SUBLETHAL DOSES OF MALATHION ALTER MALE REPRODUCTIVE PARAMETERS OF Eisenia foetida

Abstract

SUMMARY:Malathion is an organophosphorate insecticide whose main acute poisonous effect is the inhibition of the enzyme acetylcholinesterase. This pesticide is widely used and has been reported to damage mice spermatogenesis. The objective of this work was to evaluate the toxic risk of malathion, earthworm Eisenia foetida (Annelida, Oligochaeta) like biological model was used and testicles and spermatozoa of animal controls and treaties were analyzed. Earthworms with developed clitellum were used and they were dewed with sublethal single doses of 0, 80, 150, 300 and 600mg of malathion for kilogram of soil (LD50 = 880mg/kg dry soil). Control groups were added only distilled water. Each group was analyzed 1, 5, 15 and 30 days post treatment. The results observed in treated animals indicate a significant rise of the number of spermatozoa at 1 and 5 days post treatment, followed by a sperm decrease between 15 and 30 days. Acridine orange method showed a significant increase of abnormal metachromatic spermatozoa in treated animals (red fluorescence). Testicular histology of treated animals showed tissue disorganization and vacuolization, with presence of small and hyperchromatic nuclei, indicative of possible apoptosis. It was also found that malathion caused body contraction characterized by coiled tail. Besides significant alteration in count and quality of spermatozoa were seen. Eisenia foetida is then an excellent model to monitor cytotoxic damage of organophosphate pesticides.

Chronic toxicity of commercial chlorpyrifos to earthworm Pheretima peguana

“…This morula reaches a maximum of 128 germ cells after meiosis due to their synchronous development. Our histomorphological study showed that the spermatogenesis of P. peguana is similar to that in Eisenia fetida (Espinoza‐Navarro and Bustos‐Obregón, ). These morulae have different numbers of cells, which may grow in geometric progression to morulae of spermatogonia, spermatocytes, or spermatids.…”

“…Sorour and Larink () reported that pesticides could damage spermatozoa by altering the ultrastructure of the cytoskeleton of the cytophore and spermatogonial morula, thereby affecting the normal development of spermatogenesis and spermiogenesis. Espinoza‐Navarro and Bustos‐Obregón () reported that malathion affects tissue disorganization, vacuolization, and the presence of small and hyperchromatic nuclei in spermatogonial morulae indicative of possible apoptosis. This is similar to the findings of El‐Kashoury and Tag El‐Din () who reported that testes of chlorpyrifos‐treated albino rats exhibit degeneration and atrophy of nonfunctional seminal tubules and a marked decline in sperm cells within the lumen of seminiferous tubules.…”

“…The effect of pesticides (endosulfan, carbaryl, malathion) on the reproductive organs of some invertebrates ( Hirudo birmanica , Macrobrachium malcolmsoni , Eisenia foetida ) has been investigated (Kulkarni et al, ; Bhavan and Geraldine, ; Espinoza‐Navarro and Bustos‐Obregón, ). However, there is little information available on the effects of these insecticides on spermatogenesis of Pheretima peguana , which is a tropical earthworm most commonly found in Thailand agricultural fields (Gates, ).…”

Effects of Pesticides on the Growth and Reproduction of Earthworm: A Review

“…Ejection of sperm seems also to be hindered and therefore a large number of spermatozoa are found in intoxicated worms in spite of a clear effect on sperm production under parathion treatment as discussed by Bustos-Obregón and Goicochea [3]. According to Espinoza-Navarro and BustosObregon [58] malathion also has a direct cytotoxic effect causing coiling of the tail, with increase of metachromasia of the chromatin of the spermatozoa and altering the sperm count…”

“…Earthworm growth and cocoon production were significantly reduced [36] Malathion (pure) 80.150, 300, 600 mg/kg soil Applied and Environmental Soil Science Espinoza-Navarro and Bustos-Obregón [31] treated Eisenia fetida with organophosphate insecticide malathion and found that malathion decreased the spermatic viability in spermatheca, altering the cell proliferation and modifying the DNA structure of spermatogonia. Sperm count also seems to be a very sensitive marker [42,50], malathion could affect the sperm count, but in addition, its metabolites could affect sperm quality [58].…”