The expression of the COX-1 isozyme is common in most
tissues. On the other hand, COX-2 is upregulated in inflamed cells,
and is mediated by cytokines and human growth factors (Adhikari
et al., 2005; Aggarwal et al., 2006). The inhibition of COX-2 is
therefore an indicator of possible anticancer properties. All berry
extracts were tested at 100 mg/mL. The only Michigan-grown
berry extract that demonstrated activity was the hexane extract of
R. acuminatus, which inhibited COX-2 by 71%. All the hexane
extracts of the Jamaican Rubus berries were COX-active. The
hexane extracts of R. jamaicensis, R. rosifolius and R. racemosus,
inhibited COX-2 by 18–33%. The hexane extract of R. jamaicensis
selectively inhibited COX-2 at the test concentration. The said
extracts of R. rosifolius and R. racemosus inhibited COX-1 by 33 and
30%, respectively. The EtOAc extracts of R. jamaicensis and R.
rosifolius also demonstrated some COX inhibitory activity, as
shown in Fig. 4. The Michigan-grown Rubus extracts were, in
general, not COX-active, while the hexane extracts of the Jamaican
spp. were the most active. The MeOH extracts showed no activity
at the concentration tested. Considering that the inhibition of COX-
2 is an indication of possible anticancer properties, it was expected
that the latter extracts would possess the highest anticancer
potential, and this is what was observed.