Phytochemicals of <i>Minthostachys diffusa</i> Epling and Their Health-Promoting Bioactivities

• Main Authors: Immacolata Faraone, Daniela Russo, Lucia Chiummiento, Eloy Fernandez, Alka Choudhary, Magnus Monné, Luigi Milella, Dilip K. Rai
• Format: Article
• Language: English
• Published: MDPI AG 2020-02-01
• Series: Foods
• Subjects: <i>minthostachys diffusa</i>; lamiaceae; dpph; <i>beta</i>-carotene bleaching; relative antioxidant capacity index (raci); polyphenols; terpenoids; liquid chromatography–mass spectrometry analysis (uhplc-ms/ms); flavonoids
• Online Access: https://www.mdpi.com/2304-8158/9/2/144

The genus <i>Minthostachys</i> belonging to the Lamiaceae family, and is an important South American mint genus used commonly in folk medicine as an aroma in cooking. The phytochemical-rich samples of the aerial parts of <i>Minthostachys diffusa</i> Epling. were tested for pharmacological and health-promoting bioactivities using in vitro chemical and enzymatic assays. A range of radical scavenging activities of the samples against biological radicals such as nitric oxide and superoxide anion and against synthetic 2,2-diphenyl-1-picrylhydrazyl and 2,2&#8242;-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radicals, the ferric reducing antioxidant power and the lipid peroxidation inhibition were determined and ranked using the &#8216;relative antioxidant capacity index&#8217; (RACI). The ethyl acetate fraction showed the highest RACI of +1.12. Analysis of the various fractions&#8217; inhibitory ability against enzymes involved in diabetes (&#945;-amylase and &#945;-glucosidase), and against enzymes associated with Parkinson&#8217;s or Alzheimer&#8217;s diseases (acetylcholinesterase and butyrylcholinesterase) also suggested that the ethyl acetate fraction was the most active. Liquid chromatography&#8722;tandem mass spectrometry analysis of the ethyl acetate fraction showed more than 30 polyphenolic compounds, including triterpenes. The inhibitory cholinesterase effects of the triterpenes identified from <i>M. diffusa</i> were further analysed by in silico docking of these compounds into 3D-structures of acetylcholinesterase and butyrylcholinesterase. This is the first study on pharmacological activities and phytochemical profiling of the aerial parts of <i>M. diffusa</i>, showing that this plant, normally used as food in South America, is also rich in health-promoting phytochemicals.