Anti-inflammatory effect of Adiantum capillus-veneris hydroalcoholic and aqueous extracts on acetic acid-induced colitis in rats

Abstract

Objective: Colitis is an inflammatory bowel disease with unknown etiology where many factors might play a role. Adiantum capillus-veneris may have beneficial effects in colitis because of its anti-inflammatory, antioxidant, wound healing and antimicrobial effects. The aim of this study was to explore the anti-inflammatory and anti-ulcerative effects of A. capillus-veneris on acetic acid-induced colitis in a rat model.

Materials and methods: A. capillus-veneris aqueous (ACAE; 150, 300, and 600 mg/kg) and hydroalcoholic extract (ACHE; 150, 300, and 600 mg/kg) were given orally (p.o.) to male Wistar rats 2 hr before induction of colitis by intra-rectal administration of acetic acid 3%, and continued for 4 days. Prednisolone (4 mg/kg) and mesalazine (100 mg/kg) were applied p.o., as reference drugs for comparison. On day five, colitis indices of tissue specimens were evaluated and levels of biochemical markers including myeloperoxidase (MPO) and malondialdehyde (MDA) were determined.

Results: In all groups treated with ACAE and ACHE with the exception of ACAE (150 mg/kg), ulcer index and wet weight of colon as parameters of macroscopic injuries, total colitis index as marker of microscopic features and MPO activity were significantly reduced in comparison to the control group; however, MDA value was only diminished in ACAE (300 and 600 mg/kg) and ACHE (300 mg/kg) groups significantly.

Conclusion: This research showed that ACAE and ACHE had dose-related beneficial effects on acetic acid-induced colitis and these effects could be attributed to anti-inflammatory, ulcer healing and antioxidant activities of these extracts.

Keywords: Adiantum capillus-veneris; Animal model; Colitis; Inflammation; Plant extract.

Figure 1

Photos of colon tissue, 5 days after acetic acid-induced colitis in rats: (A) Normal colon treated with normal saline/tween (Sham); (B) Control colitis treated with normal saline/tween; (C) Colitis treated with ACAE (600 mg/kg); (D) Colitis treated with ACHE (300 mg/kg); (E) Colitis treated with prednisolone (4 mg/kg); (F) Colitis treated with mesalazine (100 mg/kg)

Figure 2

Microscopic illustration of colonic tissue in rats. (A) Normal tissue, treated with normal saline/tween (5 ml/kg); (B) Colitis control group tissue which shows crypt damage (white arrows), leucocytes infiltration, mucus and sub-mucosal layer edema and inflammation (black arrows); (C) Colitis treated with ACAE (600 mg/kg); (D) Colitis treated with ACHE (300 mg/kg); (E) Colitis treated with prednisolone (4 mg/kg); (F) Colitis treated with mesalazine (100 mg/kg). H&E staining at x10 magnification (panel B was x40 magnified).

Figure 3

Myeloperoxidase (MPO) activity in colonic tissue of rats. Sham and control colitis treated with normal saline/tween (5 ml/kg), A. capillus-veneris aqueous extract (ACAE; 150, 300, and 600 mg/kg), A. capillus-veneris hydroalcoholic extract (ACHE; 150, 300, and 600 mg/kg), prednisolone (Pred., 4 mg/kg) and mesalazine (Mes, 100 mg/kg). Data is presented as mean±SEM. *p<0.05, **, p<0.01, and ***p<0.001, denote a significant difference versus control. # p<0.05 denotes a significant difference versus ACAE150 mg/kg

Figure 4

Malondialdehyde (MDA) values in colonic tissue of rats. Sham and control colitis treated with normal saline/tween (5 ml/kg), A. capillus-veneris aqueous extract (ACAE), A. capillus-veneris hydroalcoholic extract (ACHE), prednisolone (Pred., 4 mg/kg) and mesalazine (Mes, 100 mg/kg). Data is presented as mean±SEM. *p<0.05, **p<0.01, and ***p<0.001, denote a significant difference versus control