**5. Conclusions and future directions**

In recent years, study on phytochemicals from plants becomes more and more popular due to their demonstrated health benefits. A number of plants having high contents of phytochemicals (particularly phenolic acids and flavonoids) with associated antioxidant activities have been increasingly utilized. Complementary research is also needed to enhance the potential functionalities of the phytochemicals in future, where such plants have shown to contain numerous phytochemicals that may be beneficial to human health. The compiled results indicated that many of their bioactive compounds remain to be fully isolated, identified, and characterized (alkaloids, diterpenoids, and so on).

Therefore, phytochemicals can be considered as the source of natural medicines. The compounds of plants are bioaccessible and bioavailable in humans with some demonstrated health benefits, including antioxidant, anti-inflammatory, anti-cancer, anti-microbial, hypoglycemic action, etc. Additional well-designed human intervention studies and clinical trials are needed to validate the health benefits of phytochemicals.
