Microbiology and Biotechnology Research: An Overview Vol. 6

Citrus aurantium L., commonly known as bitter orange, is a tree whose fruit, flowers, leaves, and peel are widely used in industry and traditional medicine. The extracts and essential oils derived from this plant and its phytoconstituents have demonstrated antimicrobial, antispasmodic, anxiolytic, antiobesity, antioxidant, and anti-inflammatory activities. Numerous reports have described the biological activities of Citrus aurantium; however, a complete summary of its anti-inflammatory properties is lacking. This chapter summarises the anti-inflammatory activities and mechanisms of action of extracts and essential oils derived from different plant parts of Citrus aurantium. Various in vitro and in vivo studies have reported that extracts and essential oils possess anti-inflammatory properties. These findings suggest that Citrus aurantium modulates pro-inflammatory mediators, such as interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α), IL-1β, nitric oxide (NO), and enzymes such as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), at the transcriptional and protein levels.

Moreover, this species has been shown to reduce acute and chronic inflammation in vivo. Additionally, this chapter describes the potential mechanisms of its anti-inflammatory activities, including inhibition of the NF-κB pathway. In conclusion, Citrus aurantium exhibits anti-inflammatory activity, highlighting its potential therapeutic application in diseases involving inflammation and its use as a source of immunomodulatory compounds.