(-)-Fenchone Prevents Cysteamine-Induced Duodenal Ulcers and Accelerates Healing Promoting Re-Epithelialization of Gastric Ulcers in Rats via Antioxidant and Immunomodulatory Mechanisms

Abstract

Background: (-)-Fenchone is a naturally occurring monoterpene found in the essential oils of Foeniculum vulgare Mill., Thuja occidentalis L., and Peumus boldus Molina. Pharmacological studies have reported its antinociceptive, antimicrobial, anti-inflammatory, antidiarrheal, and antioxidant activities.

Methods: The preventive antiulcer effects of (-)-Fenchone were assessed through oral pretreatment in cysteamine-induced duodenal lesion models. Gastric healing, the underlying mechanisms, and toxicity after repeated doses were evaluated using the acetic acid-induced gastric ulcer rat model with oral treatment administered for 14 days.

Results: In the cysteamine-induced duodenal ulcer model, fenchone (37.5-300 mg/kg) significantly decreased the ulcer area and prevented lesion formation. In the acetic acid-induced ulcer model, fenchone (150 mg/kg) reduced (p < 0.001) ulcerative injury. These effects were associated with increased levels of reduced glutathione (GSH), superoxide dismutase (SOD), interleukin (IL)-10, and transforming growth factor-beta (TGF-β). Furthermore, treatment with (-)-Fenchone (150 mg/kg) significantly reduced (p < 0.001) malondialdehyde (MDA), myeloperoxidase (MPO), interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α), and nuclear transcription factor kappa B (NF-κB). A 14-day oral toxicity investigation revealed no alterations in heart, liver, spleen, or kidney weight, nor in the biochemical and hematological parameters assessed. (-)-Fenchone protected animals from body weight loss while maintaining feed and water intake.

Conclusion: (-)-Fenchone exhibits low toxicity, prevents duodenal ulcers, and enhances gastric healing activities. Antioxidant and immunomodulatory properties appear to be involved in its therapeutic effects.

Keywords: (-)-Fenchone; duodenal ulcer; gastric ulcer; healing; immunomodulatory; monoterpene.

Figure 1

Effect of oral administration of (-)-fenchone on cysteamine-induced duodenal ulcers. Results are expressed as mean ± SD. One-way analysis of variance (ANOVA) was used: F (5.27) = 4.780, followed by Dunnett’s or Tukey’s test performed using the GraphPad 5.0 software. *** p < 0.001 compared to the negative control group (0.9% saline solution); # p < 0.001 compared to the lansoprazole group (30 mg/kg) (n = 5–7). ULA = ulcerative lesion area.

Figure 2

Macroscopic aspects of the duodenal mucosa of male Wistar rats pretreated (p.o.) with 5% tween 80 (A), lansoprazole 30 mg/kg (B), (-)-Fenchone 37.5 mg/kg (C), 75 mg/kg (D), 150 mg/kg (E), and 300 mg/kg (F) in the cysteamine-induced duodenal ulcer model. The dashed line represents the duodenal area of the animals.

Figure 3

Microscopic examination of the duodenal mucosae of rats subjected to cysteamine-induced duodenal ulcers and treated or untreated with (-)-Fenchone was conducted. Representative photomicrographs of the animals’ duodena from the experimental groups are presented: normal (A,E), 5% Tween 80 (B,F), lansoprazole 30 mg/kg (C,G), and (-)-Fenchone 150 mg/kg (D,H). Staining with hematoxylin and eosin (HE) (A–D) and Masson’s trichrome (E–H) was performed. Intestinal villi and enterocytes are denoted as (V). Graphic morphometric analysis using Masson’s trichrome staining was conducted. Results are expressed as the median (minimum–maximum) of the parameters analyzed (n = 5, three sessions per animal). Statistical analyses were performed using the Kruskal–Wallis and Dunn’s post hoc tests with, GraphPad 5.0 Software. ** p < 0.01 or * p < 0.05 compared to the control group (5% Tween 80).

