Zoonotic Diseases and Phytochemical Medicines for Microbial Infections in Veterinary Science: Current State and Future Perspective

Shin, Bora; Park, Woojun

Herbal remedies are generally characterized by wide therapeutic indexes (37) , and they consist of multicomponent mixtures acting as multi-target drugs with pleiotropic effects. In animals, self-medication remains a controversial subject because the evidence is mostly anecdotal (39) . Unlike the popular belief that most drugs are synthetic in origin, many important medicines, such as cocaine and atropine, are natural products of plant origin (40) . Plants are used as natural resources in the development of new drugs, over the counter drugs, and nutraceuticals. In recent years, the consumption of botanical supplements has increased globally due to their relatively low cost and the need to reduce antibiotic overuse (38) . For example, terpenoids and phenolic compounds extracted from plants have been extensively studied for their immunity-enhancing effects and antimicrobial activities against a broad range of infectious microorganisms ( Table 1) . As shown in Table 1 , typical phytochemicals with antioxidant activity include monoterpenes (aromatic plants), diterpenes (berries and essential oils), triterpenes (olive oil and leaves), tetraterpenes (colored fruits and vegetables), sesquiterpenes (essential oils), and polyphenols (from tea and grapes).