{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T03:49:12Z","timestamp":1788234552344,"version":"build-2803163510"},"reference-count":25,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2025,12,2]],"date-time":"2025-12-02T00:00:00Z","timestamp":1764633600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Background\/Objectives: Aldose reductase (AR) plays a crucial role in the accumulation of oxidative factors that lead to oxidative stress-related neuroinflammation. This study aims to find a novel agent from natural sources that can inhibit AR. Methods: Different extracts of Orthosiphon stamineus Benth (OS) leaves and its active constituents, eupatorin (EUP), rosmarinic acid (RA), sinensetin (SEN) and 3-hydroxy-5,6,7,4-tetramethoxyflavone (TMF), were used to identify the potential inhibition effect of AR. A new high-performance liquid chromatography (HPLC) method was developed to determine these phytochemicals using the Shimadzu LC-20AD HPLC system. In addition, the in vitro inhibition effect of OS ethanol extracts (95% and 50%) and OS components EUP, RA, and SEN was investigated in recombinant AR (AKR1B1). Results: In this study, the developed HPLC method was precise and accurate, and demonstrated clear separation of the four compounds\u2014EUP, RA, SEN, and TMF\u2014in the ethanolic extract. The contents of the four selected compounds\u2014EUP, RA, SEN, and TMF\u2014in 95% ethanolic extract were 2.35, 11.91, 0.94, and 0.18%, respectively. RA showed the highest concentration among the selected compounds, indicating that RA is the major constituent of this plant. The in vitro assay showed significant inhibition of the AR enzyme by RA and OS ethanol extracts 95% and 50% (IC50: 41.42 \u00b5M; 63.42 \u00b5g\/mL and 93.22 \u00b5g\/mL, respectively). Conclusions: The ethanolic extract of OS and RA could be a promising therapeutics option for the treatment of oxidative stress-related neuroinflammation disorders by inhibiting AR.<\/jats:p>","DOI":"10.3390\/molecules30234637","type":"journal-article","created":{"date-parts":[[2025,12,3]],"date-time":"2025-12-03T16:47:37Z","timestamp":1764780457000},"page":"4637","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Aldose Reductase Inhibition by Orthosiphon stamineus Extracts and Constituents Suggests Antioxidant Potential"],"prefix":"10.3390","volume":"30","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1457-4040","authenticated-orcid":false,"given":"Yousaf","family":"Dawood","sequence":"first","affiliation":[{"name":"School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden 11700, Malaysia"},{"name":"College of Pharmacy, University of Anbar, Ramadi 31001, Iraq"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3247-5532","authenticated-orcid":false,"given":"Atheer","family":"Zgair","sequence":"additional","affiliation":[{"name":"College of Pharmacy, University of Anbar, Ramadi 31001, Iraq"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4138-711X","authenticated-orcid":false,"given":"Mun Fei","family":"Yam","sequence":"additional","affiliation":[{"name":"School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden 11700, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1181-3969","authenticated-orcid":false,"given":"Nur Hidayah Kaz","family":"Abdul Aziz","sequence":"additional","affiliation":[{"name":"School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden 11700, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1016\/j.jare.2018.05.006","article-title":"Toxicological studies of Orthosiphon stamineus (Misai Kucing) standardized ethanol extract in combination with gemcitabine in athymic nude mice model","volume":"15","author":"Yehya","year":"2019","journal-title":"J. Adv. Res."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"473","DOI":"10.3233\/JAD-2008-15314","article-title":"Antioxidants in Central Nervous System Diseases: Preclinical Promise and Translational Challenges","volume":"15","author":"Kamat","year":"2008","journal-title":"J. Alzheimer\u2019s Dis."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"154","DOI":"10.1111\/j.1365-2567.2009.03225.x","article-title":"Inflammation in neurodegenerative diseases","volume":"129","author":"Amor","year":"2010","journal-title":"Immunology"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Chung, Y.-S., Choo, B.K.M., Ahmed, P.K., Othman, I., and Shaikh, M.F. (2020). Orthosiphon stamineus proteins alleviate pentylenetetrazol-induced seizures in Zebrafish. Biomedicines, 8.","DOI":"10.3390\/biomedicines8070191"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Retinasamy, T., Shaikh, M.F., Kumari, Y., Abidin, S.A.Z., and Othman, I. (2020). Orthosiphon stamineus standardized extract reverses streptozotocin-induced alzheimer\u2019s disease-like condition in a rat model. Biomedicines, 8.","DOI":"10.3390\/biomedicines8050104"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"678","DOI":"10.1089\/jmf.2011.1973","article-title":"Orthosiphon stamineus: Traditional uses, phytochemistry, pharmacology, and toxicology","volume":"15","author":"Ameer","year":"2012","journal-title":"J. Med. Food"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"362","DOI":"10.1089\/jmf.2006.065","article-title":"An investigation of the anti-inflammatory and analgesic effects of Orthosiphon stamineus leaf extract","volume":"11","author":"Yam","year":"2008","journal-title":"J. Med. Food"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"50","DOI":"10.1007\/s10787-008-8038-3","article-title":"Evaluation of the anti-pyretic potential of Orthosiphon stamineus Benth standardized extract","volume":"17","author":"Yam","year":"2008","journal-title":"Inflammopharmacology"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"380","DOI":"10.1210\/er.2004-0028","article-title":"Role of aldose reductase and oxidative damage in diabetes and the consequent potential for therapeutic options","volume":"26","author":"Srivastava","year":"2005","journal-title":"Endocr. Rev."