**6.** *In vitro* **studies**

#### **6.1. Colon cancer**

Based on the substitution pattern of anthocyanidins, a recent study reported that growth inhibition of HT29 cells (human colon cancer) was highly affected by delphinidin and malvidin, while pelargonidin exhibited the lowest growth inhibitory potential. Moreover, same study reported that malvidin could inhibit the activity of phosphodiesterase (PDE) and the hydrolysis of cAMP effectively in HT29 cells thereby inhibiting the MAPK signaling pathway [76]. Another research paper [77] investigated anthocyanin-rich extracts from grape (*Vitis vinifera*), bilberry (*Vaccinium myrtillus* L.), and chokeberry (*Aronia melanocarpa* E.) for their potential chemopreventive activity against colon cancer. The growth of colon-cancer-derived HT-29 and nontumorigenic colonic NCM460 cell lines exposed to semipurified anthocyanin-rich extracts (AREs) was monitored for up to 72 h. All extracts inhibited the growth of HT-29 cells, chokeberry extract being the most potent inhibitor. Most importantly, the growth of NCM460 cells was not inhibited at lower concentrations of all three extracts, illustrating better inhibition of colon cancer, as compared to nontumorigenic colon cells. Lately, another study [78] investigated and observed the effects of extracts from five cultivars of strawberries on the proliferation of colon cancer cells HT29 and breast cancer cells MCF-7. Using strawberry as a source of anthocyanins, they demonstrated that strawberry extracts decreased the proliferation of two cell lines in a dose-dependent manner.
