Contents lists available at ScienceDirect Journal of Ethnopharmacology journal homepage: www.elsevier.com/locate/jep Vasorelaxant and cardiovascular properties of the essential oil of Pogostemon elsholtzioides Arumugasamy Shiva Kumar a , Karnan Jeyaprakash b , David Raj Chellappan c , Ramar Murugan a, ⁎ a School of Chemical and Biotechnology, SASTRA University, Thanjavur 613401, Tamil Nadu, India b North Eastern Institute of Folk Medicine (Ministry of AYUSH), East Siang District, Pasighat 791102, Arunachal Pradesh, India c Central Animal Facility, School of Chemical and Biotechnology, SASTRA University, Thanjavur 613401, Tamil Nadu, India ARTICLE INFO Keywords: Pogostemon elsholtzioides Essential oil Curzerene Vasorelaxant Cardiovascular ABSTRACT Ethnobotanical relevance: Pogostemon elsholtzioides Benth. (Lamiaceae) is an aromatic shrub, endemic to eastern Himalaya region. The leaves are used for treating goiter and high blood pressure (BP) by indigenous people in Arunachal Pradesh, India. Young leaves are used as vegetable and leaf decoction is also used for cough, cold and headache by some indigenous communities in Northeast India. Aim of the study: This species is used for treating hypertension and the genus Pogostemon is rich in essential oil. Therefore, the present study was aimed at investigation of the chemical constituents, vasorelaxant and cardiovascular effects of the essential oil of P. elsholtzioides. Materials and methods: P. elsholtzioides was collected from Pasighat, Arunachal Pradesh, India and essential oil was extracted from shade dried leaves. Essential oil was analyzed by GC-FID and GC-MS and the volatile constituents were identified. Vasorelaxant and cardiovascular properties of the essential oil were studied against phenylephrine induced contraction in isolated endothelium intact aortic preparations and by measuring systolic and diastolic BP, mean arterial pressure (MAP) and heart rate (HR) after carotid artery cannulation in Wistar rats. Results: The essential oil was rich in sesquiterpenes and curzerene, benzophenone, α-cadinol and germacrone were major constituents. The essential oil exhibited significant vasodilation effect in phenylephrine induced contracted aortic rings. Vasorelaxant effect of the essential oil was also observed both in the presence and absence of Nitro-L-arginine methyl ester against phenylephrine-contracted aortic rings. It also induced reduction of systolic and diastolic BP, MAP and HR. Conclusions: Essential oil of P. elsholtzioides exhibited significant vasorelaxant effect against endothelium intact aortic preparation mediated through nitric oxide dependent pathway and also reduced BP. However, further study is needed to screen the role of calcium ions in both intracellular and extracellular pathway. 1. Introduction Raised blood pressure (BP) is detrimental and one of the important causes of premature death around the world. It is a major factor for cardiovascular disease. The World Health Organization reports that around 40% of the global population is having increased BP (WHO, 2011). Besides lifestyle and nutritional factors, a number of drugs are commercially available in the markets to reduce elevated BP and maintain the BP. However, many indigenous communities around the world use a few plant species to reduce and maintain BP. Pogostemon elsholtzioides Benth., belonging to the Family Lamiaceae, is one such plant used by an indigenous community in Northeast India to treat hypertension (Saha and Sundriyal, 2013). Pogostemon elsholtzioides is an aromatic shrubby species, endemic to eastern Himalaya and growing in Northeast region in India and Bhutan. It is locally called ‘Nakhrang sheng’ by Monpa community in Arunachal Pradesh, India, who traditionally uses the leaves for goiter and maintaining BP (Saha and Sundriyal, 2013). It is also locally called ‘Bangla Tanam’ by Bangnis people in Arunachal Pradesh, who use the leaf decoction of the species for cough, cold and headache (Gupta, 2006). Naga community in Senapati district in Manipur, India call it ‘Phiziio’ and use the young leaves as vegetable (Pfoze et al., 2011). Pogostemon is an aromatic genus, rich in mixture of volatile essential oil compounds. The traditional use of this aromatic plant for main- taining BP by an indigenous community in India and the aromatic nature of the species inspired us to carry out the present study. The http://dx.doi.org/10.1016/j.jep.2017.01.036 Received 26 May 2016; Received in revised form 19 December 2016; Accepted 19 January 2017 ⁎ Corresponding author. E-mail address: ramarmurugan@yahoo.com (R. Murugan). Journal of Ethnopharmacology 199 (2017) 86–90 Available online 26 January 2017 0378-8741/ © 2017 Elsevier B.V. All rights reserved. MARK