{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,17]],"date-time":"2026-07-17T23:01:04Z","timestamp":1784329264626,"version":"3.55.0"},"reference-count":51,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2019,1,27]],"date-time":"2019-01-27T00:00:00Z","timestamp":1548547200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004663","name":"Ministry of Science and Technology, Taiwan","doi-asserted-by":"publisher","award":["104-2320-B-259-001-MY3"],"award-info":[{"award-number":["104-2320-B-259-001-MY3"]}],"id":[{"id":"10.13039\/501100004663","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Serine protease dipeptidyl peptidase 4 (DPP-4) is involved in self\/non-self-recognition and insulin sensitivity. DPP-4 inhibitors are conventional choices for diabetic treatment; however, side effects such as headache, bronchus infection, and nasopharyngitis might affect the daily lives of diabetic patients. Notably, natural compounds are believed to have a similar efficacy with lower adverse effects. This study aimed to validate the DPP-4 inhibitory activity of clerodane diterpene 16-hydroxycleroda-3,13-dien-15,16-olide (HCD) from Polyalthia longifolia, rutin, quercetin, and berberine, previously selected through molecular docking. The inhibitory potency of natural DPP-4 candidates was further determined by enzymatic, in vitro Caco-2, and ERK\/PKA activation in myocyte and pancreatic cells. The hypoglycemic efficacy of the natural compounds was consecutively analyzed by single-dose and multiple-dose administration in diet-induced obese diabetic mice. All the natural-compounds could directly inhibit DPP-4 activity in enzymatic assay and Caco-2 inhibition assay, and HCD showed the highest inhibition of the compounds. HCD down-regulated LPS-induced ERK phosphorylation in myocyte but blocked GLP-1 induced PKA expression. For in vivo tests, HCD showed hypoglycemic efficacy only in single-dose administration. After 28-days administration, HCD exhibited hypolipidemic and hepatoprotective efficacy. These results revealed that HCD performed potential antidiabetic activity via inhibition of single-dose and long-term administrations, and could be a new prospective anti-diabetic drug candidate.<\/jats:p>","DOI":"10.3390\/ijms20030530","type":"journal-article","created":{"date-parts":[[2019,1,29]],"date-time":"2019-01-29T03:40:55Z","timestamp":1548733255000},"page":"530","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":19,"title":["Polyalthia Clerodane Diterpene Potentiates Hypoglycemia via Inhibition of Dipeptidyl Peptidase 4"],"prefix":"10.3390","volume":"20","author":[{"given":"Po-Kai","family":"Huang","sequence":"first","affiliation":[{"name":"Department of Life Science and Institute of Biotechnology, National Dong Hwa University, Hualien 97401, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4160-2361","authenticated-orcid":false,"given":"Shian-Ren","family":"Lin","sequence":"additional","affiliation":[{"name":"Department of Life Science and Institute of Biotechnology, National Dong Hwa University, Hualien 97401, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9509-2582","authenticated-orcid":false,"given":"Jirawat","family":"Riyaphan","sequence":"additional","affiliation":[{"name":"Department of Life Science and Institute of Biotechnology, National Dong Hwa University, Hualien 97401, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yaw-Syan","family":"Fu","sequence":"additional","affiliation":[{"name":"Departmental of Biomedical Science and Environmental Biology, Kaoshiung Medical University, Kaoshiung 80708, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ching-Feng","family":"Weng","sequence":"additional","affiliation":[{"name":"Department of Life Science and Institute of Biotechnology, National Dong Hwa University, Hualien 97401, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2019,1,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1016\/j.diabres.2018.02.023","article-title":"Idf diabetes atlas: Global estimates of diabetes prevalence for 2017 and projections for 2045","volume":"138","author":"Cho","year":"2018","journal-title":"Diabetes Res. Clin. Pract."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1260","DOI":"10.1016\/S0140-6736(17)32130-X","article-title":"Global, regional, and national disability-adjusted life-years (DALYs) for 333 diseases and injuries and healthy life expectancy (HALE) for 195 countries and territories, 1990\u20132016: A systematic analysis for the global burden of disease study 2016","volume":"390","author":"DALYs","year":"2017","journal-title":"Lancet"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"American Diabetes Association (2018). 8. Pharmacologic approaches to glycemic treatment: Standards of medical care in diabetes-2018. Diabetes Care, 41, S73\u2013S85.","DOI":"10.2337\/dc18-S008"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1454","DOI":"10.1111\/j.1742-1241.2006.01178.x","article-title":"DPP-4 inhibitors and their potential role in the management of type 2 diabetes","volume":"60","author":"Barnett","year":"2006","journal-title":"Int. J. Clin. Pract."