China
Africa
Explore chapters and articles related to this topic
Reverse Pharmacology and Ayurvedic Medicine
Published in Amritpal Singh Saroya, Reverse Pharmacology, 2018
L-dopa content: 2.5 g%-12.0 g% (Damodaran and Ramaswamy 1937). Other phytochemicals: mucunain, pruriendine, 5-HTP, aminoacids, dopaquinones, melanin, alanine, linolenic, methionine, and niacin, etc. M. pruriens seeds and HP-200 standardised for L-dopa content (3.9-4.2% and 3.0-3.7%, respectively). A study by Vaidya et al. (1978) reported the role of M. pruriens in the treatment of Parkinson’s disease (Fig. 11).
Pruritus in Atopic Dermatitis: Pathophysiology and Treatment Options
Published in Donald Rudikoff, Steven R. Cohen, Noah Scheinfeld, Atopic Dermatitis and Eczematous Disorders, 2014
Tejesh Surendra Patel, Gil Yosipovitch
Recent studies have revealed a distinct parallel pathway of nonhistaminergic C-nerve fibers that transmit itch in the peripheral nervous system in humans and in the spinothalamic tract of primates (Davidson et al. 2007, Johanek et al. 2007, Namer et al. 2008). These fibers are activated by spicules of the ubiquitous tropical legume cowhage (Mucuna pruriens), known to induce an intense sensation of itch when rubbed or inserted into the skin, without inducing a histaminergic axon reflex (Shelley and Arthur 1955a, 1955b). The mechanism by which cowhage induces itch involves the release of an active protease (mucunain), contained in the spicules, which activates protease activated receptor 2 (PAR-2) and PAR-4 present in the skin (Reddy et al. 2008). These C-nerve fibers are mechano-heat sensitive and not itch-specific, because they also transmit a burning sensation accompanying the itch. PAR-2 has been shown to have a major role in mediating itch in atopic eczema patients (Steinhoff et al. 2003). Nonhistaminergic polymodal C-nerve fibers stimulated by mucunain may therefore have a significant clinical relevance to atopic eczema itch.
Defining the role of mirtazapine in the treatment of refractory pruritus
Published in Journal of Dermatological Treatment, 2021
Bilal Fawaz, Bahir H. Chamseddin, John R. Griffin
Two types of nerve fibers have been shown to mediate itching: unmyelinated C-fibers and Aδ fibers (5). C-fibers are further classified according to the mediators they respond to. Microneurography experiments allowed the isolation of C-fibers that mainly respond to histamine, thus leading to the identification of a histamine-mediated pruritic pathway (3). Additionally, other C-fibers were found to respond to cowhage, specifically to its active component mucunain, a cysteine protease (6,7). As a result, a histamine-independent pathway, mediated by the proteinase-activated receptor PAR2 or PAR4, was also identified (6,7).