Protective Effects of Polyphenol Enriched Complex Plants Extract on Metabolic Dysfunctions Associated with Obesity and Related Nonalcoholic Fatty Liver Diseases in High Fat Diet-Induced C57BL/6 Mice

Abstract

Background: Currently, obesity is a global health challenge due to its increasing prevalence and associated health risk. It is associated with various metabolic diseases, including diabetes, hypertension, cardiovascular disease, stroke, certain forms of cancer, and non-alcoholic liver diseases (NAFLD).

Objective: The aim of this study to evaluate the effects of polyphenol enriched herbal complex (Rubus crataegifolius/ellagic acid, Crataegus pinnatifida Bunge/vitexin, chlorogenic acid, Cinnamomum cassiaa/cinnamic acid) on obesity and obesity induced NAFLD in the high-fat diet (HFD)-induced obese mouse model.

Methods: Obesity was induced in male C57BL/6 mice using HFD. After 8 weeks, the mice were treated with HFD+ plants extract for 8 weeks. Body weight, food intake weekly, and blood sugar level were measured. After sacrifice, changes in the treated group's liver weight, fat weight, serum biochemical parameters, hormone levels, and enzyme levels were measured. For histological analysis, tissues were stained with hematoxylin-eosin (H&E) and Oil Red-O.

Results: Our results showed that the herbal complex ameliorated body weight and liver weight gain, and decreased total body fat in HFD-fed animals. Post prandial blood glucose (PBG) and fasting blood glucose (FBG) were lower in the herbal complex-treated group than in the HFD control group. Additionally, herbal formulation treatment significantly increased HDL levels in serum and decreased TC, TG, AST, ALT, deposition of fat droplets in the liver, and intima media thickness (IMT) in the aorta. Herbal complex increased serum adiponectin and decreased serum leptin. Herbal complex also increased carnitine palmityl transferase (CPT) activity and significantly decreased enzyme activity of beta-hydroxy beta methyl glutamyl-CoA (HMG-CoA) reductase, and fatty acid synthase (FAS).

Conclusions: The results of this study demonstrated that the herbal complex is an effective herbal formulation in the attenuation of obesity and obesity-induced metabolic dysfunction including NAFLD in HFD-induced mouse model.

Keywords: 1 Cinnamomum cassia; Crataegus pinnatifida Bunge; HFD-induced mouse model; NAFLD; Rubus crataegifolius; metabolic dysfunctions; obesity; plants extract.

Figure 1

2-D HPLC chromatogram of three plants extract: (a) Ethanol extract of Rubus coreanus (ellagic acid), (b) ethanol extract of Crataegus pinnatifida Bunge (vitexin), and (c) water extract of Cinnamomum cassia (cinnamic acid).

Figure 2

Effect of plants extract on biochemical parameter in HFD-fed C57BL/6 mice (a) aspartate transaminase (AST); and (b) alanine transaminase (ALT). (c) Total cholesterol (TC); (d) triglyceride (TG); (e) high-density lipoprotein (HDL); (f) low-density lipoprotein. Data were represented as mean ± SD (n = 7). The results were compared to the HFD group using the Student’s t-test (** corresponds to p < 0.005, * corresponds to p < 0.05). The error bars represent the SD.

Figure 3

Effect of plant extracts on blood sugar at 2, 4, and 6 weeks and hormone level in C57BL/6J mice. (a) Fasting blood sugar (FBG) at 2, 4, and 6 weeks, (b) Post-prandia blood glucose (PBG) at 2, 4, and 6 weeks, (c) leptin and (d) Adiponectin. Statistical difference was determined using the independent samples t-test. Value are represented as mean ± SD (n = 7). The results were compared to the HFD group using the Student’s t-test (** corresponds to p < 0.005, * corresponds to p < 0.05). The error bars represent the SD.

Figure 4

Activity of hepatic lipid regulation enzymes fatty acid synthase (FAS), beta-hydroxy beta methyl glutamyl-CoA (HMG-CoA) reductase and carnitine palmityl transferase (CPT) in C57BL/6J mice treated with plants extract. Values are represented as mean ± SD (n = 7). The results were compared to the HFD group using the Student’s t-test (** corresponds to p < 0.005, * corresponds to p < 0.05). The error bars represent the SD. (a) FAS (Fatty acid synthase); (b) HMG-CoAR (3-hydroxy-3-methyl-glutaryl-coenzyme A reductase); (c) CPT (carnitine palmitoyltransferase).

Figure 5

Effect of plants extract on HFD-induced histopathological changes of liver tissue stained with H&E and oil red O staining (a–c) Representative image of liver tissue of normal control animal (ND) stained with Oil red O. Representative images of the liver tissues of animals treated with (A) Normal diet (B) HFD, (C) HFD + SMV, (D) HFD + R, (E) HFD + C, (F) HFD + RC and (G) HFD + RCC’. Pathophysiological examination of the tissue sections was performed under a light microscopy at 200× magnification.

Figure 6

Effect of plants extract on HFD-induced histopathological changes in H&E-stained aorta tissue. (a) Representative image of the liver tissue of normal control animal (ND). Animals fed with (b) HFD, (c) HFD + SMV, (d) HFD + R, (e) HFD + C, (f) HFD + RC, and (g) HFD + RCC’. Pathophysiological examination of the tissue sections was performed under a light microscopy at 200× magnification.