The precise mechanism of action of hesperidin is still unknown. However, a number of studies (mostly animal studies), have highlighted potential pathways through which hesperidin may exert its effects.
Hesperidin may improve lipid metabolism via several potential mechanisms: In rat models, a possible pathway involves inhibiting cholesterol synthesis by downregulating the expression of retinol-binding protein (RBP), heart fatty acid binding protein (H-FAB), and cutaneous fatty acid-binding protein (C-FAB). Animal studies suggest that hesperidin may also inhibit the enzymes 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase and acyl coenzyme A: cholesterol acyltransferase (ACAT), which play a role in cholesterol biosynthesis.[10]
Furthermore, clinical studies on G-hesperidin (see FAQ “What are the other forms of hesperidin?”) suggest that it enhances very low density lipoprotein (VLDL) catabolism, leading to reduced TG and LDL levels. G-hesperidin also appeared to work by activating the lipoprotein lipase (LPL), an enzyme responsible for hydrolyzing TG. In vitro studies further suggested that G-hesperidin may suppress excessive liver LDL secretion by decreasing the release of apolipoprotein B (a key LDL component).[10]
Regarding its anti-inflammatory effect, both in vitro and in vivo studies suggest that hesperidin may reduce inflammation by suppressing the expression of inflammatory enzymes such as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), along with inflammatory markers (e.g., TNF-α, IL-6), thereby reducing prostaglandin levels.[10]
Additionally, one hypothesis explaining hesperidin’s blood pressure-lowering effect is that it increases nitric oxide (NO) production, which induces vasodilation by relaxing blood vessels smooth muscles, leading to a reduction in blood pressure. Another potential mechanism involves hesperidin reducing levels of the vasoconstrictor angiotensin-2 through inhibition of the angiotensin-converting enzyme.[10] It’s worth noting that these mechanisms remain hypothetical, and require clinical confirmation.
Hesperidin and hesperetin also appear to moderately increase blood flow either by stimulating the production of intracellular hydrogen peroxide, which activates the Src family kinase, a group of enzymes that regulate the production of nitric oxide in blood vessels, or through estrogen signaling, which is also involved in the production of nitric oxide.[11][13]