scholarly journals Inhibitory effect of polyphenolic–rich extract from Cola nitida (Kolanut) seed on key enzyme linked to type 2 diabetes and Fe2+ induced lipid peroxidation in rat pancreas in vitro

2014 ◽  
Vol 4 ◽  
pp. S405-S412 ◽  
Author(s):  
Ganiyu Oboh ◽  
Kate E. Nwokocha ◽  
Ayodele J. Akinyemi ◽  
Adedayo O. Ademiluyi
2019 ◽  
Vol 109 ◽  
pp. 734-743 ◽  
Author(s):  
Olakunle Sanni ◽  
Ochuko L. Erukainure ◽  
Chika I. Chukwuma ◽  
Neil A. Koorbanally ◽  
Collins U. Ibeji ◽  
...  

Author(s):  
Dang Kim Thu ◽  
Le Thi Thu Huong ◽  
Tran Trong Nghia ◽  
Bui Thanh Tung

Type 2 diabetes is a fairly common chronic disease. α-glucosidase and protein tyrosine phosphatase, as enzymes, play an important role in type 2 diabetes. This study evaluates the inhibitory effect of the two enzymes in vitro of ethanol extract and fractions of Vietnam Psidium guajava’s leaves. The leaves were collected, dried and extracted with 96% ethanol and successively fractionated with n-hexane, ethyl acetate and butanol solvents. The results show that the EtOH extract, n-nexan, EtOAc and BuOH fractions had high α-glucosidase inhibitory effect with IC50 values ​​of 2.20; 2.53; 2.24 and 2.16 µg/mL, respectively. In addition, EtOAc and BuOH fractions also show strong inhibitory PTP1B effect with IC50 at 120.22 mg/mL and 97.72 mg/mL, respectively. The study results show that Psidium guajava leaves are a potential source of material to inhibit α-glucosidase and PTP1B in the treatment of diabetes. Keywords Psidium guajava, α-glucosidase, protein tyrosine phosphatase 1B, diabetes, extraction. References [1] A. Chaudhury, C. Duvoor, R. Dendi, V. Sena, S. Kraleti, A. Chada, et al. Clinical review of antidiabetic drugs: Implications for type 2 diabetes mellitus management, Frontiers in endocrinology. 8 (2017) 6.[2] F.A. Van de Laar, P.L. Lucassen, R.P. Akkermans, E. H. Van de Lisdonk, G.E. Rutten,C. Van, Alpha - glucosidase inhibitors for type 2 diabetes mellitus. The Cochrane Library (2005).[3] J. Montalibet, B.P. Kennedy. Therapeutic strategies for targeting PTP1B in diabetes. Drug Discovery Today: Therapeutic Strategies 2(2) (2005) 129.[4] S.M. Barbalho, Farinazzi-Machado, R. De Alvares Goulart, A.C.S. Brunnati, A. Otoboni, B. Ottoboni. Psidium guajava (Guava): A plant of multipurpose medicinal applications, Med Aromat Plants. 1(104) (2012) 2167.[5] R.M.P. Gutiérrez, S. Mitchell, Solis R. V. Psidium guajava: a review of its traditional uses, phytochemistry and pharmacology. Journal of ethnopharmacology 117(1) (2008) 1.[6] B. T. Tùng, Đ.K. Thu, P.T. Hải, N.T. Hải. Đánh giá tác dụng ức chế enzym α-glucosidase của các phân đoạn dịch chiết quả Lựu (Punica granatum Linn), Tạp chí Y Dược cổ truyền Việt Nam. 5(18) (2018) 59.[7] P.H. Nguyen, J.L. Yang, M.N. Uddin, S.L. Park, S.I. Lim, D.W. Jung, et al. Protein tyrosine phosphatase 1B (PTP1B) inhibitors from Morinda citrifolia (Noni) and their insulin mimetic activity, Journal of natural products. 76(11) (2013) 2080.[8] H.B.H. Khan, D. Rajendran, M.R. Bai, Sorimuthu S. Protective effect of Psidium guajava leaf extract on altered carbohydrate metabolism in streptozotocin-induced diabetic rats, Journal of dietary supplements. 10(4) (2013) 335.[9] H. Mukhtar, S. Ansari, M. Ali, T. Naved, Z. Bhat Effect of water extract of Psidium guajava leaves on alloxan-induced diabetic rats. Die Pharmazie-An International Journal of Pharmaceutical Sciences. 59(9) (2004) 734.[10] W. K. Oh, C. H. Lee, M. S. Lee, E. Y. Bae, C. B. Sohn, H. Oh, et al. Antidiabetic effects of extracts from Psidium guajava, Journal of ethnopharmacology. 96(3) (2005) 411.[11] B. Wang, H. Liu, J. Hong, H. Li, C. Huang, Effect of Psidium guajava leaf extract on alpha-glucosidase activity in small intestine of diabetic mouse. Sichuan da xue xue bao Yi xue ban, Journal of Sichuan University Medical science edition. 38(2) (2007) 298.[12] S. C. Shen, F. C. Cheng, N. J. Wu. Effect of guava (Psidium guajava Linn.) leaf soluble solids on glucose metabolism in type 2 diabetic rats, Phytotherapy Research. 22(11) (2008) 1458.      


2017 ◽  
Vol 125 (06) ◽  
pp. 392-399 ◽  
Author(s):  
Shan Zhuang ◽  
Yongmei Jian ◽  
Yongning Sun

Abstract Type 2 diabetes can elevate risk of gastric cancer and metformin, an anti-diabetic agent, has an inhibitory effect against gastric cancer cell in vitro. However, the effect of metformin on type 2 diabetes-related gastric tumorigenesis in vivo is still not clear. In the present study, we aim to detect whether metformin can inhibit increased risk of gastric cancer in diabetic db/db mice and which the potential anti-cancer mechanisms of metformin are. 4-week-old mice were divided into 3 groups (2 db/db mice groups and one wild type mice group). All diabetic and non-diabetic mice were treated with N-Methyl-N-Nitrosourea (MNU) for 20 weeks to induce gastric tumorigenesis. At week 21, one db/db mice group were treated with metformin (5 mg/ml) for 10 weeks and the other 2 groups were treated with saline. Blood samples were collected for testing insulin and insulin-like growth factor (IGF)-1. Stomach tissues were collected for histopathological evaluation and mRNAs analysis. Metformin significantly decreased incidence of MNU-induced gastric dysplasia and cancer in diabetic db/db mice. Furthermore, metformin reduced serum insulin as well as IGF-1, and also suppressed expression of insulin receptor, IGF-1, IGF-1 receptor and several pro-inflammatory cytokines mRNAs in stomach of db/db mice, but did not significantly influence IGF-2 and IGF-2 receptor expressions. The results show that metformin can prevent the risk of gastric cancer in type 2 diabetes and the protective mechanisms may involve in an inhibitory effect of metformin on insulin as well as IGF-1 signals and cancer related pro-inflammatory cytokines.


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