Male rat infertility induction/spermatozoa and epididymal plasma abnormalities after oral administration of Kalanchoe gastonis bonnieri natural juice.

Natural aqueous crude extracts (NACE) of several Crassulaceae family plants have been applied as a vaginal contraceptive by the populace. The aim of this work was to evaluate the inhibition of fertility in male Wistar rats and some physiological and biochemical changes in spermatozoa and epididymal plasma induced by NACE from Kalanchoe gastonis bonnieri (K. g. b.) (Crassulaceae). The NACE was obtained by mechanic pressure on grinding fresh plant leaves. Sublethal doses (150-300 mg/kg body weight) of NACE were orally administered to adult and fertile male rats daily for 30 days in a search for a contraceptive effect, and physiological and biochemical modifications on sperm cells and cauda epididymal plasma. The toxicity studies revealed that the lethal dose (LD(50)) calculated was 11 g/kg body weight. Sublethal doses induced 50%-100% fertility inhibition, with 100% recovery of fertility 30 days after stopping the treatment. The sperm motility, viability and spermatic density were also significantly decreased (p < 0.001). The outstanding biochemical change observed in the cauda epididymal plasma was a decrease of carnitine concentration. The NACE of K. gastonis contains one substance active on fertility by affecting spermatozoa motility, viability and sperm density with a significantly decreased carnitine and sialic acid (p < 0.001) in the caudal epididymal plasma. Copyright 2003 John Wiley & Sons, Ltd.