Conclusions
In addition to the role of herbal
products in treatment of a variety of human diseases, natural chemicals
are still considered as an inexhaustible source for the development of
new active chemotherapeutic agents. Although a great number of natural
substances demonstrate therapeutic value in preclinical investigations,
their quantity dramatically decreases when they enter the clinical trial
stage. It is still difficult for researchers to choose the best in
vitro and in vivo models demonstrating the efficacy of natural
substances and confirming their inclusion in clinical trials.
Alternative in silico and in vitro methods that can considerably reduce
the time and expense needed for in vivo studies should be
proposed to address these liabilities. The low bioavailability of
natural substances usually limits their efficacy. As a result, in
addition to the compound’s effectiveness, which should be of great
interest, researchers must focus on drug delivery systems that can
resolve the compound’s pharmacokinetic problems and the investigation of
suitable derivatives offering a number of advantages in terms of
biological availability and efficacy.