Floresta e Ambiente PLUMBAGINALES: A PHARMACOLOGICAL APPROACH Selma Ribeiro de Paiva1,2 Shirley da Silva Marques2,3 Maria Raquel Figueiredo2 Maria Auxiliadora Coelho Kaplan4 ABSTRACT lumbaginales belongs to the superorder Malviflorae and comprises two families, Plumbaginaceae and Limoniaceae. Its representatives are chemically characterized by the presence of P naphthoquinones, flavonoids, terpenoids and steroids, many of them being the responsible for biodynamic activities. The extracts of some species of Plumbaginales and also some isolated compounds revealed to be of great importance in the search of new drugs, since they have been described in literature for the treatment of many diseases such as: leishmaniasis, Chagas´ disease, malaria, cancer and others. Plants represent a valuable source of bioactive compounds and should be investigated, as a promise in the development of effective, ready available and lesscostly drugs Key words: Malviflorae, Plumbaginales, biological activities INTRODUCTION Some species of Plumbaginales have been studied on the medicinal point of view and the The limited available treatment for many results demonstrated a wide variety of biological diseases and the spread of drug resistance uses, most of them related to the presence of the emphasize the need for new therapeutic agents. It naphthoquinone plumbagin. is well known that the plant kingdom is a great This brief review covers the most important source of bioactive compounds, but in despite of biological properties of Plumbaginales species, the large amount of species, only a few of them demonstrating their great potential. has been studied in this sense. Plumbaginales belongs to the superorder Chemical and pharmacological search Malviflorae and comprises two families, Plumbaginaceae and Limoniaceae, according to The search was made in scientific reference Dahlgren (1980). It is represented by herbs and works as Chemical Abstracts (1907-2003), shrubs with a cosmopolitan distribution. Biological Abstracts (1980-2002), Web of Science Chemically, Plumbaginales is mainly characterized (1945-2003) and PubMed (1960-2003). Abstracts, by the presence of naphthoquinones, flavonoids, articles and reviews were the base for the terpenoids and steroids, the first ones being organization of the data bank on chemical considered as chemical markers (Paiva, 1999). composition, biological activities and 1 Programa de Pós-Graduação em Biotecnologia Vegetal, Universidade Federal do Rio de Janeiro 2 Laboratório de Química de produtos Naturais, Far-Manguinhos, FIOCRUZ; Rua Sizenando Nabuco, 100, Manguinhos, Rio de Janeiro, Brasil. 21041-250. E-mail: [email protected] 3 Programa de Vocação Científica, EPSJV, FIOCRUZ 4 Núcleo de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro. Recebido para publicação em 2003 98 V. 10, n.1, p.98 - 105, jan./jul. 2003 Floresta e Ambiente pharmacological uses of Plumbaginales. The data and gastrointestinal sequelae (Pereira, 1983). were divided into several groups according to the Plumbagin exhibited high potency (IC90= 1-5 following activites: leihsmanicidal, trypanocidal, ìg/ml) against six strains of T. cruzi epimastigotes, antimalarial, antiviral, antitumoral, microbiological while the dimers 3,3’-bisplumbagin and 8,8’- and inseticide. The other activities not cited bisplumbagin were less effective, with IC90 in the before were joined into a separate group, named 25-100 ìg/ml range. In this assay nifurtimox and others. benznidazole, the only drugs used in the early stages of the disease, also showed IC90 values of Leishmanicidal Activity 25-100 ìg/ml (Sepúlveda-Bozza & Cassels, 1996). Leishmaniasis is one of the major public health Antimalarial Activity problem, with two to three million humans affect by the disease annually (Iwu et al., 1994). It is a The treatment and prevention of human malaria group of tropical diseases caused by a number of reached a lot of difficulties due to the high species of protozoan parasites belonging to the endemicity of the disease in Amazonia, the new genus Leishmania. The World Health focuses in response to the intense migration and Organization classify leishmaniasis in four clinical the resistence of Plasmodium falciparum to forms: visceral, mucocutaneous, cutaneous chlorochin as well as to other usual drugs. diffuse or disseminated cutaneous (Chan-Bacab Plumbago zeylanica has been used in the & Peña-Rodríguez, 2001). traditional medicine against malaria and its In the case of leishmaniasis, Plumbago ethanolic extract has shown high in vitro activity, species have been shown to contain compounds being of special interest for further investigations with significant activity. The quinones (Simonsen et al., 2001) corresponds to promising antileishmanial Plumbagin