• Korean Journal of Pharmacognosy
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• v.41 no.3
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• pp.227-231
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• 2010

Protein tyrosine phosphatase 1B (PTP1B) is predicted to be therapeutic target in treatment of type 2 diabetes and obesity. Thus, in order to search for PTP1B inhibitors, we screened the inhibitory activity of PTP1B in the water extracts of 84 medicinal herbs. Among them, the extracts of Pini Folium, Magnoliae Cortex, Artemisiae asiaticae Herba, Schizonepetae Herba, Menthae Herba, Mume Fructus, Cimicifugae Rhizoma, and Amomi Cardamomi Fructus showed relatively significant (58-68%) inhibitory activity against PTP1B. Especially, the methylene chloride fraction of the methanol extract of Menthae Herba (81% inhibition at 30 ${\mu}g$/ml) showed more potent inhibitory activity against PTP1B than others.

• Journal of Microbiology and Biotechnology
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• v.23 no.9
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• pp.1206-1211
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• 2013

The selective inhibition of PTP1B has been widely recognized as a potential drug target for the treatment of type 2 diabetes and obesity. In the course of screening for PTP1B inhibitory fungal metabolites, the organic extracts of several fungal species isolated from marine environments were found to exhibit significant inhibitory effects, and the bioassay-guided investigation of these extracts resulted in the isolation of fructigenine A (1), cyclopenol (2), echinulin (3), flavoglaucin (4), and viridicatol (5). The structures of these compounds were determined mainly by analysis of NMR and MS data. These compounds inhibited PTP1B activity with 50% inhibitory concentration values of 10.7, 30.0, 29.4, 13.4, and 64.0 ${\mu}M$, respectively. Furthermore, the kinetic analysis of PTP1B inhibition by compounds 1 and 5 suggested that compound 1 inhibited PTP1B activity in a noncompetitive manner, whereas compound 5 inhibited PTP1B activity in a competitive manner.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.6
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• pp.1532-1536
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• 2008

Quercetin which isolated form the roots of Houttuynia cordata. was determined on the basis of IR, ID and 2D NMR specta by direct comparison with authentic compounds. Protein tyrosine phophatase 1B (PTP1B) is thought to be a negative regulator in insulin signal-transduction pathway. Insulin-resistance by the activation of PTP1B is a hallmark of both type 2 diabetes and obesity. Thus, the compound inhibiting PTP1B can improve insulin resistance and can be effective in treating type 2 diabetes and obesity. Quercetin which measured the inhibitory activity against PTP1B was 92.1% inhibition in the 30 ${\mu}g$/mL, 83.4% inhibition in the 6 ${\mu}g$/mL and 76.5% inhibition in the 3 ${\mu}g$/mL. These results suggest that quercetin retains a potential PTP1B activity.

• Korean Journal of Pharmacognosy
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• v.35 no.1 s.136
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• pp.16-21
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• 2004

Protein tyrosine phosphatase 1B(PTP1B) is thought to be a negative regulator in insulin signal-transduction pathway. Insulin-resistance by the activation of PTP1B is a hallmark of both type 2 diabetes and obesity. Thus, the compounds inhibiting PTP1B can improve insulin resistance and can be effective in treating type 2 diabetes and obesity. The methanol extracts of 160 herbal medicines were screened for the inhibitory activity against PTP1B. Among the tested extracts, methanol extracts of Amsonia elliptica, Areca catechu, Benincasa hispida, Morus alba, Salvia miltiorrhiza, Siegesbeckia orientalis, and Trichosanthes kirilowii showed relatively strong inhibitory activity against PTP1B.

• Natural Product Sciences
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• v.12 no.4
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• pp.205-209
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• 2006

The structures of flavonoids, 2(S)-5,7-dihydroxy-8,2'-dimethoxyflavanone (1), wogonin (2), 2(S)-5,7, 2'-trihydroxy-8-methoxyflavanone (3), and 2(S)-5,2',5'-trihydroxy-7,8-dimethoxyflavanone (4), isolated from Scutellaria indica were revised on the basis of 2D NMR spectroscopy, including to gCOSY, gHSQC, and gHMBC. Compounds 1-4 were tested in vitro protein tyrosine phosphatase 1B (PTP1B) inhibitory activity. Compounds 2 and 4 exhibited weak PTP1B inhibitory activity with $IC_{50}$ values of 208 and $337{\mu}M$, respectively.

