Current and future therapies for addressing the effects of inflammation on HDL cholesterol metabolism

Future aspects of plant derived bioactive metabolites as therapeutics to combat benign prostatic hyperplasia

ETHNOPHARMACOLOGICAL RELEVANCE

Benign prostatic hyperplasia (BPH), characterized by prostate enlargement due to cell proliferation, is a common urinary disorder in men over 50, manifesting as lower urinary tract symptoms (LUTS). Currently, several therapeutic options are accessible for treating BPH, including medication therapy, surgery and watchful waiting. Conventional drugs such as finasteride and dutasteride are used as 5α-reductase inhibitors for the treatment of BPH. However long-term use of these drugs is restricted due to their unpleasant side effects. Despite the range of available medical therapies, the effective treatment against BPH is still inadequate. Certain therapeutic plants and their phytochemicals have the aforementioned goals and work by regulating this enzyme.

AIM OF THE STUDY

This review aims to provide a comprehensive insight to advancements in diagnosis of BPH, modern treatment methods and the significance of ethnobotanically relevant medicinal plants as alternative therapeutics for managing BPH.

MATERIAL AND METHODS

A thorough and systematic literature search was performed using electronic databases and search engines such as PubMed, Web of Science, NCBI and SciFinder till October 2023. Specific keywords such as "benign prostatic hyperplasia", "medicinal plants", "phytochemicals", "pharmacology", "synergy", "ethnobotany", "5-alpha reductase", "alpha blocker" and "toxicology". By include these keywords, a thorough investigation of pertinent papers was assured, and important data about the many facets of BPH could be retrieved.

RESULTS

After conducting the above investigation, 104 herbal remedies were found to inhibit Phosphodiesterase-5 (PDE-5) inhibition, alpha-blockers, or 5α -reductase inhibition effects which are supported by in vitro, in vivo and clinical trial studies evidence. Of these, 89 plants have ethnobotanical significance as alpha-blockers, alpha-reductase inhibition, or PDE-5 inhibition, and the other fifteen plants were chosen based on their ability to reduce BPH risk factors. Several phytocompounds, including, rutaecarpine, vaccarin, rutin, kaempferol, β-sitosterol, quercetin, dicaffeoylquinic acid, rutaevin, and phytosterol-F have been reported to be useful for the management of BPH. The use of combination therapy offers a strong approach to treating long-term conditions compare to single plant extract drugs. Furthermore, several botanical combinations such as lycopene and curcumin, pumpkin seed oil and saw palmetto oil, combinations of extracts from Funtumia africana (Benth.) Stapf and Abutilon mauritianum (Jacq.) Medik., and Hypselodelphys poggeana (K.Schum.) Milne-Redh. and Spermacoce radiata (DC.) Sieber ex Hiern are also supported through in vitro and in vivo studies for managing BPH through recuperation in patients with chronic long-term illnesses, as measured by the International Prostate Symptom Score.

CONCLUSION

The review proposes and endorses careful utilization of conventional medications that may be investigated further to discover possible PDE-5, 5 alpha-reductase, an alpha-blocker inhibitor for managing BPH. Even though most conventional formulations, such as 5 alpha-reductase, are readily available, systemic assessment of the effectiveness and mechanism of action of the herbal constituents is still necessary to identify novel chemical moieties that can be further developed for maximum efficacy. However, there exist abundant botanicals and medicinal plants across several regions of Africa, Asia, and the Americas, which can be further studied and developed for utilization as a potential phytotherapeutic for the management of BPH.

Polysaccharides from Dendrobium officinale improve obesity-induced insulin resistance through the gut microbiota and the SOCS3-mediated insulin receptor substrate-1 signaling pathway

BACKGROUND

Obesity induces insulin resistance and chronic inflammation, impacting human health. The relationship between obesity, gut microbiota, and regulatory mechanisms has been studied extensively. Dendrobium officinale polysaccharide (DOP), a traditional Chinese herbal medicine, potentially reduces insulin resistance. However, the mechanism through which DOP affects gut microbiota and alleviates obesity-induced insulin resistance in rats requires further investigation.

