Investigation of in-vitro Anti-inflammatory Activity of Hexane Extract of Costus speciosus Leaves

Abstract

Bacground: In the current study, non-polar n-hexane fraction of C. speciosus, family Coastaceae, has been investigated for its anti-inflammatory activity. The previous investigations have proven the biological activity including anti-inflammatory activity of n hexane fractions of Costus speciosus rhizome. Objectives: To investigate in vitro anti-inflammatory activity of hexane extract of C. speciosus leaves (HECS) Methods: A soft extract of C. speciosus leaves was obtained after refluxing with haxane. The in-vitro anti-inflammatory activity (% inhibition) of HECS was investigated by ova albumin denaturation (OAD) and heat induced human red blood cell membrane stabilization (HRBC) assays against a standard, diclofenac sodium (D. sodium). The activity guided fractionation of HECS was done using a silica column fractionation, with gradial elution of n-hexane, carbon tetrachloride (CCl4) and ethyl acetate (EtOAc). Fractions were poolled into 7 sub fractions (A G) using thin layer chromatography (TLC) and determined in-vitro activity. Results: The dose dependent study showed no significant (p = 0.063) activity based on OAD assay at 1.00 mg/mL. However, the HRBC-assay showed a significant (p = 0.004) activity, when compared to D. sodium. The maximum activity of 42.32 (±1.00)% (HECS) and 37.49 (±1.50)% (D. sodium) was observed in OAD-assay and 50.93 (±1.53)% (HECS) and 28.74 (±1.11)% (D. sodium) in HRBC-assay, at a dose of 1.00 mg/mL. The sub fractions, B (100% CCl4) and G (CCl4: EtOAc 50:50, CCl4: EtOAc 25:75 and 100% EtOAc), have shown high in vitro anti-inflammatory inhibition. The % inhibitory activity was found to be, 89.7 (±6.9)% (B) and 92.0 (±8.9)% (G) for HRBC-assay and 55.9 (±4.4)% (B) and 39.4 (±7.2)% (G) for OAD assay, respectively. Conclusions: The anti-inflammatory activity of sub fractions of C. Speciosus based on OAD and HRBC assays indicate that HECS could be used as a potential source for developing novel anti-inflammatory agents.