Effets des graines de quelques espèces de courges sur des tumeurs bénignes et malignes de la prostate : études in vitro et in vivo

Abstract

Cancer and prostate hyperplasia are two pathologies of the male urogenital tract that are major public health problems. In light of thé limitations of modern medicine, the scientific community has turned to the study of medicinal plants. Cucurbits are a family of plants comprising some 130 genera divided into 960 species, used in traditional medicine to combat a number of pathologies, including prostate diseases. Cucurbits are a family of plants comprising some 130 genera divided into 960 species. They are used in traditional medicine to combat a number of pathologies, including prostate diseases. However, no study has been conducted to scientifically verify these beneficial effets. The aim of the present work was to evaluate the protective effects of the seeds of some Cameroonian cucurbits on benign and malignant prostate tumor models in rats. To achieve this objective, a comparative study of the seed "totum" of six of the most widely consumed squash species in Cameroon was carried out on human prostate cancer lines and on a Wistar rat model of induced BPH. In vitro, the cytotoxicity of pumpkin seed extracts was assessed on cancer lines using the MTT (3 [4,5-dimethylthiazol-2-yl] diphenyltetrazolium bromide) assay. In vivo, 75 rats aged 10 weeks were treated simultaneously with pumpkin seed "totum" at doses of 500 and 1000 mg/kg and testosterone for 28 days. The parameters assessed were relative mass, volume, total protein content, epithelial size, prostatic glandular diameter, and percentage inhibition of prostatic growth. Following this study, the effects of cooking, the frequency of total seed intake, and C. sativus seed oil and meal were also evaluated using the aforementioned in vitro and in vivo models. In the second part of this work, the protective effects of C. sativus seed oil (at doses of 42.5, 85, and 170 mg/kg) and "totum" at 500 mg/kg were assessed in a rat model of benzo(a)pyrene (B(a)P)-induced prostate cancer. Six-week-old rats were given cyproterone acetate (50 mg/kg), B(a)P (50 mg/kg), testosterone (10 and 100 mg/kg), and extracts, alone or in combination, for 210 days. The parameters evaluated were tumor burden, relative mass, volume, total protein, and PSA ("Prostate Specific Antigen") levels in the prostate. Oxidative status, markers of inflammation, kidney and liver function, and hematological parameters were also assessed. In the third part of this work, possible cytotoxic, anti-androgenic, estrogenic, and cellular mechanisms of action were evaluated on human prostate cell lines. This was done by determining the mechanism of cell death (necrosis or apoptosis), clone formation, anti-invasion and adhesion capacity, and integrin expression. Acute toxicity tests and a toxicological overview during pharmacological treatment were evaluated. The results obtained from the first part of this work revealed that two out of the six pumpkin species tested possess inhibitory activity in vitro on non-androgen-sensitive human prostate cells (DU145 and PC 3). In vivo, there was a significant decrease in relative mass (p < 0.05; p < 0.01; p < 0.001), volume (p < 0.05) and prostate PSA levels (p < 0.05). There was also a significant decrease in oxidative markers levels (p < 0.001) and inflammatory markers (p < 0.05; p

< 0.01; p < 0.001), especially at the 170 mg/kg dose. After 210 days of co-administration of B(a)P and testosterone, the rats developed Gleason 8 (4+4) prostatic adenocarcinoma with peri-nerve sheath characterized by altered cellular architecture, cellular hypertrophy, and dysplasia. Both oil and "totum" showed protective effects against cancer, characterized by florid glandular hyperplasia, inhibition of tumor burden, incidence, and volume. The effect was more pronounced at a dose of 170 mg/kg PC. Both C. sativus seed oil and flutamide exhibited anti-androgenic activity, resulting in a significant reduction in the relative masses of the prostate (p < 0.05; p < 0.01), seminal vesicles (p < 0.01; p < 0.001), glans (p < 0.05), and Tyson gland (p < 0.001). Additionally, the oil and "totum" administered concomitantly with E2V and letrozole showed more pronounced estrogenic activities, leading to a significant decrease in the relative masses of the testes (p < 0.05), prostate (p < 0.05; p < 0.01), vas deferens (p < 0.05; p < 0.01), and penis (p < 0.05). The seeds showed low toxicity, as evidenced by the absence of any signs of morbidity or death, resulting in an LD50 > 5000 mg/kg PC. There was a significant increase in the relative liver mass, along with a significant increase in ALAT activity and bilirubin levels, without histopathological damage. In conclusion, these results demonstrate that C. sativus seed oil has antiproliferative effects on benign hyperplasia and CaP, particularly at a dose of 170 mg/kg. Its cytotoxic effects include inhibiting tumor cell growth, inducing apoptosis, inhibiting clone formation, cell migration, and invasion, and promoting cell adhesion. These effects are attributed to linoleic acid and squalene, compounds known for their anti androgenic, anti-inflammatory, antioxidant, and anti-hyperlipidemic properties. These results provide a scientific basis for claims that pumpkin seeds have beneficial effects on the prostate in Cameroon.