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This study aimed to increase the concentrations of vindoline (VDL) and catharanthine (CAT) in Catharanthus roseus plants cultivated in an indoor farming system using artificial lighting and plasma-activated water (PAW). After a 61-days pre-treatment period under fluorescent lamps, plants were exposed to four treatments: white light (W) from the same fluorescent lamps, red light (R) from LEDs, W with PAW, and R with PAW. These combinations were evaluated at two sampling times: 45 days (T1) and 70 days (T2) after the end of pre-treatment (DAP). Results showed that R combined with PAW significantly increased VDL and CAT concentrations compared to other combinations. In particular, with PAW, R produced significantly higher VDL and CAT concentrations than W, while without PAW, VDL and CAT concentrations were comparable under W and R. Regardless of the light conditions, VDL and CAT concentrations were higher with PAW. Moreover, VDL and CAT concentrations increased from T1 to T2, reaching higher levels under R or PAW at T2. At the same sampling time, VDL and CAT levels were generally higher in plants exposed to R and in those treated with PAW. The highest VDL and CAT concentrations were observed with combined R and PAW at T2. The study concluded that: (1) VDL and CAT concentrations increase with plant age; (2) PAW enhances VDL and CAT concentrations, with its effect becoming more pronounced from T1 to T2; (3) R contributes to VDL and CAT biosynthesis, but its impact becomes significant only when combined with PAW and its effect is amplified from T1 to T2; (4) regardless of the sampling time, the treatment with R and PAW maximizes the VDL and CAT concentrations; (5) R combined with PAW at T2 is the most effective treatment; (6) if harvest timing cannot be delayed, using R and PAW offers substantial benefits.