Anti-inflammatory and gastroprotective potential of leaf essential oil of Cinnamomum glanduliferum in ethanol-induced rat experimental gastritis

Abstract

Context: Nothing could be found in the literature concerning Cinnamomum glanduliferum (Wall) Meissn (Lauraceae) bark (CG) in Egypt.

Objective: To investigate CG volatile oil chemically and its anti-inflammatory and gastroprotective effects.

Materials and methods: Essential oils were investigated by GC-MS. Leaves oil was assessed at doses of 250, 500 and 1000 mg/kg for its anti-inflammatory effect against carrageenan-induced rat oedema model. Serum inflammation markers were measured. The gastro-protective effect of the same doses of the volatile oil was also tested in ethanol-induced non-ulcerative gastritis model in rats. Stomach oxidative stress markers were examined following 1 h after intragastric ethanol administration.

Results: Twenty-five and 20 compounds were identified from leaf and branch oils, respectively (98.85 and 99.13%). The major ones were: eucalyptol (59.44%; 55.74%), sabinene (14.99%; 7.12%), α-terpineol (6.44%; 9.81%), α-pinene (5.27%; 4.71%). Following 4 h of treatment leaves volatile oil at doses of 250, 500 and 1000 mg/kg significantly reduced paw volume to 94, 82 and 69%, respectively. The same doses significantly reduced COX-2 activity to 73.8, 50.7 and 21.4 nmol/min/mL, respectively. A significant reduction of PGE2 concentration was observed (2.95 ± 0.2, 2.45 ± 0.15 and 1.75 ± 0.015 pg/mL). CG oil exhibited a significant modulatory effect on ethanol-induced gastritis in rats as the level of NO reduced to 32, 37 and 41 μM nitrate/g and also a significant inhibition of lipid peroxidation was observed via reduction of MDA concentration (1.15, 1.11 and 1.04 nmol/g).

Conclusion: CG volatile oil exhibited an anti-inflammatory effect and protected against ethanol-induced non-ulcerative gastritis.

Keywords: GC-MS; PGE2; inflammation; lipid peroxidation; oxidative stress.

Figure 1.

Time and dose-dependent effects of volatile oil in carregenin-induced rat oedema model. Each value represents mean % change of paw oedema volume ± SEM (n = 6). Statistical analysis was carried out by One-way ANOVA followed by Tukey post hoc test. a: Statistical significance as compared to the control. b: Statistical significance as compared to the Dose 250 treated group. c: Statistical significance as compared to the indomethacin treated group.

Figure 2.

Effect of different doses of volatile oil on COX II (A) & PGE2 (B) serum levels. a: Statistical significance as compared to the control. b: Statistical significance as compared to the dose 250 treated group.

Figure 3.

Photomicrographs of stomach sections of different treatment groups stained by H&E. A: Control group (vehicle treated) showing focal inflammatory cells infiltration with dilated blood vessels in submucosa (×40). B: Famotidine treated group showing normal submucosa (×40). C: Dose 250 mg/kg treated group showing focal inflammatory cells infiltration in submucosa (×40). D: Dose 500 mg/kg treated group showing focal inflammatory cells infiltration with dilated blood vessels in submucosa (×40). E: Dose 1000 mg/kg treated group showing focal inflammatory cells infiltration in base of mucosa (×40). F: Scoring the severity of the histopathological alterations (Focal inflammatory cells infiltration with dilated blood vessels in submucosa) in stomach of different experimental groups. +++: Severe histopathological alteration. ++: moderate histopathological alteration. +: mild histopathological alteration. –: nil histopathological alteration.

Figure 4.

Effect of different doses of volatile oil on NO (A) & MDA (B) gastric tissue levels. a: Statistical significance as compared to the control. b: Statistical significance as compared to the Dose 250 treated group.