Tylophora hirsuta L. leaf extract attenuates alloxan-induced diabetes in mice by suppressing oxidative stress and α-amylase

Objective:To evaluate the antidiabetic potential of leaf extracts of Tylophora hirsuta(T.hirsuta).Methods:The methanolic and ethyl acetate extracts of T.hirsuta leaves were analyzed by high pressure liquid chromatography.In vitro antioxidant activity was determined by ferric ion reduction,1,1-diphenyl-2-picrylhydrazyl,and hydrogen peroxide scavenging methods.In vitro alpha amylase(α-amylase)inhibitory activity of the plant extracts was assessed.In vivo antidiabetic potential was determined in alloxan-induced diabetic mice to assess glycated hemoglobin(HbA1c),oral glucose tolerance,serum amylase,lipid profile,fasting blood glucose,and body weight.Histopathological lesions of the pancreas,liver and kidney were observed.Oxidative stress biomarkers such as superoxide dismutase,catalase and peroxidase were also determined.Results:Quercetin,chlorogenic acid,p-coumaric acid,and m-coumaric acid were found in the plant extracts.The methanolic plant extract exhibited higher in vitro antioxidant activities than the ethyl acetate extract.Moreover,methanolic plant extract exhibited(83.90±1.56)%α-amylase inhibitory activity at 3.2 mg/mL concentration.Animal study showed that the methanolic extract of T.hirsuta improved the levels of fasting blood glucose,HbA1c,serumα-amylase,lipid profile,liver function biomarkers,and kidney functions of diabetic mice.Moreover,the methanolic extract ameliorated diabetes-related oxidative stress by increasing superoxide dismutase and catalase activities and decreasing peroxidase and malondialdehyde levels.Histopathological examination showed that the plant extract had improved the integrity of pancreatic islets of Langerhans and reduced the pathological lesions in the liver and kidney of diabetic mice.Conclusions:The methanolic extract of T.hirsuta exhibits pronounced antidiabetic activity in mice through reduction of oxidative stress.The plant extract has several natural antioxidants such as phenolic acids.T.hirsuta extract could serve as a nutraceutical for managing diabetes mellitus.

Argemone mexicana extract alleviates gastrointestinal disorders by stimulating muscarinic receptors and blocking voltage-gated L-type calcium channels

Objective:To investigate the pharmacological potential of Argemone mexicana in treating constipation and emesis by using in vitro and in vivo models.Methods:The spasmogenic and spasmolytic effects were evaluated on isolated rabbit jejunum fragments loaded in a tissue organ bath.The response was recorded with an isotonic transducer attached with Power Lab Data Acquisition System.The laxative and antiemetic activities were assessed in BALB-c mice and poultry chicks challenged with carbamylcholine and copper sulphate stimulated emesis,respectively.Results:The total phenolic and total flavonoids contents of the extract were(267.75±5.77)mg GAE/g and(73.86±6.01)mg QE/g,respectively.Argemone mexicana extract exerted spasmogenic effect on isolated rabbit jejunum segments with an EC_(50)value of 0.016 mg/m L,which was blocked by atropine(0.3μM).Argemone mexicana extract exerted spasmolytic effect in atropine treated jejunum fragments with an EC_(50)value of 2.185 mg/mL.Furthermore,Argemone mexicana extract relaxed potassium(80 mM)-induced contractions(EC_(50):9.07 mg/mL),similar to a standard drug verapamil.The calcium channel blocker activity was confirmed by a rightward shift of concentration-response curve of calcium in the presence of Argemone mexicana extract(1-5 mg/mL)and verapamil(0.1-1μM).In addition,the extract increased the distance travelled by a charcoal in the gastrointestinal tract and exhibited antiemetic effect on copper sulphate induced emesis in chicks.Conclusions:Argemone mexicana shows cholinergic agonist and calcium channel blocker activities,as well as antiemetic effect.It may be used as a potential agent for treating gastrointestinal disorders.