Figure 3

Microscopic examination of the duodenal mucosae of rats subjected to cysteamine-induced duodenal ulcers and treated or untreated with (-)-Fenchone was conducted. Representative photomicrographs of the animals’ duodena from the experimental groups are presented: normal (A,E), 5% Tween 80 (B,F), lansoprazole 30 mg/kg (C,G), and (-)-Fenchone 150 mg/kg (D,H). Staining with hematoxylin and eosin (HE) (A–D) and Masson’s trichrome (E–H) was performed. Intestinal villi and enterocytes are denoted as (V). Graphic morphometric analysis using Masson’s trichrome staining was conducted. Results are expressed as the median (minimum–maximum) of the parameters analyzed (n = 5, three sessions per animal). Statistical analyses were performed using the Kruskal–Wallis and Dunn’s post hoc tests with, GraphPad 5.0 Software. ** p < 0.01 or * p < 0.05 compared to the control group (5% Tween 80).

Figure 4

Effect of oral administration of (-)-Fenchone and lansoprazole on acetic acid-induced gastric ulcers. Results are expressed as mean ± SD. One-way ANOVA was used: F (3.23) = 211.6, followed by Dunnett’s or Tukey’s test performed using the GraphPad 5.0 software. *** p < 0.001 compared to the negative control group (Tween 80 5%) (n = 6–8). ULA = ulcerative lesion area.

Figure 5

Microscopic effects on the gastric mucosae of rats submitted to acetic acid-induced gastric ulcers and treated or not with (-)-Fenchone. Representative photomicrographs of the animals’ stomachs from the experimental groups: sham (A,E), 5% tween 80 (B,F), lansoprazole 30 mg/kg (C,G), and (-)-Fenchone 150 mg/kg (D,H). HE staining (A–D) and Masson’s trichrome staining (E–H). Stomach mucosa (M), acute inflammatory reaction (*), scarring tissue (∞). Graphic morphometric analysis by Masson’s trichrome staining. Results are expressed as the median (minimum–maximum) of the parameters analyzed (n = 5, three sessions per animal). The Kruskal–Wallis test and Dunn’s posterior test were performed using the Graph Pad Prism 5.0 software. *** p < 0.001 vs. negative control group (5% tween 80).

Figure 6

Effect of oral administration of (-)-fenchone and lansoprazole on (A) GSH, (B) SOD, (C) MDA, and (D) MPO levels in the gastric ulcer model induced by acetic acid in rats. Results are expressed as the mean ± SE of the parameters analyzed (n = 5–8). One-way ANOVA was followed by Dunnett’s test. *** p < 0.001 vs. control group.

Figure 7

Effects of (-)-fenchone and lansoprazole on (A) IL-1β, (B) TNF-α, and (C) IL-10 levels in the gastric ulcer model induced by acetic acid in rats. Results are expressed as the mean ± SE of the parameters analyzed (n  =  6–8). One-way ANOVA was followed by Dunnett’s or Tukey’s test performed using the GraphPad 5.0 software. *** p < 0.001 vs. control group.

Figure 8

Photomicrographs with immunohistochemical marking for NF-kB in stomach samples from rats: (A) sham, (B) 5% Tween 80 (10 mL/kg), (C) Lansoprazole (30 mg/kg), and (D)—(-)-Fenchone (150 mg/kg). Results are expressed as the median (minimum–maximum) of the parameters analyzed (n = 5, three sessions per animal). The Kruskal–Wallis test and Dunn’s posterior test were performed using the GraphPad 5.0 software. ** p < 0.01, *** p < 0.001 compared to the control group (5% tween 80).

Figure 9

Photomicrographs with immunohistochemical marking for TGF-β in stomach samples from rats: (A) sham, (B) 5% Tween 80 (10 mL/kg), (C) Lansoprazole (30 mg/kg), and (D) (-)-Fenchone (150 mg/kg). Results are expressed as the median (minimum–maximum) of the parameters analyzed (n = 5, three sessions per animal). The Kruskal–Wallis test and Dunn’s posterior test were performed using the GraphPad 5.0 software. ** p < 0.01, *** p < 0.001 compared to the control group (5% tween 80).