# Plant-Derived Phytobiotics as Emerging Alternatives to Antibiotics Against Foodborne Pathogens
### Phytosterols  
Phytosterols are a family of steroids essential for plant cell membranes, contributing to membrane fluidity and structure [69]. They stabilize biological membranes, ensure proper enzyme activity, and are involved in signal transduction, growth hormone production, and plant response to environmental stress, while also exhibiting significant antimicrobial activity [70; 71]. Stigmasterol, one of the best-studied phytosterols, exhibits antimicrobial activity, particularly against certain food spoilage-causing bacteria [72]. Plant extracts rich phytosterols show strong antimicrobial and antifungal properties, inhibiting the growth of various fungal strains, including _Candidia_ and _Aspergillus_ species responsible for human infections [73; 74; 75]. Their antimicrobial is multifaceted, involving interactions with macromolecules that lead to inactivation and interference with cellular components such as membranes and mitochondria, leading to pathogen death [76].  
Phytosterols are categorized into three main types: free sterols, conjugated sterols, and sterol derivatives. Free sterols, such as \(\beta\)-sitosterol, campesterol, and stigmasterol, are abundant phytosterols in plants and crucial for membrane stabilization and metabolic regulation. \(\beta\)-sitosterol is widely used in dietary supplements for its cholesterol-lowering effects. Conjugated sterols are formed by combining sterols with fatty acids, phenolic acids, or sugars, such as sterol esters found in vegetable oils (e.g., canola oil), improving fat quality and bioavailability. Sterol derivatives serve as precursors to various bioactive compounds, including steroidal saponins and brassinosteroids, which are important for plant growth and may have applications in cancer treatment and agriculture [77; 78; 79].  
Phytosterols are also based on chemical structure, particularly the presence of methyl groups in the A ring of the sterol. The first group, 4-desmethyl sterols, lacks a methyl group at the C4 position, with sitosterol as an example, known for its cholesterol-lowering properties. Another group, 4-monomethylsteroids, contains one methyl group at the C4 position, such as 24-monomethylositosterol, which exhibits anti-inflammatory properties. The third group, 4,4\({}^{\prime}\)-dimethylsteroids, includes compounds such as evenasterol from oats, known for their antioxidant and anti-inflammatory activities [80].  
\begin{table}
\begin{tabular}{p{56.9 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline
**Class** & **Examples** & **Sources** & **Properties** \\ \hline \multirow{2}{*}{Tropane} & Atropine, Scopolamine, Cocaine & _Atropa belladonna, Erythroxylum coca, Datura stramonium_ & Anticholinergic, stimulant properties, antimicrobial activity \\ \hline \multirow{2}{*}{Isoquinoline} & Morphine, Codeine, Berberine & _Opium poppy_, _Coptis chinensis_, _Hydrastis canadensis_ & Analgesic effects, pain relief, antimicrobial \\ \hline \multirow{2}{*}{Indole} & Vincristine, Vinblastine, Harlamie & _Catharanthus roseus, Pegamu harmala_ & Antineoplastic, antimicrobial \\ \hline \multirow{2}{*}{Purine} & Caffe, Theobromine, Theophylline & Coffee, tea plants, Theobroma cacao & Stimulant effects, mental alertness, antimicrobial \\ \hline \multirow{2}{*}{Imidazole} & Pilocarpine, Miconazole & _Pilocarpus_ species & Treatment of glaucoma, parasympath-omimetic, antifungal \\ \hline \multirow{2}{*}{Steroidal} & Solanine, Tomatine, Berberine & _Solanaceae_ family, _Berberis vulgaris_ & Toxic properties, effects on cell membranes, antimicrobial \\ \hline \end{tabular}
\end{table}
Table 3: _Cont._