Vehicles for atopic dermatitis therapies: more than just a placebo

A topical vehicle is a ‘carrier system’ for an active pharmaceutical (or cosmetic) substance, referred to hereafter as the drug, but a vehicle may also be used on its own as an emollient to ameliorate dry skin. It is well established that the vehicle plays an important role in determining the bioavailability of a given drug at its ultimate target within the skin. Yet in the treatment of atopic eczema/dermatitis (AD), wherein the structure and function of the skin's outer barrier play a pivotal role in the development and course of the condition, the interaction of the vehicle with this barrier carries a particular importance. It is now clear that the often-considered inert excipients of a vehicle bring about changes within the skin at the molecular level that promote barrier restoration and enhance innate immune defenses with therapeutic value to AD patients. Moreover, the vehicle control in randomized controlled trials (RCTs) increasingly displays significant efficacy. In light of this, we consider the implications of vehicle design in relation to AD pathophysiology and the role vehicles play as controls in RCTs of new drug treatments for this condition

Vintage venoms: proteomic and pharmacological stability of snake venoms stored for up to eight decades

For over a century, venom samples from wild snakes have been collected and stored around the world. However, the quality of storage conditions for "vintage" venoms has rarely been assessed. The goal of this study was to determine whether such historical venom samples are still biochemically and pharmacologically viable for research purposes, or if new sample efforts are needed. In total, 52 samples spanning 5 genera and 13 species with regional variants of some species (e.g., 14 different populations of Notechis scutatus) were analysed by a combined proteomic and pharmacological approach to determine protein structural stability and bioactivity. When venoms were not exposed to air during storage, the proteomic results were virtually indistinguishable from that of fresh venom and bioactivity was equivalent or only slightly reduced. By contrast, a sample of Acanthophis antarcticus venom that was exposed to air (due to a loss of integrity of the rubber stopper) suffered significant degradation as evidenced by the proteomics profile. Interestingly, the neurotoxicity of this sample was nearly the same as fresh venom, indicating that degradation may have occurred in the free N- or C-terminus chains of the proteins, rather than at the tips of loops where the functional residues are located. These results suggest that these and other vintage venom collections may be of continuing value in toxin research. This is particularly important as many snake species worldwide are declining due to habitat destruction or modification. For some venoms (such as N. scutatus from Babel Island, Flinders Island, King Island and St. Francis Island) these were the first analyses ever conducted and these vintage samples may represent the only venom ever collected from these unique island forms of tiger snakes. Such vintage venoms may therefore represent the last remaining stocks of some local populations and thus are precious resources. These venoms also have significant historical value as the Oxyuranus venoms analysed include samples from the first coastal taipan (Oxyuranus scutellatus) collected for antivenom production (the snake that killed the collector Kevin Budden), as well as samples from the first Oxyuranus microlepidotus specimen collected after the species' rediscovery in 1976. These results demonstrate that with proper storage techniques, venom samples can retain structural and pharmacological stability. This article is part of a Special Issue entitled: Proteomics of non-model organisms. Biological significance: •These results show that with proper storage venoms are useful for decades.•These results have direct implications for the use of rare venoms

Antimicrobial Natural Products

Although the first antibiotic, penicillin, was discovered in 1928 from a microbial natural source (a mould, Penicillium notatum), there is earlier evidence of using natural materials including moulds and herbs for the treatment of infections. Following the serendipitous discovery of penicillin by Alexander Fleming, there have been hundreds of antibiotics (natural, semisynthetic and synthetic) discovered for clinical uses. However, the pathogenic organisms have developed resistances to existing antibiotics though various mechanisms. Such antibiotic resistance or antimicrobial resistance (AMR) is a critical problem of today’s healthcare system urging the development of new antibiotics. This chapter has primarily focused into antimicrobial compounds developed through natural routes that are currently available as antibiotics for clinical uses and/or are at various developmental stages within the drug development pipeline for potential treatment of minor and life threatening infections. The chapter also provides an overview on the catastrophic problem of antimicrobial resistance, its causes, how it spreads as well as modes of developing antimicrobial resistance (AMR)