Optimization of the Extraction Process and Comprehensive Evaluation of the Antimicrobial and Antioxidant Properties of Different Polar Parts of the Ethanol Extracts of <i>Cannabis sativa</i> L.

The total flavonoids of <i>Cannabis sativa</i> L. were selected as the research object, and the extraction process of <i>C. sativa</i> L. was optimized on the basis of a single factor experiment utilizing a five-factor, three-level response surface method. Subsequently, the vitro antimicrobial and antioxidant activities of the flavonoids were evaluated. The optimized extraction conditions were as follows: ratio of liquid to solid, 24.69:1 mL/g; soaking time, 102.12 min; extraction time, 165.96 min; ethanol concentration, 46.59%; extraction temperature, 86.87 °C. The extraction rate of <i>C. sativa</i> L. flavonoids (CSF) was found to be 5.51 ± 0.04 mg/g. The extraction of crude flavonoid (i.e., flavonoids extracted under the optimal extraction process) was conducted using four solvents, resulting in five <i>C. sativa</i> L. flavonoid extracts (petroleum ether, CSF_p; <i>n</i>-butanol, CSF_b; ethyl acetate, CSF_e; aqueous phase, CSF_w; and crude flavonoid, CSF). CSF contains 10 flavonoid components. In vitro, all five CSF samples demonstrated good total reducing power, effective scavenging capacity against DPPH and ABTS⁺ radicals, and pronounced inhibitory effects against <i>Escherichia coli</i>, <i>Bacillus subtilis</i>, and <i>Bacillus pumilus</i>. Analytic Hierarchy Process (AHP) was employed to evaluate the five CSF samples in terms of antibacterial and antioxidant activity. The results indicated that petroleum-ether-extracted <i>C. sativa</i> L. flavonoids (CSF_p) exhibited the most pronounced antibacterial and antioxidant effects.