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"209","DOI":"10.1080\/713609354","article-title":"Dipeptidyl-peptidase iv from bench to bedside: An update on structural properties, functions, and clinical aspects of the enzyme DPP IV","volume":"40","author":"Lambeir","year":"2003","journal-title":"Crit. Rev. Clin. Lab. Sci."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1111\/j.1365-3083.2010.02488.x","article-title":"Soluble CD26\/dipeptidyl peptidase IV enhances human lymphocyte proliferation in vitro independent of dipeptidyl peptidase enzyme activity and adenosine deaminase binding","volume":"73","author":"Yu","year":"2011","journal-title":"Scand. J. Immunol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"166","DOI":"10.1111\/cei.13163","article-title":"Lymphocytes are a major source of circulating soluble dipeptidyl peptidase 4","volume":"194","author":"Casrouge","year":"2018","journal-title":"Clin. Exp. Immunol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1260419","DOI":"10.1126\/science.1260419","article-title":"Proteomics. Tissue-based map of the human proteome","volume":"347","author":"Uhlen","year":"2015","journal-title":"Science"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"386","DOI":"10.3389\/fimmu.2015.00386","article-title":"DPP4 in diabetes","volume":"6","author":"Rohrborn","year":"2015","journal-title":"Front. Immunol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.jsps.2015.06.009","article-title":"Uncertainties around incretin-based therapies: A literature review","volume":"25","author":"Alhabib","year":"2017","journal-title":"Saudi Pharm. J."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Lin, S.R., Fu, Y.S., Tsai, M.J., Cheng, H., and Weng, C.F. (2017). Natural compounds from herbs that can potentially execute as autophagy inducers for cancer therapy. Int. J. Mol. Sci., 18.","DOI":"10.3390\/ijms18071412"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"146","DOI":"10.2174\/157340911795677602","article-title":"Molecular docking: A powerful approach for structure-based drug discovery","volume":"7","author":"Meng","year":"2011","journal-title":"Curr. Comput. Aided Drug Des."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1016\/j.pharmthera.2017.02.034","article-title":"The impact of in silico screening in the discovery of novel and safer drug candidates","volume":"175","author":"Rognan","year":"2017","journal-title":"Pharmacol. Ther."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Huang, P.K., Lin, S.R., Chang, C.H., Tsai, M.J., Lee, D.N., and Weng, C.F. (2018). Natural phenolic compounds potentiate hypoglycemia via inhibition of dipeptidyl peptidase IV. Sci. Rep., under press.","DOI":"10.1038\/s41598-019-52088-7"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"4824","DOI":"10.1016\/S0021-9258(18)42906-7","article-title":"Dipeptidyl peptidase IV (CD 26) gene expression in enterocyte-like colon cancer cell lines HT-29 and Caco-2. Cloning of the complete human coding sequence and changes of dipeptidyl peptidase IV mRNA levels during cell differentiation","volume":"267","author":"Darmoul","year":"1992","journal-title":"J. Biol. Chem."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"R1","DOI":"10.1530\/JME-17-0005","article-title":"Role of soluble and membrane-bound dipeptidyl peptidase-4 in diabetic nephropathy","volume":"59","author":"Hasan","year":"2017","journal-title":"J. Mol. Endocrinol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1613","DOI":"10.1016\/j.bbadis.2014.06.004","article-title":"Soluble DPP4 induces inflammation and proliferation of human smooth muscle cells via protease-activated receptor 2","volume":"1842","author":"Wronkowitz","year":"2014","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1876","DOI":"10.1007\/s00125-014-3299-4","article-title":"Dipeptidyl peptidase 4 (DPP-4) is expressed in mouse and human islets and its activity is decreased in human islets from individuals with type 2 diabetes","volume":"57","author":"Omar","year":"2014","journal-title":"Diabetologia"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"570","DOI":"10.1016\/j.cellsig.2012.11.009","article-title":"Specific actions of GLP-1 receptor agonists and DPP4 inhibitors for the treatment of pancreatic beta-cell impairments in type 2 diabetes","volume":"25","author":"Dalle","year":"2013","journal-title":"Cell. Signal."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1007\/s13300-016-0167-x","article-title":"Diabetes dyslipidemia","volume":"7","author":"Schofield","year":"2016","journal-title":"Diabetes Ther."