Screening of In Vitro Health Benefits of Tangerine Tomatoes

Abstract

Tomatoes have been associated with various health benefits, including the prevention of chronic diseases. The cis-isomers of lycopene occurring in tangerine tomatoes were, through clinical trials, proven to be more bioavailable than the all-trans lycopene found in red tomatoes. Nonetheless, scientific evidence regarding the bioactivities of the tangerine tomatoes is lacking. In this article, the antioxidant, anticancer, and anti-inflammatory properties of extracts prepared from four different tomato varieties, namely Alfred, Olga’s Round Golden Chicken Egg, Golden Green, and Golden Eye, were investigated. While the antioxidant capacities of the extracts were measured through the ferric reducing antioxidant power (FRAP) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays, their anti-proliferative properties in prostate cancer cell lines were examined through the Sulforhodamine-B (SRB) assay. The anti-inflammatory activities of the extracts were assessed through the toll-like receptor (TLR)2, TLR4, and nucleotide-binding oligomerization domain containing protein 2 (NOD2)-mediated inflammatory pathways. Our results show that the tangerine tomatoes had lower IC50 values in both the anticancer and anti-inflammatory assays compared to the red tomatoes. Specifically, the half-maximal inhibitory concentration (IC50) values of the tangerine tomatoes in LNCaP cells were approximately two to three fold lower than the red tomato (IC50: 14.46, 5.62, and 8.08 mg dry tomato equivalent/mL from Alfred hexane-acetone, Olga’s Round Golden Chicken Egg hexane, and Golden Green hexane, respectively). These findings indicate that the tangerine varieties, Olga’s Round Golden Chicken Egg and Golden Green, possess greater potential to be used in conjunction with treatment and for the prevention of cancer and inflammatory-related diseases than the Alfred (red) and Golden Eye (high beta-carotene) varieties.