Polyphenol-Rich Extracts of Xylopia and Aframomum Species Show Metabolic Benefits by Lowering Hepatic Lipid Accumulation in Diet-Induced Obese Mice.

Metabolic syndrome is a complex condition
associated with a series of pathologies featuring glucose intolerance,
diabetes, high blood pressure, dyslipidemia, microalbuminuria,
overweight, and obesity. It is also related to nonalcoholic fatty liver
disease (NAFLD), recognized as the most familiar cause of chronic
liver disease worldwide. The overall prevalence of metabolic
syndrome and, consequently, the one of NAFLD is constantly
increasing worldwide. The initial management of these diseases
involves lifestyle modifications, including changes in diet and
physical exercise. In addition to conventional drugs like orlistat,
botanicals are traditionally used to counteract these disorders, and some of them are currently under evaluation. The present work
evaluated the in vivo beneficial effects of hydroalcoholic extracts of two Cameroonian spices, focusing on obesity-related hepatic lipid
injury in high-fat-fed C57BL/6 mice. Hydroethanolic extracts were prepared and characterized by reverse phase-high-performance
liquid chromatography (HPLC)-photodiode array detection and ultra performance liquid chromatography-triple time-of-flight
electrospray ionization tandem mass spectroscopy (TOF-ESI-MS/MS) analysis. Plant extracts were orally administered for 30 days
at different dose levels (100 and 200 mg kg−1 body weight (BW)) to obese C57BL/6 mice. Food intake (FI) and BW were recorded
daily. Plasma biochemical parameters and lipid content were estimated at the beginning and at the end of the experiment. Liver
tissues were subjected to histological examinations, lipid content, as well as oxidative stress markers, and FAME (fatty acid methyl
esters) were estimated. Oral administration of extracts at 200 mg kg−1 BW significantly reduced FI and prevented BW gain. A
decrease in the weight of the liver and a decrease in the hepatic and plasma lipid content were observed. Plasma enzyme (serum
glutamic-oxaloacetic transaminase, SGOT; serum glutamic pyruvic transaminase, SGPT; alkaline phosphatase, ALP) activities were
not indicative of any organ damage. Chemical analysis suggested that phenolic acids (4-caffeoylquinic acid, p-coumaric acid 4-O�glucoside, 5-caffeoylshikimic acid, caffeic acid hexose, and 4-O-methyl gallic acid) and flavonoids (morusin derivatives, naringenin-7-
O-glucoside, and homoisoflavanone) identified in the extracts could potentially justify the biological properties observed. The main
findings of this study showed that Xylopia parviflora (A. Rich.) Benth and Aframomum citratum (Pereira ex Oliv. et Hanb.) K. Shum
decreased hepatic lipid accumulation in high-fat-diet (HFD)-induced obese C57BL/6 mice and confirmed, at least in part, our
previous in vitro and ex vivo studies. The molecular mechanisms underlying these effects are still unclear and will be explored in the
future.