Agro-pesticides Use in Cameroon and Their Effect on Male Reproductive Function a Case Study in Djutitsa

Pesticides are increasingly used worldwide to enable increase production of higher quality crops and the elimination of some diseases. Unfortunately, these chemicals intended to cause harm or death to certain pests are also toxic to humans. Although this is evidenced by many epidemiological studies carried out in developed countries, less is still known about the associated degradation of health status in the developing world where very few studies have been hitherto undertaken. Therefore, we proposed to investigate the effect of exposure to some agropesticides on male reproductive function. The study was approved by the Cameroon Ethical Committee. Male farmers in Djutitsa (west-Cameroon) were submitted to a questionnaire on their health status and pesticides use in agriculture. Thereafter, their blood samples were collected for assessment of sex hormones, including serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), androstenedione, testosterone and sex hormone binding globulin (SHBG). Their serum triiodothyronine (T3) and thyroxin (T4) levels were also measured. A control group of men not exposed to agropesticides were recruited in Yaounde for the analysis of the same parameters. Twenty five different pesticides commercialised on 49 names were currently used by farmers enrolled in our study, and most their symptoms related to spread/use of these chemicals indicated affection of respiratory and nervous system. Compared to the control group, there was no significant difference of peptides (FSH, LH and SHBG) as well as thyroid hormones levels (T3 and T4). Farmers had significantly lower serum testosterone (20.60 ± 0.96 nM vs. 24.55 ± 1.25 nM; p<0.05) and higher androstenedione level (3.74 ± 0.18 nM vs. 2.92 ± 0.16 nM; p<0.05). Also, their serum free testosterone as well as bio available testosterone were lower (p<0.05). Two most used pesticides by the farmers, namely Maneb (Manganese ethylenebis (dithiocarbamate) (polymeric)) and Cypermethrin (RS9-alpha-cyano-3phenoxybenzyl (1RS) cis-trans-32,2-dichlorovinyl)-2,2dimethyl-cyclopropane carboxylate) were investigated on their effects on testosterone release by rat purified Leydig cells culture. The first was found to inhibit testosterone production and a concentration of 20 μM, whereas the mixture of both pesticides did not have any effect. Maneb also antagonized the effect of forskolin, hCG, 8-Br-cAMP, androstenedione and A23187. Our results suggest that agropesticides use in Djutitsa (West Cameroon) alter male reproductive function through inhibition of testosterone synthesis, probably by inhibiting the activity of 17ß-hydroxysteroidogenase or altering the effects of other leydig cells modulator.