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"361","DOI":"10.1007\/s13205-018-1385-x","article-title":"Adncd: A compendious database on anti-diabetic natural compounds focusing on mechanism of action","volume":"8","author":"Khatoon","year":"2018","journal-title":"3 Biotech"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1696","DOI":"10.1016\/S0140-6736(06)69705-5","article-title":"The incretin system: Glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors in type 2 diabetes","volume":"368","author":"Drucker","year":"2006","journal-title":"Lancet"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1161","DOI":"10.1039\/c2fo30139c","article-title":"Anti-diabetic effect of a traditional Chinese medicine formula","volume":"3","author":"Wang","year":"2012","journal-title":"Food Funct."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Kalhotra, P., Chittepu, V., Osorio-Revilla, G., and Gallardo-Velazquez, T. (2018). Structure(-)activity relationship and molecular docking of natural product library reveal chrysin as a novel dipeptidyl peptidase-4 (DPP-4) inhibitor: An integrated in silico and in vitro study. Molecules, 23.","DOI":"10.3390\/molecules23061368"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1016\/j.fitote.2015.08.008","article-title":"Cyanogenetic glycosides and simple glycosides from the linseed meal","volume":"106","author":"Yang","year":"2015","journal-title":"Fitoterapia"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1016\/j.cbi.2016.04.012","article-title":"PTB1B, \u03b1-glucosidase, and DPP-IV inhibitory effects for chromene derivatives from the leaves of Smilax china L.","volume":"253","author":"Zhao","year":"2016","journal-title":"Chem. Biol. Interact."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Lammi, C., Bollati, C., Ferruzza, S., Ranaldi, G., Sambuy, Y., and Arnoldi, A. (2018). Soybean- and lupin-derived peptides inhibit DPP-IV activity on in situ human intestinal Caco-2 cells and ex vivo human serum. Nutrients, 10.","DOI":"10.3390\/nu10081082"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"6393","DOI":"10.1021\/acs.jafc.5b02069","article-title":"Anti-alpha-glucosidase and anti-dipeptidyl peptidase-IV activities of extracts and purified compounds from Vitis thunbergii var. Taiwaniana","volume":"63","author":"Lin","year":"2015","journal-title":"J. Agric. Food Chem."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1016\/j.jep.2014.08.017","article-title":"Plants Fagonia cretica L. and Hedera nepalensis K. Koch contain natural compounds with potent dipeptidyl peptidase-4 (DPP-4) inhibitory activity","volume":"156","author":"Saleem","year":"2014","journal-title":"J. Ethnopharmacol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"261","DOI":"10.2147\/DMSO.S109599","article-title":"Natural dipeptidyl peptidase-iv inhibitor mangiferin mitigates diabetes- and metabolic syndrome-induced changes in experimental rats","volume":"9","author":"Suman","year":"2016","journal-title":"Diabetes Metab. Syndr. Obes."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"e3283","DOI":"10.7717\/peerj.3283","article-title":"Screening of a natural compound library identifies emodin, a natural compound from Rheum palmatum linn. that inhibits DPP4","volume":"5","author":"Wang","year":"2017","journal-title":"Peer J."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"S522","DOI":"10.4103\/0973-1296.172956","article-title":"Chemometrics optimized extraction procedures, phytosynergistic blending and in vitro screening of natural enzyme inhibitors amongst leaves of tulsi, banyan and jamun","volume":"11","author":"De","year":"2015","journal-title":"Pharmacogn. Mag."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"209","DOI":"10.4239\/wjd.v5.i2.209","article-title":"Exploration of natural enzyme inhibitors with hypoglycemic potentials amongst Eucalyptus spp. by in vitro assays","volume":"5","author":"Dey","year":"2014","journal-title":"World J. Diabetes"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.peptides.2016.03.005","article-title":"Structure activity relationship modelling of milk protein-derived peptides with dipeptidyl peptidase IV (DPP-IV) inhibitory activity","volume":"79","author":"Nongonierma","year":"2016","journal-title":"Peptides"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1016\/j.jchromb.2015.11.054","article-title":"Purification, identification and structural modelling of DPP-IV inhibiting peptides from barbel protein hydrolysate","volume":"1008","author":"Sila","year":"2016","journal-title":"J. Chromatogr. B"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"62","DOI":"10.4103\/0973-7847.65329","article-title":"The chemistry, pharmacologic, and therapeutic applications of Polyalthia longifolia","volume":"4","author":"Katkar","year":"2010","journal-title":"Pharmacogn. Rev."