• Natural Product Sciences
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• v.16 no.4
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• pp.239-244
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• 2010

Protein tyrosine phosphatase 1B (PTP1B), a negative regulator of insulin signaling, has served as a potential drug target for the treatment of type 2 diabetes. The MeOH extracts of twenty-nine medicinal plants, traditionally used in Vietnam as anti-diabetes agents, were investigated for PTP1B inhibitory activity in vitro. The results indicated that, most materials showed moderate to strong inhibitory activity with $IC_{50}$ values ranging from $3.4\;{\mu}g/mL$ to $35.1\;{\mu}g/mL$; meanwhile, eleven extracts (37.9%) could demonstrate PTP1B activity with $IC_{50}$ values less than $15.5\;{\mu}g/mL$; sixteen extracts (55.2%) could demonstrate PTP1B activity with $IC_{50}$ values ranging from $15.5\;{\mu}g/mL$ to $35.1\;{\mu}g/mL$. The study may provide a proof, at least in a part, for the ethno-medical use in diabetes disease of these plants.

• Natural Product Sciences
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• v.14 no.2
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• pp.143-146
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• 2008

Protein tyrosine phosphatase 1B (PTP1B) is emerging as a potential therapeutic target for the treatment of type-2 diabetes and obesity. To search for new types of PTP1B inhibitors, we have undertaken in vitro enzyme assay for some anthraquinones and stilbenes isolated from plants. Of the anthraquinones tested, physcion (1), 1-O-methylemodin (2), and emodin (3) showed high activities, with $IC_{50}$ values of 7.6, 7.0, and $3.8{\mu}g/mL$, respectively, while the anthraquinone glycosides, physcion-8-O-${\beta}$-D-glucopyranoside (4) and emodin-8- O-${\beta}$-D-glucopyranoside (5), were less active than their aglycones. All the stilbenens (6 - 15) slightly inhibited PTP1B activity at high concentration of $30{\mu}g/mL$. Our findings suggest that the hypoglycemic effect of anthraquinones may be associated with their PTP1B inhibitory activity.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.4
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• pp.230-233
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• 2007

Protein tyrosine phosphatase 1B (PTP1B) acts as a negative regulator of insulin signaling, and selective inhibition of PTP1B has served as a potential drug target for the treatment of type 2 diabetes. As part of our searching for PTP1B inhibitors from natural products, the extracts of marine microorganisms were screened for the inhibitory effects on the activity of protein tyrosine phosphatase 1B (PTP1B). Among the tested 304 extracts, 29 extracts exhibited inhibition rate ranging 40.1 - 83.6 % against PTP1B at the concentration level of $30{\mu}g/mL$.

• Korean Journal of Pharmacognosy
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• v.44 no.2
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• pp.176-181
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• 2013

In order to search for protein tyrosine phosphatase 1B (PTP1B) inhibitors as therapy of type 2 diabetes and obesity from Korean traditional prescriptions, we selected 58 traditional prescriptions based on a review of the Korean traditional medicine books. The hot water extracts of Korean traditional prescriptions were screened for the inhibitory activity against PTP1B. Among the tested extracts, water extracts of Jakgamhwangsinbu-tang, Seonbanghwalmyung-eum, and Takreeonjoong-tang showed relatively good inhibitory activity against PTP1B at the concentration of $30{\mu}g/ml$. Additionally, we evaluated PTP1B inhibitory effect for each herbal ingredient and composition in Jakgamhwangsinbu-tang (芍甘黃辛附湯). Of the tested ingredients from this herbal medicine, water extracts of Paeoniae Radix rubra and Rhei Rhizoma, and ethanol extracts of Paeoniae Radix alba, Rhei Rhizoma, Asiasari Radix, and Aconiti Tuber showed good PTP1B inhibitory effect. Herbal compositions composed of these active herbal ingredients exhibited significant activity for PTP1B inhibition over 70% at $7.5{\mu}g/ml$.

• Korean Journal of Pharmacognosy
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• v.47 no.1
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• pp.29-37
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• 2016

Anti-diabetic potential of the leaves of A. elata through the inhibitory activity on PTP1B and ${\alpha}$-glucosidase has not been reported. In this study, the EtOAc fraction of methanolic extract from the leaves of A. elata showed potent inhibitory activity against the PTP1B and ${\alpha}$-glucosidase with $IC_{50}$ value of $96.29{\pm}0.3$ and $264.71{\pm}14.87{\mu}g/mL$, respectively. Three known triterpenoids, oleanolic acid, oleanolic acid-28-O-${\beta}$-D-glucopyranoside and oleanolic acid-3-O-${\beta}$-D-glucopyranoside were isolated from the most active EtOAc fraction. We determined the chemical structure of these triterpenoids through comparisons of published nuclear magnetic resonance (NMR) spectroscopic data. Furthermore, we screened these triterpenoids for their ability to inhibit PTP1B and ${\alpha}$-glucosidase over a range of concentrations ($12.5-50{\mu}M$). All three terpenoids significantly inhibited PTP1B in a concentration dependent manner and oleanolic acid effectively inhibited ${\alpha}$-glucosidase. In addition, these compounds revealed potent inhibitory activity with negative binding energies toward PTP1B, showing high affinity and tight binding capacity in the molecular docking studies. Therefore, the results of the present study clearly demonstrate that A. elata leaves and its triterpenoid constituents might be beneficial in the prevention or treatment of diabetic disease.