Anti-inflammatory and antithrombotic effects of nicotine exposure in oral contraceptive-induced insulin resistance are glucocorticoid-independent

Phytochemical and pharmacological investigation of the ethanol extract of Byttneria pilosa Roxb

Background

Traditionally, the herb Byttneria pilosa Roxb. is used for bone fractures, boils, scabies, rheumatalgia, snake bites, syphilis, elephantiasis, poisoning, and eye infection. Scientific reports suggest that it has significant anti-inflammatory, analgesic, anti-diarrheal, anxiolytic, locomotion, sedative and anti-obesity effects. This study aims at the investigation of the phytochemical and pharmacological properties of the ethanol extract of this herb.

Methods

Fresh whole plant was extracted with absolute ethanol. A preliminary phytochemical investigation was followed by the evaluation of thrombolytic, anti-inflammatory, and anti-nociceptive activities by applying human clotted blood lysis, egg albumin, and acetic acid-induced writhing models, respectively.

Results

Phytochemical investigation suggests that B. pilosa possesses alkaloids, flavonoids, glycosides, terpenoids, tannins, saponins, and reducing sugars. The extract exhibited clot lysis and anti-inflammatory effects in a concentration-dependent manner. B. pilosa extract at 250 and 500 mg/kg also showed significant (p < 0.05) dose-dependent anti-nociceptive activity in Swiss albino mice.

Conclusion

The B. pilosa ethanol extract contains many important secondary metabolites and has thrombolytic, anti-inflammatory, and anti-nociceptive activities. More research is necessary on this hopeful medicinal herb.

Sodium acetate prevents nicotine-induced cardiorenal dysmetabolism through uric acid/creatine kinase-dependent pathway

BACKGROUND

Cigarette smoking or nicotine replacement therapy has been associated with cardiometabolic disorders (CMD). Hyperuricemia has been implicated in the pathogenesis of CMD and cardiorenal dysfunction. Gut microbiota-derived short chain fatty acids (SCFAs) have been reported to have beneficial glucoregulatory and cardiorenal protective effects. This study aimed at investigating the effect of acetate, a gut-derived SCFA, on nicotine-induced CMD and associated cardiorenal dysmetabolism.

MATERIALS AND METHOD

Twenty-four male Wistar rats (n = 6/group) were grouped as: vehicle (p.o.), nicotine-exposed (1.0 mg/kg; p.o.), and sodium acetate-treated (200 mg/kg; p.o.) with or without nicotine exposure daily for 6 weeks. Glucose regulation was evaluated by oral glucose tolerance test and homeostatic model assessment of insulin resistance. Cardiac and renal triacylglycerol (TG), lactate, nitric oxide (NO), uric acid (UA) levels, lactate dehydrogenase (LDH), creatine kinase (CK), adenosine deaminase (ADA), and xanthine oxidase (XO) activities were measured.

RESULTS

The CMD were confirmed in the nicotine-exposed rats that exhibited lower body weight, insulin resistance, endothelial dysfunction, glucose intolerance, increased cardiac and renal TG, TG/HDL-cholesterol, UA, lactate, lipid peroxidation, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transferase, LDH, CK, ADA and XO activities. Concurrent treatment with acetate prevented nicotine-induced glucometabolic and cardiorenal alterations.

CONCLUSION

In summary, these results implied that nicotine exposure caused glucometabolic dysregulation and surplus lipid deposit in the heart and kidney through increased UA production and CK activity. Therefore, oral acetate administration prevents cardiorenal lipotoxicity and glucometabolic dysregulation via suppression of UA production and CK activity in nicotine-exposed rats.

Estrogen-progestin oral contraceptive and nicotine exposure synergistically confers cardio-renoprotection in female Wistar rats

