Disclosed herein are novel dietary supplement compositions comprising enriched 3-O-acetyl-11-keto-β-boswellic acid and enriched demethylated curcuminoids, wherein the composition exhibits anti-inflammatory, antiulcerogenic and antioxidant activities. Also disclosed are novel compositions comprising enriched 3-O-acetyl-11-keto-β-boswellic acid, enriched demethylated curcuminoids that have a synergistic effect on specific inhibition of—COX-2 and 5-LOX activity and optionally containing glucosamine, resveratrol, garlic extract, chondroitin, methlysulphonymethane, bromelain, serratiopeptidase, quercitine, gallic acid, caffeic acid, green tea extract, aspirin and ibuprofen.