Reduction of Excessive Visceral Fat and Safety with 52-Week Administration of Lipase Inhibitor Orlistat in Japanese: Long-Term Clinical Study

Impact of the lipase inhibitor orlistat on the human gut microbiota

Orlistat, an anti-obesity agent, inhibits the metabolism and absorption of dietary fat by inactivating pancreatic lipase in the gut. The effect of orlistat on the gut microbiota of Japanese individuals with obesity is unknown. This study aimed to explore the effects of orlistat on the gut microbiota and fatty acid metabolism of Japanese individuals with obesity. Fourteen subjects with visceral fat obesity (waist circumference ≥85 cm) took orlistat orally at a dose of 60 mg, 3 times a day for 8 weeks. Body weight; waist circumference; visceral fat area; levels of short-chain fatty acids, gut microbiota, fatty acid metabolites in the feces, and gastrointestinal hormones; and adverse events were evaluated. Body weight, waist circumference, and blood leptin concentrations were significantly lower after orlistat treatment (mean ± standard deviation, 77.8 ± 9.1 kg; 91.9 ± 8.7 cm; and 4546 ± 3211 pg/mL, respectively) compared with before treatment (79.4 ± 9.0 kg; 94.4 ± 8.0 cm; and 5881 ± 3526 pg/mL, respectively). Significant increases in fecal levels of fatty acid metabolites (10-hydroxy-cis-12-octadecenoic acid, 10-oxo-cis-12-octadecenoic acid, and 10-oxo-trans-11-octadecenoic acid) were detected. Meanwhile, no significant changes were found in abdominal computed tomography parameters, blood marker levels, or short-chain fatty acid levels in the feces. Gut microbiota analysis revealed that some study subjects had decreased abundance of Firmicutes, increased abundance of Bacteroidetes, and increased α-diversity indices (Chao1 and ACE) after 8 weeks of treatment. The levels of Lactobacillus genus and Lactobacillus gasseri were significantly higher after 8 weeks of treatment. None of the subjects discontinued treatment or experienced severe adverse events. This study suggested that orlistat might alter gut microbiota composition and affect the body through fatty acid metabolites produced by the modified gut bacteria.

Screening and characterisation of potential antioxidant, hypoglycemic and hypolipidemic components revealed in Portulaca oleracea via multi-target affinity ultrafiltration LC-MS and molecular docking

INTRODUCTION

Portulaca oleracea is a commonly used nutritional vegetable and traditional herbal medicine with plenty of nutrients and manifold pharmacological activities. However, the potential active ingredients for its remarkable antioxidant, hypoglycemic and hypolipidemic activities remain unexplored.

OBJECTIVES

The present study aims to systematically evaluate the antioxidant activities of different extracts of P. oleracea and screen bioactive ligands that can interact with α-glucosidase, pancreatic lipase, and superoxide dismutase (SOD).

METHODS

In this research, the antioxidant activities of different parts of P. oleracea and their corresponding total phenolic content (TPC) and total flavonoid content (TFC) were systematically determined. Subsequently, a multi-target affinity ultrafiltration method was developed using affinity ultrafiltration with SOD, α-glucosidase, and pancreatic lipase coupled to liquid chromatography-mass spectrometry (UF-LC-MS). Later, molecular docking was used to further investigate the possible interaction mechanism between these ligands and target enzymes.

RESULTS

Among them, the ethyl acetate (EA) fraction showed the highest antioxidant activity along with the highest TPC and TFC, and four compounds in the EA fraction were quickly retrieved as potential SOD, α-glucosidase, and pancreatic lipase ligands, respectively. Molecular docking revealed that these potential ligands exhibited strong binding ability and inhibitory activities on SOD, α-glucosidase, and pancreatic lipase.

CONCLUSION

The present study revealed that P. oleracea can be used as a functional food with excellent antioxidant, hypoglycemic and hypolipidemic effects. Meanwhile, the integrated strategy based on multi-target UF-LC-MS and molecular docking also provided a powerful tool and a multidimensional perspective for further exploration of active ingredients in P. oleracea responsible for the antioxidant, hypoglycemic and hypolipidemic activities.

Understanding the Role of Exercise in Nonalcoholic Fatty Liver Disease: ERS-Linked Molecular Pathways

Nonalcoholic fatty liver disease (NAFLD) is globally prevalent and characterized by abnormal lipid accumulation in the liver, frequently accompanied by insulin resistance (IR), enhanced hepatic inflammation, and apoptosis. Recent studies showed that endoplasmic reticulum stress (ERS) at the subcellular level underlies these featured pathologies in the development of NAFLD. As an effective treatment, exercise significantly reduces hepatic lipid accumulation and thus alleviates NAFLD. Confusingly, these benefits of exercise are associated with increased or decreased ERS in the liver. Further, the interaction between diet, medication, exercise types, and intensity in ERS regulation is more confusing, though most studies have confirmed the benefits of exercise. In this review, we focus on understanding the role of exercise-modulated ERS in NAFLD and ERS-linked molecular pathways. Moderate ERS is an essential signaling for hepatic lipid homeostasis. Higher ERS may lead to increased inflammation and apoptosis in the liver, while lower ERS may lead to the accumulation of misfolded proteins. Therefore, exercise acts like an igniter or extinguisher to keep ERS at an appropriate level by turning it up or down, which depends on diet, medications, exercise intensity, etc. Exercise not only enhances hepatic tolerance to ERS but also prevents the malignant development of steatosis due to excessive ERS.