Chemical profile and biological properties of the essential oil of Thymus atlanticus (Ball) Roussine

Abstract

Aromatic and medicinal plants are an important source of natural products, including essential oils. These volatile oils are endowed with large spectra of biological and pharmacological properties. The species of Thymus genus belonging to Lamiaceae family produce significant amounts of essential oils with high bioactivity. Thymus atlanticus (Ball) Roussine. (T. atlanticus) is an endemic thyme species that grows in the Moroccan High Atlas Mountains. T. atlanticus, along with other Thymus species, have numerous traditional uses and therapeutic applications in Morocco. Regardless, toxicity, antioxidant, analgesic, and anti-inflammatory properties of the essential oils of this thyme have never been studied before. In this paper, the chemical composition, acute toxicity, antioxidant, analgesic, and anti-inflammatory activities of T. atlanticus are investigated. The results of the chemical composition using GC/MS analysis showed that thymol (23.7%) and carvacrol (22.8%) are the major volatile constituents of this thyme. Moreover, the acute toxicity assessment showed that the essential oil of T. atlanticus is not toxic at 2 g/kg bw. In addition, the oil of this thyme has an important amount of phenolic compounds (6.06 GAE mg/g EO) and a good antioxidant activity (IC50 DPPH = 0.21 mg/ml). The analgesic tests showed that the volatile oil of this thyme induced analgesic effects, suggesting anti-nociceptive actions in both chemical and thermal models of nociception. In addition, T. atlanticus essential oil produced a significant anti-inflammatory effect, as demonstrated by inhibition of ear edema induced by phenol (% of edema was 19.39% for essential oil treatment group compared to 77.59% for edema control group). These findings provide support for the traditional use of T. atlanticus in the Moroccan High Atlas folk medicine. Further investigations are recommended for the possible development of natural antioxidant, analgesic, and anti-inflammatory products from the essential oils of T. atlanticus.