Determination of antioxidant, DNA protection, enzyme inhibition potential and molecular docking studies of a biomarker ursolic acid in Nepeta species

Ursolic acid (UA), which has many biological properties such as anti-cancer, anti-inflammatory and antioxidant, and regulates some pharmacological processes, has been isolated from the flowers, leaves, berries and fruits of many plant species. In this work, UA was purified from the methanol-chloroform crude extract of Nepeta species (N. aristata, N. baytopii, N. italica, N. trachonitica, N. stenantha) using a silica gel column with chloroform or ethyl acetate solvents via bioactivity-guided isolation. The most active sub-fractions were determined under bioactivities using antioxidant and DNA protection activities and enzyme inhibitions. UA was purified from these fractions and its structure was elucidated by NMR spectroscopy techniques. The highest amount of UA was found in N. stenantha (8.53 mg UA/g), while the lowest amount of UA was found in N. trachonitica (1.92 mg UA/g). The bioactivities of UA were evaluated with antioxidant and DNA protection activities, enzyme inhibitions, kinetics and interactions. The inhibition values (IC50) of α-amylase, α-glucosidase, urease, CA, tyrosinase, lipase, AChE, and BChE were determined between 5.08 and 181.96 µM. In contrast, Ki values of enzyme inhibition kinetics were observed between 0.04 and 0.20 mM. In addition, Ki values of these enzymes for enzyme-UA interactions were calculated as 0.38, 0.86, 0.45, 1.01, 0.23, 0.41, 0.01 and 2.24 µM, respectively. It is supported that UA can be widely used as a good antioxidant against oxidative damage, an effective DNA protector against genetic diseases, and a suitable inhibitor for metabolizing enzymes.Communicated by Ramaswamy H. Sarma.

Comparing healing effect against ulcerative colitis and toxicological effects of Rosmarinus officinalis: A comprehensive in vivo study of an edible plant in rats

Ulcerative colitis (UC) is a chronic and inflammatory disorder of the gastrointestinal (GI) tract. UC usually worsens the daily life of the patient and may sometimes become mortal. There is no known remedy discovered against UC, yet. Rosmarinus officinalis consists of many flavonoids, phenolics, and terpenoids possessing various biological activities such as anti-inflammatory. For this reason, in the present study, anti-ulcerative colitis effect of ROME (Rosmarinus officinalis methanol extract) was investigated comprehensively by histopathological studies, a number of in vivo anti-inflammatory activities and several in vivo antioxidant activities, in addition to in vitro antioxidant activities and biochemical analyses. In addition, the toxic effects of ROME were examined. The results showed that ROME provided a significant healing effect against ulcerative colitis in rats. Both in vitro and in vivo assay results correlated with histopathological examinations. ROME exhibited minimal toxic alterations. When the results of rosemary are compared with the results of sulfasalazine, it can be suggested that instead of synthetic drugs with side effects, natural sources can be used for the treatment of various diseases. Although some activities of rosemary have been investigated in vitro in the previous studies, this is the first study revealing anti-ulcerative colitis effect of rosemary through histopathological studies, in vivo and in vitro assays as well as biochemical analyses overall. PRACTICAL APPLICATIONS: The results revealed and proved that ROME provided a significant healing effect against ulcerative colitis in rats. When the results of rosemary are compared with the results of sulfasalazine, a commercially available drug on the market, it can be suggested that instead of synthetic drugs with side effects, natural sources can be used for the treatment of various inflammatory diseases such as UC disease. In addition, ROME possesses limited toxic alterations, but not much more than the commercial drug. As a future perspective, lethal and therapeutic doses can be examined and determined. Thus, human studies can be started through this comprehensive in vivo study on rosemary which is commonly used as an edible plant and spice all over the world.