The Peroxisome Proliferator-Activated Receptor γ Agonist Pioglitazone Protects Vascular Endothelial Function in Hypercholesterolemic Rats by Inhibiting Myeloperoxidase

Cananga oil inhibits Salmonella infection by mediating the homeostasis of purine metabolism and the TCA cycle

ETHNOPHARMACOLOGY RELEVANCE

Cananga oil (CO) is derived from the flowers of the traditional medicinal plant, the ylang-ylang tree. As a traditional antidepressant, CO is commonly utilized in the treatment of various mental disorders including depression, anxiety, and autism. It is also recognized as an efficient antibacterial insecticide, and has been traditionally utilized to combat malaria and acute inflammatory responses resulting from bacterial infections both in vitro and in vivo.

AIM OF THE STUDY

The objective of this study is to comprehensively investigate the anti-Salmonella activity and mechanism of CO both in vitro and in vivo, with the expectation of providing feasible strategies for exploring new antimicrobial strategies and developing novel drugs.

METHODS

The in vitro antibacterial activity of CO was comprehensively analyzed by measuring MIC, MBC, growth curve, time-killing curve, surface motility, biofilm, and Live/dead bacterial staining. The analysis of the chemistry and active ingredients of CO was conducted using GC-MS. To examine the influence of CO on the membrane homeostasis of Salmonella, we conducted utilizing diverse techniques, including ANS, PI, NPN, ONPG, BCECF-AM, DiSC3(5), and scanning electron microscopy (SEM) analysis. In addition, the antibacterial mechanism of CO was analyzed and validated through metabolomics analysis. Finally, a mouse infection model of Salmonella typhimurium was established to evaluate the toxic side effects and therapeutic effects of CO.

RESULTS

The antibacterial effect of CO is the result of the combined action of the main chemical components within its six (palmitic acid, α-linolenic acid, stearic acid, benzyl benzoate, benzyl acetate, and myristic acid). Furthermore, CO disrupts the balance of purine metabolism and the tricarboxylic acid cycle (TCA cycle) in Salmonella, interfering with redox processes. This leads to energy metabolic disorders and oxidative stress damage within the bacteria, resulting in bacterial shock, enhanced membrane damage, and ultimately bacterial death. It is worth emphasizing that CO exerts an effective protective influence on Salmonella infection in vivo within a non-toxic concentration range.

CONCLUSION

The outcomes indicate that CO displays remarkable anti-Salmonella activity both in vitro and in vivo. It triggers bacterial death by disrupting the balance of purine metabolism and the TCA cycle, interfering with the redox process, making it a promising anti-Salmonella medication.

Regular transient limb ischemia improves endothelial function and inhibits endothelial cell apoptosis to prevent atherosclerosis in rabbit

AIMS

Regular transient limb ischemia (RTLI) can prevent atherosclerosis (AS) progression in hypercholesterolemic rabbits. This study aimed to investigate the minimum effective intensity and possible mechanisms of RTLI for preventing atherosclerosis.

METHODS

Eighty rabbits were divided into eight groups: normal (N), high cholesterol (H), three RTLI [three RTLI cycles every other day (R3qod), three RTLI cycles daily (R3qd), and six RTLI cycles daily (R6qd), each cycle of RTLI included 5 min of limb ischemia followed by 5 min limb reperfusion], and three correlated sham RTLI [sham ischemia for 30 min once every other day (S3qod), sham ischemia for 30 min once daily (S3qd), and sham ischemia for 60 min once daily (S6qd)]. Rabbits in group N were kept normally, while the others were fed 1% cholesterol diet for 12 weeks. The RTLI and sham RTLI groups were received RTLI or sham RTLI procedure, respectively. The plaque area in the thoracic aorta was determined by oil red O staining, and quantifying the ratio of plaque area to intimal area (PA/IA). Endothelium-dependent and -independent relaxation were also determined. Endothelial cell were isolated from abdominal aorta of rabbits, and the apoptosis ratio was detected using flow cytometry.

RESULTS

The PA/IA and early apoptotic cell ratio was significantly lower as well as the endothelium-dependent relaxation response was higher in group R6qd than those in groups H and S6qd, while those in the R3qod group was not significantly different from those in groups H and S3qod, as well as those in the R3qd group showed no significant difference compared to those in groups H and S3qd.

CONCLUSIONS

Six cycles of RTLI daily was the optimal effective intensity to prevent AS progression in rabbits. Endothelial function improvement and apoptosis inhibition might contribute to the anti-AS effects.

Targeting PPARs for therapy of atherosclerosis: A review

Atherosclerosis, a chief pathogenic factor of cardiovascular disease, is associated with many factors including inflammation, dyslipidemia, and oxidative stress. Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors and are widely expressed with tissue- and cell-specificity. They control multiple genes that are involved in lipid metabolism, inflammatory response, and redox homeostasis. Given the diverse biological functions of PPARs, they have been extensively studied since their discovery in 1990s. Although controversies exist, accumulating evidence have demonstrated that PPAR activation attenuates atherosclerosis. Recent advances are valuable for understanding the mechanisms of action of PPAR activation. This article reviews the recent findings, mainly from the year of 2018 to present, including endogenous molecules in regulation of PPARs, roles of PPARs in atherosclerosis by focusing on lipid metabolism, inflammation, and oxidative stress, and synthesized PPAR modulators. This article provides information valuable for researchers in the field of basic cardiovascular research, for pharmacologists that are interested in developing novel PPAR agonists and antagonists with lower side effects as well as for clinicians.