Approximately fifty percent of premenopausal women who smoke cigarettes or on nicotine replacement therapy are also on hormonal contraceptives, especially oral estrogen-progestin. Oral estrogen-progestin therapy has been reported to promote insulin resistance (IR) which causes lipid influx into non-adipose tissue and impairs Na⁺/K⁺ -ATPase activity, especially in the heart and kidney. However, the effects of nicotine on excess lipid and altered Na⁺/K⁺ -ATPase activity associated with the use of estrogen-progestin therapy have not been fully elucidated. This study therefore aimed at investigating the effect of nicotine on cardiac and renal lipid influx and Na⁺/K⁺ -ATPase activity during estrogen-progestin therapy. Twenty-four female Wistar rats grouped into 4 (n = 6/group) received (p.o.) vehicle, nicotine (1.0 mg/kg) with or without estrogen-progestin steroids (1.0 μg ethinyl estradiol and 5.0 μg levonorgestrel) and estrogen-progestin only daily for 6 weeks. Data showed that estrogen-progestin treatment or nicotine exposure caused IR, hyperinsulinemia, increased cardiac and renal uric acid, malondialdehyde, triglyceride, glycogen synthase kinase-3, plasminogen activator inhibitor-1, reduced bilirubin and circulating estradiol. Estrogen-progestin treatment led to decreased cardiac Na⁺/K⁺-ATPase activity while nicotine did not alter Na⁺/K⁺-ATPase activity but increased plasma and tissue cotinine. Renal Na⁺/K⁺-ATPase activity was not altered by the treatments. However, all these alterations were reversed following combined administration of oral estrogen-progestin therapy and nicotine. The present study therefore demonstrates that oral estrogen-progestin therapy and nicotine exposure synergistically prevents IR-linked cardio-renotoxicity with corresponding improvement in cardiac and renal lipid accumulation, oxidative stress, inflammation and Na⁺/K⁺-ATPase activity.

Elevated Neutrophil to Lymphocyte Ratio in Older Adults with Cocaine Use Disorder as a Marker of Chronic Inflammation

Objective

The neutrophil to lymphocyte ratio (NLR) is a non-specific, easy-to-obtain marker of inflammation associated with morbidity and mortality in systemic, psychiatric, and age-related inflammatory conditions. Given the growing trend of substance use disorder (SUD) in older adults, and the relationship between inflammation and SUD elevated NLR may serve as a useful inflammatory biomarker of the combined burden of aging and SUD. The present study focused on cocaine use disorder (CUD) to examine if cocaine adds further inflammatory burden among older adults, by comparing NLR values between older adults with CUD and a non-cocaine using, aged-matched, nationally representative sample.

Methods

The dataset included 107 (86% male) participants (aged 50-65 years) with cocaine use disorder. NLR was derived from complete blood count tests by dividing the absolute value of peripheral neutrophil concentration by lymphocyte concentration. For comparison, we extracted data from age-matched adults without CUD using the National Health and Nutrition Examination Survey. Individuals with immunocompromising conditions were excluded (e.g., rheumatoid arthritis and sexually transmitted infections such as HIV). A doubly-robust inverse probability-weighted regression adjustment (IPWRA) propensity score method was used to estimate group differences on NLR while controlling for potential confounding variables (age, gender, race, income, nicotine, marijuana and alcohol use).

Results

The IPWRA model revealed that the CUD sample had significantly elevated NLR in comparison to non-cocaine users, with a moderate effect size (β weight = 0.67).

Conclusion

Although non-specific, NLR represents a readily obtainable inflammatory marker for SUD research. CUD may add further inflammatory burden to aging cocaine users.

Oral ethinylestradiol–levonorgestrel normalizes fructose-induced hepatic lipid accumulation and glycogen depletion in female rats

The present study investigated the effects of oral ethinylestradiol–levonorgestrel (EEL) on hepatic lipid and glycogen contents during high fructose (HF) intake, and determined whether pyruvate dehydrogenase kinase-4 (PDK-4) and glucose-6-phosphate dehydrogenase (G6PD) activity were involved in HF and (or) EEL-induced hepatic dysmetabolism. Female Wistar rats weighing 140–160 g were divided into groups. The control, EEL, HF, and EEL+HF groups received water (vehicle, p.o.), 1.0 μg ethinylestradiol plus 5.0 μg levonorgestrel (p.o.), fructose (10% w/v), and EEL plus HF, respectively, on a daily basis for 8 weeks. Results revealed that treatment with EEL or HF led to insulin resistance, hyperinsulinemia, increased hepatic uric acid production and triglyceride content, reduced glycogen content, and reduced production of plasma or hepatic glutathione- and G6PD-dependent antioxidants. HF but not EEL also increased fasting glucose and hepatic PDK-4. Nonetheless, these alterations were attenuated by EEL in HF-treated rats. Our results demonstrate that hepatic lipid accumulation and glycogen depletion induced by HF is accompanied by increased PDK-4 and defective G6PD activity. The findings also suggest that EEL would attenuate hepatic lipid accumulation and glycogen depletion by suppression of PDK-4 and enhancement of a G6PD-dependent antioxidant barrier.