RESULTS

The current study aimed to assess the impact of DOP on gut microbiota and insulin resistance in rats on a high-fat diet. The results revealed that DOP effectively reduced blood lipids, glucose disorders, oxidative stress, and inflammatory infiltration in the liver of obese Sprague Dawley rats. This was achieved by downregulating SOCS3 expression and upregulating insulin receptor substrate-1 (IRS-1) by regulating the JAK/STAT/SOCS3 signaling pathway. Notably, DOP intervention enhanced the abundance of beneficial gut microbiota and reduced harmful microbiota. Correlation analysis demonstrated significant associations among intestinal microbiota, SOCS3-mediated IRS-1 expression, and inflammatory factors.

CONCLUSION

Dendrobium officinale polysaccharide regulated the gut microbiota, enhanced IRS-1 expression, and mitigated liver injury and insulin resistance due to a high-fat diet. These findings depict the potential anti-insulin resistance properties of DOP and offer further evidence for addressing obesity and its complications. © 2023 Society of Chemical Industry.

Association between HDL-C and chronic pain: data from the NHANES database 2003-2004

Objective

High-density lipoprotein cholesterol (HDL-C) has been reported to be associated with pain symptoms of various diseases, and its anti-inflammatory and antioxidant mediation is related to the pathogenesis of chronic pain. This study aims to evaluate the relationship between HDL-C levels and chronic pain in American adults.

Methods

This cross-sectional study used data from American adults aged 20 and above during the 2003-2004 National Health and Nutrition Examination Survey (NHANES) cycle. Participants were divided into 4 groups based on HDL-C quartiles. We used chi-square tests and Student's t-tests or Mann-Whitney U tests to analyze categorical variables and continuous variables to compare differences between groups. Multivariate logistic regression analysis was used to study the association between HDL-C levels and the risk of chronic pain. Likelihood ratio tests were used to assess interactions between subgroups, and sensitivity analyses were conducted.

Results

Our final analysis included 4,688 participants, of which 733 (16.4%) had chronic pain. In the multivariate logistic regression model adjusted for covariates, there was a negative correlation between HDL-C levels and chronic pain. Specifically, for every 20 unit increase in HDL-C, the risk of chronic pain decreased by 26%. Compared with the lowest HDL-C quartile (< 43 mg/dL), the highest HDL-C quartile (≥ 64 mg/dL) was associated with a 24% reduction in the risk of chronic pain. No interaction factors affecting the relationship between HDL-C and chronic pain were found in the subgroup analysis.

Conclusion

This study demonstrates a negative association between HDL-C levels and chronic pain in US adults, providing insights into the pathogenesis of chronic pain and potential improvements in chronic pain management strategies.

Benefits and Meaning of Lipids Profile in Relation to Oxidative Balance and Brain Morphology in Schizophrenia

Schizophrenia is characterized by complex metabolic dysregulations and their consequences. Until now, numerous theories have explained its pathogenesis, using a spectrum of available technologies. We focused our interest on lipid profile-periphery high-density cholesterol level and lipoproteins in the human brain and compared magnetic resonance imaging (MRI) scans of patients with schizophrenia and the healthy group. Detailed analysis of biochemical parameters was performed using magnetic resonance spectroscopy. Our study aimed to reveal correlations between periphery high-density lipoproteins levels and lipoproteins in the brain, depicted in MRI scans, and parameters of peripheral oxidative stress expressed as paraoxonase. Patients with schizophrenia have decreased levels of high-density lipoproteins, low paraoxonase activity, and slightly raised sodium in the blood. Positive significant correlations between serum high-density cholesterol and anterior cingulate cortex, unique brain area for schizophrenia pathophysiology, MR spectroscopy signals, and diffusion have been revealed. To our knowledge, this is the first study to describe the effect of an anterior cingulate disorder on high-density cholesterol levels on the development of schizophrenia.

