A comprehensive model for the biochemistry of ageing, senescence and longevity.

Various models for ageing, each focussing on different biochemical and/or cellular pathways have been proposed. This has resulted in a complex and non-coherent portrayal of ageing. Here, we describe a concise and comprehensive model for the biochemistry of ageing consisting of three interacting signalling hubs. These are the nuclear factor kappa B complex (NFκB), controlling the innate immune system, the mammalian target for rapamycin complex, controlling cell growth, and the integrated stress responses, controlling homeostasis. This model provides a framework for most other, more detailed, biochemical pathways involved in ageing, and explains why ageing involves chronic inflammation, cellular senescence, and vulnerability to environmental stress, while starting with the spontaneous formation of advanced glycation end products. The totality of data underlying this model suggest that the gradual inhibition of the AMPK-ISR probably determines the maximal lifespan. Based on this model, anti-ageing drugs in general, are expected to show hormetic dose response curves. This complicates the process of dose-optimization. Due to its specific mechanism of action, the anti-aging drug alkaline phosphatase is an exception to this rule, because it probably exhibits saturation kinetics.

The Carnitine Palmitoyl-Transferase 2 Cascade Hypothesis for Alzheimer's Disease.

Despite decades of intense research, the precise etiology of Alzheimer's disease (AD) remains unclear. In this hypothesis, we present a new perspective on this matter by identifying carnitine palmitoyl transferase-2 (CPT2) as a central target in AD. CPT2 is an enzyme situated within the inner mitochondrial membrane, playing a crucial role in beta-oxidation of fatty acids. It exhibits high sensitivity to hydrogen peroxide. This sensitivity holds relevance for the etiology of AD, as all major risk factors for the disease share a commonality in producing an excess of hydrogen peroxide right at this very mitochondrial membrane. We will explain the high sensitivity of CPT2 to hydrogen peroxide and elucidate how the resulting inhibition of CPT2 can lead to the characteristic phenotype of AD, thus clarifying its central role in the disease's etiology. This insight holds promise for the development of therapies for AD which can be implemented immediately.

3'sialyllactose and 6'sialyllactose enhance performance in endurance-type exercise through metabolic adaptation.

Human milk oligosaccharides (HMOs) belong to a group of multifunctional glycans that are abundantly present in human breast milk. While health effects of neutral oligosaccharides have been investigated extensively, a lot remains unknown regarding health effects of acidic oligosaccharides, such as the two sialyllactoses (SLs), 3'sialyllactose (3'SL), and 6'sialyllactose (6'SL). We utilized Caenorhabditis elegans (C. elegans) to investigate the effects of SLs on exercise performance. Using swimming as an endurance-type exercise, we found that SLs decrease exhaustion, signifying an increase in endurance that is strongest for 6'SL. Through an unbiased metabolomics approach, we identified changes in energy metabolism that correlated with endurance performance. Further investigation suggested that these metabolic changes were related to adaptations of muscle mitochondria that facilitated a shift from beta oxidation to glycogenolysis during exercise. We found that the effect of SLs on endurance performance required AMPK- (aak-1/aak-2) and adenosine receptor (ador-1) signaling. We propose a model where SLs alter the metabolic status in the gut, causing a signal from the intestine to the nervous system toward muscle cells, where metabolic adaptation increases exercise performance. Together, our results underline the potential of SLs in exercise-associated health and contribute to our understanding of the molecular processes involved in nutritionally-induced health benefits.

Supplementation with a 9c,11t-rich conjugated linoleic acid blend shows no clear inhibitory effects on platelet function in healthy subjects at low and moderate cardiovascular risk: a randomized controlled trial.

