Gastroprotective Activities of Ethanol Extract of Black Rice Bran (Oryza sativa L.) in Rats

Pharmacological studies of the genus rice (Oryza L.): a literature review

Rice (Oryza L.) is an essential food for more than 50 percent of the world's population and is the world's second-largest grain crop. Pigmented rice comes in various colors, such as black, red, brown, and green. Anthocyanins, like cyanidin-3-O-glucoside and peonidin-3-O-glucoside, are the primary color pigments in colored rice, whereas proanthocyanidins and flavan-3-ol oligosaccharides, with catechins as the central synthesis unit, are found in brown rice. This review article's aim is to give information and a summary of rice activities, research methods, also mechanisms of action (Oryza L.). Intake of pigmented rice was already associated with a number of health benefits, including antioxidant activity, anticancer, antitumor, antidiabetic activity, and a reduced risk of cardiovascular disease. Rice contains several bioactive compounds, such as γ-oryzanol, phenolic acid, anthocyanins, proanthocyanidins, flavonoids, carotenoids, and phytosterols, which have been widely studied and shown to have several pharmacological activities. The use of current herbal compounds is rapidly increasing, including the practice of pharmacological disease prevention and treatment. Herbal remedies have entered the international market as a result of research into plant biopharmaceuticals and nutraceuticals. Through a variety of pharmacological activities, it is clear that Oryza L. is a popular herb. As a result, additional research on Oryza L. can be conducted to investigate more recent and comprehensive pharmacological effectiveness, to provide information and an overview of Rice (Oryza L.) activities, research methods, and mechanisms of action. Several natural substances are characterized by low water solubility, low stability, and sensitivity to light and oxygen, and the potential for poor absorption of the active substances requires modification of the formulation. To improve the effectiveness of pharmacologically active substances originating from natural ingredients, drug delivery systems that use lipid-based formulations can be considered innovations.

Gastroprotective effects of Pikad Tri-phol-sa-mut-than herbal remedy on multiple gastric ulcer models in rats

In Thai traditional medicine, Pikad Tri-phol-sa-mut-than has long been used to alleviate gastrointestinal symptoms, renal disease, inflammation-related disorders, and severe malady. This recipe is composed of dried fruits of Morinda citrifolia L., Coriandrum sativum L., and Aegle marmelos (L.) Corrêa. The aim of this study was to assess the anti-gastric ulcer property of the water extract of Pikad Tri-phol-sa-mut-than (TS), using various animal models with different inducers, including restraint water immersion stress, indomethacin, and ethanol/hydrochloric acid (EtOH/HCl). Its mechanisms of anti-gastric ulcer actions were also elucidated using both in vitro and in vivo experiments. When compared with the control groups, the oral pretreatment of TS at the doses of 150, 300 and 600 mg/kg significantly reduced the gastric ulcer formation in all models. It was also found that TS at the dose of 600 mg/kg could increase gastric wall mucus in rats but could not produce the significant reduction of the gastric volume or total acidity of gastric content. Results from hematoxylin and eosin (H&E) and Periodic acid-Schiff (PAS) staining examinations of gastric tissues confirmed that TS visibly reduced gastric mucosal damage, while immunohistochemistry revealed that TS remarkably suppressed the protein expression of Bcl-2-associated X (BAX), a regulator of apoptosis, compared to those of the control group. The DPPH, ABTS, and FRAP assays showed antioxidant effects of TS. All of these findings demonstrated that TS has gastroprotective effects, which may be related to the increase in the gastric wall mucus secretion, not anti-secretory activity, as well as its antioxidant and antiapoptotic activities.

Gastroprotective effect of hydroalcoholic extract from Agaricus blazei Murill against ethanol-induced gastric ulcer in mice

ETHNOPHARMACOLOGICAL RELEVANCE

The use of mushrooms in medicine is quite old and the first report about the use of genus Agaricus in treatment of ulcers occurred in Byzantine period. This mushroom is widely consumed as food, tea, food supplements, as well as nutraceutical and cosmeceutical applications, being cultivated and appreciated in several countries such as Brazil, Korea, Japan and China.

AIM OF THE STUDY

This study aimed to characterize the chemical profile and the potential gastroprotective effect of hydroalcoholic extract from Agaricus blazei Murill (HEAb).

MATERIALS AND METHODS

The extract was chemically characterized by elemental analysis, UPLC-QTOF-MS^E, Nuclear Magnetic Resonance (NMR) and high-performance liquid chromatography (HPLC) techniques to elucidate the metabolites present in the extract. The quantification of phenolic compounds and the in vitro antioxidant activities were performed and the gastroprotective effect of this extract was evaluated against ethanol-induced gastric ulcer model. HEAb was administered by gavage at 5, 25 and 50 mg kg^-1 and N-acetylcysteine at 300 mg kg^-1 (positive control). Furthermore, the pathways of nitric oxide (NO), Cyclic Guanylate Monophosphate (cGMP), prostaglandins (PGs) and the involvement of ATP-sensitive K⁺ Channels were modulated.

RESULTS

Mannitol, malic acid, pyroglutamic acid, L-agaritine and L-valine were putatively identified by UPLC-QTOF-MS^E in HEAb. In addition, it was possible to identify mannitol by the intense signals in the NMR spectra, being still quantified as the main compound in the extract by HPLC. The contents of total phenols and flavonoids corroborated with the good antioxidant activity of HEAb. This study observed that HEAb at 25 and 50 mg kg^-1 had gastroprotection effect demonstrated by the reduction of histopathological parameters and the reduction of mastocytosis in the stomach of mice.

CONCLUSIONS

In this study was possible to conclude that HEAb has gastroprotective effect related to the involvement of NO and PG pathways in the ethanol-induced gastric ulcer model in mice.