Search

Berberine, an alkaloid from Berberis aristata Linnaeus, may be a useful drug for the treatment of visceral leishmaniasis. In both the 8-day and long-term models of Leishmania donovani infection in hamsters, it markedly diminished the parasitic load and proved to be less toxic than pentamidine. It rapidly improved the hematological picture of infected animals. Like pentamidine, it inhibited in vitro multiplication of amastigotes in macrophage culture and their transformation to promastigotes in cell free culture. Manometric studies showed that both drugs had inhibitory action on both the endogenous and the glucose-stimulated respiration of amastigotes. They inhibited incorporation of [14C]adenine, [14C]uracil, and [3H]thymidine into nucleic acids, and of [14C]leucine into the protein of amastigotes, indicating an inhibitory action on macromolecular biosynthesis. They also decreased deoxyglucose uptake. Using spectrophotometric, spectrofluorimetric, and circular dichroism techniques, berberine was found to interact in vitro with nuclear DNA from L. donovani promastigotes.

Summary Lactic dehydrogenase, alkaline phosphatase and a magnesium-independent adenosine triphosphatase were assayed in normal, diarrhoeal and cholera stools. The diarrhoeas, examined bacteriologically, included bacillary dysentery, salmonellosis, amoebiasis and non-specific gastro-enteritis. Alkaline phosphatase levels were found to be similar in normal and cholera stools, whereas lactic dehydrogenase was 30-fold higher and adenosine triphosphatase four-fold higher in cholera. The distribution of activity of lactic dehydrogenase was higher, and of the phosphatases lower in cholera than in the stools of bacterial infections showing evidence of tissue necrosis. The levels of activity of all three enzymes in cholera stool were found to reach a maximum between 9 and 17 hr after onset of purging. It is suggested that these findings indicate an increased permeability of the intestinal epithelium in cholera, leading to a leak of cell enzymes into the intestinal lumen.