SCOPE: The 9cis,11trans-conjugated linoleic acid (9c,11t-CLA) is reported to have anti-atherogenic properties in animal models and to modulate protein expression in unstimulated human platelets in vivo. Platelet function was therefore investigated after dietary supplementation with 9c,11t-CLA enriched oil (CLA80:20) in a randomized, baseline-controlled cross-over trial. METHODS AND RESULTS: Forty-three healthy adults at low to moderate risk of cardiovascular disease received 4 g/day of CLA80:20 or placebo for two weeks each. Platelet function, inflammation, and endothelial activation were assessed before and after each phase. Compared with placebo, supplementation had no significant effects on platelet function measured by Platelet Function Analyzer-100. Inhibitory effects on collagen-induced aggregation were sex-dependent (p = 0.005) that reached significance only in women (p = 0.045). Thrombin receptor-activating peptide (TRAP)-induced P-selectin expression was higher after supplementation in all subjects (p = 0.017). TRAP-induced platelet fibrinogen binding was also dependent on sex (p = 0.015), with fibrinogen binding after CLA80:20 being higher in males (p = 0.035). Plasma monocyte chemoattractant protein-1 was higher (p = 0.041) after CLA80:20. CONCLUSION: No clear evidence was found for inhibition or activation of platelet function as well as inflammation by CLA80:20 in a low to moderate cardiovascular risk group.

The "Mevalonate hypothesis": a cholesterol-independent alternative for the etiology of atherosclerosis.

The "cholesterol hypothesis" is the leading theory to explain the cause of atherosclerosis. The "cholesterol hypothesis" assumes that plasma (LDL) cholesterol is an important causal factor for atherosclerosis.However, data of at least seven placebo controlled randomized prospective trials with various cholesterol lowering drugs show that plasma cholesterol lowering does not necessarily lead to protection against cardiovascular disease. Therefore an alternative hypothesis for the etiology of cardiovascular disease is formulated. This alternative hypothesis, the "mevalonate hypothesis", assumes that after stimulation of the mevalonate pathway in endothelial cells by inflammatory factors, these cells start producing cholesterol and free radicals. In this hypothesis, only the latter play a role in the etiology of atherosclerosis by contributing to the formation of oxidized cholesterol which is a widely accepted causal factor for atherosclerosis.Regardless of how the mevalonate pathway is activated (by withdrawal of statin drugs, by inflammatory factors or indirectly by reduced intracellular cholesterol levels) in all these cases free radical production is observed as well as cardiovascular disease. Since in the "mevalonate hypothesis" cholesterol is produced at the same time as the free radicals causing atherosclerosis, this hypothesis provides an explanation for the correlation which exists between cardiovascular disease and plasma cholesterol levels. From an evolutionary perspective, concomitant cholesterol production and free radical production in response to inflammatory factors makes sense if one realizes that both activities potentially protect cells and organisms from infection by gram-negative bacteria.In conclusion, data have been collected which suggest that activation of the mevalonate pathway in endothelial cells is likely to be a causal factor for atherosclerosis. This "mevalonate hypothesis" provides a better explanation for results obtained from recent clinical studies with cholesterol lowering drugs than the "cholesterol hypothesis". Furthermore, this hypothesis explains how cholesterol can be correlated with cardiovascular disease without being a causal factor for it. Finally it provides a logical explanation for the etiology of this disease.

N'-(arylsulfonyl)pyrazoline-1-carboxamidines as novel, neutral 5-hydroxytryptamine 6 receptor (5-HT6R) antagonists with unique structural features.

The 5-HT(6) receptor (5-HT(6)R) has been in the spotlight for several years regarding CNS-related diseases. We set out to discover novel, neutral 5-HT(6)R antagonists to improve off-target selectivity compared to basic amine-containing scaffolds dominating the field. High-throughput screening identified the N'-(sulfonyl)pyrazoline-1-carboxamidine scaffold as a promising neutral core for starting hit-to-lead. Medicinal chemistry, molecular modeling, small molecule NMR and X-ray crystallography were subsequently applied to optimize the leads into antagonists (compounds 1-49) displaying high 5-HT(6)R affinity with optimal off-target selectivity. Unique structural features include a pseudoaromatic system and an internal hydrogen bond freezing the bioactive conformation. While physicochemical properties and CNS availability were generally favorable, significant efforts had to be made to improve metabolic stability. The optimized structure 42 is an extremely selective, hERG-free, high-affinity 5-HT(6)R antagonist showing good human in vitro metabolic stability. Rat pharmacokinetic data were sufficiently good to enable further in vivo profiling.

