Review of Ethnobotanical and Ethnopharmacological Evidence of Some Ethiopian Medicinal Plants Traditionally Used for Peptic Ulcer Disease Treatment

Aqueous extract of the bark of Uncaria tomentosa, an amazonian medicinal plant, promotes gastroprotection and accelerates gastric healing in rats

ETHNOPHARMACOLOGICAL IMPORTANCE

Uncaria tomentosa Willd. DC., is used in the Amazonian region of South America, wherein ethnic groups use the plant to treat diseases, including gastric disorders. However, despite its widespread popular use, this species has yet to be assessed for its anti-ulcer effects.

AIM OF THE STUDY

In this study, we aimed to evaluate the in vivo gastroprotective and gastric healing activities of an aqueous extract of the bark of Uncaria tomentosa (AEUt) and sought to gain an understanding of the pharmacological mechanisms underlying these biological effects.

MATERIALS AND METHODS

To verify the gastroprotective properties rats were treated with AEUt (30, 60, or 120 mg/kg) prior to inducing gastric ulceration with ethanol or piroxicam. Additionally, the involvement of nitric oxide, non-protein sulfhydryl compounds (NP-SH), α-2 adrenergic receptors, and prostaglandins was investigated. Furthermore, a pylorus ligature model was employed to investigate the antisecretory activity of AEUt. The gastric healing effects of AEUt (60 mg/kg) were examined in rats in which ulceration had been induced with 80% acetic acid, whereas the quality of healing was evaluated in mice with interleukin-induced recurrent ulcers. We also evaluated the in vivo thickness of the gastric wall using ultrasonography. Moreover, the levels of reduced glutathione (GSH) and malondialdehyde (MDA) were evaluated in ulcerated mucosa, and we determined the activities of the enzymes myeloperoxidase (MPO), N-acetyl-β-D-glycosaminidase, superoxide dismutase, catalase, and glutathione S-transferase. In addition, we assessed the effects of AEUt on cell viability and subjected the AEUt to phytochemical analyses.

RESULTS

Administration of the AEUt (60 or 120 mg/kg) prevented ethanol- and piroxicam-induced ulceration, which was also confirmed histologically. Moreover, we observed that pre-treatment with NEM and indomethacin abolished the gastroprotective effects of AEUt, thereby indicating the involvement of NP-SH and prostaglandins in these protective effects. In addition, we found that the administration of AEUt had no appreciable effects on the volume, acidity, or peptic activity of gastric juice. Furthermore, the AEUt (60 mg/kg) accelerated the gastric healing of acetic acid-induced ulcers by 46.2% and ultrasonographic findings revealed a reduction in the gastric wall thickness in this group. The gastric healing effect of AEUt was also accompanied by a reduction in MPO activity. The AEUt (60 mg/kg) also minimized ulcer recurrence in mice exposed to IL-1β and was associated with the maintenance of GSH levels and a reduction in MDA contents. We deduce that the biological effects of AEUt could be associated with the activities of polyphenols and the alkaloids isomitraphylline and mitraphylline, identified as predominant constituents of the AEUt. Furthermore, we found no evidence to indicate that AEUt would have any cytotoxic effects.

CONCLUSION

Collectively, our findings provide compelling evidence indicating the therapeutic efficacy of U. tomentosa. Our data indicate that compounds in AEUt confer gastroprotection and that this preventive effect of AEUt was accompanied by gastric healing and a reduction in gastric ulcer recurrence. Moreover, we provide evidence to indicate that the gastroprotective and gastric healing effects involve the antioxidant system and anti-inflammatory responses that contribute to preserving the gastric mucosa.

Gastroprotective Activities of Aqueous and 80% Methanol Leaf Extracts of Stephania abyssinica (Quart.-Dill. and A. Rich.) Walp. (Menispermaceae) in Rats

Background

An ethnobotanical study showed that the leaf of Stephania abyssinica (S. abyssinica) is used for the treatment of gastritis, but there is no scientific investigation.

Objective

The aim of this study was to evaluate the gastroprotective activities of both aqueous and 80% methanol leaf extracts of S. abyssinica in experimental rats.

