TABLE 2.

Major classes of flavonoids interacting with chemotherapeutic agents to inhibit GBM.

Source	Class	Flavonoid	Ref
Milk thistle (Silybum marianum)	Flavonolignan	Silibinin	Deep and Agarwal, (2010)
Rue (Ruta graveolens)	Flavonol Glycoside	Rutin	Ganeshpurkar and Saluja, (2017)
Horny goat weed (Epimedium)	Flavonol Glycoside	Icariin	Tan et al. (2016)
Oak (Quercus)	Flavonol	Quercetin	Kelly, (2011)
Red clover (Trifolium pratense)	Isoflavone	Formononetin	Tay et al. (2019)
Gumweed (Grindelia argentina)	Flavone	Hispidulin	Patel and Patel, (2017)
Passionflower (Passiflora)	Flavone	Chrysin	Mani and Natesan, (2018)
Green and white tea	Flavan-3-ol	epigallocatechin-3-gallate (EGCG)	Singh et al. (2011)