Pomegranate seed oil, a rich source of punicic acid, prevents diet-induced obesity and insulin resistance in mice.

BACKGROUND: Pomegranate seed oil has been shown to protect against diet induced obesity and insulin resistance. OBJECTIVE: To characterize the metabolic effects of punicic acid on high fat diet induced obesity and insulin resistance. DESIGN: High-fat diet or high-fat diet with 1% Pomegranate seed oil (PUA) was fed for 12 weeks to induce obesity and insulin resistance. We assessed body weight and composition (pSABRE DEXA-scan), energy expenditure (Columbus Instruments) and insulin sensitivity at the end of the 12 weeks. RESULTS: PSO intake resulted in a lower body weight, 30.5±2.9 vs 33.8±3.2 g PSO vs HFD respectively, p=0.02, without affecting food intake or energy expenditure. The lower body weight was fully explained by a decreased body fat mass, 3.3±2.3 vs 6.7±2.7 g for PSO and HFD fed mice, respectively, p=0.02. Insulin clamps showed that PSO did not affect liver insulin sensitivity but clearly improved peripheral insulin sensitivity, 164±52% vs 92±24% for PSO and HFD fed mice respectively, p=0.01. CONCLUSIONS: We conclude that dietary PSO ameliorates high-fat diet induced obesity and insulin resistance in mice, independent of changes in food intake or energy expenditure.

A sub-chronic (13 weeks) oral toxicity study in rats and an in vitro genotoxicity study with Korean pine nut oil (PinnoThin TG).

In this paper a sub-chronic (13 weeks) toxicity study in rats and an in vitro genotoxicity study with Korean pine (Pinus koraiensis Siebold & Zucc.) nut oil, KPNO (PinnoThin) are described. Both studies were performed in compliance with GLP, and in line with OECD guidelines applicable. In the sub-chronic toxicity study, no clinical signs, abnormalities in functional observation tests or ophthalmologic examinations or changes in body weight or food intake were noted at any of the doses of KPNO tested. Various changes in clinical biochemistry parameters were noted. Whilst these changes were not consistent in both sexes, and neither associated with any histopathological changes, nor dose-related, these were not considered to be toxicologically relevant. No toxicologically significant changes were noted in haematological parameters. There were a few histopathological observations such as a periportal vacuolation of the liver in all dose groups including the control, and renal tubular mineralisation in most females of the high dose group but also in all control female rats. These findings can be considered to be due to the high fat content of the diets, and are not related to the treatment with KPNO. Based on these findings a No Observable Adverse Effect Level (NOAEL) of 15% has been established for KPNO. This NOAEL corresponded to a mean of 8866 and 10,242 mg KPNO/kg bw/day for males and females, respectively. This dose level was the highest achievable oral dose for KPNO in rats. The in vitro reverse mutation test (Ames test), showed no significant dose-related increase in the number of revertants in two independently repeated mutation assays. The negative and strain-specific positive control values were within the laboratory historical control data ranges indicating that the test conditions were adequate and that the metabolic activation system functioned properly. Based on these results it has been concluded that KPNO is not mutagenic in the Escherichia coli and Salmonella typhimurium reverse mutation assays. In conclusion, KPNO can be considered to be non-genotoxic in the AMES test. A NOAEL of 8866 and 10,242 mg KPNO/kg bw/day has been established for male and female rats, respectively. For both sexes, the NOAEL was achieved at the highest dose tested.

The effect of Korean pine nut oil on in vitro CCK release, on appetite sensations and on gut hormones in post-menopausal overweight women.

