Characterization of Quercetin Derivatives in Crossing Combination of Habanero White and Capsicum annuum Peppers and of Anti-Inflammatory and Cytotoxic Activity

Abstract

The overproduction of reactive oxygen species and the exposure of the human body to free radicals contribute to the aetiology of many chronic health problems, such as cardiovascular disease and cancer. Supplementation with natural antioxidants could be helpful, preventing free-radical-induced tissue damage through the inhibition of the radicals’ formation. Quercetin derivatives have recently been shown to inhibit the production of inflammatory mediators and to reduce the proliferation of tumoral cells, thus being valid compounds to be promoted as dietary supplements. In this work, an HPLC-MS/MS investigation on the derivatives of quercetin in a methanolic extract of peppers deriving from an original crossing combination between Habanero white and Capsicum annuum revealed the occurrence of nine glycoconjugates, either monosaccharide, disaccharide or trisaccharide, as well as an acylated disaccharidic derivative (i.e., quercetin rhamnoside-(feruloyl-hexoside)). Due to the great variability in the quercetin derivatives’ profiles, the Habanero white hybrid pepper extract was subjected to in vitro cytotoxicity assays. The pepper extract under study was proved to have anti-inflammatory activity comparable to that shown by a Capsicum annuum pepper extract since it reduced ROS levels compared to activated cells. Due to its beneficial effects, it could be exploited as a natural constituent of nutraceutical formulations.

Exploiting the Anti-Inflammatory Potential of White Capsicum Extract by the Nanoformulation in Phospholipid Vesicles

“…In LPS-triggered U937/PMA cells, the white Capsicum extract reduced intracellular ROS levels of about 8% only at the highest tested concentration (25 µg/mL) ( Figure 3 ) [ 45 ]. No effect on ROS production was observed when cells were treated with the lower concentration (5 µg/mL), as ROS levels were approximately the same as in cells activated with LPS ( Figure 3 ) [ 45 ].…”

“…In LPS-triggered U937/PMA cells, the white Capsicum extract reduced intracellular ROS levels of about 8% only at the highest tested concentration (25 µg/mL) ( Figure 3 ) [ 45 ]. No effect on ROS production was observed when cells were treated with the lower concentration (5 µg/mL), as ROS levels were approximately the same as in cells activated with LPS ( Figure 3 ) [ 45 ]. The aim of this study was to exploit phospholipid vesicles to enhance the bioavailability of the bioactive compounds present in the white Capsicum extract and to facilitate the entry into cells in order to increase the biological response, specifically the anti-inflammatory activity.…”

“…In a previous work [ 45 ], we reported the preparation of an extract from a pepper species obtained from a specific breeding program. The white Capsicum extract was prepared by optimizing the protocol of Wahyuni et al [ 46 ]: 3 mL of methanol was added to 0.5 g of lyophilized peppers; the sample was sonicated for 15 min (25 °C) in a Sonorex Super RK 100/H sonicator (Bandelin electronic, Berlin, Germany); and the methanolic extract was filtered through 0.20 µm nylon filters, which are recommended for methanolic matrices as they do not procure changes in flow rate or bubble point of the membrane, nor visible chemical attack.…”

“…The mobile phase consisted of water containing 0.1% v / v of formic acid (solvent A) and acetonitrile (solvent B). The gradient elution program was adapted from previous works [ 45 , 51 ] as follows: from 0% B and increased to 35% B over 5 min. After holding at 35% for 5 min, mobile phase B was increased to 40% over 5 min.…”

“…In a previous work [ 45 ], we conducted a comprehensive phytochemical profiling of a methanolic extract of a new pepper genotype deriving from an original crossing combination between Habanero white, from C. chinense , and C. annuum . Furthermore, we demonstrated the anti-inflammatory properties of the extract, as it was able to reduce ROS levels in LPS-activated cells.…”