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.

Defensive potential and deleterious impact of turmeric (Curcuma longa) L rhizome powder supplemented diet on antioxidant status of indomethacin-induced ulcerated wistar rats

Effects of various concentration of turmeric (Curcuma longa [C longa]) rhizome powder (TRP) supplemented diet on the antioxidant status of selected organs (stomach, liver, kidney, and heart) of indomethacin (Indo)-induced ulcerated wistar rats were investigated in this study. The rats were fed with different percentages of TRP supplemented diet (1% [A], 2% [B], 5% [C], and 10% [D]) for 28 days. It was observed from the results that animals fed on 10% turmeric rhizome supplemented and those in the ulcerogenic group had significant reduction in kidney, cardiac gluthione (GSH), superoxide dismutase (SOD), catalase (CAT), and gastric GSH when compared with normal control animals and other pre-treated groups. However, a significant increase was observed in gastric, hepatic, cardiac, and glutathione peroxidase (GPX); kidney and hepatic SOD; cardiac, kidney, hepatic, and gastric CAT of animals pre- treated with TRP supplemented diet (1%-5%) compared with ulcerogenic group. Also, a significant reduction was observed in GPX of animals fed with 10% TRP supplemented diet in comparison with ulcerogenic group. Consumption of TRP in the diet, therefore, should be lesser than 10% of the whole recipe for it to be potent in enhancing antioxidant defensive mechanism of the aforementioned organs and thereby prevent oxidative stress related diseases. It may reduce antioxidant present in those organs which can lead to increase availability of free radical and expose the organs to oxidative stress-related diseases. PRACTICAL APPLICATIONS: Inclusion of turmeric rhizome powder in daily diet has been globally well accepted due to the knowledge of its medicinal values. Nonetheless, the extent at which it should be consumed has been controversial and unclear. Little or no effort has been put in place to educate the populace on the quantity of concentration of C. longa powder which should be in whole recipe or ingredients. Therefore, if turmeric rhizome powder should be included in diet because of its nutritional and medicinal values, this should be with caution and from the results of this study, the concentration should not be up to 100g/kg w/w of the entire recipe.

Anti-ulcerogenic effect of methanolic extract of Elaeagnus conferta Roxb. seeds in Wistar rats

ETHNOPHARMACOLOGICAL RELEVANCE

Elaeagnus conferta Roxb. (Elaeagnaceae) is a subtropical shrub mainly native to India, Vietnam, Malaysia and South China, whose various parts are used for treatment of diabetes, gastric ulcers, pain, oxidative stress and pulmonary disorders. Though the other parts of the plant have been reported for their ethnic use i.e. fruits as astringent locally and for cancer systemically, leaves for body pain and flowers for pain in chest and the seeds are mentioned as edible, there is no report per se on the medicinal use of seeds. Based on the fact that seeds of closely resembling species i.e. Elaeagnus rhamnoides has demonstrated significant anti-gastroulcerative property, the probability of the seeds of E. conferta possessing similar activity seemed quite significant.

AIM OF THE STUDY

Phytochemical investigation and assessment of pharmacological mechanism(s) involved in anti-ulcer effect of methanolic extract of the seeds of E. conferta.

MATERIALS AND METHODS

Bioactive phytoconstituents were isolated by column chromatography. These were identified by spectroscopic techniques including infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) and mass spectrometry. Methanolic extract (MEC) of the seeds was prepared by cold maceration and its anti-ulcerogenic potential was evaluated using indomethacin (50 mg/kg) and water immersion stress models in male rats. The animals were pre-treated with different doses of MEC (400 and 800 mg/kg) and the therapeutic effect was compared with standard drug i.e. ranitidine (RANT; 50 mg/kg). The ameliorative effects of MEC were investigated on gastric juice pH, total acidity, free acidity and ulcer index. The assays of malionaldehyde (MDA), catalase (CAT), superoxide dismutase (SOD), glutathione (GSH) and pro-inflammatory cytokines i.e. interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were carried out to find out the possible mechanism(s) of protection. Further, histopathological changes were also studied.

RESULTS

Chromatography studies and further confirmation by spectroscopic techniques revealed the presence of four different compounds in MEC i.e oleic acid (1), stearic acid (2), ascorbic acid (3) and quercetin (4). MEC exhibited anti-ulcerogenic effect in dose dependent manner which may be attributed to suppression of pro-inflammatory cytokines (IL-6, TNF-α) and MDA (112.7%), and up-regulation of protective factors such as CAT (90.48%), SOD (92.77%) and GSH (90.01%). Ulcer inhibition, reduction in total and free acidity and increase in gastric juice pH were observed in MEC treated rats as compared to disease control animals. Histopathological findings confirmed decreased cell infiltration, less epithelial cell damage and regeneration of gastric mucosa in dose dependent manner.

CONCLUSIONS

The anti-ulcer effect of MEC may be attributed to its ability to scavenge free radicals and anti-inflammatory property via suppression of TNF-α and IL-6, thus offers a complete and holistic approach for management of peptic ulcer.