BACKGROUND AND OBJECTIVES: Mesenchymal stromal cells (MSCs) have great therapeutic potential, particularly in the process of tissue repair and immunomodulation through the secretion of biomolecules. Thus, the aim of this study was to evaluate the hypothesis that intramuscular transplantation of allogeneic MSCs obtained from equine umbilical cord (UC-MSCs) is safe, demonstrating that this is a suitable source of stem cells for therapeutic use. METHODS AND RESULTS: For this, UC-MSCs were cultured, characterized and cryopreserved for future transplantation in six healthy mares. On day 0, transplantation of three million UC-MSCs diluted in Hank’s Balanced Solution (HBSS) was performed on right and left sides of the rump muscle. As a control, HBSS injections were performed caudally in the same muscle. Muscle biopsies were obtained as a control 30 days before transplantation (D-30). The biopsies were collected again on day 2 (left side) and day 7 (right side) post transplantation and examined histologically. All procedures were preceded by ultrasound examination and blood sampling. Hematologic evaluation remained within normal limits and no differences were observed between time points (p>0.05). Ultrasound examination was suggestive of inflammation 48 hours after transplantation in both groups (control and treated). At histological evaluation it was found only discrete inflammation signals between D-30×D2 (p<0.05) in the treated group, without differences (p> 0.05) between the groups at different time points. CONCLUSIONS: Equine UC-MSCs under the experimental conditions did not promote severe inflammation that causes tissue damage or lead to its rejection by the host organism and therefore has a good potential for clinical use.
Biopsy ; Immunomodulation ; Inflammation ; Mesenchymal Stromal Cells* ; Stem Cells ; Transplantation ; Ultrasonography ; Umbilical Cord*

Objective: To evaluate the antinociceptive activity of perillyl acetate in mice and in silico simulations. Methods: The vehicle, perillyl acetate (100, 150 and/or 200 mg/kg, i.p.), diazepam (2 mg/kg, i.p.) or morphine (6 mg/kg, i.p.) was administered to mice, respectively. Rotarod test, acetic acid-induced abdominal writhing, formalin-induced nociception, hot plate test, and tail-flick test were performed. Opioid receptors-involvement in perillyl acetate antinociceptive effect was also investigated. Results: Perillyl acetate did not affect the motor coordination of mice. However, it reduced the number of acetic acid-induced abdominal twitches and licking times in the formalin test. There was an increase of latency time in the tail-flick test of 30 and 60 minutes. Pretreatment with naloxone reversed the antinociceptive effect of perillyl acetate (200 mg/kg). In silico analysis demonstrated that perillyl acetate could bind to μ-opioid receptors. Conclusions: Perillyl acetate has antinociceptive effect at the spinal level in animal nociception models, without affecting the locomotor integrity and possibly through μ-opioid receptors. In silico studies have suggested that perillyl acetate can act as a μ-opioid receptor agonist.