RESUMO
Background: Isorhamnetin is a flavonoid that is found in medical plants. Several studies showed that isorhamnetin has anti-inflammatory and anti-obesity effects. This study aims to investigate the anti-diabetic effects of isorhamnetin in a high-fat diet and Streptozotocin-(HFD/STZ)-induced mice model of type 2 diabetes. Materials and Methods: Mice were fed with HFD followed by two consecutive low doses of STZ (40 mg/kg). HFD/STZ diabetic mice were treated orally with isorhamnetin (10 mg/kg) or (200 mg/kg) metformin for 10 days before sacrificing the mice and collecting plasma and soleus muscle for further analysis. Results: Isorhamnetin reduced the elevated levels of serum glucose compared to the vehicle control group (p < 0.001). Isorhamnetin abrogated the increase in serum insulin in the treated diabetic group compared to the vehicle control mice (p < 0.001). The homeostasis model assessment of insulin resistance (HOMA-IR) was decreased in diabetic mice treated with isorhamnetin compared to the vehicle controls. Fasting glucose level was significantly lower in diabetic mice treated with isorhamnetin during the intraperitoneal glucose tolerance test (IPGTT) (p < 0.001). The skeletal muscle protein contents of GLUT4 and p-AMPK-α were upregulated following treatment with isorhamnetin (p > 0.01). LDL, triglyceride, and cholesterol were reduced in diabetic mice treated with isorhamnetin compared to vehicle control (p < 0.001). Isorhamnetin reduced MDA, and IL-6 levels (p < 0.001), increased GSH levels (p < 0.001), and reduced GSSG levels (p < 0.05) in diabetic mice compared to vehicle control. Conclusions: Isorhamnetin ameliorates insulin resistance, oxidative stress, and inflammation. Isorhamnetin could represent a promising therapeutic agent to treat T2D.
Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Resistência à Insulina , Camundongos , Animais , Diabetes Mellitus Tipo 2/metabolismo , Resistência à Insulina/fisiologia , Dieta Hiperlipídica/efeitos adversos , Estreptozocina/farmacologia , Diabetes Mellitus Experimental/metabolismo , Inflamação/tratamento farmacológico , Modelos Animais de Doenças , Estresse Oxidativo , Glucose/farmacologia , Glicemia , Hipoglicemiantes/uso terapêuticoRESUMO
Background: Lysionotin, a natural flavonoid extracted from Lysionotus pauciflorus Maxim (Gesneriaceae), has several pharmacological effects including anti-bacterial, anti-hypertensive and anti-inflammatory effects. However, its analgesic effect has not been investigated. This study aimed to assess the antinociceptive activity of lysionotin using chemically and thermally induced nociception in a mouse model. Methods: The antinociceptive effects of various lysionotin doses (50, 100, 150, and 200 µg/kg) were assessed in mice using the acetic acid-induced writhing test, hot plate test, and formalin-induced paw licking assay. The effects were compared to those of mice treated with acetylsalicylic acid or morphine in the presence or absence of naloxone (an opioid receptor antagonist). Capsaicin- and glutamate-induced paw licking tests were also used to evaluate the involvement of the vanilloid and glutamatergic systems, respectively. Results: Lysionotin produced significant dose-dependent inhibition of nociceptive behavior in the acetic acid-induced writhing test, showing 60% inhibition at a dose of 200 µg/kg. Lysionotin also caused a significant increase in the latency period in response to the hot plate test (76.4% at 200 µg/kg), and significantly inhibited both the neurogenic and inflammatory phases in the formalin-induced paw licking test. Naloxone significantly reverses the effect of lysionotin in both hot plate test and formalin-induced paw licking test. Moreover, lysionotin significantly inhibited the neurogenic nociception induced by intraplantar injections of glutamate and capsaicin (57% and 67.2%, respectively at a dose of 200 µg/kg). Thus, lysionotin exhibited peripheral and central antinociception through the modulation of vanilloid receptors, opioid receptors, and the glutamatergic system. Conclusion: Lysionotin possesses antinociceptive activity on adult mice that is mediated through both central and peripheral pathways.
