**3. Therapeutic application of** *A. flagellaris* **essential oils**

Antioxidants of renown, thymol and its derivatives also have intriguing inhibitory potential against some bacteria [31, 32]. BHA and Ascorbic acid (93.09–90.40%) were competing with the essential oils of *A. flagellaris* leaves and roots, which had a

### *Thymol and Its Derivatives Rich Essential Oils from* Asparagus flagellaris *and Therapeutic… DOI: http://dx.doi.org/10.5772/intechopen.113197*

substantial scavenging power from 91.04–88.06% and 90.04–50.73%, respectively (92.60–90.68%). Also noted was the concentration dependence of the antioxidant properties. The chemical compounds of the essential oil, thymol and its derivatives, which make up the majority of the mixture, may be accountable for the antioxidant property seen. However, the analysis of variance revealed no distinction in antioxidant between the essential oil of the leaves and the benchmarks that was significant (*P < 0.05*).

The essential oils from the leaves and roots of *A. flagellaris* were examined for its antibacterial properties against 10 pathogenic organisms at various concentrations (1000–62.5 μg/mL) in comparison to reference standards (gentamicin and tioconazole). The antibacterial ability of the essential oils were evaluated by measuring the inhibitory zones surrounding the well. The antibacterial activity revealed that none of the examined organisms were inhibited by the essential oils at 1000 μg/mL. *R. spp*. had the lowest inhibition at 250 μg/mL. (10 mm). The bactericidal capabilities of *A. flagellaris* leaves and roots essential oil were substantially different (*P* < 0.05) from reference standards (gentamicin and tioconazole). While only a small amount or lower concentration of the oil is needed to attack a active site in the organism, a high concentration will cause accumulation and blockage of the sensitive site and, as a result, have no effect [16]. This may explain why the oils are insensitive to the tested microorganisms at a higher concentration (1000 μg/mL).

Also, it is assumed that the protein bound at higher concentrations generating resistance to the tested microorganisms, and this was diminished as the concentration of the oil reduced. Furthermore, it has been stated that an antimicrobial's microbiologic activity is restricted to its non-protein-bound portion [31]. The interactions between the compounds present in the essential oils of the plant's leaves and roots could explain the study's findings regarding the degree of antibacterial activity. Therefore, these chemical elements may affect a number of bacterial cell target locations [35]. The essential oil's function might be regarded to as a "bacteriostatic antibiotic" since it prevents bacteria from multiplying by inhibiting bacterial protein synthesis, DNA replication, or other processes involved in cellular metabolism. This class of drugs is known as bacteriostatic antibiotics, and it includes tetracyclines, sulfonamides, spectinomycin, and others [35]. This result is in line with earlier findings on leaf extracts [6] and Marchese et al. [20] claims that all thyme essential oils are bacteriostatic.

However, those from the leaves and roots of *A. flagellaris* with noteworthy chemical compositions, such as thymol methyl ether, bornyl acetate, thymol β-bisabolene, were also found to be the most common ingredients in the root essential oil of *Chaerophyllum villosum* [36, 37]. Significant antioxidant and antibacterial activities were significantly reduced by these components. Germacrene D, farnesol, bornyl acetate and β-bisabolene have all been suggested as the possible causes of the antibacterial and antioxidant effects of *Eupatorium adenoporum* essential oil [38]. All yeasts and filamentous fungi (*F. oxysporum* f. sp. *albedinis* and *M. ramanianus*) were responsive to Thymol, Thymol Methyl Ether, α-Muurolene, Germacrene D, and α-Muurolene in *Thymus fontanesii* [39]. Thymol and thymol methyl ether were two of the key components of *Thymus vulgaris* essential oil that have antioxidant and antibacterial effects [40].

The essential oil's comparatively large content of thymol derivatives may be responsible for the majority of the reported therapeutic advantages of *A. flagellaris* in folk medicine. The literature has in-depth descriptions of strong thymol derivative antiseptic, anti-inflammatory, antibacterial, antifungal, flavoring and antispasmodic properties [38]. Other minor essential oil constituents are of phytochemical relevance because of their combined impact in suppressing the biological activities observed in this study.
