Emerging antidyslipidemic drugs

Structural and pharmacological insights into cordycepin for neoplasms and metabolic disorders

Cytotoxic adenosine analogues were among the earliest chemotherapeutic agents utilised in cancer treatment. Cordycepin, a natural derivative of adenosine discovered in the fungus Ophiocordyceps sinensis, directly inhibits tumours not only by impeding biosynthesis, inducing apoptosis or autophagy, regulating the cell cycle, and curtailing tumour invasion and metastasis but also modulates the immune response within the tumour microenvironment. Furthermore, extensive research highlights cordycepin's significant therapeutic potential in alleviating hyperlipidaemia and regulating glucose metabolism. This review comprehensively analyses the structure-activity relationship of cordycepin and its analogues, outlines its pharmacokinetic properties, and strategies to enhance its bioavailability. Delving into the molecular biology, it explores the pharmacological mechanisms of cordycepin in tumour suppression and metabolic disorder treatment, thereby underscoring its immense potential in drug development within these domains and laying the groundwork for innovative treatment strategies.

Bile salts adsorption on dextran-based hydrogels

Dextran-based gels bearing two types of pendant N, N-dimethyl-N-alkyl-N-(2-hydroxypropyl) ammonium chloride groups with different alkyl chain length substituents (C₂ and C₁₂/C₁₆, respectively) at the quaternary nitrogen were synthesized and structural characteristics of the compounds were studied by elemental analysis, potentiometric titration, FTIR and NMR spectroscopy. The morphology and size of polymeric microspheres were examined by SEM and their swelling behavior in water was also investigated. The hydrogels were evaluated as sorbents for sodium cholate (NaCA) and sodium deoxycholate (NaDCA) in water and 10 mM NaCl solutions. Different isotherm models (nearest-neighbor-interaction, Langmuir, Freundlich, Dubinin-Raduskevich, Sips and Hill) were used to elucidate the adsorption mechanism and established the characteristics of the most efficient polymeric sorbent. The maximum adsorption capacity of the gels was highly controlled by gel hydrophobicity which enhanced gel-bile salt affinity but decreased binding cooperativity. Swelling porosity, ionic strength and ligand lipophilicity were other factors that also affected the adsorption process. The hydrogel having 25 mol% pendant dodecyl groups retained the maximum amount of bile salts (1051 mg NaCA/g and 1138 mg NaDCA/g). All hydrophobically modified hydrogels revealed a better affinity and strength of binding compared to commercial Cholestyramine®.

Synthesis, crystal studies and in vivo anti-hyperlipidemic activities of indole derivatives containing fluvastatin nucleus

As a part of our efforts to prepare better analogues of fluvastatin for the treatment of hyperlipidemia, we have synthesized some indole derivatives containing a fluvastatin nucleus by methanol mediated Claisen–Schmidt aldol condensation reaction.

Diabetes abrogates sex differences and aggravates cardiometabolic risk in postmenopausal women

Background

The aim of this study is to evaluate the effect of gender and menopause in cardiometabolic risk in a type 2 diabetes mellitus (T2DM) population, based on classical and non-traditional markers.

Methods

Seventy four volunteers and 110 T2DM patients were enrolled in the study. Anthropometric data, blood pressure, body mass index (BMI), waist circumference (WC) and the following serum markers were analyzed: glucose, Total-c, TGs, LDL-c, Oxidized-LDL, total HDL-c and large and small HDL-c subpopulations, paraoxonase 1 activity, hsCRP, uric acid, TNF-α, adiponectin and VEGF.

Results

Non-diabetic women, compared to men, presented lower glycemia, WC, small HDL-c, uric acid, TNF-α and increased large HDL-c. Diabetes abrogates the protective effect of female gender, since diabetic women showed increased BMI, WC, small HDL-c, VEGF, uric acid, TNF-α and hsCRP, as well as reduced adiponectin, when compared with non-diabetic. In diabetic females, but not in males, WC is directly and significantly associated with TNF-α, VEGF, hsCRP and uric acid; TNF-α is directly associated with VEGF and hsCRP, and inversely with adiponectin. Postmenopausal females presented a worsen cardiometabolic profile, viewed by the increased WC, small HDL-c, VEGF, uric acid, TNF-α and hsCRP. In this population, WC is directly and significantly associated with TNF-α, VEGF, hsCRP; TNF-α is directly associated with VEGF; and uric acid is inversely associated with large HDL-c and hsCRP with adiponectin, also inversely.

Conclusions

Diabetes abrogates the protective effect of gender on non-diabetic women, and postmenopausal diabetic females presented worsen cardiometabolic risk, including a more atherogenic lipid sketch and a pro-inflammatory and pro-angiogenic profile. The classical cardiovascular risk factors (CVRFs) fail to completely explain these differences, which are better clarified using “non-traditional” factors, such as HDL-c subpopulations, rather than total HDL-c content, and markers of inflammation and angiogenesis, namely TNF-α, hsCRP, uric acid and VEGF. Multi-therapeutic intervention, directed to obesity, atherogenic lipid particles and inflammatory mediators is advisory in order to efficiently prevent the serious diabetic cardiovascular complications.