Involvement of glucocorticoid and mineralocorticoid receptors in lipid accumulation and depressed G6PD activity in the livers of rats treated with postpartum oral estrogen-progestin

Postpartum contraception is an important step for preventing closely spaced pregnancy. Combined oral contraceptive (COC) has been linked to cardiometabolic disturbances. We therefore hypothesized that postpartum oral estrogen-progestin use induces hepatic lipid accumulation that is associated with glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) activation via adenosine deaminase (ADA)/xanthine oxidase (XO)/uric acid (UA)-dependent pathway. Female Wistar rats weighing 130-150 g were mated to achieve timed pregnancy and delivery. Twenty-four (24) dams were randomly assigned to receive vehicle (po), COC (1.0 μg ethinylestradiol and 5.0 μg levonorgestrel; po), COC with GR blockade (mifepristone; 80.0 mg/kg; po) and COC with MR blockade (spironolactone; 0.25 mg/kg; po) daily between 3rd and 11th week postpartum. Data showed that postpartum COC resulted in glucose dysregulation, increased visceral adiposity, liver weight, plasma corticosterone, aldosterone, circulating and hepatic free fatty acid (FFA), triglyceride (TG), adenosine deaminase (ADA), uric acid production, lactate production, and oxidative marker injury. On the other hand, G6PD-dependent antioxidant defenses were depressed by postpartum COC. However, these effects were attenuated by GR or MR blockade. Our data demonstrate that enhanced G6PD-dependent antioxidant defenses and suppressed ADA/XO/UA pathway in the liver by GR or MR blockade improves glucose dysregulation and hepatic TG accumulation induced by postpartum COC. This study implies a plausible involvement of GR and MR via defective G6PD-dependent antioxidant barrier and increased activity of ADA/XO/UA pathway in postpartum COC-induced hepatic lipid accumulation.

Dipeptidyl peptidase-4 inhibition protects the liver of insulin-resistant female rats against triglyceride accumulation by suppressing uric acid

Dipeptidyl peptidase-4 (DPP-4) inhibition has been shown to exert beneficial effects against insulin resistance (IR) and type 2 diabetes. Combined oral contraceptive (COC) treatment is associated with impaired glucose and lipid metabolism but the mechanisms are elusive. We therefore, hypothesized that DPP-4 inhibition ameliorates COC-induced glucose dysregulation and hepatic triglyceride (TG) accumulation through adenosine deaminase (ADA) /xanthine oxidase (XO) /uric acid-dependent pathway. Female Wistar rats received (po) vehicle and COC (1.0 μg ethinylestradiol plus 5.0 μg levonorgestrel; po) with or without DPP-4 inhibitor (sitagliptin; 100 mg/kg; po) for 8 weeks (n = 6/group). Glucose dysmetabolism was assessed by elevated fasting blood glucose, impaired oral glucose tolerance test and homeostatic model assessment of IR. Treatment with COC led to increased plasma fasting glucose, triglyceride-glucose index, 1-h postload glucose response, insulin, free fatty acid, IR and impaired glucose tolerance. COC treatment also resulted in increased plasma and hepatic TG, TG/HDL-cholesterol ratio, malondialdehyde, uric acid (plasma; 25.2 ± 0.6 mg/dl; hepatic 128.9 ± 8.0 mg/100 mg tissue), lactate dehydrogenase, DPP-4, ADA and XO (plasma;10.5 ± 1.1 U/L; hepatic 21.2 ± 1.4 U/g protein) activities. Likewise, COC led to reduction in nitric oxide level. However, DPP-4 inhibition significantly ameliorated these alterations induced by COC treatment through suppression of uric acid (plasma; 15.1 ± 1.0 mg/dl, hepatic; 75.6 ± 5.0 mg/100 mg tissue), XO (plasma; 4.1 ± 0.9 U/L, hepatic; 8.7 ± 0.4 U/g protein), ADA and DPP-4 activities suggesting their involvement in glucose dysregulation and hepatic TG accumulation induced by COC treatment. Therefore, DPP-4 inhibition would impact positively on cardiometabolic disorders, at least in part, through XO, ADA and uric acid suppression.

