Abstract

Background:
Renal tubulointerstitial fibrosis is a major pathological endpoint of progressive kidney disease and is closely associated with oxidative stress and inflammation. DLBS2411, a standardized bioactive fraction derived from Cinnamomum burmannii, has been investigated mainly for gastroprotective and mucoprotective effects, but its potential activity in renal fibrosis remains unclear.

Aim:
This study evaluated the effect of C. burmannii bioactive fraction DLBS2411 (CB) on renal histopathology, serum malondialdehyde (MDA), and tumor necrosis factor-alpha (TNF-α) in a unilateral ureteral obstruction (UUO)-induced renal fibrosis model in male rats.

Methods:
Thirty male Sprague–Dawley rats underwent UUO and were randomized on Day 7 into five groups (n = 6/group): UUO + vehicle, UUO + methylprednisolone 1 mg/kgBW, and UUO + CB at 50, 100, or 200 mg/kgBW. Treatments were administered orally once daily for 14 days. Serum MDA and TNF-α were measured at baseline, Day 7, and Day 21. At Day 21, obstructed kidneys were collected for hematoxylin–eosin staining and blinded semiquantitative histopathological scoring.

Results:
UUO increased serum MDA and TNF-α by Day 7. The UUO vehicle group showed severe tubular dilatation and interstitial inflammation, moderate protein casts, and mild interstitial fibrosis. CB treatment improved renal histopathology, particularly at 100 and 200 mg/kgBW. The CB200 group showed the most favorable renal morphology, with no detectable interstitial fibrosis. Serum MDA decreased significantly after CB treatment at 50 mg/kgBW (p = 0.017), 100 mg/kgBW (p = 0.007), and 200 mg/kgBW (p = 0.009), with the greatest reduction in the CB100 group. Between-group ΔMDA analysis showed greater MDA reduction in CB-treated groups than in the UUO vehicle group. Serum TNF-α decreased significantly in the CB100 group (p = 0.033) and methylprednisolone group (p = 0.011). Between-group ΔTNF-α analysis showed a significantly greater reduction in CB100 than in the UUO vehicle group.

Conclusion:
DLBS2411 improved renal histopathological injury and reduced systemic oxidative stress in UUO-induced renal fibrosis. CB200 showed the most favorable histological profile, whereas CB100 showed the most consistent biochemical response.

Key words: Cinnamomum burmannii; DLBS2411; Malondialdehyde; Renal fibrosis; Unilateral ureteral obstruction.