Effets pro-sexuels et repro-toxicité de l’extrait aqueux de Eremomastax speciosa (Acanthaceae) chez le rat

Abstract

Eremomastax speciosa (Hochst) Cufod (Acanthaceae) is a shrub used in traditional medicine to remedy several ailments such as dysentery, microbial infections, anemia, diarrhea, gastric ulcer. This plant is also used for the treatment of infertility problems in men and women. Although the general toxicity studies have been performed on the aqueous extract of this plant, the effects on sexual performance as well as on repro-toxicity have not been studied. The aim of this work was thus to study the pro-sexual effects of the extract and to evaluate the reproductive and developmental toxicity during the three major periods of the reproductive cycle (gametogenesis, organogenesis, perinatal and lactation) in male and female rats. The assessment of copulatory activity consisted in daily administration of the extract (100 and 500mg/kg) to sexually experienced male rats for 14 consecutive days. Sexual behavior (mount, intromission and ejaculation) were measured on days 0; 1; 4; 7 and 14, plus on day 28 (post treatment). The copulatory activity rats given a single dose (500 mg/kg) of the extract were also evaluated after pretreatment with Lω-NAME (10 mg/kg), haloperidol (1 mg/kg), or Atropine (5 mg/kg). To evaluate the effects of E. speciosa administered during gametogenesis, 36 male and 36 female albino rats were divided into groups of nine rats each.Males and females received the extract at doses of 0; 250; 500 and 1000 mg/kg for 60 and 14 days, respectively, followed by a 10 days fertility study with a male and a treated female an untreated female. Thirty-six other female rats were treated with the extract at doses of 0; 250; 500 and 1000 mg/kg (14 days) and were crossed with untreated males. The effects of the extract on sperm characteristics, fertility parameters, and body and organs weights were assessed. To evaluate the effects of the extract administered during organogenesis (day 6 to day 15 of gestation), 48 rats divided into 4 groups of 12 animals each received the extract at the different doses. Developmental parameters, skeletal and visceral abnormalities were evaluated. The effects of E. speciosa during the perinatal and lactation periods were also studied. Thus, 32 rats divided into 4 groups of 8 animals each were treated with the extract. Females were examined for standard parameters of reproductive performance, fetal development and visible external malformations. Some biochemical, haematological and histological parameters were evaluated during the stages of the reproductive cycle. The extract (administered from day 1-14) did not have a significant effect on the frequencies of mount, intromission, and ejaculation; In contrast to day 28 (post treatment) a significant increase (p < 0.05) in mount and intromission frequencies at the 500 mg / kg dose was noted. Pretreatment with atropine (5 mg/kg) or haloperidol (1 mg/kg) resulted in complete reduction and suppression of the pro-sexual effects of E. speciosa (500 mg/kg), while Lω-NAME increased the latency by 50 % and potentiated the effect of the extract on latencies of intromission and ejaculation. In male rats, extract of E. speciosa (250-1000 mg/kg, p < 0.01) induced a decrease in testis and spleen weights, increased epididymis weights (250-500 mg/kg, p < 0.001) and increased sperm density and motility at the dose of 250 mg/kg. In treated and untreated rats, the extract had no adverse effects on fertility and pregnancy. The extract resulted in decreased fertility and pregnancy rates in treated females crossed with untreated males and resulted in a 50-60 % decrease in the weights of the reproductive organs (ovaries, uterus). In the rats that received the extract during the organogenesis phase, developmental parameters (body weight, cervico-sacral length and body length) experienced significant decreases in fetuses (20th day of gestation) compared to those of the control group. The ossification rate was high in fetuses in the test groups with no skeletal and visceral abnormalities. After development, the development parameters (body weight, cervico-sacral length, tail length and body length) in the F1 and F2 animals from the test groups showed no significant variation to those from the respective control groups. Females treated during the perinatal and lactation periods did not show symptoms of toxicity, and the extract did not cause the death of young rats or macroscopic abnormalities. This study shows that the aqueous extract of E. speciosa possesses sexual stimulant properties, which would justify its use in traditional medicine as an aphrodisiac. The fertility rates increase when the females are treated with the extract concomitantly with males and fuck when they they receive the extract alone. The extract administered during organogenesis or during the perinatal / lactation period had no adverse effect on the development of offspring from the first to the second generation.