Through the Microscope: MAHSA Researchers Shed Preliminary Light on Effect of Extract from Yemen's Dragon Blood Tree in Prevention of Oral Cancer
The most commonly seen human cancers in the world are oral squamous cell carcinoma (OSCC). Approximately 60–70% of the cases of oral cavity carcinoma are diagnosed once the tumours have become locally progressive. OSCC represent over 90% of these oral cancers which arise in the mucosal (epithelium) lining of the oral cavity, pharynx, and larynx. The World Health Organization (WHO) stated that cancer of oral cavity has one of the highest ratios of mortality among all malignancies due to the extensive local invasion and distant metastasis even at initial diagnosis. However, in a recent study titled Prevention of oral carcinogenesis in rats by Dracaena cinnabari resin extracts conducted by MAHSA University’s researcher from the Faculty of Dentistry, Dr Aied Mohammed, with four of his peers, Dr Nashwan Al-Afifi , Dr. Fahmi Kaid , Dr. Marina Bakri1 of the Department of Oral and Craniofacial Sciences, Faculty of Dentistry, University of Malaya, Malaysia, and Dr Anand Ramanathan of the Department of Oral & Maxillofacial Clinical Sciences, Faculty of Dentistry, University of Malaya, Malaysia, new insights into systemic administration of the DC resin methanol extract has anticarcinogenic potency on oral carcinogenesis.
The incidence of oral cancer is increasing in many countries mainly because of the prevalence of risk-associated behaviour’s (e.g., smoking and alcohol consumption). Alcohol itself is not carcinogenic but can be metabolized by the human or microorganisms in the oral cavity, via acetaldehyde dehydrogenase activity to produce acetaldehyde, a well known carcinogen. In many Asian countries including Malaysia, betel quid chewing plays an essential role in the development of oral cancer. Importantly, the mortality ratios do not take into consideration a serious morbidity arising from the facial defacement and aerodigestive dysfunction related to surgery/radiotherapy. Unfortunately, unacceptable results are always related to the commonly used cancer chemotherapy, as the therapy is detrimental to patient health by making patients more vulnerable to other diseases and often cause death by debilitating the immune system of the patient. In addition, the recurrence of tumours and the poor prognosis for patients due to the drug-resistant cancer cells stay alive after chemotherapy. The occurrence of drug resistance results in the failure of tumour treatment. Therefore, healthcare represents a major prevention role of this malignancy.
This study involves administration of 4NQO solution for 8 weeks alone (cancer induction) or with Dracaena cinnabari (DC) extract at 100, 500, and 1000 mg/kg. DC extract administration started 1 week before exposure until 1 week after the carcinogen exposure was stopped. All rats were sacrificed after 22 weeks, and histological analysis was performed to assess any incidence of pathological changes. Immunohistochemical expressions of selected tumour marker antibodies were analysed using an image analyser computer system, and the expression of selected genes involved in apoptosis and proliferative mechanism related to oral cancer were evaluated using RT2 –PCR.
The research specifies that the incidence of OSCC decreased with the administration of DC extract at 100, 500, and 1000 mg/kg compared to the induced cancer group. The developed tumour was also observed to be smaller when compared to the induced cancer group. The DC 1000 mg/kg group inhibits the expression of Cyclin D1, Ki-67, Bcl-2, and p53 proteins. It was observed that DC 1000 mg/kg induced apoptosis by upregulation of Bax and Casp3 genes and downregulation of Tp53, Bcl-2, Cox-2, Cyclin D1, and EGFR genes when compared to the induced cancer group.
The results of the present study highlighted that the DC extract possesses anticarcinogenic potency on the oral carcinogenesis and has the potential to be developed as an anticancer agent for oral cancer. Chemopreventive efficacy was expressed as body weight gain maintained, reduction in oral cancer-related mortality, and reduction in the incidence of OSCC using an animal model. This makes Dracaena cinnabari a promising candidate for further investigation as a natural chemopreventive agent and future clinical trials would benefit the usage and benefits on dragon tree extract as a traditional supplement in treating oral cancer.