A role for flavonoids in the prevention and/or treatment of cognitive dysfunction, learning, and memory deficits: a review of preclinical and clinical studies.

OBJECTIVE: Natural food substances, due to high rates of antioxidants, antiviral and anti-inflammatory properties, have been proposed to have the potential for the prevention or treatment of cognitive deficits, learning and memory deficits and neuro inflammation. In particular, medicinal plants with rich amounts of beneficial components such as flavonoids are one of the most promising therapeutic candidates for the cognitive deficit and memory loss. Herein, we aimed to review the impact of medicinal plants with focus on flavonoids on cognitive dysfunction, learning and memory loss by considering their signaling pathways. METHODS: We extracted 93 preclinical and clinical studies related to the effects of flavonoids on learning and memory and cognition from published papers between 2000 and 2021 in the MEDLINE/PubMed, Cochrane Library, SCOPUS, and Airiti Library databases. RESULTS: In the preclinical studies, at least there seem to be two main neurological and biological processes in which flavonoids contribute to the improvement and/or prevention of learning, memory deficit and cognitive dysfunction: (1) Regulation of neurotransmission system and (2) Enhancement of neurogenesis, synaptic plasticity and neuronal survival. CONCLUSION: Although useful effects of flavonoids on learning and memory in preclinical investigations have been approved, more clinical trials are required to find out whether flavonoids and/or other ingredients of plants have the potent to prevent or treat neurodegenerative disorders.

Evaluation of anti-inflammatory effects of leaf and seed extracts of Plantago major on acetic acid-induced ulcerative colitis in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Plantago major (P. major) has traditionally been used in Iranian Persian medicine to treat gastrointestinal ulcers and bleeding. RESEARCH OBJECTIVES: This study aimed to investigate the anti-inflammatory effects of the leaf and seed extracts of P. major in rats with acetic acid-induced ulcerative colitis (UC). MATERIALS AND METHODS: To this end, 49 rats were randomly divided into seven groups. UC was induced in all groups but the control (vehicle) group using a single intra-rectal administration of 2 ml of 4% acetic acid. Other groups received daily intraperitoneal (i.p.) injections of the seed extract of P. major (400 mg/kg and 700 mg/kg), the leaf extract of P. major (400 mg/kg and 700 mg/kg), and sulfasalazine (400 mg/kg) for seven consecutive days, respectively. The rats' rectum was surgically removed and evaluated for macroscopic and microscopic damage. The tissue levels of oxidative stress and inflammatory markers were measured using the ELISA method. RESULTS: The high-dose leaf extract significantly decreased ulcer index and histopathologic damage as well as the tissue levels of IL-6, TNF-α, PGE2, IL-1ß, MPO, and MDA compared to the damage group. The low-dose leaf extract also significantly reduced the levels of some markers. The seed extract in the two used doses caused a modest decrease in the histopathological damages and ulcer index. CONCLUSIONS: P. major leaf extract effectively reduces inflammation and mucosal damage in rats with UC, especially when administered in high doses. P. major seed extract has minimal protective effects on UC.

Antioxidant Activity and Phenolic and Flavonoid Contents of the Extract and Subfractions of Euphorbia splendida Mobayen.

INTRODUCTION: The harmful action of the free radicals which cause the oxidative stress can be blocked by antioxidant substances, and different plant extracts showed antioxidant activity. The aim of this study is was evaluation the antioxidant activity of total methanol extract (ME) and subfractions of Euphorbia splendida Mobayen. MATERIALS AND METHODS: Aerial part of E. splendida was extracted by maceration with methanol and then subfractionated by liquid-liquid fractionation using petroleum ether, chloroform, ethyl acetate, and water. Antioxidant activity was assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity assay, reduction of ferric ions and ferrous ion chelating potential. Total phenolic contents (TPC) and total flavonoid contents (TFC) were estimated with Folin-Ciocaltue and aluminum chloride methods, respectively. RESULTS: The findings revealed that E. splendida ME and subfractions showed a dose-dependent antioxidant activity. ME showed the highest antioxidant activity based on total reduction capability and ferrous ions chelating assay tests. Aqueous fraction and then ethyl acetate fraction showed the best IC50in DPPH radical scavenging test in comparison to butylated hydroxytoluene. ME showed the highest value of TPC and TFC (270.74 ± 0.005 mg/g and 208.23 ± 0.007 mg/g, respectively). CONCLUSION: This study showed that the extract and subfractions of E. splendida have antioxidant activity. The antioxidant activity of the extract and fractions might be attributed to the presence of phenolic compounds. More studies are needed to determine the active antioxidant compounds of this plant. SUMMARY: Total extract and subfractions of Euphorbia splendida showed antioxidant activity. Abbreviations Used: TPC: Total phenolic content, TFC: Total flavonoid content, DPPH: 2, 2'- diphenyl-1-picrylhydrazyl, BHT: Butylated hydroxytoluene, EDTA: Ethylene Diamine Tetra Acetic acid, ME: Total methanol extract, EAF: Ethyl acetate fraction, AQF: Aqueous fraction, PEF: Pertolium ether fraction, CHF: Chloroformic fraction.

Using the pollen viability and morphology for fluoride pollution biomonitoring.

The methods using plants for biomonitoring of air and soil quality are simple, cheap, and fast and can supplement the classical physicochemical methods. In this study, biological pollen characterization of some collected legume species from an aluminum smelter area in Iran (IRALCO) was carried out to determine the actual value of pollen as a bioindicator of the effects of soil and atmospheric pollution. Young buds and flowers of six legumes (Cercis siliquastrum L., Medicago sativa L., Robinia pseudoacacia L., Melilotus officinalis (L.) lam, Trifolium repens L., and Sophora alopecuroides L.) in polluted and control plants were removed and compared. Studies of light and electron microscopic preparation showed some abnormalities during pollen development in affect of fluoride pollution. The viability of pollen grains estimated by staining with acetocarmine shows sharp differences in smearing advanced pollen grains from abnormal ones. Except M. officinalis, the pollen grains of C. siliquastrum, M. sativa, R. pseudoacacia, T. repens, and S. alopecuroides in polluted areas showed light, partial, or no staining with acetocarmine, whereas almost all of the control ones clearly stained. Observation of the pollen grains by light microscopy and scanning electron microscopy showed the significant effect of fluoride on shapes and sizes of pollen grains. The stimulation and inhibition of these pollen characteristics depend on the pollen species as well as on the pollutant and its concentration. Therefore, pollen grains provide essential information on biological impact of pollutants and they are good candidates for biomonitoring the atmospheric and edaphic pollutions.