Formulation and Characterization of Quercetin-loaded Oil in Water Nanoemulsion and Evaluation of Hypocholesterolemic Activity in Rats

Abstract

Due to poor water solubility and high susceptibility to chemical degradation, the applications of quercetin have been limited. This study investigated the effects of pH on the formation of quercetin-loaded nanoemulsion (NQ) and compared the hypocholesterolemic activity between quercetin and NQ to utilize the quercetin as functional food ingredient. NQ particle size exhibited a range of 207–289 nm with polydispersity index range (<0.47). The encapsulation efficiency increased stepwise from 56 to 92% as the pH increased from 4.0 to 9.0. Good stability of NQ was achieved in the pH range of 6.5–9.0 during 3-month storage at 21 and 37 °C. NQ displayed higher efficacy in reducing serum and hepatic cholesterol levels and increasing the release of bile acid into feces in rats fed high-cholesterol diet, compared to quercetin alone. NQ upregulated hepatic gene expression involved in bile acid synthesis and cholesterol efflux, such as cholesterol 7 alpha-hydroxylase (CYP7A1), liver X receptor alpha (LXRα), ATP-binding cassette transporter A1 (ABCA1) and ATP-binding cassette sub-family G member 1 (ABCG1). These results suggest at least partial involvement of hepatic bile acid synthesis and fecal cholesterol excretion in nanoemulsion quercetin-mediated beneficial effect on lipid abnormalities.

Development of edible gelatin composite films enriched with polyphenol loaded nanoemulsions as chicken meat packaging material

“…Encapsulation efficiency of curcumin in NE found in this study (90.36 ± 0.002%) was in accordance with the results of Mohanty and Sahoo (2010) with entrapment efficiency of (90 ± 2.55%), and 90.56 ± 0.47% reported by Sari et al (2015). The encapsulation efficiency for quercetin was reported to vary from 56% to 92% with the increase in pH from 4 to 9 (Son et al, 2019). In this study, encapsulation efficiency for quercetin was found to be 92.58 ± 0.001%, while due to hydrophilic nature of gallic acid, low encapsulation efficiency 86.85 ± 0.3 was found in this study.…”

Therapeutic Potential of Quercetin as an Antiatherosclerotic Agent in Atherosclerotic Cardiovascular Disease: A Review

“…Promote conversion of cholesterol to bile acids and cholesterol efflux by increasing hepatic CYP7A1 activity and hepatic LXRα, ABCG1, and LDLR protein expressions [116] ApoE −/− mice Elevate cholesterol accepting ability of HDL and increase ABCA1/G1 expression levels of proteins related to RCT [117] Sprague-Dawley rats Influence gene and protein expression of SREBP1c and HMGR to lower lipid [118] Sprague-Dawley rats Upregulate hepatic gene expression CYP7A1, LXRα, ABCA1, and ABCG1 to promote cholesterol efflux [119] Zucker rats Lower the level of HDL cholesterol and increase phosphorus level by increasing the ratio of ASAT/ALAT activity induced by leptin [56] ApoE −/− mice Regulate expressions of ABCA1, LXRα, and PCSK9 [26] ApoE −/− mice Downregulate PCSK9 and CD36 protein expression and upregulate PPAR c, LXRα, and ABCA1 protein expression levels in both the aortic and liver tissues [65] Alter the gut microbiota ApoE −/− mice Regulate primary bile acid biosynthesis [95] C57BL/6J mice Improve composition and functionality of gut microbiome and production of short chain fatty acids [120] Wistar rats Stimulate bacterial enzymatic activity and increase enzymatic activity of the intestinal microbiota [121] Ldlr −/− mice Reduce MDA, cholesterol, and LPC 18 : 1 and increase IL-6 and coprostanol levels [98] Humans Anti-inflammation…”

Progress on Design of Emulsion Delivery System for Insoluble Bioactive Substances

“…In the pH range of 6.5-9, NQ was stored for 3 m at 21 and 37 °C with good stability. [35] Compared with quercetin, NQ was more effective in reducing serum liver cholesterol levels and increasing the release of bile acids into feces in rats fed a high-cholesterol diet. Chen et al prepared quercetin emulsions to improve the biological availability of quercetin, a hydrophobic nutrient.…”