Pharmacognostic profiling of Bridelia ovata leaves and evaluation of signal transducer and activator of transcription 3-mediated antiproliferative effects in triple-negative breast cancer.

Bridelia ovata Decne. is a Thai traditional medicinal plant whose pharmacognostic standards, validated analytical methods, and anticancer mechanisms against triple-negative breast cancer (TNBC) remain unreported. The objective of this study was to establish a pharmacognostic monograph for B. ovata leaves, validate a high performance liquid chromatography (HPLC) method for epigallocatechin (EGC) quantification, profile the extract by liquid chromatography/quadrupole time-of-flight mass spectrometry (LC-QTOF-MS), and investigate signal transducer and activator of transcription 3 (STAT3)-mediated anti-proliferative mechanisms in MDA-MB-231 TNBC cells. One authenticated and 14 commercial B. ovata leaf samples were evaluated by macroscopic and microscopic examination, thin-layer chromatography fingerprinting, phytochemical screening, physicochemical analysis, validated HPLC, LC-QTOF-MS profiling, network pharmacology, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, and Western blotting. Key diagnostic features included paracytic stomata, lignified fibers, and calcium oxalate crystals. Most physicochemical parameters met World Health Organization general guidelines. The HPLC method showed excellent linearity (r 2 > 0.9995; 20-500 μg/mL); EGC content ranged from 0.20 to 11.05% w/w. LC-QTOF-MS tentatively identified 24 metabolites spanning phenolic acids, catechins, flavonoid glycosides, and terpenoids. Furthermore, network pharmacology identified STAT3 as the key hub target. B. ovata extract selectively inhibited MDA-MB-231 viability (IC50 = 413 ± 23 μg/mL vs. IC50 > 800 μg/mL in MCF-10A), induced G2/M arrest, and suppressed p-STAT3 (Tyr705) and cyclin D1 expression in a dose-dependent manner. These findings integrate pharmacognostic identification, physicochemical standardization, and mechanistic evidence of STAT3 pathway modulation, collectively supporting B. ovata as a phytopharmaceutical candidate for TNBC. B. ovata leaves demonstrate reproducible pharmacognostic identity, consistent EGC-based chemical quality markers, and STAT3-mediated antiproliferative activity, warranting further preclinical investigation.