Therapeutic Potential of Plantago ovata Bioactive Extracts Obtained by Supercritical Fluid Extraction as Influenced by Temperature on Anti-Obesity, Anticancer, and Antimicrobial Activities.

Plantago ovata has been utilized as an effective natural remedy with minimal side effects, offering a promising alternative to synthetic pharmaceuticals. The supercritical fluid extraction (SFE) of Plantago ovata leaves yielded 0.417 g and 0.532 g at 40 °C and 80 °C, respectively. The 40 °C extract exhibited stronger antimicrobial activity, with minimum inhibitory concentrations (MICs) as low as 15.62 µg/mL and minimum bactericidal concentrations (MBCs) as low as 31.25 µg/mL against Bacillus subtilis and Candida albicans. In contrast, the 80 °C extract demonstrated reduced activity, with MICs and MBCs up to 250 and 500 µg/mL, respectively. The 40 °C extract also showed superior lipase inhibition (IC50 = 17.21 µg/mL) compared to the 80 °C extract (IC50 = 26.42 µg/mL), although orlistat remained the most potent (IC50 = 6.02 µg/mL). In addition, cytotoxicity assays revealed stronger effects of the 40 °C extract on Caco-2 colon cancer cells (IC50 = 109.47 µg/mL) compared to the 80 °C extract (IC50 = 174.81 µg/mL). These results suggest that the lower-temperature SFE of P. ovata yields extracts with enhanced antimicrobial, anti-obesity, and anticancer activities, supporting its potential for pharmaceutical and nutraceutical applications.