Fat lowers fat: purified phospholipids as emerging therapies for dyslipidemia

Dyslipidemia is a major coronary heart disease (CHD) risk factor. In spite of the proven efficacy of statin drugs in reducing CHD burden, there is still much room for the discovery of novel therapeutic agents to address the considerable residual cardiovascular risk that remains after treatment with currently available medications. In particular, there is an urgent demand for drugs capable of boosting the concentration and/or function of high-density lipoprotein (HDL) and apolipoprotein A-I (apo A-I), thereby promoting reverse cholesterol transport. Phospholipids are naturally occurring fats that play indispensible role in human health via their structural, energy storage, signal transduction and metabolic functions. Supplementation with either purified or mixed preparations of bioactive phospholipids has been reported to ameliorate a range of nutritional and cardiovascular disorders. Moreover, several lines of evidence have supported the efficacy of dietary phospholipids in reducing serum and hepatic contents of cholesterol and triglycerides, while increasing HDL-C and apo A-I levels. These beneficial effects of phospholipids could be attributed to their ability in reducing intestinal cholesterol absorption, enhancing biliary cholesterol excretion and modulating the expression and activity of transcriptional factors and enzymes that are involved in lipoprotein metabolism. Given their extreme safety and biocompatibility, dietary supplementation with phospholipid preparations, in particular phosphatidylinositol, appears as a novel and effective strategy that could be used as an alternative or adjunctive therapy to the current medications. The present review outlines the in-vitro, in-vivo and clinical findings on the anti-dyslipidemic effects of three most abundant phospholipids in the human body and diet namely phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol.

Beneficial effects of cordycepin on metabolic profiles of liver and plasma from hyperlipidemic hamsters

In this study, (1)H NMR-based metabonomics was applied to evaluate the beneficial effects of cordycepin (3'-deoxyadenosine), a natural monomer compound, on endogenous metabolic profiles of liver and plasma from hyperlipidemic Syrian golden hamsters. Hyperlipidemia was successfully established in hamsters fed by a high-fat diet for 2 weeks. The hyperlipidemic hamsters were treated with an oral administration of simvastatin (2 mg kg(- 1)) or cordycepin (140 mg kg(- 1)) for consecutive 4 weeks. The metabolic profiles of plasma and intact liver tissues were established using (1)H NMR spectroscopy. The results showed higher contents of lipids (triglyceride and cholesterol), lactate, acetate, alanine, glutamine together with lower contents of choline-containing compounds (e.g. phosphocholine, phosphatidylcholine, and glycerophosphocholine), glucose, and glycogen in plasma and liver samples from hyperlipidemic hamsters than those in controls. Cordycepin afforded a little lipid-regulating activity on plasma but more beneficial effects on liver, implicating that cordycepin might have a protective effect on liver under fatty liver condition.

Potential mechanisms of hypocholesterolaemic effect of Thai spices/dietary extracts

Several Thai spices/dietary ingredients were previously shown to have hypocholesterolaemic effects. These studies were mostly conducted in animal models in which the mechanisms of action were not yet well-established. Therefore, this study aimed to investigate the potential mechanism of hypocholesterolaemic action of 12 selected plants, namely Hibiscus sabdariffa L., Moringa oleifera Lam., Cucurbita moschata Duchesne, Ananas comosus (L.) Merr., Zingiber officinale, Morus alba L., Camellia sinensis (L.) Kuntze, Piper nigrum L., Alpinia galanga (L.) Willd., Curcuma zedoaria Rose, Bacopa monnieri (L.) Wettst. and Piper retrofractum Vahl., widely used as spices and ingredients in various types of Thai food. The extract of P. nigrum at 100 µg mL(-1) was found to be the most effective cholesterol uptake inhibitor whereas those of A. galanga and C. sinensis effectively inhibited pancreatic lipase activity with IC50 values of 8.99±3.41 and 12.36±1.23 µg mL(-1), respectively. The potency of extracts from H. sabdariffa, M. oleifera and C. moschata at 100 µg mL(-1) were found to be similar to 0.4 µg mL(-1) pravastatin in inhibiting HMG-CoA reductase and possibly reduced cholesterol biosynthesis. This study also demonstrated that several of the tested plants possessed multiple sites of action that were possibly responsible for their cholesterol-lowering effect in the in vivo model.

Antibody-mediated disruption of the interaction between PCSK9 and the low-density lipoprotein receptor

PCSK9 (proprotein convertase subtilisin/kexin type 9) promotes degradation of the LDLR [LDL (low-density lipoprotein) receptor] through an as-yet-undefined mechanism, leading to a reduction in cellular LDLc (LDL-cholesterol) and a concomitant increase in serum LDLc. Central to the function of PCSK9 is a direct protein–protein interaction formed with the LDLR. In the present study, we investigated a strategy to modulate LDL uptake by blocking this interaction using specific antibodies directed against PCSK9. Studies using surface plasmon resonance demonstrated that direct binding of PCSK9 to the LDLR could be abolished with three different anti-PCSK9 antibodies. Two of these antibodies were raised against peptide epitopes in a region of the catalytic domain of PCSK9 that is involved in the interaction with the LDLR. Such antibodies restored LDL uptake in HepG2 cells treated with exogenous PCSK9 and in HepG2 cells engineered to overexpress recombinant PCSK9. This latter observation indicates that antibodies blocking the PCSK9–LDLR interaction can inhibit the action of PCSK9 produced endogenously in a cell-based system. These antibodies also disrupted the higher-affinity interaction between the natural gain-of-function mutant of PCSK9, D374Y, and the LDLR in both the cell-free and cell-based assays. These data indicate that antibodies targeting PCSK9 can reverse the PCSK9-mediated modulation of cell-surface LDLRs.