Modulation of Stem Cell Factor by Forskolin Inhibits the Progression of Tubule Interstitial Fibrosis

Purpose: Forskolin is primarily found in the roots of the Coleus forskohlii plant, historically employed in Southeast Asian and Indian Ayurvedic medicine. Mast cells play a crucial role in fibrosis progression, yet their activation and inhibition in animal models are understudied; thus, we explored forskolin’s impact on kidney fibrosis. Materials and Methods: Forskolin was evaluated in a mouse model for stem cell factor-induced histamine release, and plasma histamine levels were measured using the enzyme-linked immunosorbent assay. Kidney fibrosis was developed by unilateral ureteral obstruction (UUO). Renal function was assessed by spectrophotometric measurements of serum blood urea nitrogen (BUN) and creatinine. The gene expression of collagen, transforming growth factor-beta (TGF-β), α-smooth muscle actin (α-SMA), interleukin-1 beta (IL-1β), and mast cell protease-5 (MCPT-5) in the kidney was analyzed by reverse transcription polymerase chain reaction (RT-PCR). Histopathological changes in the renal tissues were examined by hematoxylin and eosin (H&E) and Masson’s trichome stain. Results: Our results showed that 3 mg/kg forskolin inhibited SCF-induced plasma histamine release in a mouse model. In the 7-day UUO model, forskolin significantly showed inhibition of serum creatinine and blood urea nitrogen compared with the disease group. Forskolin significantly inhibited elevated expression of collagen, TGF-β, α-SMA, IL-1β, and MCPT-5 in the kidneys. Histopathological observation of H&E and Masson trichome-stained kidney forskolin demonstrated a reduction in inflammatory cells, pelvic and tubular dilation, and fibrosis. Conclusion: Forskolin showed an anti-fibrotic effect in UUO-induced renal fibrotic mice. Most significantly, forskolin administration showed a decrease in the expression of the mast cell protease MCPT5 in the kidneys. These results imply that forskolin, through modifying SCF activity, may be a viable potential treatment for the attenuation of tubule-interstitial fibrosis.