Tongxinluo enhances the effect of atorvastatin on the treatment of atherosclerosis with chronic obstructive pulmonary disease by maintaining the pulmonary microvascular barrier

Atherosclerosis (AS) is a common comorbidity of chronic obstructive pulmonary disease (COPD), and systemic inflammation is an important mechanism of COPD with AS. Tongxinluo (TXL) improves the function of vascular endothelial cells. We aimed to prove that impairment of pulmonary microvascular barrier function is involved in COPD-mediated aggravation of AS and investigate whether TXL enhances the effect of Ato (atorvastatin) on COPD with AS by protecting pulmonary microvascular endothelial barrier function. In vivo, a COPD with atherosclerotic apolipoprotein E knockout (AS ApoE^-/-) mouse model was established by cigarette smoke combined with a high-fat diet. The animals were administered TXL, Ato, and TXL + Ato once a day for 20 weeks. Lung function, lung microvascular permeability, lung inflammation, systemic inflammation, serum lipid levels, atheromatous plaque formation, and endothelial damage biomarkers were measured. In vitro, human pulmonary microvascular endothelial cells (HPMECs) were pretreated with TXL and incubated with cigarette smoke extract to establish the model. The permeability of the endothelial monolayer, inflammatory cytokines, endothelial damage biomarkers, and tight junction (Tj) proteins were determined. Cigarette smoking significantly exacerbated the high-fat diet-induced pulmonary function decline, pulmonary microvascular endothelial barrier dysfunction, inflammation, and atherosclerotic plaques. These changes were reversed by TXL-Ato; the combination was more effective than Ato alone. Furthermore, TXL protected the HPMEC barrier and inhibited inflammation in HPMECs. COPD aggravates AS, possibly through the destruction of pulmonary microvascular barrier function; thus, lung inflammation triggers systemic inflammation. In treating COPD with AS, TXL enhances the antiatherosclerotic effect of Ato, protecting the pulmonary microvascular barrier.

Functional Food and Bioactive Compounds on the Modulation of the Functionality of HDL-C: A Narrative Review

Cardiovascular diseases (CVD) remain a serious public health problem and are the primary cause of death worldwide. High-density lipoprotein cholesterol (HDL-C) has been identified as one of the most important molecules in the prevention of CVD due to its multiple anti-inflammatories, anti-atherogenic, and antioxidant properties. Currently, it has been observed that maintaining healthy levels of HDL-C does not seem to be sufficient if the functionality of this particle is not adequate. Modifications in the structure and composition of HDL-C lead to a pro-inflammatory, pro-oxidant, and dysfunctional version of the molecule. Various assays have evaluated some HDL-C functions on risk populations, but they were not the main objective in some of these. Functional foods and dietary compounds such as extra virgin olive oil, nuts, whole grains, legumes, fresh fish, quercetin, curcumin, ginger, resveratrol, and other polyphenols could increase HDL functionality by improving the cholesterol efflux capacity (CEC), paraoxonase 1 (PON1), and cholesteryl ester transfer protein (CETP) activity. Nevertheless, additional rigorous research basic and applied is required in order to better understand the association between diet and HDL functionality. This will enable the development of nutritional precision management guidelines for healthy HDL to reduce cardiovascular risk in adults. The aim of the study was to increase the understanding of dietary compounds (functional foods and bioactive components) on the functionality of HDL.

