2.2.2. Determination of Median Lethal Dose (LD50)
LD50 of the alcoholic extract (70%) of Pteranthus dichotomus was determined [12]. Albino
mice (25-30 g) were divided into groups each of 5 animals. Preliminary experiments were done to
determine the minimal dose that kills all mice and the maximal dose that fails to kill any animal.
Animals were kept under observation for 24 h during which symptoms of toxicity and rate of
mortality were recorded.