Inhibitory effects of a standardized extract of Justicia pectoralis in an experimental rat model of airway hyper- responsiveness Carlos T. M. Moura a , Francisco J. Batista-Lima a , Teresinha S. Brito a , Alfredo A. V. Silva a , Luan C. Ferreira a ,C assia R. Roque a , Karoline S. Arag~ ao a , Alexandre Havt a , Francisco N. Fonseca b , Luzia K. A. M. Leal b and Pedro J. C. Magalh~ aes a a Department of Physiology and Pharmacology, School of Medicine and b Department of Pharmacy, School of Pharmacy, Odontology and Nursing, Federal University of Cear a, Fortaleza, Brazil Keywords biological evaluation of natural products; tissue and cellular pharmacology Correspondence Pedro J. C. Magalh~ aes, Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Cear a, R. Cel. Nunes de Melo 1127, Rodolfo Te ofilo, 60430-270 Fortaleza, CE, Brazil. E-mail: pjcmagal@ufc.br Received September 7, 2016 Accepted December 10, 2016 doi: 10.1111/jphp.12689 Abstract Objective Justicia pectoralis is a plant useful for the treatment of respiratory dis- eases. Here, we studied the antiasthmatic properties of a standardized extract of J. pectoralis (Jp). Methods Ovalbumin (OVA)-sensitized rats were actively challenged with saline or OVA to study airway hyper-responsiveness after oral treatment with saline or Jp. The ability of Jp to inhibit hyper-reactivity was evaluated in isolated trachea mounted in isolated organ bath chamber. Key findings Using KCl or carbachol as contractile agents, tracheal rings of OVA-challenged rats contracted with higher magnitude than trachea of rats chal- lenged with saline. Such hyper-responsive phenotype of OVA-challenged tissues decreased with Jp administration. In Ca + -free medium, Jp or its major con- stituent coumarin inhibited preferentially the contractions induced by Ca 2+ addi- tion in tissues of OVA-challenged rats stimulated with KCl or acetylcholine. In tissues depleted of their internal Ca + stores in the presence of thapsigargin, Jp inhibited the contraction induced by capacitative Ca 2+ entry. By gavage, Jp abol- ished the increase caused by challenge with OVA on the levels of IL-1b and TNF- a in the bronchoalveolar fluid and also impaired the changes in gene expression of canonical transient receptor proteins. Conclusions Jp has antiasthmatic properties in an experimental model that reproduces tracheal hyper-reactivity. Introduction Justicia pectoralis Jacq. var. stenophylla Leonard (Acan- thaceae) is a herb largely used in folk medicine of South and Central America to treat respiratory complaints. [1] Named popularly as ‘chamb a’ in the Brazilian north-east, this spe- cies is useful as expectorant and is in the list of plants poten- tially useful for phytotherapy purposes according to the Brazilian Health Surveillance Agency (Anvisa). [2] A few studies reinforce the notion that J. pectoralis can be effective in the respiratory system, [1,3] and a recent preliminary study revealed potential antiasthmatic properties of an aqueous extract obtained from J. pectoralis by its ability to inhibit histamine-induced contraction on guinea-pig trachea. [4] In the city of Fortaleza, Brazil, pharmacists involved with a project named Farm acias Vivas (Living Pharmacies) maintain species of J. pectoralis in cultivated gardens under low-light conditions, to produce traditional remedies for respiratory diseases. [5] De Vries et al. [6] firstly revealed that extracts of J. pectoralis yielded after purification several coumarin compounds. From the local species of J. pec- toralis cultivated in Fortaleza, Lino et al. [7] reported the occurrence of coumarin and 7-hydroxycoumarin (umbellif- erone) as major constituents, besides small amounts of acetylated coumaric acid, acetylated melilotic acid and b-sitosterol. Coumarin and umbelliferone are candidate compounds to be involved in the principle active of the beneficial effects of this plant in folk medicine. © 2017 Royal Pharmaceutical Society, Journal of Pharmacy and Pharmacology, 69 (2017), pp. 722–732 722 Research Paper Downloaded from https://academic.oup.com/jpp/article/69/6/722/6127768 by guest on 26 July 2022