Grape skin and loquat leaf extracts and acai puree have potent anti-atherosclerotic and anti-diabetic activity in vitro and in vivo in hypercholesterolemic zebrafish.
Study Goal
The researchers aimed to evaluate the anti-atherosclerotic and anti-diabetic potential of loquat leaf (LL) extracts compared to grape skin and acai puree using in vitro and in vivo models.
Results Summary
Loquat leaf extracts demonstrated antioxidant activity, reduced serum cholesterol and triglycerides in zebrafish, and showed anti-inflammatory effects, including attenuation of fatty liver and reduced oxidized species. It also contributed to lowering hyperglycemia in the high-cholesterol diet group.
Population
Zebrafish fed a high-cholesterol diet.
Effective Dosage
Final concentration of 0.1 mg/ml in vitro; dosage in vivo not specified.
Duration
4 weeks.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
loquat leaf (LL), grape skin (GS) and acai puree extracts | decrease | ferric ion reductive capacity, radical-scavenging activity and inhibition of low-density lipoprotein (LDL) oxidation | in vitro macrophage model | at a final concentration of 0.1 mg/ml | demonstrated potent | #1 |
loquat leaf (LL), grape skin (GS) and acai puree extracts | decrease | fructose-mediated protein glycation | in vitro assay | - | could abrogate | #2 |
loquat leaf (LL), grape skin (GS) and acai puree extracts | decrease | cholesteryl ester transfer protein (CETP) | in vitro assay | - | mildly inhibit | #3 |
acai treatment | decrease | cellular uptake of oxidized or acetylated LDL into macrophages | in vitro macrophage model | final concentration, 0.1 mg/ml | inhibited | #4 |
GS and LL extracts | decrease | cellular uptake of oxidized or acetylated LDL into macrophages | in vitro macrophage model | - | moderately diminished | #5 |
high cholesterol diet (HCD) | increase | serum total cholesterol (TC) and triglyceride (TG) levels | zebrafish | 2.5-fold higher than those fed a normal diet (ND) | exhibited | #6 |
acai | decrease | serum TC and CETP activity | HCD-fed zebrafish | - | demonstrated the lowest | #7 |
LL | decrease | serum TC and TG | HCD-fed zebrafish | - | showed a reduction in | #8 |
high cholesterol diet (HCD) | increase | serum glucose levels | zebrafish | threefold above the ND group | increased | #9 |
GS and LL feeding | decrease | hyperglycemia | HCD-fed zebrafish | - | elicited the greatest reduction in | #10 |
acai and LL | decrease | hepatic inflammation | HCD-fed zebrafish | - | showed much less | #11 |
acai and LL | decrease | fatty liver | HCD-fed zebrafish | - | attenuation of | #12 |
acai and LL | decrease | oxidized species | HCD-fed zebrafish | - | reduced content of | #13 |
Three major sources of flavonoids and phenolic compounds, which are commonly used in food industry, namely loquat leaf (LL), grape skin (GS) and acai puree, were tested in regard to their potential anti-atherosclerotic and anti-diabetic activity. The compounds were evaluated by in vitro antioxidant assay using a macrophage model and for in vivo hypolipidemic activity using zebrafish. In assays in vitro, all extracts demonstrated potent ferric ion reductive capacity, radical-scavenging activity and inhibition of low-density lipoprotein (LDL) oxidation at a final concentration of 0.1 mg/ml. Extracts could also abrogate fructose-mediated protein glycation and mildly inhibit cholesteryl ester transfer protein (CETP). Cellular uptake of oxidized or acetylated LDL into macrophages was inhibited by acai treatment (final concentration, 0.1 mg/ml) and moderately diminished by GS and LL extracts. After 4 weeks of feeding on a high cholesterol diet (HCD), zebrafish exhibited serum total cholesterol (TC) and triglyceride (TG) levels 2.5-fold higher than those fed a normal diet (ND). Within the experimental group, those fed acai demonstrated the lowest serum TC and CETP activity, while the LL-consuming group showed a reduction in serum TC and TG relative to HCD-fed fish. Serum glucose levels also increased in the HCD group, to threefold above the ND group; GS and LL feeding elicited the greatest reduction in hyperglycemia. The groups consuming acai and LL showed much less hepatic inflammation, as well as attenuation of fatty liver and a reduced content of oxidized species. In conclusion, extracts of LL, GS, and acai shared antioxidant, anti-inflammatory and anti-atherosclerotic activity in cellular assays and in a hypercholesterolemic zebrafish model.