Evaluation of the cytotoxic activity of extracts from medicinal plants used for the treatment of malaria in Kagera and Lindi regions, Tanzania.

A number of medicinal plants used for treatment of malaria in Tanzania have been documented, but information on their safety and efficacy is still based on traditional knowledge accumulated over years and not on pre-clinical and clinical evaluation. The present study aimed to assess the cytotoxic activity of extracts of selected plant species used for treatment of malaria in Tanzania. Ethanol extracts were evaluated for cytoxicity by using MTT assay on LLC-MK2 cells and by brine shrimp lethality assay. Forty five (93.75%) out of 48 crude extracts assessed using LLC-MK2 cells were non-cytotoxic while three extracts (6.25%) were cytotoxic with CC50 <30 μg/mL (cut-off point). In the brine shrimp assay 30 (65.2%) out of 46 extracts tested were non-toxic while 16 extracts (34.8%) were toxic (LC50 <100 μg/mL). Antiaris toxicaria stem bark extract was the most cytotoxic to mammalian cells. This study demonstrates that, most of the antimalarial plants tested were non-toxic. These observations corroborate with traditional healers’ claims that the herbal medicines used in their areas are safe. However, further studies using different toxicity models are suggested to further confirm their claims.

Reserva hormonal en tumores hipofisarios no funcionantes. / Hormonal reserve in nonfunctioning hypophyseal tumors

Se establecio el perfil hormonal anterohipofisario en portadores de tumores hipofisarios (TH) no funcionantes. Se incluyeron 27 pacientes consecutivos con TH posteriormente operado; 21 cromofobos, 5 eosinofilos y 1 craneofaringioma; edades: 18 a 63 anos; 17 mujeres. Los resultados se analizaron estadisticamente asignandoseles indices de sensibilidad y especificidad. La alteracion de mayor prevalencia en ambos sexos fue la disminucion de la LH basal, seguida por su falta de respuesta al LH-RH. En mujeres, la prolactinemia basal -PRL B- (media 366.25 +/- 321.43) tuvo el mismo valor indicador que la LH basal. En varones la PRL B (media DS 59.7 +/- 75.37) mostro alta sensibilidad pero baja especificidad. Atribuimos esta diferencia a que la mayoria de los TH masculinos, presentaban silla turca muy agrandada, encontrandose relacion inversa entre PRL B y area selar. La somatotrofina mostro alta incidencia de respuestas patologicas post ejercicio o L-Dopa, pero esto se relativizo por la alta frecuencia de falsos negativos en controles normales. 4/8 pacientes con respuestas negativas mostraron respuesta normal al glucagon. FSH, TSH y cortisol evidenciaron poca utilidad para la deteccion de TH. Estos hallazgos aportan al diagnostico precoz de pacientes con clinica sugestiva de TH cuya radiologia selar no muestra aun evidencia de su presencia