shows also antimalarial effects. substances. Suraveratum et al. (2000) isolated a Plasmodium The ethanolic stem extract of Plumbago falciparum enzyme, the succinate dehydrogenase scandens inhibited the growth of Leishmania (SDH) from which the activity has been 50% amazonensis promastigotes by 88% at 100ìg/ml. inhibited by the naphthoquinone plumbagin at an At the same concentration the amastigote growth inhibitory concentration of 5mM. It also inhibited was inhibited by 61% (Santos et al., 1997). the in vitro growth of the parasite with a 50% Plumbagin, a naphthoquinone isolated from inhibitory concentration of 0,27mM. Plumbago species is reported to have an activity ì Antiviral activity (IC50) of 0.42 and 1.1 g/ml against amastigotes of Leishmania donovani and L. amazonensis (Chan- Bacab & Peña-Rodríguez, 2001). Plumbagin and Viruses are constituted basically by proteins its dimers, 3,3’-bisplumbagin and 8,8’- and nucleic acids and are reponsible for many bisplumbagin have been used in the treatment of diseases from a common cold till more serious cutaneous leishmaniasis in Amazonian Bolivia diseases as AIDS (Acquired Imuno Deficiency (Sepúlveda-Bozza & Cassels, 1996). Syndrome), small-pox and poliomyelitis. Preliminary biological screening indicated that Trypanocidal Activity the ethanolic extract of the root of Limonium sinense showed potent suppressory effect on Chagas´ disease is a complex clinical problem herpes simplex virus type-1 (HSV-1) replication. caused by the flagellate protozoan Trypanosoma Two constituents, (-)-epigallocatechin 3-O-gallate cruzi. This microorganism is a mostly intracellular and samarangenin B, isolated from the L. sinense parasite, able to infect a broad range of vertebrates. extract demonstrated activity against HSV-1, The disease is characterized by an acute illness showing higher inhibitory effects than the positive that is followed in some patients by chronic cardiac control acyclovir (Lin et al., 1999). Generally, V. 10, n.1, p.98 - 105, jan./jul. 2003 99 Floresta e Ambiente quinones are responsible for the plant activity, Antitumoral Activity however in this case, flavonoids were reported as the active molecules. The tumor is formed by cells with defects in In the search for novel anti-human the mithotic cycle. The transformation of a normal immunodeficiency virus type I (anti HIV-1) agents cell into a tumor cell is frequently caused by DNA from natural sources, the methanol root extract of alteration, with the participation of a virus, Limonium tetragonum was screened for its chemical compounds or physical agents as certain inhibitory effect against RNA-dependent DNA- types of radiation (Junqueira & Carneiro, 2000). polymerase (RT). The extract showed significant Some Plumbaginales species has been inhibitory activity on RT activity with 50% described to possess antitumoral activity. Several inhibitory activity (IC50) of 7,5ìg/ml (Min et al., types of tumors and carcinomas has been used in 2001). tests with plant extracts and drugs isolated from them, as it could be seen in table 1. Table 1. Antitumoral effect of plant extracts and compounds from Plumbaginales. Plant Plant Organ/ Type of Results Reference Extr ac t/ tumors Compound Plumbago rosea Roots S-180 solid The extract have only a weak tumor (Devi et al., (syn. P. indica) ethanolic extract tumor and effect, it may be a good candidate for 1994) Ehrlich use with radiation to enhance the tumor ascites killing effect carcinoma Limonium axillare Geraniin The tannin s howed a slightly higher (Ahmed et al. , activity than the extract 1999) Limonium axillare Leaves Ehrlich ascites Active with ED50=19.5±1.50 (in vitro) (Kandil et al. , alcoholic extract carcinoma In vivo, the mean survival time of the 2000) treated mice was 23 days while that of control was 10 days only Limonium axillare Myricetin-3-O-β- Ehrlich ascites Active with ED50=17.8±1.20 (in vitro) (Kandil et al. , D-sorboside carcinoma In vivo, the mean survival time of the 2000) treated mice was 24 days while that of control was 10 days Plumbagosp. Plumbagin Dalton´s After 14 days, plumbagin-treated groups (Kavimani et a. , ascitic were able to reverse the changes in 1996) lymphoma hematological parameters and proteins, consequent to tumor inoculation The leaf alcoholic extract of Limonium axillare many types of leukemia and cancer such as: non- and a flavonol glycoside (myricetin-3-O-â-D- small cell lung cancer, colon cancer, CNS cancer, sorboside) were used in cytotoxic assays. Many melanoma, ovarian cancer, prostate cancer, renal types of cells lines were used, corresponding to cancer and breast cancer. The results indicated 100 V. 10, n.1, p.98 - 105, jan./jul. 2003 Floresta e Ambiente that the isolated compound was more active than depending on its