Leishmanicidal, trypanocidal, and cytotoxic activities of endophytic fungi associated with bioactive plants in Brazil

One hundred and twenty-one isolates of endophytic fungi were recovered from leaves of the bioactive Brazilian plant species Ageratum myriadenia, Palicourea tetraphylla, Piptadenia adiantoides, and Trixis vauthieri. All fungal isolates were cultivated in liquid media and crude extracts were obtained with ethyl acetate. The crude extracts were tested in bioassay panels using Leishmania amazonensis, Trypanosoma cruzi, the enzyme trypanothione reductase (TryR) from Trypanosoma cruzi, and three human cancer cell lines. Thirty-three extracts (27.2 percent) exhibited at least one biological activity. Seventeen extracts (14 percent) were cytotoxic against one or more human cancer cell line with the IC50 values ranged of >0.2 to 25 µg/mL. Twenty-four extracts (19.8 percent) inhibited the activity of TryR, and three showed ability to inhibit the growth of T. cruzi above 60 percent and their IC50 values ranged among 1 to 10 µg/mL. Eleven extracts (9 percent) were able to inhibit the growth of L. amazonensis and showed with IC50 values ranged among 4.6 to 24.4 µg/mL. The endophytic fungi were identified as belonging to the genera Alternaria, Arthrinium, Cochliobolus, Colletotrichum, Penicillium, Fusarium, and Gibberella. An interesting result was obtained for the bioactive isolates UFMGCB 508, 537, 899 and 903, which were related to fungi associated with medicinal plants native to Asia, Australia, Africa, and Polynesia. These results indicate that bioactive plants living in Brazilian ecosystems are a potential host of endophytic fungi able to produce bioactive prototype molecules for drug development against neglected tropical diseases.

Lesion aspirate culture for the diagnosis and isolation of Leishmania spp. from patients with cutaneous leishmaniasis

The detection of Leishmania spp. in skin lesion aspirates, using a puncture technique, was evaluated in 76 patients with cutaneous leishmaniasis (CL) who were referred to a Leishmaniasis Reference Centre in Brazil. CL was defined based on skin lesions suggestive of the disease and on a positive result of the Montenegro skin test or Giemsa-stained imprints of biopsy fragments. The aspirates were cultured using a vacuum tube device containing culture medium and evaluated for the presence of Leishmania spp. The biphasic medium culture was examined once a week for three weeks. Promastigotes were observed in 53/76 (69.7 percent) cultures. Stained smears from 60 of the 76 patients were evaluated using PCR-RFLP to detect the conserved minicircle region of Leishmania spp. and to classify the parasite. Of these patients, 45 (75 percent) showed positive results in aspirate culture and 15 presented negative results. The PCR was positive in 80 percent (53/60) samples. The PCR-RFLP profile was determined in 49 samples, of which 45 (92 percent) showed a pattern compatible with Leishmania (Viannia) braziliensis. The aspirate culture is a sensitive and feasible method for diagnosing CL and may be routinely adopted by health services for L. (V.) braziliensis isolation and identification.