The interaction between ABCA1 polymorphism and physical activity on the HDL-cholesterol levels in a Japanese population

Few studies have investigated the interactions between HDL-C-related SNPs identified by genome-wide association (GWA) study and physical activity (PA) on HDL-C. First, we conducted a sex-stratified GWA study in a discovery sample (2,231 men and 2,431 women) and replication sample (2,599 men and 3,109 women) to identify SNPs influencing log-transformed HDL-C in Japanese participants in the baseline survey of the Japan Multi-Institutional Collaborative Cohort Study. We also replicated previously reported HDL-C-related SNPs in a combined (discovery plus replication) sample (4,830 men and 5,540 women). We then analyzed the interactions of the HDL-C-related SNPs with PA on HDL-C. The sex-stratified GWA analyses identified 11 and 10 HDL-C-related SNPs in men and women as targets for an interaction analysis. Among these, only one interaction of ABCA1 rs1883025 with PA was statistically significant in men, after Bonferroni correction [P-interaction = 0.001 (α = 0.05/21 = 0.002)]. The per-major-allele (C allele) increase in log-transformed HDL-C was lost in men with low PA (β = 0.008) compared with those with medium (β = 0.032) or high PA (β = 0.034). These findings suggest that the benefit of carrying a C allele of ABCA1 rs1883025 on enhancing HDL-C may be attenuated in inactive men.

Participation of white adipose tissue dysfunction on circulating HDL cholesterol and HDL particle size in apparently healthy humans

OBJECTIVE

To use the combined presence of the elevated insulin resistance index in adipose tissue (Adipo-IR) and low values of adiponectin as a marker of dysfunctional adipose tissue, and to analyze its possible association with low values of high-density lipoprotein cholesterol (HDL-C) and small size of HDL particles.

RESEARCH DESIGN AND METHODS

The analysis included 253 subjects with functional adipose tissue and 253 with dysfunctional adipose tissue, considering similar gender, age, and body mass index (BMI). Adipo-IR was considered when index values (free fatty acids × insulin concentrations) were ≥75th percentile. Low levels of adiponectin were considered when concentration in serum was <25th percentile (determined by ELISA). HDL size was estimated by a quantitative validated equation. Small HDL size was considered when values were <25th percentile.

RESULTS

When comparing subjects with functional adipose tissue with those of dysfunctional adipose tissue, the latter had a higher prevalence of low HDL-C (51.4% vs. 64.0%; p = 0.004) and small HDL (56.9% vs. 67.6%; p = 0.009). Multivariate analysis indicated that independently from other metabolic risk factors, dysfunction of adipose tissue is significantly associated with low HDL-C (OR: 1.624 [CI 95%: 1.100-2.397]) and small HDL (OR: 1.462 [CI 95%: 1.000-2.139]). Adding BMI, waist circumference, and subcutaneous or visceral adipose tissue did not modify the association.

CONCLUSIONS

Dysfunction of adipose tissue is associated with a 65 and 50% higher probability of having low HDL-C and small HDL. Identification of dysfunctional adipose tissue could be a useful tool in the clinical setting to prevent the cardiometabolic risk independently from adiposity.

Hot Water Extract of Curcuma longa L. Improves Serum Inflammatory Markers and General Health in Subjects with Overweight or Prehypertension/Mild Hypertension: A Randomized, Double-Blind, Placebo-Controlled Trial

To investigate the effect of a hot water extract of C. longa L. (WEC) containing anti-inflammatory agents, bisacurone, and turmeronol on chronic inflammation, a randomized double-blind placebo-controlled study was conducted in middle-aged and elderly subjects aged 50–69 years with overweight or prehypertension/mild hypertension. The subjects consumed 900 mg WEC tablets, containing 400 μg bisacurone, 80 μg turmeronol A and 20 μg turmeronol B (WEC group: n = 45), or placebo tablets without WEC (placebo group: n = 45) daily for 12 weeks. Serum inflammatory and metabolic markers were measured. The subjects also completed the MOS 36-item short-form health survey (SF-36) and the Profile of Mood States scale (POMS). In the WEC group, the serum levels of C-reactive protein, tumor necrosis factor-α, interleukin-6, and soluble vascular cell adhesion molecule-1 decreased significantly. Compared with the placebo group, the WEC group had significantly lower serum levels of glucose, hemoglobin A1c, and triglycerides, as well as higher serum levels of high-density lipoprotein cholesterol. The WEC group also showed significant improvement of SF-36 scores (for general health, vitality, mental health, and mental summary component) and POMS scores for positive mood states (vigor-activity and friendliness). In conclusion, WEC may ameliorate chronic low-grade inflammation, thus contributing to the improvement of associated metabolic disorders and general health.

