Reactive Oxygen Species, Apoptosis, Antimicrobial Peptides and Human Inflammatory Diseases

Abstract

Excessive free radical generation, especially reactive oxygen species (ROS) leading to oxidative stress in the biological system, has been implicated in the pathogenesis and pathological conditions associated with diverse human inflammatory diseases (HIDs). Although inflammation which is considered advantageous is a defensive mechanism in response to xenobiotics and foreign pathogen; as a result of cellular damage arising from oxidative stress, if uncontrolled, it may degenerate to chronic inflammation when the ROS levels exceed the antioxidant capacity. Therefore, in the normal resolution of inflammatory reactions, apoptosis is acknowledged to play a crucial role, while on the other hand, dysregulation in the induction of apoptosis by enhanced ROS production could also result in excessive apoptosis identified in the pathogenesis of HIDs. Apparently, a careful balance must be maintained in this complex environment. Antimicrobial peptides (AMPs) have been proposed in this review as an excellent candidate capable of playing prominent roles in maintaining this balance. Consequently, in novel drug design for the treatment and management of HIDs, AMPs are promising candidates owing to their size and multidimensional properties as well as their wide spectrum of activities and indications of reduced rate of resistance.

Antimicrobial peptides as natural bio-preservative to enhance the shelf-life of food

“…From the structural study, it was confirmed that plant defensins are characterized by 8 cysteine and 2 glycine at position 13 and 34 with an aromatic acid and glutamic acid in its structure. Plant defensins do not show antibacterial activity but possess antifungal activity against plants and human pathogens (Oyinloye et al 2015).…”

“…There are about 30 cathelicidins reported from mammals. The cathelicidin (LL-37) present in the human body is known for its activity against bacteria, fungi and viruses (Oyinloye et al 2015).…”

“…(ii) Amino acid enriched peptides These peptides are rich in amino acids, such as proline and glycine. These are generally found in mammals and insects with strong antimicrobial activity (Bagley 2014;Oyinloye et al 2015).…”

Cationic PEGylated liposomes incorporating an antimicrobial peptide tilapia hepcidin 2–3: an adjuvant of epirubicin to overcome multidrug resistance in cervical cancer cells

“…1 For example, cotreatments of magainin analog, one AMP derivative and two anticancer drugs, cis-Platinum, and etoposide have shown synergistic antitumor effects, primarily due to the formation of voltagedependent ion channels that change membrane potential and functionality. 1,46 Hepcidin, composed of 20 amino acids, functions as an important regulator of intestinal iron absorption by binding to the iron exporter ferroportin, thus inhibiting iron absorption. 47 In the process of inflammation, hepcidin can be secreted by the liver and retains mammalian iron balance.…”

“…AMPs also exhibit anticancer activity by inducing cytolytic action on tumor cells. 1,2 Hepcidin, an AMP, was originally isolated from Oreochromis mossambicus. 3 There are three hepcidin isoforms, namely hepcidin 1-5, hepcidin 2-2, After membrane attachment, such AMPs may form pores via insertion into lipid bilayers or cause membrane perturbation to disrupt intracellular pathways.…”