Lisozima è una proteina del tipo enzimatico litico che si trova nel corpo umano (fegato, milza. saliva) uova ed in altri tessuti animali, un peptide con attività antimicrobica.

Il nome definisce la struttura della molecola:

• "Liso-" indica che l'enzima ha la capacità di lisare, ovvero di distruggere o rompere, le pareti cellulari dei batteri.
• "-zima" indica che si tratta di un enzima, che è una classe di proteine con attività catalitica.

Pertanto, il nome "lisozima" indica un enzima che ha la capacità di lisare le pareti cellulari dei batteri.

La lisozima può essere prodotta sia attraverso un processo di sintesi naturale che in modo sintetico a livello industriale. Di seguito è riportato un riassunto dei due processi, prima in italiano e poi in inglese:

Sintesi naturale:

La lisozima è prodotta in modo naturale da vari organismi, inclusi gli esseri umani. Viene sintetizzata negli organi come le ghiandole salivari, le ghiandole lacrimali e i globuli bianchi. La sintesi avviene a livello cellulare attraverso i meccanismi di trascrizione e traduzione del DNA e dell'RNA, che portano alla formazione dell'enzima lisozima.

Sintesi chimica industriale:

Il processo di sintesi chimica industriale della lisozima prevede i seguenti passaggi:

• Isolamento della lisozima. La lisozima può essere isolata da fonti naturali, come le uova di gallina, che sono una delle principali fonti commerciali di lisozima.
• Estrazione. La lisozima viene estratta dalle uova di gallina o da altre fonti naturali utilizzando tecniche di estrazione chimica o di purificazione.
• Purificazione. Il campione estratto viene sottoposto a processi di purificazione, come la filtrazione, la cromatografia o la precipitazione, per ottenere una lisozima pura.
• Formulazione:.La lisozima pura viene formulata in soluzioni o polveri utilizzate per applicazioni mediche.

Industrialmente si presenta in forma di polvere bianca.

A cosa serve e dove si usa

Lisozima ha diverse applicazioni nel campo medico. È utilizzata come agente antimicrobico naturale, poiché può distruggere le pareti cellulari dei batteri gram-positivi. Viene utilizzata anche come conservante in alcuni prodotti farmaceutici e alimentari. Inoltre, la lisozima viene studiata per le sue proprietà immunomodulanti e antinfiammatorie, e potrebbe avere un potenziale utilizzo nella terapia delle malattie infiammatorie e come biomarcatore per alcune condizioni patologiche.

Alimentazione

Ingrediente inserito nella lista degli additivi alimentari europei come  E1105 con funzione di conservante e viene addizionato nei formaggi (ad esempio il grana padano) per mantenerne l'integrità e per contrastare i batteri  Clostridia spp

Medicina

Ha funzioni antiossidanti, antinfiammatorie ed antibatteriche in particolar modo contro batteri Gram-positivi e Gram-negativi (1), svolge un'attività protettiva nella malattia di Alzheimer (2), nel trattamento di infezioni dal batterio Staffilococcus Aureus (3) è un sostituto efficace alla clorexidina e alla benzidamina nel trattamento della faringite acuta (4).

Cosmetica

Agente condizionante della pelle.  Rappresenta il perno del trattamento topico della pelle in quanto ha la funzione di ripristinare, aumentare o migliorare la tolleranza cutanea a fattori esterni, compresa la tolleranza dei melanociti. La funzione più importante dell'agente condizionante è  prevenire la disidratazione della pelle, ma il tema è piuttosto complesso e coinvolge emollienti ed umettanti che possono essere aggiunti nella formulazione.

• Formula molecolare  C₉₉H₁₅₉N₃₇O₂₃
• Peso molecolare  2235.6
• CAS   9001-63-2   235-747-3
• UNII   
• EC number   232-620-4

Bibliografia_________________________________________________________________________

(1) Vilcacundo R, Méndez P, Reyes W, Romero H, Pinto A, Carrillo W. Antibacterial Activity of Hen Egg White Lysozyme Denatured by Thermal and Chemical Treatments. Sci Pharm. 2018 Oct 30;86(4):E48. doi: 10.3390/scipharm86040048.

