Hematological and toxicological effects of aqueous leaf extract of Stevia rebaudiana Bertoni in normal rat modals.

Stevia rebaudiana Bertoni a non-caloric, safe and natural sweetener has been shown pharmaceutically important in the management of blood disorders. This study was designed to investigate hematology and safety of stevia aqueous extract through animal modeling. For this purpose, fifty albino rats were categorized into 5 groups and all the groups were received aqueous stevia extract at different dosage levels (200, 300, 400 and 500 ppm/kg b. wt) for 8 weeks except control group. Hematological and toxicological analyses were conducted using standard recommended procedures. The results indicated that biochemical parameters (RBC, HB, HCT, MCV, MCH, MCHC, WBC, eosinophils, lymphocytes and neutrophils) of albino rats significantly (P<0.05) increased and PLT, MPV and monocytes levels non-significantly decreased by using aqueous extract of stevia at different levels after eight weeks of study. Furthermore, Stevia aqueous extracts had non-toxic effect on liver functioning tests. However, stevia aqueous extracts were insignificant in their impression regarding organ to body weight ratios. The stevia aqueous extract has positive effect on hematological parameters of albino rats and is toxicologically safe. Therefore it could be used as a natural remedy for the management of hematological disorders without any health hazards.

A research on the genotoxicity of stevia in human lymphocytes.

Stevia extracts are obtained from Stevia rebaudiana commonly used as natural sweeteners. It is ∼250-300 times sweeter than sucrose. Common use of stevia prompted us to investigate its genotoxicity in human peripheral blood lymphocytes. Stevia (active ingredient steviol glycoside) was dissolved in pure water. Dose selection was done using ADI (acceptable daily intake) value. Negative control (pure water), 1, 2, 4, 8 and 16 µg/ml concentrations which were equivalent to ADI/4, ADI/2, ADI, ADI × 2 and ADI × 4 of Stevia were added to whole-blood culture. Two repetitive experiments were conducted. Our results showed that there was no significant difference in the induction of chromosomal aberrations and micronuclei between the groups treated with the concentrations of Stevia and the negative control at 24 and 48 h treatment periods. The data showed that stevia (active ingredient steviol glycosides) has no genotoxic activity in both test systems. Our results clearly supports previous findings.

Toxicity study of an antidipsotropic Chinese herbal mixture in rats: NPI-028.

OBJECTIVES: To determine the potential toxicity and safety of the Chinese herbal medicine NPI-028 in rats following subchronic (3-month) exposure via daily oral consumption. DESIGN: Subchronic toxicity was evaluated in four groups of rats (n = 10 per group) receiving NPI-028 orally at a dose of either 0.0 (normal diet control), 0.5, 1.0, or 2.0 g/kg, ingested as part of their daily diet for 3 months. NPI-028 was incorporated into powdered rat chow diet as a specific percent of the total diet provided each day. The primary active isoflavone content of NPI-028 (puerarin) used in the rat diet was also determined. OUTCOME MEASURES: Subchronic toxicity was assessed over a 3-month period by biweekly measurement of water and food intake, weight gain, and visual inspection for maintenance of grooming and normal behavior. At the end of the study period rats were euthanized and blood was obtained for hematologic and chemical analysis. Organs were removed for histopathologic examination. RESULTS: Rats in all three NPI-028 dose groups were similar to the control group in weight gain, food intake, and water intake over the study period. Hematology, blood chemistries, and organ histology in rats at all three NPI-028 doses did not significantly differ from control rats. Minor exceptions were elevated urea nitrogen values at all NPI-028 doses, and increased triglyceride and thyroid-stimulating hormone values in the lowest NPI-028 dose-treated group. Puerarin (used as a dietary isoflavone marker) content of NPI-028 was 26 mg/g dry weight. CONCLUSIONS: NPI-028 ingested orally at doses up to 2.0 g/kg per day in the rat diet for up to 3 months resulted in normal growth with no changes in hematologic or hepatic parameters, and only minor alterations in renal and blood chemistry parameters. There was no evidence of abnormal histology. These data suggest the long-term daily oral consumption of NPI-028 as a part of the daily diet for 3 months, at the doses studied, is safe in rats. Thus, NPI-028 may potentially be safe for clinical use as an antidipsotropic agent.