Anti-obesity effect of ethanolic extract from Cosmos caudatus Kunth leaf in lean rats fed a high fat diet

Abstract

Background: Obesity is a major health concern both in developed and developing countries. The use of herbal medicines became the subject of interest for the management of obesity due to its natural origin, cost effectiveness and minimal side effects. The present study aimed at investigating anti-obesity potential of ethanolic extract from Cosmos caudatus Kunth leaf (EECCL).

Methods: In this study, the rats were randomly divided into six groups i.e., (1) Normal Diet (ND); (2) Normal Diet and 175 mg/kgBW of EECCL (ND + 175 mg/kgBW); (3) Normal Diet and 350 mg/kgBW of EECCL (ND + 350 mg/kgBW); (4) High Fat Diet (HFD); (5) High Fat Diet and 175 mg/kgBW of EECCL (HFD + 175 mg/kgBW); (6) High Fat Diet and 350 mg/kgBW of EECCL (HFD + 350 mg/kgBW). The anti-obesity potential was evaluated through analyses of changes in body weight, visceral fat weight, and blood biochemicals including total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), leptin, insulin, adiponectin, ghrelin and fecal fat content. In addition, metabolite profiling of EECCL was carried out using NMR spectroscopy.

Results: Rats receiving EECCL together with HFD showed significant (p < 0.05) reduction in body weight gain compared to rats receiving HFD only. At the end of study, the body weight gain of EECCL treated rats was not significantly (p > 0.05) different with those of ND rats. Other related obesity biomarkers including plasma lipid profiles, insulin, leptin, ghrelin and adiponectin levels also showed significant improvement (p < 0.05). Administration of EECCL caused significant (p < 0.05) increase in fecal fat excretion, which validates the hypothesis of lipase inhibition, an anti-obesity mechanism similar to standard drug of Orlistat. The ¹H-NMR spectra of EECCL ascertained the presence of catechin, quercetin, rutin, kaempherol and chlorogenic acid in the extract.

Conclusion: Conclusively, EECCL showed anti-obesity properties by inhibition of intestinal lipid absorption and modulation of adipocytes markers.

Keywords: Anti-obesity; Herb; High fat diet; NMR; Rats.

Fig. 1

Experimental design for the determination of EECCL on prevention of obesity in lean rats fed a high fat diet. N: Normal diet, HFD: High fat diet, ND + 175 mg/kg: Normal diet + 175 mg/kg body weight of EECCL, ND + 350 mg/kg: Normal diet + 350 mg/kg body weight of EECCL, HFD + 175 mg/kg: High fat diet + 175 mg/kg body weight of EECCL, HFD + 350 mg/kg: High fat diet + 350 mg/kg body weight of EECCL, BW: Body weight

Fig. 2

Representative of 500 MHz ¹H-NMR spectra of EECCL from δ 0.50 to 10.0

Fig. 3

Expended 500 MHz ¹H-NMR spectra of EECCL from δ 6.1 to 7.1. Values above the spectra indicate peak picking of 1H-NMR signals (ppm) of bioactive metabolites identified in EECCL

Fig. 4

Expended 500 MHz ¹H-NMR spectra of EECCL from δ 7.1 to 8.1. Values above the spectra indicate peak picking of 1H-NMR signals (ppm) of bioactive metabolites identified in EECCL

Fig. 5

Structure of major compounds found in EECCL

Fig. 6

The effects of EECCL on percent body weight gain in rats for 11 weeks of treatment. Values are expressed as means ± SD (n = 6). Different letters (^{a, b, c}) indicate significant difference (p < 0.05) between different groups as shown by ANOVA using SPSS Version 20. Body weight gain (%) = [(New weight–Initial weight)/Initial weight × 100]. N: Normal diet, HFD: High fat diet, ND + 175 mg/kg: Normal diet + 175 mg/kg body weight of EECCL, ND + 350 mg/kg: Normal diet + 350 mg/kg body weight of EECCL, HFD + 175 mg/kg: High fat diet + 175 mg/kg body weight of EECCL, HFD + 350 mg/kg: High fat diet + 350 mg/kg body weight of EECCL, BW: Body weight

Fig. 7

The effects of EECCL on total percent body weight gain in rats after 11 weeks of treatment. Values are expressed as means ± SD (n = 6). Different letters (^{a, b}) indicate significant difference (p < 0.05) between different groups as shown by ANOVA using SPSS Version 20. Total percentage of body weight gain = [(Weight at week 11–Weight at week 0)/Weight at week 0 × 100%]. N: Normal diet, HFD: High fat diet, ND + 175 mg/kg: Normal diet + 175 mg/kg body weight of EECCL, ND + 350 mg/kg: Normal diet + 350 mg/kg body weight of EECCL, HFD + 175 mg/kg: High fat diet + 175 mg/kg body weight of EECCL, HFD + 350 mg/kg: High fat diet + 350 mg/kg body weight of EECCL, BW: Body weight

Fig. 8

The effects of EECCL on percentage of visceral fats in rats for 11 weeks of treatment. Values are expressed as means ± SD (n = 6). Different letters (^{a, b, c}) indicate significant difference (p < 0.05) between different groups as shown by ANOVA using SPSS Version 20. Fat (%) = [(Weight of fats/Weight of rats) × 100%]. N: Normal diet, HFD: High fat diet, ND + 175 mg/kg: Normal diet + 175 mg/kg body weight of EECCL, ND + 350 mg/kg: Normal diet + 350 mg/kg body weight of EECCL, HFD + 175 mg/kg: High fat diet + 175 mg/kg body weight of EECCL, HFD + 350 mg/kg: High fat diet + 350 mg/kg body weight of EECCL, BW: Body weight

Fig. 9

The effects of EECCL on food and energy intake in rats for 11 weeks of treatment. Values are expressed as means ± SD (n = 6). Different letters (^{a, b}) indicate significant difference (p < 0.05) between different groups as shown by ANOVA using SPSS Version 20. Energy intake = Weight of food (g) × Total calorie of ND or HFD. ND = 3.27 kcal/g, HFD = 4.39 kcal/g. N: Normal diet, HFD: High fat diet, ND + 175 mg/kg: Normal diet + 175 mg/kg body weight of EECCL, ND + 350 mg/kg: Normal diet + 350 mg/kg body weight of EECCL, HFD + 175 mg/kg: High fat diet + 175 mg/kg body weight of EECCL, HFD + 350 mg/kg: High fat diet + 350 mg/kg body weight of EECCL, BW: Body weight

Fig. 10

The effects of EECCL on fecal fat content in rats for 11 weeks of treatment. Values are expressed as means ± SD (n = 6). Different letters (^{a, b, c, d}) indicate significant difference (p < 0.05) between different groups as shown by ANOVA using SPSS Version 20. N: Normal diet, HFD: High fat diet, ND + 175 mg/kg: Normal diet + 175 mg/kg body weight of EECCL, ND + 350 mg/kg: Normal diet + 350 mg/kg body weight of EECCL, HFD + 175 mg/kg: High fat diet + 175 mg/kg body weight of EECCL, HFD + 350 mg/kg: High fat diet + 350 mg/kg body weight of EECCL, BW: Body weight