Table 3.

Current obstacles and solutions for chemopreventive natural compounds in HNSCC

Current
Natural compoundObstaclesSolutionsSource
Vitamin AToxicityIn combination, analogues, bioadjuvant(6–8, 11–13)
CurcuminBioavailabilityAnalogues, bioadjuvant, liposomal, nanoparticles, phospholipid complex, in combination(4, 5, 15–17, 21, 23)
IsothiocyanateLack of studies specific to HNSCCIn combination, analogues(37)
Green teaBioavailabilityIn combination, analogues(1, 47, 49)
LuteolinBioavailability, lack of studies specific to HNSCCNanoparticles, in combination(100)
ResveratrolBioavailability, lack of studies specific to HNSCCNanoparticles, in combination, bioadjuvant(61, 70–72)
GenisteinLack of studies specific to HNSCCIn combination(3, 83)
LycopeneLack of studies specific to HNSCCIn combination, bioadjuvant(3, 84)
Bitter melonLack of studies specific to HNSCCEarly stages of investigation(93–95)
Withaferin ALack of studies specific to HNSCCEarly stages of investigation(96)
GuggulsteroneLack of studies specific to HNSCCEarly stages of investigation(97)