In vivo assessment of the toxic potential of Dissotis rotundifolia whole plant extract in Sprague–Dawley rats

Flavonoid-Rich Extract of Dissotis rotundifolia Whole Plant Protects against Ethanol-Induced Gastric Mucosal Damage

Dissotis rotundifolia is a plant in the family Melastomataceae. The methanolic extract of the whole plant is reported to be rich in C-glycosylflavones such as vitexin and orientin. Though there are several reports on the ethnomedicinal use of this plant extract in stomach ulcers, experimental-based data is unavailable. The drive for carrying out this research was to obtain data on the possible ameliorative effect of the whole plant extract of Dissotis rotundifolia (DRE) in gastric ulcerations induced by ethanol in Sprague Dawley (SD) rats. SD rats were pretreated with 100, 300, and 500 mg/kg of DRE for 14 days after which an ulcerogen-ethanol was administered. Gross examinations of the stomach lining and histological analysis of gastric lesions were carried out coupled with an assessment of the antioxidant activity of gastric mucosa using MDA, GSH, CAT, and SOD as indicators. The data suggested a significant attenuation in gastric mucosal damage in DRE-pretreated ethanol-induced gastric ulcer reflected in the antioxidant status. There was also a reduction or absence of hemorrhage, edema, and leucocytes infiltration in DRE-treated groups compared to the negative control group. DRE conserved glutathione (GSH) levels, reduced malondialdehyde (MDA) levels, and enhanced catalase (CAT) and superoxide dismutase (SOD) enzyme levels. The present study shows that DRE possess protective effects against ethanol-induced ulcer damage in the stomach of rats, which could be attributed to its antioxidant activity.

Isolation of Helicobacter pylori from Gastric Biopsy of Dyspeptic Patients in Ghana and In Vitro Preliminary Assessment of the Effect of Dissotis rotundifolia Extract on Its Growth

Helicobacter pylori (H. pylori) is a gram-negative bacterium that colonizes the human stomach. Infection with this microaerophilic bacterium causes gastric and duodenal ulcer. This study sought to isolate H. pylori, from gastric biopsy samples of dyspeptic patients in Ghana using a 2,3,5-triphenyltetrazolium chloride (TTC) dye incorporated medium method. This TTC dye method was further used in an antimicrobial susceptibility assay involving Dissotis rotundifolia extract (DRE). H. pylori were successfully isolated from gastric biopsy of dyspeptic patients. Pure cultures of H. pylori in 2,3,5-triphenyltetrazolium chloride (TTC) dye incorporated medium were seen as sparkling colonies. Isolates, identified as H. pylori, were gram-negative and urease, catalase, and oxidase positive and showed characteristic morphology as spiral-shaped bacteria under the microscope. The organisms were found to be susceptible to cephalothin and resistant to nalidixic acid. Above all, the observation that H. pylori grew only at 37°C and not 25°C or 42°C affirms that the bacterium is neither Helicobacter cinaedi nor Helicobacter fenneliae. The anti-H. pylori study depicts a statistically lower zone of inhibition for DRE compared to standard drugs [amoxicillin and clarithromycin] (p<0.05), whereas metronidazole showed no zone of inhibition. This study reports the first successful isolation and culturing of H. pylori in Ghana using TTC dye. It also shows that DRE possess an in vitro anti-H. pylori activity and that DRE has some therapeutic potential against H. pylori infection.

Antidiarrheal Activity of Dissotis multiflora (Sm) Triana (Melastomataceae) Leaf Extract in Wistar Rats and Subacute Toxicity Evaluation

The present work was undertaken to evaluate antidiarrheal activity of ethanolic leaf extract of Dissotis multiflora (Sm) Triana (D. multiflora) on Shigella flexneri-induced diarrhea in Wistar rats and its subacute toxicity. Diarrhea was induced by oral administration of 1.2 × 10⁹ cells/mL S. flexneri to rats. Antidiarrheal activity was investigated in rats with the doses of 111.42 mg/kg, 222.84 mg/kg, and 445.68 mg/kg. The level of biochemical parameters was assessed and organs histology examined by 14 days' subacute toxicity. S. flexneri stool load decreased significantly in dose-dependent manner. The level of ALT increased (p < 0.05) in male rats treated with the dose of 445.68 mg/kg while creatinine level increased in rats treated with both doses. In female rats, a significant decrease (p < 0.05) of the level of AST and creatinine was noted in rats treated with the dose of 222.84 mg/kg of D. multiflora. Histological exams of kidney and liver of treated rats showed architectural modifications at the dose of 445.68 mg/kg. This finding suggests that D. multiflora leaf extract is efficient against diarrhea caused by S. flexneri but the treatment with doses lower than 222.84 mg/kg is recommended while further study is required to define the exact efficient nontoxic dose.