Anti-inflammatory and bronchodilatory constituents of leaf extracts of Anacardium occidentale L. in animal models

Oluwakemi Josephine Awakan; Sylvia Omonirume Malomo; Abdullahi Adeyinka Adejare; Adedoyin Igunnu; Olubunmi Atolani; Abiodun Humphrey Adebayo; Bamidele Victor Owoyele

doi:10.1016/j.joim.2017.12.009

Anti-inflammatory and bronchodilatory constituents of leaf extracts of Anacardium occidentale L. in animal models

J Integr Med. 2018 Jan;16(1):62-70. doi: 10.1016/j.joim.2017.12.009. Epub 2017 Dec 20.

Authors

Oluwakemi Josephine Awakan¹, Sylvia Omonirume Malomo², Abdullahi Adeyinka Adejare³, Adedoyin Igunnu⁴, Olubunmi Atolani⁵, Abiodun Humphrey Adebayo⁶, Bamidele Victor Owoyele⁷

Affiliations

¹ Department of Biological Sciences, College of Science and Engineering, Landmark University, PMB 1001, Omu-Aran, Nigeria. Electronic address: amira.oluwakemi@lmu.edu.ng.
² Department of Biological Sciences, College of Science and Engineering, Landmark University, PMB 1001, Omu-Aran, Nigeria; Department of Biochemistry, Faculty of Life Sciences, University of Ilorin, PMB 1515, Ilorin, Nigeria.
³ Department of Physiology, Faculty of Basic Medical Sciences, College of Medicine of the University of Lagos, PMB 12003, Lagos, Nigeria.
⁴ Department of Biochemistry, Faculty of Life Sciences, University of Ilorin, PMB 1515, Ilorin, Nigeria.
⁵ Department of Chemistry, Faculty of Physical Sciences, University of Ilorin, PMB 1515, Ilorin, Nigeria.
⁶ Department of Biochemistry, College of Science and Technology, Covenant University, PMB 1023, Ota, Nigeria.
⁷ Department of Physiology, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, PMB 1515, Ilorin, Nigeria.

PMID: 29397096
DOI: 10.1016/j.joim.2017.12.009

Abstract

Objective: Anacardium occidentale L. leaf is useful in the treatment of inflammation and asthma, but the bioactive constituents responsible for these activities have not been characterized. Therefore, this study was aimed at identifying the bioactive constituent(s) of A. occidentale ethanolic leaf extract (AOEL) and its solvent-soluble portions, and evaluating their effects on histamine-induced paw edema and bronchoconstriction.

Methods: The bronchodilatory effect was determined by measuring the percentage protection provided by plant extracts in the histamine-induced bronchoconstriction model in guinea pigs. The anti-inflammatory effect of the extracts on histamine-induced paw edema in rats was determined by measuring the increase in paw diameter, after which the percent edema inhibition was calculated. The extracts were analyzed using gas chromatography-mass spectrometry to identify the bioactive constituents. Column chromatography and Fourier transform infrared spectroscopy were used respectively to isolate and characterize the constituents. The bronchodilatory and anti-inflammatory activities of the isolated bioactive constituent were evaluated.

Results: Histamine induced bronchoconstriction in the guinea pigs and edema in the rat paw. AOEL, hexane-soluble portion of AOEL, ethyl acetate-soluble portion of AOEL, and chloroform-soluble portion of AOEL significantly increased bronchodilatory and anti-inflammatory activities (P < 0.05). Oleamide (9-octadecenamide) was identified as the most abundant compound in the extracts and was isolated. Oleamide significantly increased bronchodilatory and anti-inflammatory activities by 32.97% and 98.41%, respectively (P < 0.05).

Conclusion: These results indicate that oleamide is one of the bioactive constituents responsible for the bronchodilatory and anti-inflammatory activity of A. occidentale leaf, and can therefore be employed in the management of bronchoconstriction and inflammation.

Keywords: Anacardium occidentale L.; Anti-inflammatory; Asthma; Bioactive constituent; Bronchodilatory; Oleamide.

MeSH terms

Anacardium / chemistry*
Animals
Anti-Inflammatory Agents / administration & dosage*
Anti-Inflammatory Agents / chemistry
Bronchoconstriction / drug effects
Bronchodilator Agents / administration & dosage*
Bronchodilator Agents / chemistry
Edema / drug therapy*
Edema / physiopathology
Female
Guinea Pigs
Humans
Male
Oleic Acids / administration & dosage
Oleic Acids / chemistry
Plant Extracts / administration & dosage*
Plant Extracts / chemistry
Plant Leaves / chemistry
Rats
Rats, Wistar

Substances

Anti-Inflammatory Agents
Bronchodilator Agents
Oleic Acids
Plant Extracts
oleylamide