Topical anti-inflammatory effect and HPLC fingerprint of ethanol extract of the rhizome of <i>Costus spectabilis</i> (Fenzl) <i>K. Schum</i>

Abstract

Background: Aqueous extract of Costus spectabilis (Fenzl) K. Schum (Costaceae) has been used traditionally as remedy for arthritis and rheumatism.

Methods: Extract was screened for the different classes of phyto-constituents using standard methods. HPLC analysis was developed to establish the fingerprint of the extract, while the topical anti-inflammatory  study was evaluated  following xylene-induced ear oedema model in mice.

Results: Topical application of xylene to both surfaces of the ear caused inflammation as indicated by increased thickness of the ear and mass of the ear punches. Extract (5 mg/ml) significantly (p≤ 0.01) decreased mean increase in the ear thickness comparable to the standard anti-inflammatory drug, indomethacin (0.5 mg/ml). Also, extract (5 mg/ml) and indomethacin (0.5 mg/ml) inhibited inflammation by 76% and 68%, respectively. Additionally, C. spectabilis extract conferred a dose-dependent decrease in mass of ear punches. Doses of 5 and 2.5 mg/ml elicited greater inhibition (p≤ 0.001) of the initial increase in mass of the ear punches in the control group than indomethacin. The phytochemical constituents of the extract were identified as flavonoids, saponins, steroids and triterpenes, with saponins being most abundant (457.2 mg/g). Furthermore, HPLC fingerprint profile of the extract was established.

Conclusion: Extract of C. spectabilis demonstrated topical anti-inflammatory effect in xylene-induced ear oedema model in mice and this could be due to one or some of the phytometabolites.