Multitargeted protective effect of Abacopteris penangiana against carrageenan-induced chronic prostatitis in rats

Abacopteris penangiana (Hook.) Ching (AP) is traditionally used in Chinese medicine to promote blood circulation, remove blood stasis and dampness and for the treatment of edema and inflammation. In order to further support and develop the traditional use of Abacopteris penangiana as Chinese folk medicine, the aim of this study is to investigate the protective effect of the total flavanol glycosides (TFA) from AP and its acid hydrolysate (AHT) on chronic non-bacterial prostatitis (CNP) by measuring the levels of oxidative stress and inflammatory responses in rats.

First, the antioxidant and anti-inflammatory activities of AHT and TFA were investigated. Then the experimental chronic non-bacterial prostatitis was induced by carrageenan. The prostate index (PI) and prostate specific antigen (PSA) were determined. The activities of AHT and TFA on inhibiting free radicals and oxidative stress were investigated. Subsequently, the degree of chronic inflammatory cell infiltrates, acinar changes and interstitial fibrosis were evaluated by histopathological examination. In addition, the relative inflammatory factors, tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), cyclooxygenase-2 (COX-2), prostaglandin E2 (PEG2), transforming growth factor-β1 (TGF-β1) and connective tissue growth factor (CTGF) were measured. Finally, the prostatic expression of nuclear transcription factor-κB (NF-κB) was determined by immunohistochemistry and western blot analysis.

The whole results showed that AHT and TFA had strong antioxidant and anti-inflammatory activities. In CNP model, AHT and TFA successfully decreased PI and PSA. The activities of antioxidant enzymes in AHT or TFA group were enhanced. Additionally, a morphometric analysis of the prostate gland of AHT or TFA treated rats demonstrated a significant reduction in chronic inflammatory cell infiltrates and interstitial fibrosis compared to model group. The reduced values of TNF-α, IL-1β, COX-2, PEG2, inducible nitric oxide synthase (iNOS) and nitric oxide (NO) were observed both in AHT and TFA treated groups. Moreover, the levels of TGF-β1 and CTGF in AHT and TFA treated groups were significantly decreased along with the alleviation of the inflammatory state of the prostate gland. Besides, the prostatic expression of NF-κB was inhibited.

These results suggest that AHT and TFA have anti-prostatitis properties via inhibiting oxidative stress, NF-κB dependent pro-inflammatory cytokines, fibrosis-related factors and antinociceptive activity. Hence, AP represents a potential herb for the treatment of prostatitis.