Aibika Flower Flavonoid Extract Exhibits Antiulcer Activity in a Murine Model of Ethanol-Induced Acute Gastric Injury

Aibika (Abelmoschus manihot (L.) Medic) is a garden vegetable whose flower has been shown to have various bioactivities. This study investigated the protective effect of aibika flower flavonoid extract (AFF) on ethanol-induced gastric injury in mice. The experimental results showed that pre-feeding 125 and 250 mg AFF/kg BW for 1 week significantly reduced the gastric injury area in the negative control group from 19.2% to 6.7% and 0.6%, respectively. The results of the pathological sections staining also showed that AFF had a protective ability against alcohol-induced injury of gastric tissue and liver tissue. When the mice were exposed to high concentrations of ethanol, AFF pretreatment significantly upregulated the expression of antioxidant enzymes. The pretreatment also promoted the production of the intracellular antioxidant, reduced glutathione, in both gastric tissue and serum. On the contrary, AFF delayed the lipid peroxidation process, which, in turn, reduced the damage to the gastric mucosa. When acute inflammation was induced by ethanol stimulation, AFF significantly downregulated the proinflammatory cytokines and mediators such as TNF-α, IL-1β, IL-6, NF-κB, COX-2, and iNOS. Furthermore, AFF pretreatment greatly promoted the production of healing factors, such as matrix metalloproteinase (MMP)-2, MMP-7, and MMP-9, in the gastric tissue. In addition, AFF significantly reduced gastric cell apoptosis induced by ethanol stimulation. These results demonstrate that AFF has a good protective effect on alcohol-induced gastric ulcer and has the potential to be used in gastrointestinal health care.