<![CDATA[The postpartum period is a phase in which a woman’s reproductive organs return to their pre-pregnancy state, followed by the adaptation phase in maternal and infant care. Breastfeeding can be hindered when the mother experiences breast wounds or pain. One of the most common postpartum infections is mastitis, affecting approximately 9–20% of mothers. This study aims to determine the active compounds in langsat leaves and their inhibitory effects on Staphylococcus aureus bacteria. A true experimental laboratory design with a post-test–only approach was used to assess the significant differences between treatment and control groups, using langsat leaf extract concentrations of 20% and 40%. Phytochemical analysis showed a positive color reaction (+) indicating the presence of flavonoids and saponins. Total flavonoids (anti-inflammatory) measured using spectrophotometry were found to be 0.50% (w/w). Using the gravimetric method, 10 grams of dried extract contained 5.76% moisture. Univariate analysis showed that in the 20% extract group, 2 samples (33.3%) had no inhibition zone (0 mm), while 4 samples (66.7%) produced an inhibition zone of 1–5 mm. Thus, at 20% concentration, langsat leaf extract demonstrated weak antibacterial activity. In the 40% concentration group, 4 samples (66.7%) showed an inhibition zone of 5 mm, and 2 samples (33.3%) showed an inhibition zone of 6–9 mm. These results indicate an increase in antibacterial activity with higher extract concentration. Bivariate analysis using the Kruskal–Wallis test (due to non-normal data distribution) showed a significant difference (p < 0.05) between treatment groups on the inhibition of Staphylococcus bacteria: the 40% extract produced an average inhibition zone of 5.83 mm, while the 20% extract produced 2.33 mm. The negative control showed no antibacterial activity (0 mm). The increase in extract concentration corresponded with an enhanced inhibitory effect against Staphylococcus, although its effectiveness remained below that of the positive-control antibiotic. Further research is recommended, particularly involving selected postpartum mothers experiencing inflammation or mastitis.]]>