Methods

Decoction and maceration techniques were used to prepare aqueous and 80% methanol leaf extracts, respectively. The extracts were evaluated against pyloric ligation, indomethacin, and ethanol-induced gastric ulcer models at doses of 100, 200, and 400 mg/kg. Negative control received 2% tween 80, while positive controls received 20 mg/kg of omeprazole and 100 µg/kg of misoprostol. Parameters, such as ulcer index, gastric mucin content, gastric juice volume, pH, and free and total acidity were measured.

Results

In the pyloric ligation induced gastric ulcer model, all doses of both extracts significantly reduced the ulcer index and gastric juice volume, while doses of 200 and 400 mg/kg exhibited a significant increment in mucus content and gastric juice pH as well as decrease in free and total acidity as compared to negative control. In indomethacin and ethanol induced gastric ulcer models, pretreatment with both extracts significantly reduced the ulcer index and enhanced gastric mucin content in a dose-dependent manner. Phytochemical screening of both extracts showed the existence of flavonoids, phenols, tannins, saponins, alkaloids, and coumarins with high contents of phenols, flavonoids, and alkaloids in 80% methanol extract.

Conclusion

This study revealed that aqueous and 80% methanol leaf extracts of S. abyssinica possessed remarkable gastroprotective activities against experimentally induced gastric ulcer models, and this possibly justify the traditional use of S. abyssinica leaves to treat gastritis.

A Review of the Popular Uses, Anatomical, Chemical, and Biological Aspects of Kalanchoe (Crassulaceae): A Genus of Plants Known as "Miracle Leaf"

Species of the genus Kalanchoe have a long history of therapeutic use in ethnomedicine linked to their remarkable healing properties. Several species have chemical and anatomical similarities, often leading to confusion when they are used in folk medicine. This review aims to provide an overview and discussion of the reported traditional uses, botanical aspects, chemical constituents, and pharmacological potential of the Kalanchoe species. Published scientific materials were collected from the PubMed and SciFinder databases without restriction regarding the year of publication through April 2023. Ethnopharmacological knowledge suggests that these species have been used to treat infections, inflammation, injuries, and other disorders. Typically, all parts of the plant are used for medicinal purposes either as crude extract or juice. Botanical evaluation can clarify species differentiation and can enable correct identification and validation of the scientific data. Flavonoids are the most common classes of secondary metabolites identified from Kalanchoe species and can be correlated with some biological studies (antioxidant, anti-inflammatory, and antimicrobial potential). This review summarizes several topics related to the Kalanchoe genus, supporting future studies regarding other unexplored research areas. The need to conduct further studies to confirm the popular uses and biological activities of bioactive compounds is also highlighted.

Closed-Loop Gastric Outlet Obstruction Secondary to Duodenal Ulcer in a Patient With Esophageal Stricture

Closed-loop gastric outlet obstruction (GOO) is a rare complication that results from a mechanical obstruction in the pylorus or duodenum. In the early 1990s, the common cause of GOO was peptic ulcer disease, accounting for 5% to 10% of hospital admissions. Peptic ulcer disease is the disruption of the mucosal integrity in the stomach and duodenum and can be categorized into gastric ulcers and duodenal ulcers. With the treatment for Helicobacter  pylori and the increased use of proton pump inhibitors (PPI), GOO now occurs in fewer than 5% of patients with duodenal ulcer disease and even less in those with gastric ulcer disease. Although the morbidity of duodenal ulcers has been declining in recent years, the incidence of post-bulbar duodenal ulcer (PBDU) remains at a constant 9.33%, primarily due to diagnostic and therapeutic difficulties. Additionally, fewer than 5% of obstructing duodenal ulcers are caused by PBDU, and even fewer are located in the second or third portions of the duodenum. Ulcers located in the distal part of the duodenum raise concern for syndromes associated with hypersecretion of acid, including Zollinger-Ellison syndrome (ZES). The ZES is rare, accounting only for 0.1% of all duodenal ulcers. Here, we present a case where a patient with esophageal stricture developed a rare case of closed-loop GOO secondary to a duodenal ulcer. The patient, initially treated for esophageal perforation, developed an esophageal stricture. The patient was being worked up for ZES and multiple endocrine neoplasia link type 1 (MEN1) syndrome due to his concerning laboratory findings and rare clinical presentation.