Appetite suppressants may be one strategy in the fight against obesity. This study evaluated whether Korean pine nut free fatty acids (FFA) and triglycerides (TG) work as an appetite suppressant. Korean pine nut FFA were evaluated in STC-1 cell culture for their ability to increase cholecystokinin (CCK-8) secretion vs. several other dietary fatty acids from Italian stone pine nut fatty acids, oleic acid, linoleic acid, alpha-linolenic acid, and capric acid used as a control. At 50 muM concentration, Korean pine nut FFA produced the greatest amount of CCK-8 release (493 pg/ml) relative to the other fatty acids and control (46 pg/ml). A randomized, placebo-controlled, double-blind cross-over trial including 18 overweight post-menopausal women was performed. Subjects received capsules with 3 g Korean pine (Pinus koraiensis) nut FFA, 3 g pine nut TG or 3 g placebo (olive oil) in combination with a light breakfast. At 0, 30, 60, 90, 120, 180 and 240 minutes the gut hormones cholecystokinin (CCK-8), glucagon like peptide-1 (GLP-1), peptide YY (PYY) and ghrelin, and appetite sensations were measured. A wash-out period of one week separated each intervention day.CCK-8 was higher 30 min after pine nut FFA and 60 min after pine nut TG when compared to placebo (p < 0.01). GLP-1 was higher 60 min after pine nut FFA compared to placebo (p < 0.01). Over a period of 4 hours the total amount of plasma CCK-8 was 60% higher after pine nut FFA and 22% higher after pine nut TG than after placebo (p < 0.01). For GLP-1 this difference was 25% after pine nut FFA (P < 0.05). Ghrelin and PYY levels were not different between groups. The appetite sensation "prospective food intake" was 36% lower after pine nut FFA relative to placebo (P < 0.05). This study suggests that Korean pine nut may work as an appetite suppressant through an increasing effect on satiety hormones and a reduced prospective food intake.

The effect of Korean pine nut oil (PinnoThin) on food intake, feeding behaviour and appetite: a double-blind placebo-controlled trial.

Certain free fatty acids have been shown to have potent effects on food intake and self-reported changes in appetite; effects associated with increases in the release of endogenous cholecystokinin (CCK) and glucagon like peptide-1 (GLP-1). In the current study, the effects of a Korean pine nut oil product, PinnoThin, at doses 2 g, 4 g and 6 g triglyceride (TG) and 2 g free fatty acid (FFA), on food intake and appetite were examined in a cross-over double-blind placebo-controlled randomised counter-balanced design in 42 overweight female volunteers. 2 g FFA PinnoThin, given 30 minutes prior to an ad-libitum buffet test lunch, significantly reduced food intake (gram) by 9% (F(4,164) = 2.637, p = 0.036) compared to olive oil control. No significant effect of PinnoThin on macronutrient intake or ratings of appetite were observed. Given the recent data showing that the TG form of PinnoThin may also reduce appetite by increasing CCK release, the lack of any effect of the TG form found in this study could be attributed to the timing of the dosing regime. Collectively, these data suggest that PinnoThin may exert satiating effects consistent with its known action on CCK and GLP-1 release, and previously observed effects on self-reported appetite ratings.

7-Azaindole derivatives as potential partial nicotinic agonists.

We have investigated a series of 7-azaindoles as potential partial agonists of the alpha4beta2 nicotinic acetylcholine receptor (nAChR). Three series of 7-azaindole derivatives have been synthesized and evaluated for rat brain neuronal nicotinic receptor affinity and functional activity. Compound (+)-51 exhibited the most potent nAChR binding (Ki = 10 nM). Compound 30A demonstrated both moderate binding affinity and partial agonist potency, thus representing a promising lead for the indications of cognition and smoking cessation.

Synthesis, structure-activity relationships, and biological properties of 1-heteroaryl-4-[omega-(1H-indol-3-yl)alkyl]piperazines, novel potential antipsychotics combining potent dopamine D2 receptor antagonism with potent serotonin reuptake inhibition.

