Olive leaf extract attenuates adriamycin-induced focal segmental glomerulosclerosis in spontaneously hypertensive rats via suppression of oxidative stress, hyperlipidemia, and fibrosis

Olive (Olea europaea L.) leaf extract (OLE) possesses powerful antioxidant, antihyperlipidemic, and anti-inflammatory properties. The aim was to investigated the effects of OLE on the hyperlipidemia, antioxidant defense, heme oxygenase/biliverdin reductase (HO/BVR) pathway, inflammation, and fibrosis in spontaneously hypertensive rats with focal segmental glomerulosclerosis (FSGS, a progressive form of chronic kidney disease) induced by adriamycin (2 mg/kg, i.v., twice in a 21-day period). Daily treatment of OLE (80 mg/kg, p.o.) for 6 weeks suppressed protein oxidation and lipid peroxidation (p < .01 and p < .001, respectively), significantly increased antioxidant enzymes activities and normalized antioxidant capacity, leading to the improvement of antioxidant defense independently of the HO/BVR pathway. Furthermore, the values of triglycerides (p < .01), total, and low-density lipoprotein cholesterol (p < .05, both) were improved by OLE. OLE strongly prevented glomerulosclerosis, interstitial inflammation, and fibrosis (renal injury score, FSGS: 8 +/- 0.45 vs. FSGS+OLE: 4.20 +/- 1.07; p < .01), as evidenced by normalized fibronectin content (p < .001), suppressed interstitial inflammatory cells infiltration and collagen deposition, without changing cytokines expressions. OLE decreased blood pressure with a tendency to reduce urine albumin loss. These data suggest that OLE may be effective in slowing down the progression of FSGS.

Automated summary

Olive leaf extract has shown beneficial effects on hyperlipidemia, oxidative stress, inflammation, and fibrosis in spontaneously hypertensive rats with focal segmental glomerulosclerosis induced by adriamycin. The extract suppressed protein and lipid oxidation, increased antioxidant enzyme activities, improved lipid levels, prevented glomerulosclerosis and interstitial inflammation, and decreased blood pressure, suggesting its potential in slowing down the progression of chronic kidney disease.