Health-Beneficial Phenolic Aldehyde in Antigonon leptopus Tea

Abstract EN

Tea prepared from the aerial parts of Antigonon leptopus is used as a remedy for cold and pain relief in many countries.

In this study, A.

leptopus tea, prepared from the dried aerial parts, was evaluated for lipid peroxidation (LPO) and cyclooxygenase (COX-1 and COX-2) enzyme inhibitory activities.

The tea as a dried extract inhibited LPO, COX-1 and COX-2 enzymes by 78%, 38% and 89%, respectively, at 100 μg/mL.

Bioassay-guided fractionation of the extract yielded a selective COX-2 enzyme inhibitory phenolic aldehyde, 2,3,4-trihydroxy benzaldehyde.

Also, it showed LPO inhibitory activity by 68.3% at 6.25 μg/mL.

Therefore, we have studied other hydroxy benzaldehydes and their methoxy analogs for LPO, COX-1 and COX-2 enzymes inhibitory activities and found that compound 1 gave the highest COX-2 enzyme inhibitory activity as indicated by a 50% inhibitory concentration (IC50) at 9.7 μg/mL.

The analogs showed only marginal LPO activity at 6.25 μg/mL.

The hydroxy analogs 6, 7 and 9 showed 55%, 61% and 43% of COX-2 inhibition at 100 μg/mL.

However, hydroxy benzaldehydes 3 and 12 showed selective COX-1 inhibition while compounds 4 and 10 gave little or no COX-2 enzyme inhibition at 100 μg/mL.

At the same concentration, compounds 14, 21 and 22 inhibited COX-1 by 83, 85 and 70%, respectively.

Similarly, compounds 18, 19 and 23 inhibited COX-2 by 68%, 72% and 70%, at 100 μg/mL.

This is the first report on the isolation of compound 1 from A.

leptopus tea with selective COX-2 enzyme and LPO inhibitory activities.