Natural lipid-lowering agents and their effects: an update

Pharmaceutical Food Science: Search for Bio-Functional Molecules Obtained from Natural Resources to Prevent and Ameliorate Lifestyle Diseases

In this review, our resent pharmaceutical food science research for bio-functional molecules obtained from natural resources that contribute to i) suppression of postprandial blood glucose elevation and/or improvement of glucose tolerance and ii) reduction of visceral fat accumulation and improvement of lipid metabolism were summarized. Based on studies using MONOTORI science, salacinol (1), neokotalanol (4), and trans-tiliroside (20) have been approved or notified by the Consumer Affairs Agency in Japan as functional substances in food with health claims, Food for Specified Health Use and Food with Functional Claims.

Aromatic Acids and Leucine Derivatives Produced from the Deep-Sea Actinomycetes Streptomyceschumphonensis SCSIO15079 with Antihyperlipidemic Activities

Six new aromatic acids (1–6) and three new leucine derivatives containing an unusual oxime moiety (7–9) were isolated and identified from the deep-sea-derived actinomycetes strain Streptomyces chumphonensis SCSIO15079, together with two known compounds (10–11). The structures of 1–9 including absolute configurations were determined by detailed NMR, MS, and experimental and calculated electronic circular dichroism spectroscopic analyses. Compounds 1–9 were evaluated for their antimicrobial and cytotoxicity activities, as well as their effects on intracellular lipid accumulation in HepG2 cells. Compounds 3 and 4, with the most potent inhibitory activity on intracellular lipid accumulation at 10 μM, were revealed with potential antihyperlipidemic effects, although the mechanism needs to be further studied.

An Insight into Antihyperlipidemic Effects of Polysaccharides from Natural Resources

Hyperlipidemia is a chronic metabolic disease caused by the abnormal metabolism of lipoproteins in the human body. Its main hazard is to accelerate systemic atherosclerosis, which causes cerebrovascular diseases such as coronary heart disease and thrombosis. At the same time, although the current hypolipidemic drugs have a certain therapeutic effect, they have side effects such as liver damage and digestive tract discomfort. Many kinds of polysaccharides from natural resources possess therapeutic effects on hyperlipidemia but still lack a comprehensive understanding. In this paper, the research progress of natural polysaccharides on reducing blood lipids in recent years is reviewed. The pharmacological mechanisms and targets of natural polysaccharides are mainly introduced. The relationship between structure and hypolipidemic activity is also discussed in detail. This review will help to understand the value of polysaccharides in lowering blood lipids and provide guidance for the development and clinical application of new hypolipidemic drugs.

Anti-hyperlipidemic potential of natural product based labdane-pyrroles via inhibition of cholesterol and triglycerides synthesis

Hyperlipidemia is the clinical condition where blood has an increased level of lipids, such as cholesterol and triglycerides. Therefore controlling hyperlipidemia is considered to be a protective strategy to treat many associated diseases. Thus, a novel natural product derived pyrrole, and pyrazole-(E)-Labda-8(17),12-diene-15,16-dial conjugates with cholesterol and triglycerides synthesis inhibition potential was designed through scaffold hopping approach and synthesized via one-pot selective cycloaddition. Amongst the tested hybrids, 3i exhibited excellent activity against triglyceride and cholesterol synthesis with the percentage inhibition of 71.73 ± 0.78 and 68.61 ± 1.19, which is comparable to the positive controls fenofibrate and atorvastatin, respectively. Compounds 3j and 3k also exhibited the considerable potential of promising leads. The HMG CoA reductase inhibitory activity of the compounds was consistent with that of inhibitory activity of cholesterol synthesis. Compound 3i showed the highest inhibitory potential (78.61 ± 2.80) percentage of suppression, which was comparable to that of the positive control pravastatin (78.05 ± 5.4). Favourably, none of the compounds showed cytotoxicity (HepG2) in the concentration ranging from 0.5 to 100 μM.

Cyanidin-3-rutinoside acts as a natural inhibitor of intestinal lipid digestion and absorption

BACKGROUND

Cyanidin-3-rutinoside (C3R), a naturally occurring anthocyanin, possesses anti-oxidant, anti-hyperglycemic, anti-glycation and cardioprotective properties. However, its mechanisms responsible for anti-hyperlipidemic activity have not been fully identified. The aim of the study was to investigate the lipid-lowering mechanisms of C3R through inhibition of lipid digestion and absorption in vitro.

METHODS

The inhibitory activity of C3R against pancreatic lipase and cholesterol esterase was evaluated using enzymatic fluorometric and enzymatic colorimetric assays, respectively. An enzyme kinetic study using Michaelis-Menten and the derived Lineweaver-Burk plot was performed to understand the possible types of inhibition. The formation of cholesterol micelles was determined using the cholesterol assay kit. The bile acid binding was measured using the colorimetric assay. The NBD cholesterol uptake in Caco-2 cells was determined using fluorometric assay. The mRNA expression of cholesterol transporter (Niemann-Pick C1-like 1) was determined by RT-PCR.

RESULTS

The results showed that C3R was a mixed-type competitive inhibitor of pancreatic lipase with the IC₅₀ value of 59.4 ± 1.41 μM. Furthermore, C3R (0.125-1 mM) inhibited pancreatic cholesterol esterase about 5-18%. In addition, C3R inhibited the formation of cholesterol micelles and bound to primary and secondary bile acid. In Caco-2 cells, C3R (12.5-100 μM) exhibited a significant reduction in cholesterol uptake in both free cholesterol (17-41%) and mixed micelles (20-30%). Finally, C3R (100 μM) was able to suppress mRNA expression of NPC1L1 in Caco-2 cells after 24 h incubation.

CONCLUSIONS

The present findings suggest that C3R acts as a lipid-lowering agent through inhibition of lipid digestion and absorption.

Synthesis and Antihyperlipidemic Activity of Piperic Acid Derivatives

A series of piperic acid derivatives were designed and synthesized from piperine/ piperlonguminine, and their antihyperlipidemic activities evaluated in diet-induced hyperlipidemic rats with respect to simvastatin. Two promising analogues 3 and 10 were discovered and their antihyperlipidemic activities were comparable to or better than those of simvastatin.