Antimicrobial potential of essential oil artemisia sieversiana: a medicinal plant from the high altitude nubra valley, Ladakh

Abstract

Artemisia sieversiana Ehrh. ex Willd. (common name: wormwood; family: Asteraceae) is a medicinal plant thriving at high altitudes. It is extensively utilized in traditional folk medicine by various ethnic communities to alleviate and treat a wide range of health issues. However, despite its widespread use, the chemical characterization and identification of bioactive compounds responsible for these benefits is still incomplete, especially in the context of Trans−Himalayan region. Prior research has demonstrated the substantial efficacy of this plant against various pathogenic bacteria, although these studies utilized essential oil (EO) extracted from different geographic regions. There is a need for further research to explore the antibacterial activity of A. sieversiana EO from the Trans−Himalayan, Ladakh region, as the unique environmental conditions of this region may influence the plant’s chemical composition and biological activity. This research therefore focusses on characterizing the phytochemical composition and evaluating the antibacterial properties of EO extracted from A. sieversiana, specifically from the Nubra valley, Ladakh (India). The antimicrobial potential of A. sieversiana essential oil was tested against a diverse spectrum of gram-negative (Erwinia herbicola and Pseudomaonas syringae) and gram-positive bacteria (Bacillius cereus, B. pumilus, Rhodococcus fasciens, and Streptomyces scabiei) plant and food pathogenic bacteria. Gas Chromatography−Mass Spectrometry (GC−MS) analysis led to the identification of 28 components with camphor (18.8%), borneol (11.2%), and 1,8−cineole (9.7%) as the major constituents. Further, the EO was more active against gram−positive bacteria, with a greater inhibition percentage for all gram−positive bacteria (24.68%−38.90%) than for gram−negative bacteria (0%−50.19%) at 10 µg mL−1. Moreover, the antibacterial activity showed a concentration dependent response, escalating from 24.68% to complete inhibition (100%) as the EO concentration increased from 10 to 160 µg mL−1. Notably, the EO demonstrated strongest activity against B. pumilus, even more than the common antibiotic Rifampicin. Among gram−negative bacteria, Erwinia herbicola showed the highest susceptibility. This observation shows that the essential oil of A. sieversiana exhibits promising antimicrobial activity and highlighted their potential for further exploration and utilization.