Abstract. The aim of this study was to increase the antibacterial spectrum of modified hen egg white lysozyme (HEWL) with thermal and chemical treatments against Gram-negative bacteria. The antibacterial activity of heat-denatured HEWL and chemical denatured HEWL against Gram-negative and Gram-positive bacteria was evaluated in 15 h of incubation tests. HEWL was denatured by heating at pH 6.0 and pH 7.0 and chemical denaturing was carried out for 1.0, 1.5, 2.0, and 4.0 h with DL-Dithiothreitol (DTT). HEWL modified by thermal and chemical treatments was characterized using the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis method. Heat-denatured HEWL lytic activity against Micrococcus lysodeikticus lessened with increasing temperature and time of incubation with the chemical agent (DTT). The loss of lytic activity in modified HEWL suggests that the mechanism of action of the antibacterial activity is not dependent on the lytic activity. Thermal and chemical treatments of HEWL enabled the production of oligoforms and increased antibacterial activity over a wider spectrum. Heat-denatured HEWL at pH 6.0 and chemically-denatured HEWL increased the HEWL antibacterial spectrum against Gram-negative bacteria (Escherichia coli ATCC 25922). HEWL at 120 °C and pH 6.0 (1.0 mg/mL) inhibited 78.20% of the growth of E. coli. HEWL/DTT treatment for 4.0 h (1.0 mg/mL) inhibited 68.75% of the growth E. coli. Heat-denatured HEWL at pH 6.0 and pH 7.0 and chemically-denatured HEWL (1.0, 1.5, 2.0, and 4.0 h with DTT) were active against Gram-positive bacteria (Staphylococcus carnosus CECT 4491T). Heat-denatured and chemical-denatured HEWL caused the death of the bacteria with the destruction of the cell wall. LIVE/DEAD assays of fluorescent dye stain of the membrane cell showed membrane perturbation of bacteria after incubation with modified HEWL. The cell wall destruction was viewed using electron microscopy. The results obtained in this study suggest that heat-denatured HEWL at pH 6.0 and chemical-denatured HEWL treatments increase the HEWL antibacterial activity against Gram-negative bacteria.

(2) Helmfors L, Boman A, Civitelli L, Nath S, Sandin L, Janefjord C, McCann H, Zetterberg H, Blennow K, Halliday G, Brorsson AC, Kågedal K. Protective properties of lysozyme on β-amyloid pathology: implications for Alzheimer disease. Neurobiol Dis. 2015 Nov;83:122-33. doi: 10.1016/j.nbd.2015.08.024. 

(3) Chen, L.L., Shi, W.P., Zhang, T.D., Zhou, Y.Q., Zhao, F.Z., Ge, W.Y., Jin, X.Q., Lin, W.J., Guo, W.H. and Yin, D.C., 2022. Antibacterial activity of lysozyme-loaded cream against MRSA and promotion of scalded wound healing. International Journal of Pharmaceutics, 627, p.122200.

Abstract. Staphylococcus aureus (S. aureus) infection, especially its drug-resistant bacterial infection, is a great challenge often faced by clinicians and patients, and it is also one of the most important threats to public health. Finding a safe and effective antibacterial agent is of great significance for the prevention and treatment of S. aureus infection. Lysozyme is known to have antibacterial effects against Gram-positive bacteria including S. aureus. Here, high-quality lysozyme with a purity of more than 99% and an activity of more than 60, 000 U/mg was prepared from egg white, which showed excellent antibacterial activity against three strains of S. aureus, especially against MRSA. Furthermore, an antibacterial cream loaded with lysozyme was prepared and tested in scald wound healing. The lysozyme-loaded cream exhibited the effect of preventing wound infection and promoting wound healing on scalds, and no toxicity was found in animal organs. Overall, lysozyme showed great application potential in the prevention and treatment of infections caused by S. aureus and scalded wound healing. The most remarkable discovery in this work is the unexpectedly powerful inhibitory effect of lysozyme on the drug-resistant bacterial, especially MRSA, which is usually very difficult to deal with using normal antibacterial drugs.

(4) Golac-Guzina, N., Novaković, Z., Sarajlić, Z., Šukalo, A., Džananović, J., Glamočlija, U., Kapo, B., Čordalija, V. and Mehić, M., 2019. Comparative study of the efficacy of the lysozyme, benzydamine and chlorhexidine oral spray in the treatment of acute tonsillopharyngitis-results of a pilot study. Acta Medica Academica, 48(2), pp.140-146.

Abstract. Objective. Lysozyme is a natural antimicrobial and immunomodullatory enzyme, which is produced as a host response to infectious agents. The objective of this study was to compare the efficacy and safety of lysozyme-based versus benzydamine and chlorhexidine-based oral spray in patients with an acute tonsillopharyngitis associaated with a common cold. Patients and Methods. A prospective two-arm pilot study (lysozyme/cetylpyridinium/lidocaine spray versus: benzydamine spray—arm 1; chlorhexidine/lidocaine spray—arm 2) was conducted in the primary health care unit. Efficacy was evaluated by the patient’s self-assessment of pain, difficulty in swallowing and the throat swelling, by using the visual analog scale (VAS) at baseline and three follow-up visits. Safety was evaluated by the assessment of the frequency and severity of adverse effects. Results. Lysozyme-based spray reduced pain faster than benzydamine-based spray and slower than chlorhexidine-based spray. Lysozyme-based and chlorhexidine-based sprays similarly reduced difficulty in swallowing, but were faster than benzydamine-based spray. Similar effects on the reduction of throat swelling were seen in all treated groups. All tested products showed proper safety and were well tolerated, with no serious adverse events reported. Conclusions. The lysozyme-based oral spray was shown to be effective and safe in the reduction of pain, difficulty in swallowing and throat swelling in patients with acute tonsillopharyngitis associated with a common cold. Lysozyme-based oral spray (containing natural compound with advantages of influencing immune system and preventing recurrences) had similar activity to benzydamine and chlorhexidine-based oral antiseptic sprays.