Potential Active Constituents from Opophytum forsskalii (Hochst. ex Boiss.) N.E.Br against Experimental Gastric Lesions in Rats

Abstract

Opophytum forsskalii (O. forsskalii) is a desert plant that belongs to the Aizoaceae family. Although it is a natural food source for Bedouin tribes in northern Saudi Arabia, there is little information on its active metabolites. Therefore, the secondary metabolites of the hydroalcoholic extract from the leaves of this species were analyzed by liquid chromatography-mass chromatography (LC-MS). LC-MS identified a total of 30 secondary metabolites. These compounds represented two main categories among sixteen classes. Among them, flavonoids represented the largest proportion with eleven metabolites while fatty acids provided seven compounds. In addition, the extract was evaluated for its gastroprotective effect against gastric lesions induced by different models, such as indomethacin, stress, and necrotizing agents (80% ethanol, 0.2 mol/L NaOH, and 25% NaCl), in rats. For each method, group 1 was used as the control group while groups 2 and 3 received the leaf extract at doses of 200 and 400 mg/kg, respectively. The ulcer index (UI) and intraluminal bleeding score (IBS) were measured for each method. In addition, gastric tissue from the ethanol method was used for the analysis of nonprotein sulfhydrates (NP-SH), malondialdehyde (MDA), total protein (TP), and histopathologic evaluation. Pretreatment with O. forsskalii significantly decreased UI (p < 0.01) and IBS (p < 0.01) at 400 mg/kg. Pretreatment with O. forsskalii significantly improved total protein levels (p < 0.01) and NP-SH (p < 0.001) compared to the ethanol ulcer groups. MDA levels increased from 0.5 to 5.8 nmol/g in the normal groups compared to the ethanol groups and decreased to 2.34 nmol/g in the O. forsskalii pretreatment. In addition to the gastroprotective markers, histopathological examination of gastric tissue confirmed the gastroprotective potential of O. forsskalii extract against ethanol.

Keywords: Opophytum forsskalii; Saudi Arabia; gastro-protective; indomethacin; necrotizing agents; stress.

Figure 1

Chemical structure (drawn using PubChem Sketcher V2.4) of flavonoids and their glycosides.

Figure 1

Chemical structure (drawn using PubChem Sketcher V2.4) of flavonoids and their glycosides.

Figure 2

Effect of O. forsskalii extracts on the MDA concentration in gastric ulcer induced by 80% ethanol. Six rats were used in each group. p values (*** p < 0.001). Where, a: 80% ethanol treated group was statistically compared to the normal group; b: O. forsskalii treated groups were compared to the ethanol-treated group.

Figure 3

Effect of O. forsskalii extracts on the NP-SH concentration in gastric ulcer induced by 80% ethanol. Six rats were used in each group. p values (** p < 0.01, *** p < 0.001). Where, a: 80% ethanol treated group was statistically compared to the normal group; b: O. forsskalii treated groups were compared to the ethanol-treated group.

Figure 4

Effect of O. forsskalii extracts on the total phenol concentration in gastric ulcer induced by 80% ethanol. Six rats were used in each group. p values (* p < 0.05, *** p < 0.001). Where, a: 80% ethanol treated group was statistically compared to the normal group; b: O. forsskalii treated groups were compared to the ethanol-treated group.

Figure 5

(A–C), Hematoxylin and eosin (H&E, magnification is ×400, scale bar is 20 µ) stain, where (A) is the standard stomach sample that displays a typical appearance of stomach tissue; (B) is an 80% ethanol stomach sample showing the toxic effects, which are indicated by loss of the ability for secretion and presence of vacuolation in the cytoplasm, necrosis, degeneration, dysplastic cells, basement membrane and atrophic mucosa detachment, and reduction in gland size or even absence of gland structure; (C) is 400 mg/kg O. forsskalii extract and 80% ethanol stomach sample showing considerable improvement and restoration of the secreting stomach microanatomical architecture. However, some glands suffer from the remaining effects of degeneration and atrophy of the stomach’s mucosa. (D–F) Periodic acid Schiff (PAS, magnification is ×400, scale bar is 20 µ) stain, where (D) is a normal stomach sample showing the high activity of mucosa in production. The presence of PAS-positive materials that exhibit a dark magenta color, especially towards the lumen, which is in the left half of this photomicrograph and basement membranes are intact for each gland; (E) is the 80% ethanol stomach sample showing a severe reduction and the absence of the mucosal activity of production of PAS-positive materials. Basement membranes also exhibit damage and weakness in multiple areas; (F) is 400 mg/kg O. forsskalii extract, and the 80% ethanol stomach sample exhibits considerable improvement in the inability of stomach gland cells to secrete PAS-positive materials, and the basement membrane also improved. (G–I) Mason trichrome (magnification is ×400, scale bar is 20 µ) stain, where (G) is a normal stomach sample showing a normal distribution of connective tissue; (H) is the 80% ethanol stomach sample: this group shows massive fibrosis due to the accumulation of collagen fibers in the submucosa and infiltration of collagen fibers into mucosa; (I) is 400 mg/kg O. forsskalii extract and 80% ethanol stomach sample, exhibiting considerable improvement and the presence of a few areas of collagen fiber infiltrates into the mucosa.

Figure 6

Gradient elution profile used for the LC-MS separation, decreasing order of mobile phase (water and 0.1% formic acid), increasing order of mobile phase (methanol and 0.1% formic acid).