## 4 Pharmacological Potential
### Common Pharmaceutical Potentials of Leaves and Fruits of L. nobilis  
The potential of L. nobilis EO as an antimicrobial agent has been investigated. It is worth noting that steam distillation-derived oils exhibited greater antimicrobial and antioxidant activities than extracts produced by hydrodistillation [36]. L. nobilis demonstrated important antimicrobial activity against all tested microorganisms at a low concentration of 0.4 \(\upmu\)L/mL of essential oil from leaves, producing inhibition zones ranging from 6.33 to 8.66 mm. These findings were particularly noteworthy in light of the inhibition zone produced by tetracycline. Moreover, the results of the halo inhibition test were supported by the MIC test (Table 3), which showed that the EO inhibited the growth of all the microbial strains studied at a lower concentration than that of 1,8-cineole (except for Bacillus cereus 4313) [11]. \begin{table}
\begin{tabular}{c c c} \hline \hline  & \multicolumn{2}{c}{**MIC (\(\upmu\)L/mL)**} \\ \hline
**Microorganisms** & _L. nobilis_ **EO** & **1,8-cineole** \\ \hline _Escherichia coli_ & 0.8 & 1.5 \\ _Staphylococcus aureus_ & 0.4 & 1 \\ _Pseudomonas aeruginosa_ & 0.4 & 1 \\ _Bacillus cereus_ 4384 & 0.2 & 0.4 \\ _Bacillus cereus_ 4313 & 0.2 & 0.2 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Minimal inhibitory concentration of _L. nobilis_ EO and 1,8-cineole, reproduced from [11]. Bay leaf essential oils have shown efficacy against a large panel of Gram-negative and Gram-positive bacteria [76; 77]. It has been tested against fungal and bacterial strains of food origin: four Gram-positive bacteria (_Staphylococcus aureus_, _Listeria monocytogenes_, _Bacillus cereus_, and _Enterococcus faecalis_), four Gram-negative bacteria (_Salmonella choleraeusus_, _Pseudomonas aeruginosa_, _Escherichia coli_, and _Yersinia enterocolitica_) and three fungi (_Penicillium islandicum_, _Aspergillus flavus_, and _Candida albicans_). The antimicrobial activities of the EO against microorganisms were determined. The _E. faecalis_ strain was the most sensitive, followed by _S. aureus_, among the Gram-positive bacteria. Among the _Candida_ species, _C. albicans_ was the most sensitive to the laurel leaf essential oils [39]. The antimicrobial potential of _L. nohilis_ EO, cultivated in Morocco, was studied, and it was found that all bacterial strains tested had a minimum inhibitory concentration (MIC) of 0.01 mg/mL of EO dissolved in dimethyl sulfoxide (DMSO) [78]. A study was conducted to test the activity of _L. nohilis_ EO in combating significant plant pathogens. The EO, used in vitro, totally inhibited the growth of _Sclerotinia scleroorum_, the agent of white mold, and _Alternaria solani_, responsible for Alternaria blight of tomatoes and potatoes [79]. [PERSON] et al. [80] conducted an in vivo test to evaluate the antifungal properties of _L. nohilis_ EO from China against _Alternaria alternata_ on cherry tomatoes. The study found an inhibition rate of 33.9%, which is consistent with the in vitro results (36% inhibition at 1 mg/mL of EO) obtained from the EO extracted from cucurbits [81]. In addition to the inhibited species of bacteria mentioned in Table 3, some fungal species (_Penicillium digitatum_ and _Alternaria_ sp.) were also found to be sensitive to the essential oils of _L. nohilis_[82]. It was suggested that _L. nohilis_ EO could serve as a natural preservative for cereal products because of its significant antifungal activity. It was also tested against _Aspergillus flavus_ during storage for 6 months in fumigated wheat grains; the results showed an 86% reduction in the production of aflatoxin B1 with 1.5 mg/mL of EO (diluted in 15 mL of polydopamine) in vitro and protection of between 51.5 and 76.7% against the tested strain [83]. Furthermore, regarding the antifungal property of _L. nohilis_ extracts, their highest antifungal activity was against _Botrytis cinerea_, a plant pathogenic fungus.