Enhanced Anticancer Effect of Unripe Rubus occidentalis on Gastric Cancer Cells

Abstract

Background Black raspberry ( Rubus occidentalis L.) has various bioactive properties, including antioxidant, anti-inflammatory, and anticancer activities. Recently, it has been proposed that the pharmacological efficacy of black raspberry varies with its maturation stage. In the current study, we explored the relationship between maturation stage and anticancer activity in gastric cancer cell lines. Materials and Methods Black raspberry extracts were prepared from both ripe samples 41 days after the fruit set and unripe samples 22 days after the fruit set. Their anticancer activities were compared by assessing the effects on proliferation, apoptosis, invasiveness, and clonogenicity in gastric cancer cell lines. Results Both the ripe and unripe black raspberry samples were effective in inhibiting cell proliferation, invasion, and clonogenic activity. However, the unripe black raspberry extract showed a stronger effect on these activities compared to ripe black raspberry extract. Additionally, the unripe fruit extract increased apoptotic body formation, caspase-3 activity, Bak expression and decreased Bcl2 expression. Furthermore, the unripe black raspberry sample was found to contain higher contents of ellagic acid and gallic acid, and had a stronger suppressive effect on p-ERK and p-AKT protein levels compared to the ripe black raspberry sample. Conclusion Unripe black raspberry has greater anti-cancer effects than fully ripe black raspberry in gastric cancer cells.