Effects of progesterone on FSH-stimulated indomethacin ulcers in rats

Use of Callistemon citrinus as a gastroprotective and anti-inflammatory agent on indomethacin-induced gastric ulcers in obese rats

Background

Obesity leads to an elevated risk of developing gastrointestinal disease such as gastric ulcers. Callistemon citrinus leaf extract has shown antioxidant, antimicrobial, hepatoprotective, and chemoprotective effects against colon cancer. The aim of this study is to evaluate the gastroprotective effect of C. citrinus leaf extract on indomethacin-induced gastric ulcers in obese rats.

Methods

Gastric ulcers were induced in female obese Wistar rats using a single oral dose of indomethacin (IND). In the first stage, the rats were fed with a high fat sugar diet (HFSD) for 15 weeks to induce obesity and, at the same time, the diet of the other group of animals included daily administration of ethanolic C. citrinus leaf extract (250 mg/kg) in addition to HFSD. In the second stage, gastric ulcers were induced with IND (30 mg/kg). The gastroprotective activity of C. citrinus, the inflammatory enzyme activities, and cytokines in the stomach were determined.

Results

C. citrinus produced a reduction of gastric lesions caused by IND. Myeloperoxidase (MPO), cyclooxygenase-2 (COX-2), and 5-lipoxygenase (5-LOX) activities also decreased. Although inflammatory biomarkers such as TNFα, IL-6, AOPP, and leptin were significantly decreased by C. citrinus, adiponectin levels increased. Moreover, C. citrinus decreased weight gain and morphological and biochemical parameters.

Conclusion

The use of indomethacin in rats fed with a high fat-sugar diet increased gastric ulcers. Gastroprotective effect of C. citrinus in obese rats is attributed to the reduction of pro-inflammatory cytokines and the inflammatory enzymes.

Impact of progesterone on the gastrointestinal tract: a comprehensive literature review

Women are more prone to gastrointestinal symptoms than men. A comprehensive literature search was performed to assess the impact of sex steroid hormone, especially progesterone, on the (healthy and diseased) gastrointestinal tract. Overall, 37 articles were identified. Based on these we conclude that progesterone has a dose-dependent and sex-dependent effect on gastric emptying (especially in mammals), slows down gastrointestinal motility, reduces the gallbladder's response to contractile stimulants, may support gastroesophageal reflux by reducing the esophageal sphincter pressure, may protect from Helicobacter pylori infection gastrointestinal sequelae (especially in mammals) and does not affect inflammatory bowel disease-specific symptoms. However, for several gastrointestinal symptoms and diseases no studies have yet been performed addressing the impact of sex hormone steroids.

Can the gastric healing effect of Eugenia punicifolia be the same in male and female rats?

ETHNOPHARMACOLOGICAL RELEVANCE

Eugenia punicifolia (Kunth) DC. (Myrtaceae), an Amazonian medicinal plant known as "pedra-ume-caá," is popularly used as a natural remedy for inflammation, wounds, infections, diabetes, fever, and flu. Its anti-inflammatory, antinociceptive, and gastroprotective effects have already been characterized. We evaluated the gastric healing effect of the hydroalcoholic extract of the leaves of E. punicifolia (HEEP) in male and female Wistar rats against nonsteroidal anti-inflammatory drugs (NSAIDs) and ethanol.

MATERIALS AND METHODS

The healing effect of HEEP on the gastric mucosa of adult male and female Wistar rats was measured after the chronic application of aggressive factors such as NSAIDs or 80% ethanol. Male, and intact and ovariectomized (OVZ) female rats were treated with HEEP for two days (NSAIDs) or one, two, four, and six days (80% ethanol). The stomachs were analyzed macroscopically for ulcerative lesions (mm²), and the healing process was measured using biochemical analysis with anti-inflammatory and antioxidant parameters.

