EFFECTS OF CHLOROFORM EXTRACT OF CARICA PAPAYA SEED ON PREGNANCY OUTCOME AND POSTNATAL DEVELOPMENT IN RATS

Abstract

Increasing frequency of reproductive disorders has been attributed to exposure to harmful exogenous substances during pregnancy. Studies have shown that Carica papaya seed inhibits fertility in male and oestrous cycle of female rat. There is paucity of information on reproductive effects of C. papaya seed exposure during pregnancy and offspring development. The effect of Chloroform Extract of C. papaya Seeds (CECS) and its purified compounds on pregnancy and offspring development were evaluated. Phytochemical analysis, acute toxicity and Gas Chromatography-Mass Spectroscopy (GCMS) of CECS were carried out using standard methods. Pregnant wistar rats (190-220g, n=110) were administered 50mg/kg CECS during the first (D7), second (D14) and third (D21) trimesters of pregnancy. Pre-coital group served as control and received 1mL/kg olive oil. In another experiment (190-220g, n=25), pregnant rats were divided into three (first, second and third) trimesters and were continuously treated with 1000mg/kg of one of the purified compounds of CECS. Rats delivered naturally and pups were studied for post-natal variables from birth to puberty. Body weights, Anogenital Index (AGI), somatic and pubertal landmarks were measured using vernier calliper. Sperm motility, count and viability were assessed microscopically. Hormones (Testosterone, Luteinizing Hormone, Follicle-Stimulating Hormone, Prolactin, Corticosterone) and antioxidants markers (Superoxide Dismutase and Glutathione Peroxidase) were measured by Enzyme Immunosorbent assay and spectrophotometer respectively. Testicular histology was done using haematoxylin and eosin stains. Data were analysed using descriptive statistics, ANOVA and Student’s t-test at p=0.05. Alkaloids, polyphenols, saponins, flavonoids were identified, while the GCMS analysis yielded oleic acid (40.7%), cis-13-octadecenoic acid (27.9%), cis-vaccenic acid (20.7%), trans-13-octadecenoic acid (6.0%), n-hexadecanoic acid (2.4%) and tetradecanoic acid (1.8%). There was no mortality with CECS treatment up to 3000mg/kg and OA treatment up to 2000mg/kg. Pregnancy outcome showed significant increase in gestation length of OA treated dams. Litter sizes in CECS (7.5±0.1, 7.5±0.8, 5.5±0.9) and OA (5.5±0.9, 7.5±0.8, 5.5±0.9, 3.5±0.1) groups were significantly reduced when compared with the control (10.7±0.6). Body weight of CECS offspring significantly increased while OA offspring had alterations from birth to puberty. The AGI on post-natal D4 significantly reduced in OA (1.9±0.0) and CECS D14 (1.8±0.0) offspring when compared with the control (2.3±0.1). Significant delay occurred in day of eye opening and fur appearance in CECS and OA offspring. Puberty onset was significantly delayed in OA and CECS D14 offspring while CECS pretreated offspring had an earlier onset. Corticosterone level in OA, CECS pretreated offspring increased. Follicle-stimulating hormone significantly decreased in OA offspring and in CECS pretreatment and D14 offspring of treated dams. Luteinizing hormone was decreased in OA and increased in CECS offspring. Testosterone level, sperm motility, count and viability were significantly decreased in all offspring. Offspring treated with OA had reduced testicular prolactin level. The superoxide dismutase (3.9±0.1 and 2.8±0.0) and glutathione peroxidase (8.8±0.8 and 0.6±0.0) were significantly reduced in CECS and OA offspring compared with control (8.2±0.6 and 19.2±1.5) respectively. Continuous exposure of rat to chloroform extract of Carica papaya seed and oleic acid for two trimesters showed foetotoxic effect.