Antidiarrheal activity of a myricitrin-enriched standardised extract of <i>Eugenia uniflora</i> L

Eugenia uniflora L. has been traditionally used for the treatment of gastrointestinal disorders, including diarrhoea, however, pharmacological studies using chemically standardised preparations remain limited. In this study, a myricitrin-enriched extract from E. uniflora leaves was developed and chemically standardised. Myricitrin was quantified by a validated HPLC–PDA method to ensure batch reproducibility. Antidiarrheal activity was evaluated in a castor oil-induced diarrhoea model in mice, and safety was assessed by cytotoxicity assays (MTT and neutral red uptake) and acute oral toxicity (2000 mg/kg). The extract showed marked flavonoid enrichment and low cytotoxicity, with no mortality observed in vivo (LD50 > 2000 mg/kg). Oral administration significantly reduced diarrheal episodes in a dose-dependent manner, with effects comparable to loperamide at the highest dose. These findings support the pharmacological relevance of a chemically standardised E. uniflora extract.