Antiulcerogenic Activity and Toxicity of Bauhinia holophylla Hydroalcoholic Extract

Abstract

Several species of Bauhinia are used in traditional medicine for the treatment of gastrointestinal diseases, diabetes, and inflammation, among other conditions. The aim of this study was to investigate the antiulcer effect of a hydroalcoholic extract from the leaves of B. holophylla. The chemical profile of the extract was determined by HPLC-PAD-ESI-IT-MS. A dose-effect relation was constructed using the ethanol-induced gastric ulcer model in male Wistar rats. Histological analyses and studies of antioxidant and anti-inflammatory activities were performed in stomach samples. The involvement of SH compounds, NO, K(+) ATP channels, and α 2-adrenergic receptors in the gastroprotective effect was evaluated. A toxicity study was performed with a single oral dose of 5000 mg/kg. The extract was composed mainly of cyanoglucoside and flavonol-O-glycosides derivatives of quercetin and myricetin. SH compounds, NO release, K(+) ATP channel activation, and presynaptic α 2-adrenergic receptor stimulation each proved to be involved in the antiulcer effect. The levels of GSH and activity of GR and GPx were increased, and the levels of TNF-α, IL-6 and IL-10 were modulated. There was an antidiarrheal effect and there were no signs of toxicity. B. holophylla presents antiulcer activity mainly by decreasing oxidative stress and attenuating the inflammatory response, without inducing side effects.

Figure 1

HPLC-PAD analytical chromatogram of 70% EtOH leaf extract of Bauhinia holophylla. Experimental conditions: eluents A (H₂O + 0.1% formic acid) and B (MeOH + 0.1% formic acid). Gradient system: 25–100% B over 70 min. Column: Phenomenex Luna C18 (250 × 4.6 mm i.d., 5 μm). Flow rate: 0.8 mL·min⁻¹ and λ = 360 nm. Injected volume: 10 μL. Identified compounds: 1, myricetin-O-deoxyhexoside, 2, quercetin-O-hexoside, 3, quercetin-O-pentoside, 4, quercetin-O-deoxyhexoside, and 5, isorhamnetin.

Figure 2

Macroscopic appearance of rat stomachs with ethanol-induced gastric ulcers after treatment with (a) vehicle, (b) carbenoxolone (100 mg/kg), or (c) Bauhinia holophylla (150 mg/kg). Arrows indicate ulcer formation.

Figure 3

Gastric ulcer area (mm²) of rat stomachs with ethanol-induced gastric ulcers after treatment with vehicle, carbenoxolone (100 mg/kg), or Bauhinia holophylla (50, 100, or 150 mg/kg). The results are reported as the mean ± SEM. ANOVA followed by Dunnett's test, P < 0.05.

Figure 4

Rat stomachs with ethanol-induced gastric ulcers after treatment with (a, d) vehicle, (b, e) carbenoxolone (100 mg/kg), or (c, f) Bauhinia holophylla (150 mg/kg). In the HE staining (a, b, c), the gastric mucosa is more preserved in (b) and (c), besides desquamation, indicated by +. Arrow indicates ulcer formation. In the PAS staining (d, e, f), purple stained area (∗) indicates the mucus secretion in the gastric glands and # indicates glandular damage.