Probiotic Lactobacillus gasseri SBT2055 improves insulin secretion in a diabetic rat model

The probiotic Lactobacillus gasseri SBT2055 (LG2055) has a protective effect against metabolic syndrome in rats and humans. Metabolic syndrome increases the risk of type 2 diabetes mellitus. In this study, Goto-Kakizaki rats were used as a diabetic model and fed diets containing LG2055-fermented or nonfermented skim milk for 4 wk. Indices of diabetes such as blood glucose levels, serum glucagon levels, plasma levels of insulin, C-peptide, and glucagon-like peptide-1, tissue glycogen contents, and pancreatic mRNA levels were measured. The plasma C-peptide levels and pancreatic mRNA levels of insulin genes (Ins1 and Ins2) and Pdx1 (a transcriptional factor of insulin genes) were increased in LG2055 diet-fed rats. The increase in insulin secretion corresponded to an improvement in serum and pancreatic inflammatory status, associated with decreases in serum levels of serum amyloid P and pancreatic levels of granulocyte colony-stimulating factor. Insulin resistance in Goto-Kakizaki rats was ameliorated by increased glycogen storage in the liver and quadriceps femoris muscles and decreased serum free fatty acid levels. This improvement may be related to the increased cecal production of short-chain fatty acids. In conclusion, dietary LG2055 improved insulin secretion in diabetic rats by improving the inflammatory status in the pancreas and serum.

Targeting inflammation to reduce cardiovascular disease risk

This joint themed section of the British Journal of Pharmacology and the British Journal of Clinical Pharmacology stems from a joint British Pharmacological Society - Italian Society of Pharmacology symposium held at the 37^th National Congress of the Italian Society of Pharmacology in Naples (Italy) from 27 to 30 October 2015.

LINKED ARTICLES

This article is part of a themed section on Targeting Inflammation to Reduce Cardiovascular Disease Risk. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.22/issuetoc and http://onlinelibrary.wiley.com/doi/10.1111/bcp.v82.4/issuetoc.

Inflammation, not Cholesterol, Is a Cause of Chronic Disease

Since the Seven Countries Study, dietary cholesterol and the levels of serum cholesterol in relation to the development of chronic diseases have been somewhat demonised. However, the principles of the Mediterranean diet and relevant data linked to the examples of people living in the five blue zones demonstrate that the key to longevity and the prevention of chronic disease development is not the reduction of dietary or serum cholesterol but the control of systemic inflammation. In this review, we present all the relevant data that supports the view that it is inflammation induced by several factors, such as platelet-activating factor (PAF), that leads to the onset of cardiovascular diseases (CVD) rather than serum cholesterol. The key to reducing the incidence of CVD is to control the activities of PAF and other inflammatory mediators via diet, exercise, and healthy lifestyle choices. The relevant studies and data supporting these views are discussed in this review.

Current and future therapies for addressing the effects of inflammation on HDL cholesterol metabolism

