Gastroprotective role of a flavonoid-rich subfraction from Fridericia chica (Bonpl.) L. G. Lohmann: a medicinal plant used in the Amazon region.

Fridericia chica is an Amazonian plant used to treat stomach disorders. However, the pharmacological activity of flavonoids in the extract has yet to be investigated. Therefore, we considered that a flavonoid-rich F. chica subfraction (FRS) has gastroprotective functions. For this, before the induction of gastric ulcers with ethanol or piroxicam, the rats received vehicle (water), omeprazole (30 mg/kg), or FRS (30 mg/kg), and the ulcer area was measured macro and microscopically, and the antisecretory action was investigated in pylorus-ligated rats. In addition, the roles of nitric oxide (NO) and nonprotein sulfhydryl compounds (NP-SH) in the gastroprotective effects of FRS were studied. FRS reduced ethanol- and piroxicam-induced ulcerations by 81% and 77%, respectively, as confirmed histologically. Antioxidant effects were observed for FRS through the maintenance of GSH and LPO levels, and the SOD and CAT activity similar to those found in the nonulcerated group. Moreover, FRS avoided the increase in MPO activity and TNF, IL-6, IL-4 and IL-10 levels. Moreover, mucin staining increased in ulcerated rats receiving FRS, and the pharmacological mechanism gastroprotective seems to involve the NO and NP-SH in addition to antisecretory actions. The chemical study by mass spectrometry confirmed the presence of flavonoids in FRS, and molecular docking studies have shown that these compounds interact with cyclooxygenase-1 and NO synthase. Furthermore, there was no indication that FRS had cytotoxic effects. Our results support the popular use of F. chica, and we conclude that the gastroprotection effect promoted by FRS can be attributed to the combined effect of the flavonoids.

Toxicological effects of acute and repeated doses (180 days) of fruits from Malpighia emarginata (acerola) in rodents.

Malpighia emarginata has a high amount of vitamin C with pharmacological or food preservation potential. However, despite its wide use and application possibilities its toxicity in repeated doses and for a long time (6 months) has not yet been studied. In this context, this study aimed to evaluate the acute toxicity and repeated doses from fruits of this plant. The extract was produced with the pulp (EMe) of the lyophilized fruit and submitted to chromatographic and spectroscopic analysis (HPLC and ESI-IT-MSn). In the acute test, the EMe was administered orally and parenterally to rodents (mice and rats) for 14 days, at a dose of 2000 mg/kg. Subsequently, the repeated dose toxicity test was administered orally for 180 days at doses of 50, 300 or 1000 mg/kg. The HPLC assay revealed a high concentration of vitamin C (16.3%), and spectroscopic analyses pointed to the presence of five other polyphenolic compounds. In the acute test, the plant extract showed no apparent toxicity or lethality in rodents. The LD50 was estimated to be greater than 2000 mg/kg and falls into category 5 (low toxicity). In the repeated dose assay, there was no evidence of toxicity, and no differences were observed in water intake, food, weight development, or behavior of the animals in relation to the vehicle group (water). However, hematological and biochemical evaluations pointed out some nonconformities in the levels of cholesterol, leukocytes, and neutrophils of the male rats, but overall, these results did not reveal significant toxicity. Therefore, the Level of Unobserved Adverse Effects (NOAEL) was 1000 mg/kg. Together, the results suggest that the extract obtained from the fruits of M. emarginata does not present representative toxicity in rodents.

Sonchus oleraceus L. Promotes Gastroprotection in Rodents via Antioxidant, Anti-Inflammatory, and Antisecretory Activities.

Sonchus oleraceus L. is an edible and medicinal plant used to treat stomachache and gastric ailments around the world. Thus, this study aimed to determine the gastroprotective mode of action of hydroalcoholic extract of S. oleraceus (HES). Mice were treated with HES before induction of gastric ulceration by ethanol/HCl. The area and histological appearance of ulcers were quantified, and mucus was measured histochemically. The effects of HES on inflammatory and oxidative markers were assessed in the ulcerated tissue. In addition, we investigated the gastric acid antisecretory activity of HES in pylorus-ligated rats. Chemical analyses of HES and its antioxidant activity were also performed in vitro. The HES (30 or 300 mg/kg) reduced the ulceration by 71.5 and 76.2%, respectively, compared with vehicle (p < 0.001), and the histological analysis confirmed the macroscopic results with elevation in mucin levels by 361.4 and 477.5%, respectively, compared with vehicle (p < 0.001). Moreover, the gastroprotection was accompanied by increases in GSH levels and in SOD, CAT, and GST activities; in parallel to a reduction in MPO activity and TNF levels. Furthermore, HES reduced the total acidity, and pepsin activity of the gastric juice of rats by 61 and 63%, respectively, compared to the vehicle. Phytochemical analysis indicated that luteolin-7-O-ß-D-glucoside is the main active compound annotated in HES. Was also found that HES scavenged the DPPH radical with an IC50 of 15.41 µg/mL. In conclusion, the gastroprotective effects of HES involve reductions in oxidative stress and inflammatory injury, in conjunction with an increase in mucus layer and inhibition of gastric secretion. This study advances in elucidating the modes of the antiulcer potential of S. oleraceus and contributes to the prospection of new gastroprotective molecules.