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.
