ABSTRACT
Herbal plants contain many bioactive phytochemicals of which terpenoids (also called “isoprenoids”) constitute one of the largest families of natural products and which have been shown to be available for pharmaceutical applications. The chapter describes several bioactive terpenoids contained in herbal plants that can modulate liver-specific metabolic diseases such as nonalcoholic steatohepatitis, nonalcoholic fatty liver and chronic liver disease, and even alcohol-induced, hyperglycemia-induced, and drug-induced liver damage. They also have a role in controlling lipid metabolism by modulating peroxisome proliferator–activated receptors (PPARs), β-hydroxy-β-methylglutaryl-CoA (HMG-CoA) activities, and energy homeostasis and might be useful for managing obesity-induced metabolic disorders, such as type 2 diabetes, insulin resistance, and hyperlipidemia. Hepatoprotection is demonstrated by terpenoids through their inhibition of apoptosis in liver cells by restraining the cytosolic release of cytochrome c, decreasing the Bax/Bcl-2 ratio, and inhibiting I-κB, JNK, and ERK phosphorylation. Terpenoids contain extracts that exhibit significant radical-scavenging activity that can increase total antioxidant potential and decrease the inflammatory conditions associated with hepatitis. They play an important role in the biotransformation of xenobiotics by altering the activity of cytochrome P450 enzymes. Other effects such as modulating TGF-β–stimulated collagen type I expression associated with liver fibrosis are elucidated in detail and the individual effects of different terpenoids are further illustrated in this chapter.
