PGP and breast cancer: et Wils., have a variety of pharmacological effects, such as inducing long-lasting central muscle relaxation and central nervous system inhibition, as well as anti-inflammatory, antibacterial, anti-ulcer, anti-tumor, etc. Hyo-Kyung Han et al. [131] evaluated the inhibitory effects of honokiol and magnolol on P-pg activity, and found that honokiol can inhibit P-gp activity through a competitive mechanism, and both compounds can inhibit the expression of P-gp and help to improve the resistance of breast cancer to neoadjuvant chemotherapy drugs.