Mutagenic potential and modulatory effects of the medicinal plant Luehea divaricata (Malvaceae) in somatic cells of Drosophila melanogaster: SMART/wing.

Luehea divaricata is a native plant of the Brazilian Cerrado, known as "açoita-cavalo". It is used as a popular herbal medicine in the treatment of dysentery, bleeding, arthritis, tumors, ulcers, and gangrenous wounds. Considering that herbal medicines sometimes provoke tumors and/or may prevent mutational events, it is important to study the action of these natural drugs on DNA. Aqueous extract of the bark of L. divaricata was evaluated at three different concentrations (0.10, 0.30, 0.50 mg/mL), individually and in combination with the neoplastic drug doxorubicin (DXR), by the somatic mutation and recombination test (SMART/wing) in Drosophila melanogaster. Distilled water was included as a negative control. The mutation frequency in the treatments with L. divaricata extract alone was not significantly higher than in the negative control for standard (ST) and high bioactivation (HB) crosses. When L. divaricata extract was combined with DXR, there was a significant reduction in the frequency of spots when compared to DXR alone, in both crosses. Further studies with other experimental models would be useful to confirm that L. divaricata extract is not harmful and that it could be used in the prevention of cancer.

Modulatory effect of Palicourea coriacea (Rubiaceae) against damage induced by doxorubicin in somatic cells of Drosophila melanogaster.

Palicourea coriacea, popularly known as "douradinha", is a medicinal plant from the Brazilian Cerrado region used in folk medicine to treat kidney and urethral stones and kidney inflammation. We evaluated the cytotoxic, genotoxic, and possible antigenotoxic activities of an aqueous extract of P. coriacea on somatic cells of Drosophila melanogaster, using the somatic mutation and recombination test. We used third-stage larvae of D. melanogaster from a standard cross and a high bioactivation cross and tested 10 different doses of P. coriacea aqueous extract (5, 15, 25, 35, 50, 65, 80, 95, 110, and 125 mg/mL). Doxorubicin (0.125 mg/mL) was used as a positive control and distilled water as a negative control. None of the doses was lethal to the larvae.There was no genotoxic effect at 5, 10, or 15 mg extract/mL. However, a significant decrease in the frequency of spots induced by doxorubicin was observed when administered with P. coriacea aqueous extract at these same doses. We conclude that P. coriacea aqueous extract is not cytotoxic or genotoxic at these doses, but it does protect against the genotoxic action of doxorubicin.

Modulatory effect of Byrsonima verbascifolia (Malpighiaceae) against damage induced by doxorubicin in somatic cells of Drosophila melanogaster.

Byrsonima verbascifolia, popularly known in Brazil as murici, is a medicinal plant widely used in the treatment of bacterial and viral infections, Chagas's disease, diarrhea, bronchitis, cough and fever, as well as for protection of the intestinal mucosa. Since chemotherapy and radiotherapy, broadly employed in the treatment of cancer, can have undesirable side effects, such as inducing DNA damage in normal cells, it would be useful to investigate compounds that inhibit or reduce these effects. A lyophilized water extract of murici, used at three different concentrations (25, 50, and 100 mg/mL), was tested to determine if it could reduce damage induced by the antineoplastic compound doxorubicin in somatic cells of Drosophila melanogaster, analyzed by SMART/wing. The frequency of mutant spots in descendants from standard and high bioactivation crosses was significantly reduced by treatment with murici extract. Further studies are needed using other experimental models, to determine if murici has the potential to be employed by cancer patients receiving chemotherapy.