Prunus mahaleb L. belongs to the genus Prunus of Rosaceae family, with more than 400 species worldwide. Other names for this plant in English are Mahaleb cherry, Rock cherry and St. Lucie cherry, also known in Persian as cherry blossom, Mahlab and Malham. This species is native to Mediterranean, southern and central Europe, northwest Africa and southwest Asia, such as Pakistan, Turkey, Iraq and Iran (Sabeti, 2008). This plant prefers warm, dry weather and well-drained soils and is resistant to several diseases. The different parts of this species have gardening value, forestry and green space, edible, export, by-products, secondary metabolites and industrial raw materials for pharmaceutical-medical industries, dyeing and cosmetics. It is a transplant base for sour and sweet cherries and a wildlife sanctuary. The edible parts of the plant are fruit and seed. The seeds are used in confectionery, bread production and biscuit making. Dried seeds are also used in Greece, Turkey and Armenia as food additives. However, it should be used with caution because of the hydrogen cyanide present in the leaves and seeds (Kunkel, 1984). In traditional medicine, the plant seeds are used to strengthen the liver, relieve internal pain, expel various internal parasites, remove moisture from the chest and lungs, strengthen the senses, treat suffocation (Arrhythmia) and pain of back and colic. If the grain is poured into the bread, it speeds up the digestion of food. Its wood and leaves are tonics for the body, and it is considered useful for removing bad body odour and insect bites, as well as the incense of the bark to repel insects. If it is boiled in oil with Ruta and Mastic, it is useful for paralysis and tetanus, tremors and joints orally or rubbed on the sore spot (Tonekaboni, 2007).
On the one hand, bacteria became resistant to antibiotics, and on the other hand, new antibiotics are less discovered. For this reason, researchers are looking at different treatments, such as traditional herbal medicine, bacteriophage treatments, and combination therapies (Cheesman, Ilanko, Blonk, & Cock, 2017). The herbal compounds have antimicrobial effects against pathogens. Moreover, these compounds are also inexpensive, available, and low-risk, so they have always been of interest to researchers (Alanis, Calzada, Cervantes, Torres, & Ceballos, 2005; Bonjar, 2004; Meléndez & Capriles, 2006).
The secondary metabolites of plants have many bioactive and biochemical properties that are used in various pharmaceutical, chemical, cosmetic and especially food industries (Gourine et al., 2010). The phenolic or secondary nitrogen-free compounds have various biological effects, including antibacterial activity (Yadegarinia et al., 2006).
Costerton described bacterial biofilms in 1978. Biofilm-forming bacteria can be one or more different community types (Lear & Lewis, 2012). In a biofilm, microorganisms produce a matrix for attaching to the surface (Mah & O'Toole, 2001). The interactions between microorganisms with the surface and other microorganisms play an essential role in the development of biofilms. Biofilms are a significant cause of nosocomial infections. However, the external polysaccharides of bacteria were attached to the surface and prevented antibiotics effect against bacteria. The biofilm increases bacterial distribution and pathogenicity. The multidrug resistance bacteria are resistant to various antibiotics; therefore, researchers use herbal extracts to eliminate multidrug-resistant pathogens (Kojic & Darouiche, 2004; Peterson, 2007)
Mohammadi Bazargani et al. applied Peppermint, Anise and Coriander extract for biofilm inhibition of S. aureus and E. coli clinical strains (Bazargani & Rohloff, 2016). Navasivayam et al. reported biofilm inhibition of Azadirachta indica, Vitex negundu, Tridax procumbens, and Ocimum tenuiflorumi extracts against E. coli clinical strain (Namasivayam & Roy, 2013).
This study aimed to identify the chemical constituents of the n-hexane fraction of methanol extract of P. mahaleb L. leaves. The phenolic and flavonoid compounds of methanol extract were evaluated. Moreover, antioxidant and anticancer activity were investigated. Also, its ability to inhibit biofilm against clinical strains of E. coli were determined.