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

The total flavonoids of Cannabis sativa L. were selected as the research object, and the extraction process of C. sativa 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 C. sativa 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 C. sativa L. flavonoid extracts (petroleum ether, CSF_p; n-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 Escherichia coli, Bacillus subtilis, and Bacillus pumilus. 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 C. sativa L. flavonoids (CSF_p) exhibited the most pronounced antibacterial and antioxidant effects.