A series of novel bicyclic 1-heteroaryl-4-[omega-(1H-indol-3-yl)alkyl]piperazines was synthesized and evaluated on binding to dopamine D(2) receptors and serotonin reuptake sites. This class of compounds proved to be potent in vitro dopamine D(2) receptor antagonists and in addition were highly active as serotonin reuptake inhibitors. Some key representatives showed potent pharmacological in vivo activities after oral dosing in both the antagonism of apomorphine-induced climbing and the potentiation of 5-HTP-induced behavior in mice. On the basis of the preclinical data, 8-{4-[3-(5-fluoro-1H-indol-3-yl)propyl]piperazin-1-yl}-4H-benzo[1,4]oxazin-(R)-2-methyl-3-one (45c, SLV314) was selected for clinical development. In vitro and in vivo studies revealed that 45c has favorable pharmacokinetic properties and a high CNS-plasma ratio. Molecular modeling studies showed that the bifunctional activity of 45c can be explained by its ability to adopt two different conformations fitting either the dopamine D(2) receptor pharmacophore or the serotonin transporter pharmacophore.

Bioisosteric replacements of the pyrazole moiety of rimonabant: synthesis, biological properties, and molecular modeling investigations of thiazoles, triazoles, and imidazoles as potent and selective CB1 cannabinoid receptor antagonists.

Series of thiazoles, triazoles, and imidazoles were designed as bioisosteres, based on the 1,5-diarylpyrazole motif that is present in the potent CB(1) receptor antagonist rimonabant (SR141716A, 1). A number of target compounds was synthesized and evaluated in cannabinoid (hCB(1) and hCB(2)) receptor assays. The thiazoles, triazoles, and imidazoles elicited in vitro( )()CB(1) antagonistic activities and in general exhibited considerable CB(1) vs CB(2) receptor subtype selectivities, thereby demonstrating to be cannabinoid bioisosteres of the original diarylpyrazole class. Some key representatives in the imidazole series showed potent pharmacological in vivo activities after oral administration in both a CB agonist-induced hypotension model and a CB agonist-induced hypothermia model. Molecular modeling studies showed a close three-dimensional structural overlap between the key compound 62 and rimonabant. A structure-activity relationship (SAR) study revealed a close correlation between the biological results in the imidazole and pyrazole series.

Synthesis, biological properties, and molecular modeling investigations of novel 3,4-diarylpyrazolines as potent and selective CB(1) cannabinoid receptor antagonists.

A series of novel 3,4-diarylpyrazolines was synthesized and evaluated in cannabinoid (hCB(1) and hCB(2)) receptor assays. The 3,4-diarylpyrazolines elicited potent in vitro CB(1) antagonistic activities and in general exhibited high CB(1) vs CB(2) receptor subtype selectivities. Some key representatives showed potent pharmacological in vivo activities after oral dosing in both a CB agonist-induced blood pressure model and a CB agonist-induced hypothermia model. Chiral separation of racemic 67, followed by crystallization and an X-ray diffraction study, elucidated the absolute configuration of the eutomer 80 (SLV319) at its C(4) position as 4S. Bioanalytical studies revealed a high CNS-plasma ratio for the development candidate 80. Molecular modeling studies showed a relatively close three-dimensional structural overlap between 80 and the known CB(1) receptor antagonist rimonabant (SR141716A). Further analysis of the X-ray diffraction data of 80 revealed the presence of an intramolecular hydrogen bond that was confirmed by computational methods. Computational models and X-ray diffraction data indicated a different intramolecular hydrogen bonding pattern in the in vivo inactive compound 6. In addition, X-ray diffraction studies of 6 revealed a tighter intermolecular packing than 80, which also may contribute to its poorer absorption in vivo. Replacement of the amidine -NH(2) moiety with a -NHCH(3) group proved to be the key change for gaining oral biovailability in this series of compounds leading to the identification of 80.