Osteoprotective Effects of Tribulus terrestris L.: Relationship Between Dehydroepiandrosterone Levels and Ca2+-Sparing Effect.

Osteoporosis is a systemic bone disease that is characterized by impairments in bone strength that predispose an individual to a higher risk of fractures. Despite the various etiologies, undoubtedly the most important factors are aging of the population and hypogonadism. Although several therapeutic options are available, pharmacological treatments have some risks. Among these are increases in the incidence of thrombosis, breast cancer, ovarian cancer, endometrial cancer, and muscle injury, among others. Herbal medication may be an alternative for the treatment of osteoporosis. Thus, the aim of this study was to evaluate the therapeutic effect of a standardized extract of Tribulus terrestris L. (TT) on ovariectomy (OVX)-induced bone loss in rats. Female rats were first subjected to OVX and treated with TT (3, 30, and 300 mg/[kg·day]) or furosemide (25 mg/kg) orally for 28 days. Bone densitometry and tibial histology were performed, and acute renal function and testosterone, dehydroepiandrosterone (DHEA), and estradiol levels were assessed. Prolonged treatment with TT stimulated bone mass gain in all ovariectomized animals, raising bone mass to levels that were similar to sham-operated rats. DHEA levels significantly increased in TT-treated rats. The TT group also had lower calcium (Ca2+) excretion that OVX control and furosemide-treated rats. Finally, the histopathological analyses showed the maintenance of bone turnover in all TT-treated groups. Overall, the results indicate that the standardized extract of T. terrestris exerted a bone-protective effect by increasing bone mineral density. This activity may be at least partially attributable to an increase in serum DHEA levels and a Ca2+-sparing effect.

Evaluation of Reproductive Toxicology of Aqueous Extract of Yerba Mate (Ilex paraguariensis A. St.-Hil.), a Traditional South American Beverage.

Yerba mate (Ilex paraguariensis A. St.-Hil.; Aquifoliaceae) is a popular tonic and stimulant beverage that is widely consumed in different South American countries. Estimates indicate the consumption of >1 L per day in southern Brazil and Uruguay. Despite its relatively high consumption, data on reproductive toxicity during critical periods of gestation remain unclear. Thus, we evaluated the effects of an aqueous extract of I. paraguariensis leaves ("chimarrão" [IPC]) at two critical periods of gestation in Wistar rats: preimplantation embryonic stage and fetal organogenesis. Pregnant Wistar rats were orally treated with IPC (3, 30, and 300 mg/kg) from days 1 to 7 or 8 to 21 of pregnancy. The respective control groups received vehicle. During treatment, clinical signs of maternal toxicity, maternal body weight, and food and water intake were monitored. The rats were killed on days 8 and 20 of pregnancy, and the following parameters were evaluated: weight of the maternal uterus, weight of the liver, weight of the kidneys, weight of the spleen, total embryo implantation, preimplantation loss, the mean of live fetuses, the percentage of dead fetuses, fetus weight, and fetal malformation. The aqueous extract of the leaves of I. paraguariensis L. did not present any deleterious effects on preimplantation embryos or the organogenesis of offspring from female Wistar rats. These safety data provide evidence that IPC may be safe for consumption during gestation.

90-Day Oral Toxicity Assessment of Tropaeolum majus L. in Rodents and Lagomorphs.

Tropaeolum majus L., popularly known as nasturtium, is a species widely used in the form of infusions and salads. In the last years, the antihypertensive, diuretic, and calcium and potassium sparing activities of T. majus preparations were shown. Moreover, no preclinical 90-day oral toxicity studies were conducted. Thus, this study evaluated the toxicity of the hydroethanolic extract obtained from T. majus (HETM) leaves in female and male mice, rats, and rabbits. Swiss mice and Wistar rats were treated with HETM (75, 375, and 750 mg/kg). The doses of rabbits (30, 150, and 300 mg/kg) were calculated by allometric extrapolation. The control groups received vehicle. The animals were orally treated, daily, for 90 days. At the end, the animals were anesthetized, and body weight gain, relative weight of liver, kidney, and spleen, and histopathological changes were evaluated. Serum hematological and biochemical parameters were also analyzed. No alterations were found in body and organ weights or in histopathological and biochemical evaluation. Hematological analyses revealed small changes in lymphocytes and neutrophil counts in rats after administration of 750 mg/kg of HETM. These results showed that 90-day use of T. majus is safe in rodents and lagomorphs.

Effects of extracts from Echinacea purpurea (L) MOENCH on mice infected with different strains of Toxoplasma gondii.

In recent years, due to the growing concern about recurrent epidemics by Toxoplasma gondii and other pathogens in Brazil, there has been an increase in the use of different preparations obtained from Echinacea purpurea in order to test their effectiveness against these infections. Although studies have suggested the beneficial effects of this species against the influenza virus, no data are available on the use of E. purpurea aqueous extract in T. gondii infections. Thus, the aim of this study was to analyze the effect of its administration in Swiss mice submitted to acute and prolonged infection with different T. gondii strains. This study showed that E. purpurea extract induced a significant reduction in the number of tachyzoites in the peritoneal fluid and liver imprints from mice infected by the RH strain. Moreover, prolonged treatment significantly increased the number of brain cysts of animals infected with ME 49 strain. The results obtained in this study suggest that the crude extract obtained from E. purpurea has important protective activities against infection with different T. gondii strains.