Phytocompounds Analysis and Antimicrobial Potential of Callistemon Viminalis Essential Oil from North-East India

Abstract

There has been a rise in the percentage of microbes that are resistant to antibiotics but no new and effective medications have been introduced in the market for a long time. This ultimately led to the need to search for alternative approaches that deal with infections caused by microbes that are resistant to drug treatments. In the context of the advances that have been achieved in the scientific sector, there has been a great deal of interest in the therapeutic characteristics of plants due to the fact that these properties include low toxicity, pharmacological activity, and economic feasibility. These kinds of studies have concentrated on the positive effects that phytocompounds obtained from plants have on human health of individuals. Compounds, combinations of compounds, or essential oils are examples of the types of additives that can be derived organically from plants. The genus Callistemon, which has 34 different species, is a member of the family Myrtaceae and is distinguished by the cylindrical, brush-like blooms that resembles those found on typical bottlebrushes. Callistemon viminalis, also known as weeping bottle brush, is a species of plant that has been claimed to possess a variety of medical capabilities, including antimicrobial, antifungal, and antioxidant activity, in addition to other pharmacological and insecticidal qualities. Callistemon viminalis essential oil (CVEO) is high in monoterpenoids, which have antifungal, antibacterial, insecticidal, and antioxidant properties. The objective of this study was to extract and analyze the phytocompounds of essential oil from leaves of Callistemon viminalis found in the Gangtok district of Sikkim, India. The essential oil content in the leaves of the Callistemon viminalis was found to be of 0.40 ± 0.07% v/w fresh weight. GC-MS analysis of Callistemon viminalis essential oil led to the identification of 10 major compounds. Eucalyptol (32.09%) was the major constituent in CVEO, followed by 2-Phenyl-4-methyl-thiazolidine (24.45%) and Amrinone (21.29%). This work reports the antimicrobial activity against bacterial and fungal strains. CVEO exhibited antibacterial activity against Bacillus subtilis (18.7 ± 0.5 mm) and Klebsiella pneumonia (17.5 ± 0.5 mm). In a manner comparable to its antibacterial action, CVEO exhibited improved antifungal activity against the several fungal strains that were evaluated. CVEO showed the highest growth inhibition of C. albicans (19.5 ± 0.5 mm) for the ATCC90028 strain and 20.15 ± 0.5 mm for MTCC277. Further, the antimicrobial activity by broth dilution methods also showed that MIC ranged from 1.25 to 0.625% against Bacillus subtilis and Klebsiella pneumonia and 0.625–0.312% against C. albicans (ATCC90028 and MTCC27). One could speculate that certain abundant and efficient elements found in essential oils could be used in the production of powerful antimicrobials. This is owing to the fact that they exhibit distinct compositions and chemotypes, which could provide a wonderful possibility for the creation of new medications. The reason for this is that they possess these characteristics. Therefore, CVEO provides a potent treatment for bacterial and fungal infections by functioning as a refinement in drug design.