RESULTS

Macroscopic evaluation of the gastric mucosa showed that gastric lesions induced by NSAIDs were significantly healed (66%) and pro-inflammatory interleukin 5 cytokine level was decreased after two-day oral treatment with HEEP compared with those in the negative control group (p < 0.05). However, the gastric lesions induced by NSAIDs did not heal in HEEP-treated female rats (p > 0.05). In addition, four-day treatment with HEEP significantly healed the gastric lesions induced by ethanol in male and female rats (63% and 78%, respectively) compared to those of the negative control group (p < 0.05). However, the OVZ group required six days of HEEP treatment to heal gastric ulcers (67% compared to the control group). HEEP exerts the healing effect against ethanol by significantly reducing neutrophil infiltration into the gastric mucosa by decreasing myeloperoxidase activity in male and OVZ rats after four and six days of treatment, respectively (p < 0.05). Four-day treatment with HEEP also increased the level of a non-enzymatic antioxidant, reduced glutathione in intact females compared to that of the negative control group (p < 0.05).

CONCLUSION

These findings indicated that HEEP was effective in promoting the healing of gastric ulcers induced by NSAIDs or ethanol. The gastric healing effects of this extract could be affected by female sex hormone interference; in future, comprehensive studies should be performed by considering sex differences.

Effect of acute and chronic administration of progesterone, estrogen, FSH and LH on oxidant and antioxidant parameters in rat gastric tissue

This study was conducted to investigate whether gastro-protective and gastro-toxic effects of acute and chronic administration of progesterone, estrogen, FSH and LH were related to oxidant and antioxidant parameters. Chronic administration of progesterone at a low dose (1mg/kg), which probably could not stimulate progesterone receptors (PRs), inhibited oxidative stress of FSH in gastric tissue by suppressing FSH. Progesterone (5mg/kg) may have been caused oxidative stress as reflected by PR stimulation. FSH may have decreased antioxidant parameters and increased oxidant parameters via PRs. Chronic administration of low dose of estrogen (1mg/kg) inhibited LH and but could not stimulate alpha-2 adrenergic receptors, which resulted in oxidative stress in gastric tissue. The higher dose of estrogen (5mg/kg), however, could stimulate alpha-2 receptors, exhibited antioxidant activity in acute and chronic administration. While antioxidant activity of estrogen and LH was blocked with yohimbine (an alpha-2 adrenergic receptor blocker), mifepristone prevented the oxidative stress of progesterone and FSH in gastric tissue. It is concluded that low doses of progesterone may inhibit FSH, whereas high doses of estrogen may stimulate alpha-2 receptors, suggesting that LH could have protective and antioxidant hormone effects.

Role of alpha-2 adrenergic receptors in anti-ulcer effect mechanism of estrogen and luteinising hormone on rats

OBJECTIVE

To evaluate anti-ulcer effect of estrogen and luteinising hormone (LH) on indomethacin-induced ulcer model in female rats.

STUDY DESIGN

Ovariectomy in healthy adult famale rats. Acute administration of estradiol to ovariectomised rats. Acute administration of LH to intact rats. Combined administration of tamoxifen with estradiol or LH to intact rats. Combined administration of yohimbin with estradiol or LH to intact rats. Combined administration of piperoxan with estradiol or LH to intact rats. Indomethacin administration to all rats.

RESULTS

Results have shown that LH exerted anti-ulcer activity at all doses we used but estradiol at 5 and 10 mg/kg. In rats administered yohimbine and piperoxan estradiol and LH could not prevent indomethacin-induced ulcers. In rats administered tamoxifen, estradiol and LH could prevent indomethacin-induced ulcers.

CONCLUSIONS

LH is a very potent endogen anti-ulcer factor, and the anti-ulcerative activities of estrogen and LH are mediated via alpha-2 adrenergic receptors, but not es receptors. The resistance of gastric mucosa to aggressive factors may decrease as a result of LH inhibition when estrogen is secreted chronically in the human body.