In the same study as mentioned above, Reid et al. [45] also observed the cyclooxygenase-1 (COX-1) inhibitory activity of the
same species. It was found that only the extracts of D. burgessiae, D. cymosa and H. depressa which exhibited high COX-1 inhibitory activity, while the leaf extract of C. greenwayi and C. natalensis showed good and low activity in inhibiting the COX-1, respectively.