Estragole prevents gastric ulcers via cytoprotective, antioxidant and immunoregulatory mechanisms in animal models

BACKGROUND

Estragole is an aromatic organic compound belonging to the class of phenylpropanoids derived from cinnamic aldehydes and present in essential oils of plant species, such asRavensara anisata (madeira), Ocimum basilicum (manjericão/alfavaca) and Croton zehntneri (canelinha). Pharmacological studies report its anti-inflammatory, antioxidant and vasorelaxant activity.

HYPOTHESIS/PURPOSE

This study aimed to evaluate the acute non-clinical toxicity, gastroprotective activity and the related mechanisms of action.

METHODS

Acute toxicity was assessed according to OECD guide 423 in mice. Ethanol, stress, piroxicam and pylorus ligation-induced gastric ulcer models were used to investigate antiulcer properties. The related mechanisms of action were using the ethanol-gastric lesions protocol.

RESULTS

In the acute oral toxicity assay, doses of 300 or 2000 mg/kg of estragole administered orally in Swiss mice did not induce any behavioral changes. However, the dose of 2000 mg/kg showed a decrease in water and feed intake. Lethal dose 50 % (LD50) was set to be equal to or greater than 2500 mg/kg, according to OECD. In all evaluated protocols, estragole (31.25, 62.5, 125 and 250 mg/kg) significantly reduced the area of ​​ulcerative lesion when compared to control groups. To investigate the mechanisms involved in the gastroprotective activity, the antisecretory or neutralizing of gastric secretion, cytoprotectant, antioxidant and immunoregulatory effects were evaluated. Results showed that treatment with estragole (250 mg/kg) reduced (p < 0.05) the volume of the gastric juice. Besides, sulfhydryl groups, nitric oxide, mucus and prostaglandins seems to be involved in the gastroprotective property. Treatment also increased (p < 0.001) levels of reduced glutathione (GSH), interleukin-10 (IL-10) and positive cells marked for glutathione peroxidase (GPx) and cyclooxygenase 2 (COX-2). It also reduced (p < 0.001) malondialdehyde (MDA), myeloperoxidase (MPO), interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α) and inducible nitric oxide synthase (iNOS) (p < 0.05) levels.

CONCLUSION

Thus, it is possible to infer that estragole presents gastroprotective activity related to antisecretory, cytoprotective, antioxidant and immunomodulatory mechanisms.

Carbohydrates, volatile and phenolic compounds composition, and antioxidant activity of calabura (Muntingia calabura L.) fruit

Soluble carbohydrates, volatile and phenolic compounds from calabura fruit as well as its antioxidant activity were assessed. The low amount of fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs) and similar amount of glucose and fructose allow us to classify the calabura berry as low-FODMAPs. The terpenes β-Farnesene and dendrolasin identified by SPME-GC-MS were the major volatile components. UHPLC-MS/MS analysis revelled gallic acid (5325 μg/g dw) and cyanidin-3-O-glucoside (171 μg/g dw) as the main phenolic compounds, followed by gentisic acid, gallocatechin, caffeic acid and protocatechuic acid. In addition, gallic acid was found mainly in esterified (2883 μg/g dw) and insoluble-bound (2272 μg/g dw) forms. Free and glycosylated forms showed however the highest antioxidant activity due to occurrence of flavonoids (0.28-27 μg/g dw) in these fractions, such as catechin, gallocatechin, epigallocatechin, naringenin, and quercetin. These findings clearly suggest that calabura is a berry with low energy value and attractive colour and flavour that may contribute to the intake of several bioactive compounds with antioxidant activity. Furthermore, this berry have great potential for use in the food industry and as functional food.