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"2049","DOI":"10.3390\/molecules19022049","article-title":"Three new clerodane diterpenes from Polyalthia longifolia var. Pendula","volume":"19","author":"Wu","year":"2014","journal-title":"Molecules"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1055\/s-0029-1186005","article-title":"6-hydroxycleroda-3,13-dien-15,16-olide protects neuronal cells from lipopolysaccharide-induced neurotoxicity through the inhibition of microglia-mediated inflammation","volume":"76","author":"Shih","year":"2010","journal-title":"Planta Med."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"886","DOI":"10.1016\/j.lfs.2011.09.011","article-title":"16-hydroxycleroda-3,13-dien-15,16-olide regulates the expression of histone-modifying enzymes PRC2 complex and induces apoptosis in CML K562 cells","volume":"89","author":"Lin","year":"2011","journal-title":"Life Sci."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/j.phymed.2017.09.021","article-title":"16-hydroxycleroda-3, 13-dien-15, 16-olide inhibits the proliferation and induces mitochondrial-dependent apoptosis through Akt, mTOR, and MEK-ERK pathways in human renal carcinoma cells","volume":"36","author":"Liu","year":"2017","journal-title":"Phytomedicine"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"78379","DOI":"10.18632\/oncotarget.18987","article-title":"The autophagic inhibition oral squamous cell carcinoma cancer growth of 16-hydroxy-cleroda-3,13-dien-15,16-olide","volume":"8","author":"Cheng","year":"2017","journal-title":"Oncotarget"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"202","DOI":"10.1016\/j.etap.2016.06.005","article-title":"16-hydroxy-cleroda-3,13-dien-16,15-olide induced glioma cell autophagy via ROS generation and activation of p38 MAPK and ERK-1\/2","volume":"45","author":"Thiyagarajan","year":"2016","journal-title":"Environ. Toxicol. Pharmacol."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Velmurugan, B.K., Wang, P.C., and Weng, C.F. (2018). 16-hydroxycleroda-3,13-dien-15,16-olide and n-methyl-actinodaphne potentiate tamoxifen-induced cell death in breast cancer. Molecules, 23.","DOI":"10.3390\/molecules23081966"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"7679","DOI":"10.2147\/OTT.S173378","article-title":"16-hydroxycleroda-3,13-dien-15,16-olide induces anoikis in human renal cell carcinoma cells: Involvement of focal adhesion disassembly and signaling","volume":"11","author":"Chen","year":"2018","journal-title":"Onco Targets Ther."},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Riyaphan, J., Jhong, C.H., Lin, S.R., Chang, C.H., Tsai, M.J., Lee, D.N., Sung, P.J., Leong, M.K., and Weng, C.F. (2018). Hypoglycemic efficacy of docking selected natural compounds against alpha-glucosidase and alpha-amylase. Molecules, 23.","DOI":"10.3390\/molecules23092260"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"242","DOI":"10.1002\/biof.1219","article-title":"Screening alpha-glucosidase and alpha-amylase inhibitors from natural compounds by molecular docking in silico","volume":"41","author":"Jhong","year":"2015","journal-title":"Biofactors"},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Huang, P.K., Lin, S.X., Tsai, M.J., Leong, M.K., Lin, S.R., Kankala, R.K., Lee, C.H., and Weng, C.F. (2017). Encapsulation of 16-hydroxycleroda-3,13-dien-16,15-olide in mesoporous silica nanoparticles as a natural dipeptidyl peptidase-4 inhibitor potentiated hypoglycemia in diabetic mice. Nanomaterials, 7.","DOI":"10.3390\/nano7050112"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1016\/j.colsurfb.2016.01.038","article-title":"A focal adhesion kinase inhibitor 16-hydroxy-cleroda-3,13-dien-16,15-olide incorporated into enteric-coated nanoparticles for controlled anti-glioma drug delivery","volume":"141","author":"Thiyagarajan","year":"2016","journal-title":"Colloids Surf. B"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1186\/s13020-018-0171-3","article-title":"Coptidis rhizoma and its main bioactive components: Recent advances in chemical investigation, quality evaluation and pharmacological activity","volume":"13","author":"Meng","year":"2018","journal-title":"Chin. Med."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"305","DOI":"10.1016\/j.biopha.2017.10.001","article-title":"Mechanisms of antidiabetic effects of flavonoid rutin","volume":"96","author":"Ghorbani","year":"2017","journal-title":"Biomed. Pharmacother."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1007\/978-3-319-41342-6_17","article-title":"Quercetin and its role in chronic diseases","volume":"929","author":"Oboh","year":"2016","journal-title":"Adv. Exp. Med. Biol."}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/20\/3\/530\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T12:28:56Z","timestamp":1760185736000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/20\/3\/530"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,1,27]]},"references-count":51,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2019,2]]}},"alternative-id":["ijms20030530"],"URL":"https:\/\/doi.org\/10.3390\/ijms20030530","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,1,27]]}}}