Anti-inflammatory activity of raw and processed stingless bee honey

Abstract

The anti-inflammatory activity of raw and processed Kelulut stingless bee honey was investigated for its ability to inhibit nitric oxide (NO) production in lipopolysaccharide-stimulated RAW 264.7 cells. Raw honey was optimally processed by thermal processing and thermosonication at 90°C. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) cell viability assay showed that Kelulut honey from 7.8 to 500 µg/mL was not cytotoxic to RAW 264.7 cells as it resulted in at least 80% viable cells after 24 hr. Both raw and processed honey from 10 to 300 µg/mL displayed an increase and decrease in NO concentrations, suggesting a mixed effect of NO inhibition and enhancement. Maximum NO inhibition of 17.5% was recorded from 20 µg/mL of thermally processed honey while the highest NO enhancement of 7.8% was from 10 µg/mL of thermosonicated honey. The NO effects were independent of honey concentration and processing techniques, suggesting its potential robustness in medicinal properties as part of the diet.