Pioglitazone restores phosphorylation of downregulated caveolin-1 in right ventricle of monocrotaline-induced pulmonary hypertension

BACKGROUND

Caveolin-1 (cav-1) plays a role in pulmonary arterial hypertension (PAH). Monocrotaline (MCT)-induced PAH is characterized by a loss of cav-1 in pulmonary arteries; however, less is known regarding its role in the hypertrophied right ventricle (RV). We aimed to characterize the role of cav-1 and Hsp90 in the RV of MCT-induced PAH and their impact on endothelial nitric oxide synthase (eNOS). Additionally, we focused on restoration of cav-1 expression with pioglitazone administration.

METHODS

Male 12-week-old Wistar rats were injected subcutaneously with monocrotaline (60 mg/kg). Selected proteins (cav-1, eNOS, pSer1177eNOS, Hsp90) and mRNAs (cav-1α, cav-1β, eNOS) were determined in the RV and left ventricle (LV) 4 weeks later. In a separate MCT-induced PAH study, pioglitazone (10 mg/kg/d, orally) administration started on day 14 after MCT.

RESULTS

MCT induced RV hypertrophy and lung enlargement. Cav-1 and pTyr14cav-1 were decreased in RV. Caveolin-1α (cav-1α) and caveolin-1β (cav-1β) mRNAs were decreased in both ventricles. Hsp90 protein was increased in RV. eNOS and pSer1177eNOS proteins were unchanged in the ventricles. eNOS mRNA was reduced in RV. Pioglitazone treatment increased oxygen saturation and pTyr14cav-1 vs. MCT group.

CONCLUSIONS

Restoration of pTyr14cav-1 did not lead to amelioration of the disease, nor did it prevent RV hypertrophy and fibrosis, which was indicated by an increase in Acta2, Nppb, Col3a1, and Tgfβ1 mRNA.

Nuclear Receptors and Transcription Factors in Obesity-Related Kidney Disease

Both obesity and chronic kidney disease are increasingly common causes of morbidity and mortality worldwide. Although obesity often co-exists with diabetes and hypertension, it has become clear over the past several decades that obesity is an independent cause of chronic kidney disease, termed obesity-related glomerulopathy. This review defines the attributes of obesity-related glomerulopathy and describes potential pharmacologic interventions. Interventions discussed include peroxisome proliferator-activated receptors, the farnesoid X receptor, the Takeda G-protein-coupled receptor 5, and the vitamin D receptor.

Finding inhibitors for PCSK9 using computational methods

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is one of the key targets for atherosclerosis drug development as its binding with low-density lipoprotein receptor leads to atherosclerosis. The protein-ligand interaction helps to understand the actual mechanism for the pharmacological action. This research aims to discover the best inhibitory candidates targeting PCSK9. To start with, reported ACE inhibitors were incorporated into pharmacophore designing using PharmaGist to produce pharmacophore models. Selected models were later screened against the ZINC database using ZINCPHARMER to define potential drug candidates that were docked with the target protein to understand their interactions. Molecular docking revealed the top 10 drug candidates against PCSK9, with binding energies ranging from -9.8 kcal·mol^-1 to -8.2 kcal·mol^-1, which were analyzed for their pharmacokinetic properties and oral bioavailability. Some compounds were identified as plant-derived compounds like (S)-canadine, hesperetin or labetalol (an antihypertensive drug). Molecular dynamics results showed that these substances formed stable protein-ligand complexes. (S)-canadine-PCSK9 complex was the most stable with the lowest RMSD. It was concluded that (S)-canadine may act as a potential inhibitor against atherosclerosis for the development of new PCSK9 inhibitory drugs in future in vitro research.

Pulmonary and vascular effects of acute ozone exposure in diabetic rats fed an atherogenic diet

Air pollutants may increase risk for cardiopulmonary disease, particularly in susceptible populations with metabolic stressors such as diabetes and unhealthy diet. We investigated effects of inhaled ozone exposure and high-cholesterol diet (HCD) in healthy Wistar and Wistar-derived Goto-Kakizaki (GK) rats, a non-obese model of type 2 diabetes. Male rats (4-week old) were fed normal diet (ND) or HCD for 12 weeks and then exposed to filtered air or 1.0 ppm ozone (6 h/day) for 1 or 2 days. We examined pulmonary, vascular, hematology, and inflammatory responses after each exposure plus an 18-h recovery period. In both strains, ozone induced acute bronchiolar epithelial necrosis and inflammation on histopathology and pulmonary protein leakage and neutrophilia; the protein leakage was more rapid and persistent in GK compared to Wistar rats. Ozone also decreased lymphocytes after day 1 in both strains consuming ND (~50%), while HCD increased circulating leukocytes. Ozone increased plasma thrombin/antithrombin complexes and platelet disaggregation in Wistar rats on HCD and exacerbated diet effects on serum IFN-γ, IL-6, KC-GRO, IL-13, and TNF-α, which were higher with HCD (Wistar>GK). Ex vivo aortic contractility to phenylephrine was lower in GK versus Wistar rats at baseline(~30%); ozone enhanced this effect in Wistar rats on ND. GK rats on HCD had higher aortic e-NOS and tPA expression compared to Wistar rats. Ozone increased e-NOS in GK rats on ND (~3-fold) and Wistar rats on HCD (~2-fold). These findings demonstrate ways in which underlying diabetes and HCD may exacerbate pulmonary, systemic, and vascular effects of inhaled pollutants.