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2',3,3,5'-Tetramethyl-4'-nitro-2'H-1,3'-bipyrazole (TMNB) is a novel bipyrazole compound with unknown therapeutic potential in diabetes mellitus. This study aims to investigate the anti-diabetic effects of TMNB in a high-fat diet and streptozotocin-(HFD/STZ)-induced rat model of type 2 diabetes mellitus (T2D). Rats were fed HFD, followed by a single low dose of STZ (40 mg/kg). HFD/STZ diabetic rats were treated orally with TMNB (10 mg/kg) or (200 mg/kg) metformin for 10 days before terminating the experiment and collecting plasma, soleus muscle, adipose tissue, and liver for further downstream analysis. TMNB reduced the elevated levels of serum glucose in diabetic rats compared to the vehicle control group (p < 0.001). TMNB abrogated the increase in serum insulin in the treated diabetic group compared to the vehicle control rats (p < 0.001). The homeostasis model assessment of insulin resistance (HOMA-IR) was decreased in the diabetic rats treated with TMNB compared to the vehicle controls. The skeletal muscle and adipose tissue protein contents of GLUT4 and AMPK were upregulated following treatment with TMNB (p < 0.001, < 0.01, respectively). TMNB was able to upregulate GLUT2 and AMPK protein expression in liver (p < 0.001, < 0.001, respectively). LDL, triglyceride, and cholesterol were reduced in diabetic rats treated with TMNB compared to the vehicle controls (p < 0.001, 0.01, respectively). TMNB reduced MDA and IL-6 levels (p < 0.001), and increased GSH level (p < 0.05) in diabetic rats compared to the vehicle controls. Conclusion: TMNB ameliorates insulin resistance, oxidative stress, and inflammation in a T2D model. TMNB could represent a promising therapeutic agent to treat T2D.
Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Resistência à Insulina , Metformina , Ratos , Animais , Diabetes Mellitus Tipo 2/metabolismo , Resistência à Insulina/fisiologia , Diabetes Mellitus Experimental/metabolismo , Proteínas Quinases Ativadas por AMP , Metformina/farmacologia , Metformina/uso terapêuticoRESUMO
[This corrects the article DOI: 10.1016/j.heliyon.2022.e10400.].
RESUMO
Background: Ceratonia siliqua L. (Leguminosae) has neuroprotective, mutagenic, hypotensive, anti-bacterial, hypoglycaemic, and anti-inflammatory effects through extracts from its leaves. Therefore, the aim of this study is to assess the anti-nociceptive activity of ethanol extracts of Ceratonia siliqua leaves. Methods: Ethanol extract of Ceratonia siliqua leaves were studied using well-established animal models of inflammation and pain. A hot plate latency assay (55 °C) was used to assess the analgesic effect of 10, 31.6, 100, and 316 mg/kg doses of ethanol extracts in addition to paw licking time in early and late phase using a formalin-induced paw licking assay test. Paw oedema induction using carrageenan and cotton pellet granuloma assays were used to assess the anti-inflammatory effect of 10, 31.6, 100, and 316 mg/kg doses of ethanol extract. Results: The ethanol extract of Ceratonia siliqua leaves reduces paw licking time in early and late phase after formalin injection. The same effect was also observed when the hotplate test was performed. Ethanol extract of Ceratonia siliqua leaves caused dose dependent inhibition in paw oedema after the injection of carrageenan and cotton pellet granuloma in mice. These effects were not antagonized when opioid receptors were blocked by naloxone (5 mg/kg). The preliminary phytochemical analysis of the ethanol extract of Ceratonia siliqua leaves showed the presence of tannins, alkaloids, flavonoids and terpenoids. Conclusion: The present data indicate that ethanol extract of Ceratonia siliqua leaves might possess anti-inflammatory and anti-nociception properties and should be considered for further therapeutic research.