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Objective: To determine inhibitory activity of methanolic leaf extract of Piper umbellatum and Persea americana (P. americana) (traditionally used in Cameroon against diabetes) on α-glucosidase, β-glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities, enzymes involved in starch digestion or diabetic complications. Methods: The methanol extracts from Piper umbellatum and P. americana were prepared by maceration. To assess relative efficacy of these extracts, the determination of concentrations that were needed to inhibit 50% of enzyme activity was done, whereas, gas chromatography-mass spectrum was used to identify components from extracts that may be responsible for the activities. Results: The tested extracts strongly inhibited α-glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities with IC
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Objective:To determine inhibitory activity of methanolic leaf extract of Piper umbellatum and Persea americana (P.americana) (traditionally used in Cameroon against diabetes) on α-glucosidase,β-glucosidase,maltase-gluconmylase,aldose reductase and aldehyde reductase activities,enzymes involved in starch digestion or diabetic complications.Methods:The methanol extracts from Piper umbellatum and P.americana were prepared by maceration.To assess relative efficacy of these extracts,the determination of concentrations that were needed to inhibit 50％ of enzyme activity was done,whereas,gas chromatography-mass spectrum was used to identify components from extracts that may be responsible for the activities.Resullts The tested extracts strongly inhibited α-glucosidase,maltase-glucoamylase,aldose reductase and aldehyde reductase activities with IC50 ranging from (1.07 ± 0.03) to 01.77 + 1.17) μg/mL.Among the tested extracts,P.americana was the most active against sensitive enzymes (IC50 of 1.07 ± 0.03 to 15.63 ± 1.23).But,none of the extracts showed interesting inhibitory effect against β-glucosidase as their percentage inhibitions were less than 16％.From gas chromatographymass spectrum analysis,10 and 8 compounds were identified in Piper umbellatum and P.americana extracts respectively,using NIST library 2014.Conclusions:Results of this study provide the scientific credential for a prospective usage of these plants to treat diabetes.
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Objective To investigate the inhibition of aldose reductase (AR) and antioxidant activity of fractions of ethyl acetate extract from Toona Sinensis seeds. Methods The antioxidant activities of fractions of ethyl acetate extract from Toona Sinensis seeds was evaluated with total antioxidant capacity and DPPH?free radicals scavenging. The inhibition and inhibition types of AR were investigated and the relationship of antioxidant activity and AR inhibitory activity was analyzed. Results Fractions of ethyl acetate extract from Toona Sinensis seeds exhibited antioxidant activity, total antioxidant capacity ordered by Fr.B>Fr.A>Fr.D>Fr.C. The DPPH?free radicals scavenging were ordered by Fr.A>Fr.B>Fr.D>Fr.C. The fractions exhibited AR inhibitory activity and the order was Fr.B>Fr.A>Fr.C>Fr.D. The inhibition mechanism of Fr.B was noncompetitive inhibition and IC50 was 0.401 mg/ml. The AR inhibitory activity of fractions was related to antioxidant activity with correlation index over 0.9. Conclusion This study will provide theoretical basis for exploitation of Toona Sinensis seeds.
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Objectives To examine the clinical effects of α-lipoic acid(ALA)combined with epalrestat in elderly patients with diabetic peripheral neuropathy(DPN)and its influence on plasma levels of high-sensitivity C-reactive protein(hs-CRP)and homocysteine(Hcy).Methods A total of 120 DPN patients aged over sixty years were randomly divided into the control group and the treatment group with 60 cases in each group.The control group received 0.6 g ALA in 250 ml saline given by an intravenous drip once a day and the treatment group was additionally given 50 mg epalrestat orally three times a day.Both groups were treated for two weeks.Improvement in clinical symptoms,nerve conduction velocity,and peripheral blood levels of hs-CRP and Hcy were compared between the two groups before and after treatment.Results TSS scores of all items and the total scores of the two groups decreased after treatment,with greater margins seen in the treatment group than in the control group(each P＜0.05).NCV increased in both groups after treatment (each P＜ 0.05),with greater increase in the treatment group(each P＜0.05).Levels of hs-CRP and Hcy were significantly reduced (each P＜0.05).A statistically significant difference was observed in hs-CRP(t =2.620,P=0.010) but not in Hcy(t =0.380,P =0.700)between the two groups.Conclusions ALA combined with epalrestat can significantly improve the symptoms of patients with DPN,with better outcomes than ALA alone,and effectively decrease the peripheral blood level of hs-CRP.
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Objective To investigate the effects of mannitol on the activity of erythrncyte aldose reduclase (AR),plasma nitric oxide(NO)and malondialdehyde(MDA)concentrations in patients undergoing hepatolobectomy.Methods Forty ASA Ⅰ or Ⅱ patients(aged 24-63 yr and weighing 50-68 kg),receiving combined general and epidural anesthesia and undergoing selective hepatolobectomy,were randomly assigned into a mannitol group (group M)and a normal saline group(group C).During hepatic portal occlusion,normal saline 1.5 ml/kg and 20％ mannitol 1.5 ml/kg were intravenously infused in groups C and M respectively for 30 min.Venous blood samples were collected to measure the erythrocyte AR activity and plasma NO and MDA concentrations at the following time points:before anesthesia induction(T0),at the end of hepatic portal occlusion(T1),at the end of operation(T2),one day after operation(T3)and three days after operation(T4),respectively.Results Compared with group C at T1,2,the erythrocyte AR and plasma MDA concentration decreased while plasma NO concentration increased in group M(P ＜ 0.05).Conclusion Mannitol can reduce hepatic ischemia and reperfusion injury in patients undergoing hepatolobectomy,which may be related to the mechanism of mannitol removing oxygenderived free radicals and inhibiting lipid peroxidation.