In silico and in vivo protective effect of Morus nigra leaves on oxidative damage induced by iron overload.

Morus nigra L. is a plant popularly known as 'amoreira preta', very used in folk medicine. Iron overload (hemochromatosis) is a clinical condition that causes damage to various tissues due to oxidative stress. Therapy to control iron overload is still unsatisfactory. The protective effect on oxidative stress induced by iron overload was verified. Phytochemical characterization was evaluated by UHPLC-MS/MS. The in silico toxicity predictions of the main phytochemicals were performed via computer simulation. To induce iron overload, the animals received iron dextran (50 mg/kg/day). The test groups received doses of 500 and 1000 mg/kg of M. nigra extract for six weeks. Body weight, organosomatic index, serum iron, hepatic markers, cytokines, interfering factors in iron metabolism, enzymatic and histopathological evaluations were analyzed. Vanillic acid, caffeic acid, 6-hydroxycoumarin, p-coumaric acid, ferulic acid, rutin, quercitrin, resveratrol, apigenin and kaempferol were identified in the extract. In addition, in silico toxic predictions showed that the main compounds presented a low probability of toxic risk. The extract of M. nigra showed to control the mediators of inflammation and to reduce iron overload in several tissues. Our findings illustrate a novel therapeutic action of M. nigra leaves on hemochromatosis caused by iron overload.

Antidiabetic effects of Olea europaea L. leaves in diabetic rats induced by high-fat diet and low-dose streptozotocin.

ETHNOPHARMACOLOGICAL RELEVANCE: Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycemia, insulin resistance, and dyslipidemia. It has broad occurrence worldwide, affecting millions of people, and can cause serious complications. The olive (Olea europaea L.) has important pharmacological functions, including anti-inflammatory, antioxidant, and hypoglycemic activities. Olive leaves are used in traditional medicine for diabetes and hypertension. AIM OF THE STUDY: To evaluate the effect of the ethanolic extract of olive leaves (EEOL) on the metabolism of rats with diabetes induced by a high-fat diet and low dose of streptozotocin (STZ). MATERIALS AND METHODS: Male Wistar rats were either given normal feed or a high-fat diet (70% standard laboratory feed, 15% sucrose, 10% lard and 5% yolk powder) for four weeks, followed by administration of STZ (35 mg/kg, via ip). Animals with fasting glucose levels above 200 mg/dL were considered diabetic. Animals were divided into 5 groups, which received ethanol (10 mL/kg), metformin (250 mg/kg), or EEOL at doses of 200 and 400 mg/kg during 10 weeks by oral gavage. Blood samples were used to measure hematological and biochemical parameters, and kidneys were removed for posterior analysis. Body weight was recorded weekly. RESULTS: A significant decrease in body weight was observed among diabetic animals treated with ethanol and EEOL compared to the control group. Moreover, animals treated with EEOL showed an improvement in glucose levels and in levels of inflammatory and metabolic markers when compared to diabetic animals. CONCLUSIONS: The results indicate a potential anti-diabetic activity of olive leaves, however more studies are needed to validate clinical effects.

Acute toxicity and antimicrobial activity of leaf tincture Baccharis trimera (Less).

BACKGROUND: The present study aimed to evaluate the possible acute oral toxicity of Baccharistrimera leaf dye as well as its antimicrobial activity. METHOD: Organization for Economic co-operation and development (OECD) 423 was used to assess acute oral toxicity and as per protocol a dose of 2000 mg/kg of tincture was administered to Wistar rats, male and female, and observed for 14 days. Biochemical and hematological analyzes were performed with sample collected of rat. The dye was evaluated for antimicrobial activity by agar diffusion and microdilution methods, which allow to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) and antibiofilm potential. RESULTS: The results showed that there was no loss of animals and no significant changes in hematological and biochemical parameters after oral administration of 2000 mg/kg of tincture and was considered safe by the OECD, classified as category 5. The dyeing also showed an important antimicrobial activity against gram positive and gram negative bacteria also significantly decreased the microbial biofilm. CONCLUSION: The tincture of B.trimera leaf when given orally once can be considered safe and has a relevant antimicrobial potential that should be elucidated in subsequent research.

Safety assessment of Morus nigra L. leaves: Acute and subacute oral toxicity studies in Wistar rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Morus nigra L. is a plant native to Asia, and well adapted to the Brazilian climate. It is popularly known as "amoreira preta", and is part of the National List of Plants of Interest to the Brazilian Unified Health System. It is used in folk medicine mainly to soften the effects of menopause, as anti-inflammatory, antidiabetic and antihypertensive. However, information on safe doses and use is still precarious. AIM OF THE STUDY: To identify the chemical composition of the ethanolic extract of Morus nigra L. leaves (EEMN), as well as perform a toxicological study in male and female rats. MATERIALS AND METHODS: The chemical composition of the extract was performed by HPLC/DAD. In the acute study, the dose administered was 2000 mg/kg, and signs of toxicity and mortality was observed. In the sub-acute study, the extract was administered at doses of 500, 750 and 1000 mg/kg for 28 days. Behavioral changes, object recognition test, renal and hepatic tissue assessments, biochemical and hematological parameters were determined. The extract was administered orally to male and female rats in both studies. RESULTS: Quercetin and caffeic acid showed as major compounds in the extract. In the acute treatment, the extract was classified as safe (category 5), according to the protocol. In the subacute study, there was a decrease in AST in males (750 and 1000 mg/kg) and females (1000 mg/kg), reduction of total cholesterol in females (750 and 1000 mg/kg), and increase in renal and hepatic change the LPO levels. CONCLUSION: The present investigation showed that EEMN did not present significant toxic effects when administered orally. Moreover, presented a potentially protective action of organs and possesses hypocholesterolemic activity, thus, it is shown as a promising natural source to be used in pharmacology.

Safety assessment of ethanolic extract of Olea europaea L. leaves after acute and subacute administration to Wistar rats.

Olea europaea L., popularly known as olive, is a plant widely used worldwide. Its leaves, fruit and oil are extensively consumed and present important pharmacological properties. However, studies regarding the toxicity of olive leaves are still limited in the literature. Therefore, the aim of the study was to investigate acute and subacute oral toxicities of the ethanolic extract of olive leaves (EEO) in Wistar rats through histopathology and biochemical and hematological parameters. Acute toxicity was assessed using a single dose of 2000 mg/kg of EEO administered by oral gavage to male and female rats. To assess subacute toxicity, EEO was administered during 28 days at different doses (100, 200 and 400 mg/kg) to male and female rats. At the end of the experiments, the liver and kidney were removed and examined microscopically, and blood was collected for hematological and biochemical parameters. A single dose of 2000 mg/kg did not induce mortality or any signs of toxicity among the animals treated. Animals exposed to EEO during 28 days did not present sign of abnormalities. Results demonstrated that EEO did not induce toxicity after exposure to single and repeated doses. However, more studies are needed to fully understand implications for human safety.