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1515\/bmc.2011.002","article-title":"Aldose reductase: New insights for an old enzyme","volume":"2","author":"Ramana","year":"2011","journal-title":"Biomol. Concepts"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"365","DOI":"10.1111\/imm.12443","article-title":"Immune mechanisms linked to depression via oxidative stress and neuroprogression","volume":"144","author":"Bakunina","year":"2015","journal-title":"Immunology"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"330","DOI":"10.1016\/j.cbi.2011.02.023","article-title":"Aldose reductase inhibition suppresses oxidative stress-induced inflammatory disorders","volume":"191","author":"Srivastava","year":"2011","journal-title":"Chem. Interactions"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Correia, A.S., Cardoso, A., and Vale, N. (2023). Oxidative Stress in Depression: The Link with the Stress Response, Neuroinflammation, Serotonin, Neurogenesis and Synaptic Plasticity. Antioxidants, 12.","DOI":"10.3390\/antiox12020470"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Huang, Y.-K., Liu, C.-C., Wang, S., Cheng, H.-C., Meadows, C., and Chang, K.-C. (2022). The Role of Aldose Reductase in Beta-Amyloid-Induced Microglia Activation. Int. J. Mol. Sci., 23.","DOI":"10.3390\/ijms232315088"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1091","DOI":"10.2174\/1389200221666201016124125","article-title":"Natural Compounds as Source of Aldose Reductase (AR) Inhibitors for the Treatment of Diabetic Complications: A Mini Review","volume":"21","author":"Grewal","year":"2020","journal-title":"Curr. Drug Metab."},{"key":"ref_16","first-page":"41","article-title":"Inhibitory activity of flavonoids on the lens aldose reductase of healthy and diabetic rats","volume":"44","author":"Goodarzi","year":"2006","journal-title":"Acta Med. Iran."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2189","DOI":"10.2147\/DDDT.S493779","article-title":"Quercetin Improves Hippocampal Neurogenesis in Depression by Regulating the Level of Let-7e-5p in Microglia Exosomes","volume":"19","author":"Xie","year":"2025","journal-title":"Drug Des. Dev. Ther."},{"key":"ref_18","unstructured":"U.S. Department of Health and Human Services Food and Drug Administration Center for Drug Evaluation and Research (2018). Bioanalytical Method Validation: Guidance for Industry, U.S. Department of Health and Human Services."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"97","DOI":"10.4314\/tjpr.v10i1.66548","article-title":"Simultaneous analysis of bioactive markers from Orthosiphon stamineus benth leaves extracts by reverse phase high performance liquid chromatography","volume":"10","author":"Siddiqui","year":"2011","journal-title":"Trop. J. Pharm. Res."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"23","DOI":"10.4103\/0974-8490.147195","article-title":"A novel reverse phase high-performance liquid chromatography method for standardization of Orthosiphon stamineus leaf extracts","volume":"7","author":"Ismail","year":"2015","journal-title":"Pharmacogn. Res."},{"key":"ref_21","first-page":"V612","article-title":"Anti-tumor Activity of NuvastaticTM (C5OSEW5050ESA) of Orthosiphon stamineus and Rosmarinic Acid in an Athymic Nude Mice Model of Breast Cancer","volume":"6","author":"Yehya","year":"2022","journal-title":"J. Angiother."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"559","DOI":"10.1016\/j.foodchem.2004.01.008","article-title":"Sinensetin, eupatorin, 3\u2032-hydroxy-5,6,7,4\u2032-tetramethoxyflavone and rosmarinic acid contents and antioxidative effect of Orthosiphon stamineus from Malaysia","volume":"87","author":"Akowuah","year":"2004","journal-title":"Food Chem."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"156765","DOI":"10.1155\/2011\/156765","article-title":"Antiapoptotic and antioxidant properties of Orthosiphon stamineus benth (Cat\u2019s Whiskers): Intervention in the Bcl-2-mediated apoptotic pathway","volume":"2011","author":"Abdelwahab","year":"2010","journal-title":"Evidence-Based Complement. Altern. Med."},{"key":"ref_24","first-page":"2737","article-title":"Orthosiphon stamineus extracts inhibits proliferation and induces apoptosis in uterine fibroid cells","volume":"19","author":"Pauzi","year":"2018","journal-title":"Asian Pac. J. Cancer Prev."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"488","DOI":"10.1002\/ptr.5774","article-title":"Artichoke Leaf Extract Inhibits AKR1B1 and Reduces NF-\u03baB Activity in Human Leukemic Cells","volume":"31","year":"2017","journal-title":"Phytother. Res."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/30\/23\/4637\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,3]],"date-time":"2025-12-03T16:54:11Z","timestamp":1764780851000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/30\/23\/4637"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,12,2]]},"references-count":25,"journal-issue":{"issue":"23","published-online":{"date-parts":[[2025,12]]}},"alternative-id":["molecules30234637"],"URL":"https:\/\/doi.org\/10.3390\/molecules30234637","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,12,2]]}}}