Background & Objective: Toxico-pathological effects of herbal plants have always been a major concern, but little information is provided on the toxico-pathological effects of origanum on the fetus. Due to ethical rules and regulations, no drug experiment on the human fetus is permitted; hence, the chick embryo model is used as an ideal opportunity to study the adverse effects of drugs. This study aims to assess the histopathological effects of the various doses of Origanum vulgare (O. vulgare) using the chick embryo model.
Materials & Methods: Ross chicken eggs were subjected into four experimental groups (n=7); phosphate buffered saline-injected group and Origanum-injected groups that were treated with O. vulgare leaf-extract at doses of 25, 50, and 100 mg per kg egg-weight, respectively. After injecting the embryos with the extracts, re-incubation was performed and allowed to develop until day 18, when embryos were evaluated for pathological lesions.
Results: Treated embryos were normal in the Origanum-injected groups and no defect was noticed on the body features. The microscopic lesions including congestion and edema were made in the brain, liver, kidney, heart, and lung in a dose-dependent manner.
Conclusion: It can be concluded that O. vulgare at a concentration higher than 25 mg per kg is toxic for chick embryo in a dose-dependent manner; therefore, more attention should be given to the toxicity of O. vulgare in the period of fetal development.

Background & Objective: Perovskia abrotanoides Karel locally known as Brazambal, is widely used in medical practice to treat various disorders. Burn is a common source of injury and Brazambal ointment has been extensively used in burn wound healing in North of Iran. The purpose of this study was to examine the healing effect of Brazambal ointment in experimental model of burn. In addition, in-vitro healing characteristics and antibacterial activity of P. abrotanoides was investigated.
Materials & Methods: Scald burn injury was produced by pouring 2.5cc of boiling water (95ºC) on the posterior surface of rat’s neck for 10 seconds. Twenty-eight adult male Sprague Dawley rats were divided into 4 groups (7 rats each) and followed for 7 days. Control group (no treatment); Silver sulfadiazine-treated group; Brazambal ointment-treated group; and vehicle-treated group received the complete ointment without Brazambal part. The effects of Brazambal aqueous extract on fibroblast cells and antibacterial activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were evaluated.
Results: Topical application of Brazambal ointment can accelerate wound healing process by initiating re-epithelialization and formation of granulation tissue. Proliferative activity of the aqueous extract on fibroblast cells was observed after 48 h in concentrations of 7.5% and 10% (P<0.0001). However, P. abrotanoides Karel extract had no significant antibacterial effect.
Conclusion: The presence of hair follicles, re-epithelialization and granulation tissue is suggestive of Brazambal ointment relative effectiveness on experimental scald burn in rats. However, further studies are warranted to reveal the healing mechanisms of P. abrotanoides.