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Monographs of Topical Drugs that Have Caused Contact Allergy/Allergic Contact Dermatitis
Published in Anton C. de Groot, Monographs in Contact Allergy, 2021
Gramicidin is a heterogeneous mixture of 6 peptide antibiotics (PubChem) obtained from the soil bacterium Bacillus brevis. Gramicidin C or S is a cyclic, ten-amino acid polypeptide and gramicidins A, B, D are linear. Gramicidin is one of the two principal components of tyrothricin (ChemIDplus). It is active against most gram-positive bacteria and some gram-negative organisms. Gramicidin D is used primarily as a topical antibiotic for the treatment of skin lesions, surface wounds and eye infections (1).
Antibiotics: The Need for Innovation
Published in Nathan Keighley, Miraculous Medicines and the Chemistry of Drug Design, 2020
Other antibacterial agents are designed to act on the plasma membrane. The polypeptides valinomycin and gramicidin A cause the uncontrolled movement of ions across the cell membrane. Valinomycin acts as an inverted detergent and complexes a ‘naked’ potassium ion. The hydrophobic outer of the complex can pass the cell membrane and deposit the potassium ion outside the cell, resulting in fatality. Typically, K+ is in high concentration inside the cell and can only pass the membrane via specialised transport proteins and this equilibrium is disrupted by valinomycin. Valinomycin is selective towards K+, having the correct spatial arrangement of donor atoms to displace water ligands and form bonds to K+. Other ions, such as Na+, are not the correct size to fit and displacing water ligands is too difficult. Unfortunately, the toxicity is not selective to bacteria; affecting mammal cells as well. Gramicidin A is a peptide consisting of 15 amino acids, which coil into a helix where hydrophobic side chains point outwards and interact with the membrane. Two helices of gramicidin A must combine to span the membrane and the hydrophobic interior of the helix serves as a channel for the passage of ions. However, gramicidin A is also toxic to humans. Producing compounds to serve as drugs which employ the ‘magic bullet’ approach is a challenge for medicinal chemists. Compounds must be toxic to bacteria, but safe to use and to achieve this, target specificity is essential when developing effective antibiotics in the future.
Bacitracin and Gramicidin
Published in M. Lindsay Grayson, Sara E. Cosgrove, Suzanne M. Crowe, M. Lindsay Grayson, William Hope, James S. McCarthy, John Mills, Johan W. Mouton, David L. Paterson, Kucers’ The Use of Antibiotics, 2017
Gramicidin is highly active against many Gram-positive bacteria including Staphylococcus, Streptococcus, and Enterococcus species. Neisseria species are relatively resistant. Gram-negative bacilli including Pseudomonas aeruginosa are susceptible, although conflicting data exist about the degree of susceptibility (Kondejewski et al., 1996; Zhang et al., 2000). Gramicidin has a bactericidal activity against Mycoplasma species and is known to be active against several Mycobacterium species and several pathogenic fungi, including Candida albicans. Interesting to note, it also appears to have antiviral activity against HIV and herpes simplex viruses (HSV-1, HSV-2) (Bourinbaiar et al., 1994; Bourinbaiar and Lee-Huang, 1994; Bourinbaiar and Lee, 1996; Bourinbaiar and Coleman, 1997).
Gramicidin inhibits cholangiocarcinoma cell growth by suppressing EGR4
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2020
Xiaoli Gong, Liming Zou, Miaomiao Wang, Yingheng Zhang, Shuxian Peng, Mingtian Zhong, Jiankui Zhou, Xun Li, Xiaodong Ma
Gramicidin is a linear 15 residue peptide of amino acids and functions as an antibiotic by disrupt cellular transmembrane potential (Figure 1(A)). To explore the role of gramicidin in cholangiocarcinoma cell proliferation, we treated two cholangiocarcinoma cell lines, RBE and HuCCT1, with gramicidin. We found that cholangiocarcinoma cell lines were sensitive to gramicidin treatment and the IC50 for both cell lines was as lower as 50 nM (Figure 1(B,C)). In addition, the two type of cholangiocarcinoma cell lines were all shown the necrotic cell death demonstrated as floating cellular debris (Figure 1(D)). To further analyse the cytotoxicity of gramicidin, we detect the necrotic cell death by using Calcein AM (green, live cells) and ethidium homodimer-1 (red, necrotic dead cells) staining. As shown in Figure 1(D), RBE and HuCCT1 cells exhibited necrotic dead cells after gramicidin treatment.
Balamuthia mandrillaris: pathogenesis, diagnosis, and treatment
Published in Expert Opinion on Orphan Drugs, 2020
Mohammad Ridwane Mungroo, Naveed Ahmed Khan, Ruqaiyyah Siddiqui
Gramicidin, an antibiotic which is a mixture of gramicidin A, B, and C, forms a β-helix conformation within membranes and consequently induces local membrane deformation. The drug showed amoebicidal activity against B. mandrillaris at a concentration of 10 μg/mL but was not effective at a concentration of 1 μg/mL [63].