Peptic ulcer disease (PUD) is a multifactorial and complex disease caused by an imbalance of protective and aggressive factors (endogenous and exogenous). Despite advances in recent years, it is still responsible for substantial mortality and triggering clinical problems. Over the last decades, the understanding of PUD has changed a lot with the discovery of Helicobacter pylori infection. However, this disease continues to be a challenge due to side-effects, incidence of relapse from use of various anti-ulcer medicines, and the rapid appearance of antimicrobial resistance with current H. pylori therapies. Consequently, there is the need to identify more effective and safe anti-ulcer agents. The search for new therapies with natural products is a viable alternative and has been encouraged. The literature reports the importance of monoterpenes based on the extensive pharmacological action of this class, including wound healing and anti-ulcerogenic agents. In the present study, 20 monoterpenes with anti-ulcerogenic properties were evaluated by assessing recent in vitro and in vivo studies. Here, we review the anti-ulcer effects of monoterpenes against ulcerogenic factors such as ethanol, nonsteroidal anti-inflammatory drugs (NSAIDs), and Helicobacter pylori, highlighting challenges in the field.

Citral is a mixture of monoterpenes present in the essential oil of several plants, such as Cymbopogon citratus and Zingiber officinale, possessing anti-inflammatory, anti-ulcerogenic, and antipyretic actions. We investigated the action of citral on body temperature (Tb) and inflammatory signaling in eutrophic and obese mice during Systemic Inflammation (SI) induced by Lipopolysaccharide (LPS). Thus, we assessed the effect of citral (25, 100, and 300 mg/kg) and ibuprofen in LPS-induced SI in Swiss male mice fed a standard diet (SD) or high-fat diet (HFD) for 12 weeks. Following SI induction, we measured Tb and collected the serum, hypothalamus, and gastric mucosa for biochemical measurements. Acute treatment with citral decreased the Tb of both SD and HFD-fed animals. Citral (300 mg/kg) treatment caused a significantly lower Tb variation in HFD-fed animals than in those fed the SD. Citral reduced peripheral levels of tumor necrosis factor (TNF)-α in SD and HFD mice and decreased serum leptin concentration in HFD mice 90 min after the LPS challenge. Furthermore, citral also reduced interleukin (IL)-6 levels in the hypothalamus of obese mice. In summary, citral effectively reduced Tb during SI by reducing inflammatory mediators with a distinct action profile in HFD mice when compared with SD.

Obesity causes low-grade inflammation that results in the development of comorbidities. In people with obesity, exacerbation of gastric lesion severity and delayed healing may aggravate gastric mucosal lesions. Accordingly, we aimed to evaluate the citral effects on gastric lesion healing in eutrophic and obese animals. C57Bl/6 male mice were divided into two groups: animals fed a standard diet (SD) or high-fat diet (HFD) for 12 weeks. Gastric ulcers were induced using acetic acid (80%) in both groups. Citral (25, 100, or 300 mg/kg) was administered orally for 3 or 10 days. A vehicle-treated negative control (1% Tween 80, 10 mL/kg) and lansoprazole-treated (30 mg/kg) were also established. Lesions were macroscopically examined by quantifying regenerated tissue and ulcer areas. Matrix metalloproteinases (MMP-2 and -9) were analyzed by zymography. The ulcer base area between the two examined periods was significantly reduced in HFD 100 and 300 mg/kg citral-treated animals. In the 100 mg/kg citral-treated group, healing progression was accompanied by reduced MMP-9 activity. Accordingly, HFD could alter MMP-9 activity, delaying the initial healing phase. Although macroscopic changes were undetectable, 10-day treatment with 100 mg/kg citral exhibited improved scar tissue progression in obese animals, with reduced MMP-9 activity and modulation of MMP-2 activation.

Background: Obesity is a growing global epidemic associated with changes in the gut microenvironment and metabolic endotoxemia, which can exacerbate metabolic and inflammatory processes. Citral (CT), a monoterpene present in essential oils, has been investigated for its anti-inflammatory, antioxidant, and immunomodulatory properties. However, its role in modulating the gut axis during metabolic and inflammatory alterations in obesity remains unknown. In this study, we investigated the effects of CT on intestinal and metabolic impairment induced by lipopolysaccharide (LPS) and high-fat diet (HFD) in in vitro and in vivo models.Methods: Male C57BL/6J mice were fed a standard diet and HFD for 17 weeks, with daily oral administration of CT treatment (25, 100, or 300 mg/kg) or vehicle. Morphological and histological parameters, lipid profiles, adipose index, cytokine levels, and colonic gene expression were determined. In vitro, murine rectal carcinoma (CMT-93) cells were stimulated with LPS (10 μg/mL) to assess tight junction and inflammatory protein expression.Results: CT treatment showed anti-obesity activity against HFD-induced body mass gain in mice, which was attributed to a significant reduction in body fat, glycemia, and cholesterol levels. Systemic inflammation during obesity also decreased after CT treatment, with a significant reduction in serum levels of endotoxin, interleukin-1β, and tumor necrosis factor-α. Additionally, CT stimulation reduced inducible nitric oxide synthase expression and maintained ZO-1 levels in LPS-stimulated CMT-93 cells.Conclusion: CT has anti-obesogenic, anti-inflammatory, and anti-hyperlipidemic properties mediated by its protective effects on the intestinal epithelium in obesity. Thus, our results highlight the promising preclinical results of CT treatment as a protective agent against the detrimental effects of HFD and LPS in mice.

Chemotherapy with irinotecan (CPT-11) induces intestinal mucositis via oxidative stress and NF-κB-driven cytokine amplification. We investigated the protective effects of the anthocyanidins cyanidin and malvidin (5 mg/kg) in a murine CPT-11 mucositis model. Both compounds increased duodenal glutathione level (GSH) and reduced lipid peroxidation (MDA), with distinct antioxidant profiles: malvidin enhanced catalase (CAT) activity, while cyanidin elevated superoxide dismutase (SOD). In the colon, cyanidin lowered MDA, whereas other oxidative and inflammatory markers remained largely unchanged. Malvidin significantly reduced IL-1β and IL-17 in both intestinal segments; cyanidin selectively decreased IL-6 in the colon, and this reduction was also observed for malvidin treatment. Gene expression analysis revealed broad transcriptional suppression in the duodenum for both compounds (Nrf2, NF-κB, TNF-α, IL-1β, IL-6, IL-17, IL-10), while colonic effects were more limited (suppression in IL-6 for both compounds). Despite these biochemical and transcriptional improvements—which were more pronounced with malvidin—neither compound prevented CPT-11-induced weight loss or colonic histopathology, indicating that redox and cytokine modulation alone are insufficient to restore mucosal integrity. Overall, malvidin demonstrated a more significant modulation in the antioxidant response in the duodenum, with anti-inflammatory activity in both segments, while cyanidin showed targeted modulation of oxidative stress. These findings position both anthocyanidins as complementary agents with distinct mechanistic profiles, warranting further investigation into dose–response, pharmacokinetics, NRF2 protein dynamics, and barrier-repair strategies. Early-phase clinical evaluation is recommended to assess their potential as adjunctive therapies for chemotherapy-induced intestinal mucositis.