Cardiovascular disease (CVD) is a major cause of morbidity and mortality worldwide. Inflammatory processes arising from metabolic abnormalities are known to precipitate the development of CVD. Several metabolic and inflammatory markers have been proposed for predicting the progression of CVD, including high density lipoprotein cholesterol (HDL-C). For ~50 years, HDL-C has been considered as the atheroprotective 'good' cholesterol because of its strong inverse association with the progression of CVD. Thus, interventions to increase the concentration of HDL-C have been successfully tested in animals; however, clinical trials were unable to confirm the cardiovascular benefits of pharmaceutical interventions aimed at increasing HDL-C levels. Based on these data, the significance of HDL-C in the prevention of CVD has been called into question. Fundamental in vitro and animal studies suggest that HDL-C functionality, rather than HDL-C concentration, is important for the CVD-preventive qualities of HDL-C. Our current review of the literature positively demonstrates the negative impact of systemic and tissue (i.e. adipose tissue) inflammation in the healthy metabolism and function of HDL-C. Our survey indicates that HDL-C may be a good marker of adipose tissue health, independently of its atheroprotective associations. We summarize the current findings on the use of anti-inflammatory drugs to either prevent HDL-C clearance or improve the function and production of HDL-C particles. It is evident that the therapeutic agents currently available may not provide the optimal strategy for altering HDL-C metabolism and function, and thus, further research is required to supplement this mechanistic approach for preventing the progression of CVD.

LINKED ARTICLES

This article is part of a themed section on Targeting Inflammation to Reduce Cardiovascular Disease Risk. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.22/issuetoc and http://onlinelibrary.wiley.com/doi/10.1111/bcp.v82.4/issuetoc.

Capsaicin Supplementation Improved Risk Factors of Coronary Heart Disease in Individuals with Low HDL-C Levels

Low high-density lipoprotein cholesterol (HDL-C) is associated with an increased risk of coronary heart disease (CHD). This study aimed to evaluate the effects of capsaicin intervention on the serum lipid profile in adults with low HDL-C. In a randomized, double-blind, controlled clinical trial, 42 eligible subjects were randomly assigned to the capsaicin (n = 21, 4 mg of capsaicin daily) or to the control group (n = 21, 0.05 mg of capsaicin daily) and consumed two capsaicin or control capsules, which contained the powder of the skin of different peppers, twice daily for three months. Thirty-five subjects completed the trial (18 in the capsaicin group and 17 in the control group). The baseline characteristics were similar between the two groups. Compared with the control group, fasting serum HDL-C levels significantly increased to 1.00 ± 0.13 mmol/L from 0.92 ± 0.13 mmol/L in the capsaicin group (p = 0.030), while levels of triglycerides and C-reactive protein and phospholipid transfer protein activity moderately decreased (all p < 0.05). Other lipids, apolipoproteins, glucose, and other parameters did not significantly change. In conclusion, capsaicin improved risk factors of CHD in individuals with low HDL-C and may contribute to the prevention and treatment of CHD.

Sex-dependent difference in the relationship between adipose-tissue cholesterol efflux and estradiol concentrations in young healthy humans

BACKGROUND

Impaired adipose tissue function and lower levels of high density lipoprotein cholesterol (HDL-C) have been implicated in the development of vascular dementia, and metabolic diseases such as hypertension, atherosclerosis, type 2 diabetes (T2D) and metabolic syndrome. Interestingly, both the substrate fluxes in adipose tissue and HDL-C concentration differ between men and women. Moreover, adipose tissue cholesterol efflux has been implicated in modulation of HDL-C levels. Thus, we aimed to determine if the association between serum estradiol levels and adipose tissue cholesterol efflux is sex-dependent.

METHOD

We evaluated the serum estradiol levels and adipose tissue cholesterol efflux in young healthy men (n=5) and women (n=3). Adipose tissue cholesterol efflux was determined using subcutaneous microdialysis probes. Linear regression analyses were used to determine the relationship between the parameters, p<0.05 was considered as statistically significant.

RESULTS

Our data demonstrated that serum estradiol levels directly associated with adipose tissue cholesterol efflux; however, the relationships may be sex-dependent. We discussed our results in the context of currently available data regarding sex-dependent variability in adipose tissue function and HDL-C metabolism as a potential contributor to higher rates of vascular dementia in men. Further research is required to understand the sex-dependent and -independent variabilities in adipose tissue metabolism to determine novel targets for interventions to prevent the development of vascular dementia.