5 Gy), followed by evaluation of the effects upon cell viability, apoptosis, and migration after 24, 48, and 72 h of incubation.

RESULTS

The application of curcumin or lycopene to the tumor cells during 24, 48, and 72 h without irradiation exerted an inhibitor effect upon cell viability and increased cell apoptosis. The maximum reduction in cell viability and the peak apoptotic effect was recorded with the 5.50 and 6.75 μM doses, for both curcumin and lycopene. Likewise, curcumin and lycopene exerted a synergic effect upon both variables on applying irradiation. Lastly, the 5.50 and 6.75 μM drug doses, together with 5 Gy of irradiation, yielded the greatest decrease in cell migration capacity with both curcumin and lycopene.

CONCLUSIONS

Curcumin and lycopene increase cytotoxic activity in the PE/CA-PJ15 cell line and reduce cell migration capacity, while the combination of curcumin or lycopene with irradiation exerts a synergic effect.

Combinatorial strategies employing nutraceuticals for cancer development

Cancer is the second leading cause of death worldwide. Therefore, the fight against cancer is one of the most important areas of research in medicine, and one that possibly contributes to the increased interest in chemoprevention as an alternative approach to the control of cancer. Cancer prevention by nutraceuticals present in fruits and vegetables has received considerable attention because of their low cost and wide safety margin. A substantial amount of evidence from human, animal, and cell culture studies has shown cancer chemopreventive effects from these natural products. However, single-agent intervention has failed to produce the expected outcome in clinical trials; therefore, combinations of nutraceuticals are gaining increasing popularity. Thus, combinations of nutraceuticals that mimic real-life situations and are competent in targeting multiple targets with very little or virtually no toxicity are needed. In this review, we summarize the results of those studies that report combinatorial cancer chemopreventive action of various nutraceuticals and their combinations with anticancer drugs.