Chemical profiling and in-vitro anti-oxidant, anti-diabetic, anti-inflammatory, anti-bacterial and anti-fungal activities of essential oil from Rosmarinus officinalis L.

Abstract

Rosmarinus officinalis L. commonly known as Rosemary is a well-known genus belongs to Lamiaceae family, which is one of the major plant families with a high concentration of essential oils. Rosemary is well known to produce herbal essential oils owing to the presence of therapeutic and medicinal elements in the plant’s by-products. In the present study, rosemary essential oil (REO) was extracted from Rosmarinus officinalis and it was evaluated for its phytochemicals, antioxidant, antibacterial, antifungal, anti-diabetic and anti-inflammatory activities. GC-FID analysis and fingerprint analysis was performed. Different antioxidant assays were performed like DPPH (1,1-diphenyl-2-picrylhydrazyl), ABTS (2,2-azinobis-3-ethylbenzothiazoline-6-sulphonic acid), nitric oxide radical, hydroxyl radical, iron reducing potential, iron chelating activity. Anti-bacterial activity was observed by the disk diffusion method against Gram-positive (G+), Gram-negative (G−) bacteria. Anti-diabetic and anti-inflammatory activities were also performed. Antifungal activity against Aspergillosis and Mucormycosis causing fungal strains was also evaluated. GC-FID revealed the presence of vertocitral, α-pinene andhumulene oxidemajor component of REO along with other bioactive components. The IC50 value (µl/ml) for various assays was observed in the following order: OH- (16.6118), iron chelating (32.0115), iron reducing (92.534), DPPH (101.929), and ABTS (172.2765). The best antimicrobial activity was against Bacillus subtilis (MTCC 121), with an inhibition zone of 2.5 cm. REO showed strong anti-inflammatory and anti-diabetic potential and can be employed as an anti-diabetic agent due to its inhibitory effect on α-amylase activity. Based on these findings it was concluded that REO can be widely employed across a variety of sectors, including food, aromatherapy, herbal and allopathic medicine, cosmetics, and as a natural biocide, fungicide, and preservative.