ABSTRACT
1Hematology and Stem Cell Transplantation Unit, IRCCS Centro di Riferimento Oncologico della Regione Basilicata (CROB), Rionero in Vulture (Pz)
2Department of Clinical Experimental Medicine and Pharmacology, University of Messina
3Department of Pharmaceutical and Biomedical Sciences, University of Salerno
Medicinal herbs are extensively used in patients with cancer. This complementary and alternative medicine is become particularly popular among patients with hematological malignancies [1,2]. Moreover, the costs associated to these therapies are not minimal. Several questions arose from the use of natural drugs in the treatment of the neoplastic disease of the blood. First of all, the interference with chemotherapy concurrently given is not well completely understood. For instance, despite the anti-tumour properties of green tea and its active ingredient, epigallocatechin gallate, there are some evidences that this constituent is able to block the effects of bortezomib, a drug now increasingly used to treat multiple myeloma patients. On the contrary, it has been reported that the same compound induce apoptosis and cell death when combined with bortezomib. A second issue is the real clinical efficacy of these compounds. In fact, evidence for herbal efficacy is mostly limited to in vitro rather than clinical studies even if the number of literature reports is increasing. A critical point concerns the safety in the use of these compounds, particularly in cancer patients. Another issue to be addressed is the possibility to give a natural compound in the setting of prevention of disease progression in pathologic conditions in which a 'wait and see' policy is scheduled at diagnosis. This is the case of chronic lymphocytic leukemia, monoclonal gammopathy of uncertain significance, and stage IA multiple myeloma, as well. In these conditions, a treatment is scheduled when the disease progress to a overt malignancy and the possibility to find a natural compound able to prolong the time to treatment is a very important issue. We are conducting a trial in which green tea is daily given to patients with early stage CLL to verify whether a reduction of the number of circulating tumoral lymphocytses and regulatory T-cells, as well, is seen. Moreover, we showed the ability of Verbena officinalis essential oil and citral, its major constituent, to induce apoptosis in CLL cells in vitro, via the activation of Caspase-3 [3,4]. Results of these studies may have implications both for primary prevention of hematologic malignancies and for treatment and/or recurrence prevention.
[1] Hamblin T (2006) Natural products and the treatment of leukemia. Leuk Res 30, 649-650.
[2] De Martino et al. (2011) Natural compounds in anti-leukaemic therapy: a review. Mini Reviews in Medicinal Chemistry, in press.
[3] De Martino et al. (2009) Verbena officinalisand its component citral as apoptotic inducing agent in chronic lymphocytic leukemia.International Journal of Immunopathology and Pharmacology 22,1097-1104.
[4] De Martino et al. (2011) Active caspase-3 detection to evaluate apoptosis induced by Verbena officinalis essential oil and citral in chronic lymphocytic leukemia. Braz J Pharmacogn, in press.