Shahriar Shahi1 , Elham Ahmadian1,2, *
1 Dental and Periodontal Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
2Students’ Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
*Correspondence: Elham Ahmadian, Dental and Periodontal Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. Tel: +98 (41) 33372250, E-mail: ahmadiane@tbzmed.ac.ir
Abstract
Carotenoids are natural pigments abundant in plant-derived food, in particular colorant fruits and vegetables. Lycopene is a well-known carotenoid in tomato which could be detected in serum and in high levels in other tissues such as prostate and adrenal glands. Literature search has fetched protective role of lycopene in different chronic disease such as cancer and heart dysfunction. Oral cancer, periodontal disease, lichen planus and leukoplakia are among the most important disease affecting oral health. Several epidemiological, in vivo and in vitro studies have supported the positive role of lycopene in these ailments. Since lycopene is a potent antioxidant agent, scavenging free radicals via lycopene is deemed to be the chief mechanism of protection. More studies will reveal the beneficial effects of this valuable natural pigment in oral health. This mini review is a short view of the protective role of lycopene in the management of oral disease.
Keywords: Lycopene, oral health, oral cancer, antioxidant, carotenoid
Introduction
Implementation of natural pigments in different coloration techniques is not their sole usage, since these agents encompass several biological functions [1]. Carotenoids are among the most well-known classifications of natural pigments with broadly investigated therapeutic effects [2]. They act commonly as potent antioxidants showing protective role in the preservation of overall individual health. Also, carotenoids show favorable effects in several human diseases such as cancer, cardiovascular dysfunction and oral health.
Lycopene as a powerful antioxidant, is a well-recognizes carotenoid which shows superiority in the management of different disease [1]. Tomato based products as the major sources of this compound inserted into human food chain [3]. It has been documented that lycopene protects against cardiovascular disease via its anti-atherogenic impacts [1]. Moreover, lycopene has been implicated within the reduced risk of prostate, breast and oral cancer [4].
Recent epidemiological surveys, in vivo and in vitro researches as well as clinical trials have proposed the potential role of lycopene in treatment of oral cavity raised disease including periodontal disease and oral cancers [5, 6]. Thus, the aim of the present review is to address the plausible protective role of lycopene in different oral disease such as oral leukopenia, periodontal inflammation and oral cancer.
Lycopene and human health
Due to variability of reported lycopene values in the food source, the ideal intake of lycopene is unknown; although it has been suggested that 6 mg/day of lycopene may be sufficient to promote its beneficial antioxidant properties and at least 5-10 g fat intake is essential for lycopene absorption [7]. Epidemiological studies implicated lycopene has been attributed with therapeutic effects in a wide array of chronic diseases, such as cardiovascular and neurodegenerative, diabetes, asthma as well as cancer [7]. Lycopene has been shown to inhibit several types of cancer, including endometrium, breast and lung. Induction of apoptotic machinery and cell cycle arrest have been observed to occur in prostate cancer cell line after lycopene treatment [8]. Although the exact mechanism of the mentioned cellular events are unclear, the antioxidant role of lycopene is considered to be the chief mechanism since free radicals could induce cancer via stimulation of DNA damages. In addition, lycopene supplements in prostate cancer patients have shown superiority in disease control [9]. Hence, implementation of lycopene as an adjuvant chemotherapeutic/antioxidant agent could be promising in different human cancers and also chronic ailments.
