Cytotoxic activity of the dichloromethane fraction from Vernonia scorpioides (Lam.) Pers. (Asteraceae) against Ehrlich's tumor cells in mice

Vernonia scorpioides has been widely used in Brazil to treat skin problems and chronic wounds, such as ulcers of the lower limbs and diabetic lesions. In the present study, we investigated the effect of a dichloromethane (DCM) fraction of V. scorpioides leaf extract on Ehrlich ascitic and solid tumor-bearing mice. The animals were treated once a day with the DCM fraction at a concentration of 5 mg/kg, administered ip during and after the development of the tumor. The lifespan, weight, number and type of leukocytes, number of tumor cells, volume of solid and ascitic tumors were measured. The development of the tumor with pre-treated tumor cells in vitro with the DCM fraction (5 mg/kg) was analyzed and the animals were sacrificed after 7 days. The DCM fraction (5 mg/kg) totally inhibited tumor development when in direct contact with tumor cells, and also ascitic tumor development with in vitro treatment or when administered ip, in loco (after 7 days). Animals treated with the DCM fraction increased their lifespan ca. 2 weeks and maintained their body weight for 30 days. When applied immediately after the inoculation of the tumor cells in vivo, it totally abolished tumor development, with tumor development only decreasing when treatment was started 3 days after the tumor challenge. These data suggest an antineoplastic activity of the fraction. Oral or ip administration of DCM fraction (5 mg/kg) for 7 days did not reduce the solid tumor volume. The cytotoxic activity described here differs from the conventional immune suppressing profile of standard chemotherapy because it increases neutrophil influx to the peritoneal cavity. These results show that, besides exhibiting a tumoricidal activity, the DCM fraction also exhibits inflammatory activity.

Effects of the topical application of the extract of Vernonia scorpioides on excisional wounds in mice

Vernonia scorpioides is traditionally widely used in Brazil to treat skin problems, including healing of chronic wounds, such as ulcers of the lower limbs and diabetic wounds. This work investigated the healing process on excisional wounds in the skin of mice, treated daily with an ointment containing 20 percent of the ethanol extract of the leaves of Vernonia scorpioides, compared with the control. A skin wound area of about 4 mm was excised on anaesthetised mice, and after 3, 7 and 14 days of treatment, the lesions were surgically removed and histologically processed. Wound healing activity was determined by the percentage of necrosis area, mononuclear inflammatory cells, fibroblasts and blood vessels. In the acute phase of healing, treatment with piracá extract enlarged the lesions and intensified the necrosis area, compared with the control group. However, the treatment did not inhibit either the recruitment and stimulation of inflammatory cells or the repair process. The results obtained indicate a harmful action of the extract immediately after tissue excision, demonstrated by the increased area of necrotic tissue, clotting and exudates formed in the treated groups. However, the extract did not inhibit the formation of granulation tissue.