Sodium acetate improves disrupted glucoregulation and hepatic triglyceride content in insulin-resistant female rats: involvement of adenosine deaminase and dipeptidyl peptidase-4 activities

Combined oral contraceptive (COC) treatment has been shown to be associated with glucose deregulation and increased triglyceride levels, but the mechanisms are elusive. Soluble dipeptidyl peptidase-4 (sDPP-4) and adenosine deaminase (ADA) are involved in the initiation and/or progression of cardiometabolic disorders. We therefore, hypothesized that increased DPP-4 and ADA activities are involved in glucose deregulation and hepatic triglyceride accumulation induced by COC treatment. This study also investigated whether short-chain fatty acid, acetate, would protect against COC-induced dysmetabolic effects. Female Wistar rats received (p.o.) vehicle and COC (1.0 μg ethinylestradiol plus 5.0 μg levonorgestrel) with or without sodium acetate (ACE; 200 mg) for 8 weeks. Treatment with COC led to increased plasma triglyceride-glucose index, 1-h postload glucose response, insulin, free fatty acid, insulin resistance, and impaired glucose tolerance. COC treatment also resulted in increased plasma and hepatic triglycerides (TG), TG/HDL-cholesterol ratio, malondialdehyde, uric acid, lactate dehydrogenase, DPP-4, ADA, and xanthine oxidase (XO) activities. On the other hand, COC led to reduction in nitric oxide level. However, ACE significantly ameliorated the alterations induced by COC treatment, but XO activity remains elevated during COC treatment. This result also demonstrates that increased DPP-4 and ADA activities are at least in part involved in glucose deregulation and hepatic TG accumulation induced by COC treatment. Therefore, sodium acetate would impact positively on cardiometabolic disorders, at least in part, by inhibition of DPP-4 and ADA activities.

Oral ethinylestradiol-levonorgestrel attenuates cardiac glycogen and triglyceride accumulation in high fructose female rats by suppressing pyruvate dehydrogenase kinase-4

Fructose (FRU) intake has increased dramatically in recent decades with a corresponding increased incidence of insulin resistance (IR), particularly in young adults. The use of oral ethinylestradiol-levonorgestrel (EEL) formulation is also common among young women worldwide. The present study aimed at determining the effect of EEL on high fructose-induced cardiac triglyceride (TG) and glycogen accumulation. The study also investigated the possible involvement of pyruvate dehydrogenase kinase-4 (PDK-4) in EEL and/or high fructose metabolic effects on the heart. Ten-week-old female Wistar rats were allotted into four groups. The control, EEL, FRU, and EEL + FRU rats received distilled water (vehicle, p.o.), 1.0 μg ethinylestradiol plus 5.0 μg levonorgestrel (p.o.), 10% fructose (w/v), and 1.0 μg ethinylestradiol plus 5.0 μg levonorgestrel and 10% fructose, respectively, daily for 8 weeks. Data showed that EEL or high fructose caused IR' impaired glucose tolerance' hyperlipidemia' increased plasma lactate, lactate dehydrogenase, PDK-4, uric acid, xanthine oxidase (XO), adenosine deaminase (ADA), malondialdehyde (MDA), cardiac uric acid, TG, TG/HDL- cholesterol, glycogen synthesis, MDA, and visceral fat content and reduced glutathione. High fructose also resulted in impaired pancreatic β-cell function, hyperglycemia, and increased cardiac PDK-4, lactate synthesis, and mass. Nonetheless, these alterations were ameliorated in EEL plus high fructose rats. This study demonstrates that high fructose-induced myocardial TG and glycogen accumulation is attributable to increased PDK-4. Besides, EEL could be a useful pharmacological utility for protection against cardiac dysmetabolism by inhibiting PDK-4.

