Gastric Ulcers in Middle-Aged Rats: The Healing Effect of Essential Oil from Citrus aurantium L. (Rutaceae).

The elderly population has experienced increased life expectancy as well as the increased incidence of gastric ulcers. The peels of fruits from Citrus aurantium L., popularly known in Brazil as orange bitter, are commonly used asatea form for the treatment of gastrointestinal tract disorders, such as ulcer and gastritis. We evaluated the healing effects of essential oil from the peels of Citrus aurantium fruits (OEC) on gastric ulcers in middle-aged rats. We examined the effects of a 14-day chronic OEC treatment on gastric mucosa in middle-aged male Wistar rats that were given acetic-acid-induced gastric lesions by morphometric and immunohistological analyses. Oral OEC treatment significantly reduced the lesion area (76%) within the gastric mucosa and significantly increased (P < .05) the height of regenerated mucosa (59%) when compared to the negative control group. Immunohistochemical analysis of the molecular markers such as COX-2, HSP-70, VEGF, and PCNA in the gastric mucosa confirmed that OEC treatment induced healing effects by increasing the number of new blood vessels and by augmenting gastric mucus in the mucosa glands. These results suggest that the oil from Citrus aurantium effectively heals gastric ulcers in middle-aged animals; however, safe use of OEC demands special care and precautions.

Differences in gastroprotective and mutagenic actions between polar and apolar extracts of Ananas ananassoides.

Several plants are used in folk medicine to treat gastrointestinal disorders. Ananas ananassoides (Baker) L.B. Smith (Family Bromeliaceae) is a medicinal plant commonly used in the central region of Brazil against gastric pain. We evaluated two extracts (methanol [MeOH] and dichloromethane [DCM]) obtained from the leaves of A. ananassoides for their ability to protect the gastric mucosa against injuries caused by necrotizing agents (0.3 M HCl/60% ethanol, absolute ethanol, non-steroidal anti-inflammatory drugs, and pylorus ligation) in mice and rats. The best results were obtained after pretreatment with the DCM extract, whereas the MeOH extract did not show any significant anti-ulcerogenic activity but presented mutagenic action. The mechanism of action of the DCM extract suggested the effective participation of endogenous sulfhydryl group in the gastroprotective action. The data, taken together with the absence of acute toxicity and mutagenicity, indicate the apolar extract, instead of the polar, extract of A. ananassoides as a safe and potential new anti-ulcerogenic drug.

Flavonoids and antiulcerogenic activity from Byrsonima crassa leaves extracts.

Byrsonima crassa Niedenzu (IK) (Malpighiaceae) is used in Brazilian folk medicine for the treatment of diseases related mainly to gastric ulcers. In this study, we evaluated the potential antiulcerogenic effect of three different extracts obtained from the leaves of Byrsonima crassa namely hydromethanolic (80% MeOH), methanolic (MeOH) and chloroformic extracts (CHCl(3)). The oral administration (250, 500 and 1000 mg/kg) of all the extracts reduced the formation of lesions associated with HCl/ethanol administration in mice. The 80% MeOH extract significantly reduced the incidence of gastric lesions by 74, 78 and 92% at doses of 250, 500 and 1000 mg/kg, respectively (P<0.01). The MeOH extract reduced the ulceration by 93 and 99% only at the doses of 500 and 1000 mg/kg (P<0.01). The lower gastroprotective action (69%) was observed when animals were treated with CHCl(3) extract at the dose of 1000 mg/kg (P<0.01). Phytochemical investigation of Byrsonima crassa afforded five known substances: quercetin-3-O-beta-d-galactopyranoside, quercetin-3-O-alpha-l-arabinopyranoside, the biflavonoid amentoflavone, (+)-catechin and (-)-epicatechin. The presence of these phenolic compounds may probably explain the antiulcerogenic effect of the extracts of Byrsonima crassa leaves.

Hormonal influence on the response of the uterus of the Brazilian marsupial Didelphis albiventris to adrenergic drugs.

The influence of catecholamines on the estrogenized uterus of the Didelphis albiventris was studied in an in vitro preparation. It was observed that the D. albiventris uterus reacts to both alpha and beta-adrenergic agonists but not dopaminergic ones. Adrenaline is more potent in inducing a contractile response than is noradrenaline. Isoprenaline, when added to the bath, is able neither to induce a response nor to interfere with a contraction previously induced by acetylcholine. It is, however, able to block the contractile response brought about by electric field stimulation. In an in vitro preparation from animals previously treated with estrogen and progesterone, the sensitivity to both alpha- and beta-adrenergic drugs was greatly increased. This is demonstrated by a higher pD2 in progesteronized animals compared to that in estrogenized ones. The increased sensitivity to beta-agonists after progesterone treatment is illustrated by the fact that isoprenaline is effective in inducing a relaxation of the uterus, in these conditions. These results indicate that the Brazilian opossum should be included among those animals in which progesterone enhances uterine sensitivity to drugs.