Lycopene and oral cancer
Oral cancer is a dilapidating disease affecting around 600,000 patients worldwide annually with high rate of morbidity and mortality [10]. Based on the reports–year survival rate of oral cancer is approximately 50-60% which relies on several factors such as lifestyle, detection time and the initiative tumor site [11]. Therefore, oral cancer is recognized with poor prognosis. The risk factors of the disease include alcohol and tobacco consumption, dental caries, oral infections and insufficient oral hygiene [12]. Also, the prevalence and annual death of oral cancers cases have been evaluated to be higher in men than women. Thus, searching for novel chemotherapeutic agents with minimal side effects in the control of oral malignancy has drawn interest in last years. It has been reported that fruit and vegetable-rich diets have dramatically reduced the risk of oral cancer [13]. Vegetables containing vitamin A and C have reduced oral cancer incidence as presented in several studies [14]. Lycopene is mainly fund in tomato and tomato-based food products with several beneficiary effect in human disease [15]. Different epidemiological studies have revealed that lycopene could significantly reduce oral cancer rate as clinical trials in different world regions such as china, Italy and Uruguay [16, 17]. Designation of several animal studies have come up with the results that lycopene is implicated in oral cancer prevention. Administration of both tomato and tomato paste could substantially reduce the incidence of buccal pouch carcinogenesis via the attenuation of lipid peroxidation, replenishment of glutathione pools and activation of antioxidant enzymes in hamster [18]. Also, Cheng et al, reported the preventative effects of lycopene and other carotenoids in betel quid extract (BQE)-induced hamster oral cancer model [19].
Emergence of with plaques or patches in oral cavity are defined as leukoplakia which is the most precancerous lesion with the ability of malignancy induction [20]. Tobacco for sure is the most important risk factor of oral leukoplakia [21]. Moreover, tobacco usage play a key role in etiopathogenesis of oral cancer via elevation of reactive species which ultimately induces cancer through genetic alterations. Tobacco cessation along with the consumption of antioxidant agents have been proposed to treat precancerous lesions like leukoplakia [6]. In a study conducted by Nagao et al, fasting serum levels of lycopene and other micronutrient were fund to be lower in leukoplakia suffered men [22]. So, increment of lycopene amount could successfully assist in disease control. Eight mg lycopene for 3 months has efficiently reduced oral leukoplakia against placebo in a clinical trial [ 6] which was confirmed in histopathological analysis.
Lycopene and periodontal disease
Periodontal inflammation is a condition in which augmentation of inflammatory cell infiltration is simultaneous within the occurrence of oxidative hazard. Periodontitis is also in a tight relation with the risk of congestive heart failure. Lycopene consumption has positively affected periodontal problem in these patients [23].
The combination of lycopene along with other antioxidants like Vitamin C potentiates its protective impacts [24] since Vitamin C itself has been shown to mitigate reactive oxygen species formation in periodontal inflammatory conditions [25]. In a clinical study conducted by Chandera et al, 8 mg lycopene daily for 2 weeks was systematically administrated to patient with gingivitis. The result indicated that lycopene effectively reduced inflammation in oral cavity [26].
Lycopene and oral lichen planus
The chronic inflammation of oral muco-cutaneous tissue which afflicts about 4% of global population in known as lichen planus [27]. Induction of oxidative stress and production of free radicals are considered to be the chief mechanism of disease [28]. In spite of application of several treatment regimes, lichen planus complete therapy remains unsolved [29]. The promising results of lycopene in treatment and prevention of different oral cavity raised disease such as oral cancer suggested the possible protective role of lycopene in lichen planus. The serum level of lycopene has been reported to be significantly low in erosive and atrophic lichen planus patients [30]. However, the number of studies in this context are scanty requiring further investigations. Figure 1 depicts the protective role of lycopene in different oral disease.
Figure 1. The protective role of lycopene in prevention and treatment of different oral disease.Lycopene exerts its protective role via the free radical scavenging properties reported in different studies.
Conclusion
Since large amounts of lycopene administration has not shown any side effect on human, it is considered to be a safe supplement or even treating agent in several disease especially in oxidative stress related problems. Involvement of oxidative damage in different oral cavity related disease make lycopene a promising candidate in this issue. In spite of obtained positive results in this context, more studies are needed to clarify the exact mechanism of action in modulation of oral health.
Conflict of interest
The authors have no conflict of interest.
References