Inhibition of adenosine deaminase and xanthine oxidase by valproic acid abates hepatic triglyceride accumulation independent of corticosteroids in female rats treated with estrogen-progestin

Elevated circulating uric acid has been postulated to play an important pathophysiological role in estrogen-progestin combined oral contraceptive (COC)-induced hypertension and endothelial dysfunction. We hypothesized that disruption of glucoregulation and liver triglyceride (TG) accumulation induced by COC use would be abated by valproic acid (VPA) treatment through suppression of adenosine deaminase (ADA) and xanthine oxidase (XO) activities. Female Wistar rats aged 9-10 weeks were treated with a combination of estrogen-progestin COC steroids (1.0 μg ethinylestradiol and 5.0 μg levonorgestrel; p.o.) with or without VPA (100.0 mg/kg; p.o.) daily for 6 weeks. The result shows that the disrupted glucoregulation and associated elevated hepatic ADA activity, plasma and hepatic XO activity, uric acid (UA), TG/HDL-cholesterol, total cholesterol, and malondialdehyde induced by COC treatment were attenuated by VPA treatment. However, VPA did not have any effect on plasma aldosterone, corticosterone, ADA, circulating and hepatic free fatty acid. Our results demonstrate that suppression of plasma and hepatic XO activities, along with hepatic ADA activity and UA by VPA treatment, protects against disrupted glucoregulation and increased liver TG by COC independent of elevated corticosteroids. The findings imply that VPA would provide protection against the development of cardiometabolic disorder via inhibition of the ADA/XO/UA-mediated pathway.

Gestational glucocorticoid exposure disrupts glucose homeostasis that is accompanied by increased endoglin and DPP-4 activity instead of GSK-3 in rats

Gestational glucocorticoid (GC) treatment has been associated with cardiometabolic disorder (CMD) in offspring's in later life. Elevated dipeptidyl peptidase-4 (DPP-4) activity, endoglin and glycogen synthase kinase-3 (GSK-3) has also been implicated in the development of insulin resistance (IR) and/or vascular inflammation. We aimed to investigate the impact of GC exposure on glucose metabolism and the circulating levels of inflammatory biomarkers, DPP-4 activity and GSK-3 in pregnant rats. Pregnant Wistar rats received either vehicle or dexamethasone (DEX; 0.2 mg/kg; po) between gestational days 14 and 19. Gestational GC exposure resulted in impaired glucose homeostasis that is accompanied with elevated circulating levels of inflammatory biomarkers (endoglin, uric acid, and platelet/lymphocyte ratio), oxidative stress (malondialdehyde), blood viscosity, reduced NO level and increased DPP-4 activity. However, these effects were associated with atherogenic dyslipidemia and reduced GSK-3.We conclude that plasma endoglin, a marker of vascular inflammation, and plasma DPP-4 activity are increased in pregnant rats treated with GC during late gestation. Therefore, glucose deregulation associated with gestational GC exposure is through endoglin-/DPP-4-dependent but GSK-3-independent pathway.

Oral hormonal therapy with ethinylestradiol–levonorgestrel improves insulin resistance, obesity, and glycogen synthase kinase-3 independent of circulating mineralocorticoid in estrogen-deficient rats

Estrogen deficiency has been associated with increased incidence of cardiovascular diseases , and recent clinical trials of standard formulations of hormonal therapies have not demonstrated consistent beneficial effects. Estrogen–progestin therapy has been used as exogenous estrogen to normalize depressed estrogen level during menopause. Ovariectomized rodents mimic an estrogen-deficient state in that they develop cardiometabolic dysfunction, including insulin resistance (IR). We therefore hypothesized that hormonal therapy with combined oral contraceptive steroids, ethinylestradiol–levonorgestrel (EEL), improves IR, obesity, and glycogen synthase kinase-3 (GSK-3) through reduction of circulating mineralocorticoid in ovariectomized rats. Twelve-week-old female Wistar rats were divided into 4 groups: sham-operated (SHM) and ovariectomized (OVX) rats were treated with or without EEL (1.0 μg ethinylestradiol and 5.0 μg levonorgestrel) daily for 8 weeks. Results showed that OVX or SHM + EEL treated rats had increased HOMA-IR (homeostatic model assessment of IR), 1 h postload glucose, HOMA-β, triglycerides (TG), total cholesterol (TC), TC/HDL cholesterol, TG/HDL cholesterol, plasma insulin, GSK-3, corticosterone, and aldosterone. On the other hand, OVX + EEL treatment ameliorated all these effects except that of aldosterone. Taken together, the results demonstrate that oral hormonal replacement with EEL improves IR and pancreatic β-cell function and suppresses GSK-3 and glucocorticoid independent of circulating aldosterone, suggesting a positive cardiometabolic effect of oral EEL therapy in estrogen-deficient rats.