Subacute toxicity study in Wistar rats fed with StemEnhanceTM, an extract from Aphanizomenon flos-aquae

Abstract

This study evaluated the safety (absence of toxicity) of StemEnhance™, an extract of the blue-green alga Aphanizomenon flos-aquae that is used as a health supplement. Groups of 12 rats of each sex were given either 5% glycerin in water (control) or 600 mg/kg of StemEnhance prepared in 5% glycerin in water for 2 weeks by oral gavage followed by 2 weeks of observation. The administration of StemEnhance had no effect on behavior, food and water intake, growth, or survival. Values at the end of dosing and observation periods did not reveal differences between treated and control groups for hematology and clinical chemistry. There were no significant differences in the gross and histopathology of the reproductive organs in either males or females. Sperm motility parameters were similar for control and treated males. Our results show that StemEnhance at doses ∼20 times the maximum label-recommended daily dose did not produce adverse effects in Wistar rats after subacute treatment.

Subchronic toxicity (90 days) of StemEnhance™ in Wistar rats

“…Gross pathology was performed by a veterinary pathologist as described in an earlier publication. 9 Briefly, all of the animals were submitted to full necropsy procedures, including examination of the following organs and/or sites: external surface of the body; all orifices; cranial cavity; cervical tissues and organs; thoracic cavity and its contents, organs, and tissues; and abdominal cavity and its contents, organs, and tissues. Wet weight was determined for the following organs: liver, brain, spinal cord, heart, kidneys, spleen, adrenals, testes, epididymides, uterus, and ovaries as described in an earlier publication.…”

“…Wet weight was determined for the following organs: liver, brain, spinal cord, heart, kidneys, spleen, adrenals, testes, epididymides, uterus, and ovaries as described in an earlier publication. 9 Organ weights were expressed as absolute values (g) and as relative (organ to body weights) values (gram per 100 g of body weight).…”

“…Full histopathology was carried out by a veterinary pathologist on all animals as described previously. 9 Briefly, harvested tissues were fixed in 10% neutral buffered formalin for a minimum of 48 h prior to trimming. Following fixation, tissues composed of bone were decalcified with a standard decalcifying solution (formic acid and sodium citrate).…”

“…Standard serum chemistry and hematology profiles were determined. 9 The following hematological examinations were made: packed cell volume (PCV), hemoglobin concentration (Hb), erythrocyte count (RBC), total and differential leukocyte count (white blood cell (WBC)), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC). Additionally, the following clinical biochemical analyses of blood were carried out: glucose, calcium, phosphorus, creatinine, total protein, albumin, globulin, cholesterol, bicarbonate, anion gap, sodium, potassium, chloride, triglycerides, gamma-glutamyltransferase (GGT), alkaline phosphatase (ALP), alanine aminotransferase (ALT), blood urea nitrogen (BUN), and bilirubin.…”

“…12 In the current study, the degree of uterine cellular proliferation in treated and control females was evaluated and compared with each other using Ki-67 immunohistochemistry (IHC) and image analysis IHC for Ki-67. 9 epididymal sperm count, motility, and morphology At necropsy, the right cauda epididymis was immediately removed, weighed, and the tissue was processed. 9 Briefly, sperm counts were determined in six standard viewing fields and calculated per cauda and per gram of testis.…”