Cinnamomum sp. and Pelargonium odoratissimum as the Main Contributors to the Antibacterial Activity of the Medicinal Drink Horchata: A Study Based on the Antibacterial and Chemical Analysis of 21 Plants

Molecules. 2023 Jan 10;28(2):693. doi: 10.3390/molecules28020693.

Abstract

Horchata, a herbal infusion drink from Ecuador containing a mixture of medicinal plants, has been reported to exhibit anti-inflammatory, analgesic, diuretic, and antioxidant activity. The antibacterial activity of each of the plants contained in the horchata mixture has not been fully evaluated. Thus, in this study, we analysed the antibacterial activity of 21 plants used in horchata, collected from the Ecuadorian Andes region, against bacterial strains of clinical importance. The methanolic extract of Cinnamomum sp. showed minimal inhibitory concentration (MIC) values of 250 µg/mL against Staphylococcus aureus ATCC25923 and Methicillin-resistant S. aureus (MRSA), while Pelargonium odoratissimum exhibited a MIC value of 500 µg/mL towards S. aureus ATCC25923. The high-performance liquid chromatography-diode array detector-tandem mass spectrometry (HPLC-DAD-MS/MS) analyses identified in Cinnamomum sp. epicatechin tannins, cinnamaldehyde, and prehelminthosporol molecules, whereas in P. odoratissimum, gallocatechin and epigallocatechin tannins, some flavonoids, and gallic acid and derivatives were identified. Finally, Cinnamomum sp. and P. odoratissimum showed partial inhibition of biofilm formation of S. aureus ATCC25923 and MRSA. Overall, our findings revealed which of the plants used in horchata are responsible for the antibacterial activity attributed to this herbal drink and exhibit the potential for Cinnamomum sp. and P. odoratissimum secondary metabolites to be explored as scaffolds in drug development.

Keywords: Cinnamomum sp.; Pelargonium odoratissimum; antibacterial activity; biofilm; horchata; natural products.

MeSH terms

  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology
  • Cinnamomum* / chemistry
  • Gas Chromatography-Mass Spectrometry
  • Methicillin-Resistant Staphylococcus aureus*
  • Microbial Sensitivity Tests
  • Pelargonium*
  • Plant Extracts / chemistry
  • Plant Extracts / pharmacology
  • Staphylococcus aureus
  • Tandem Mass Spectrometry
  • Tannins

Substances

  • Plant Extracts
  • Anti-Bacterial Agents
  • Tannins

Grants and funding

This study was funded by the Universidad de Las Américas (UDLA) (grant number MED.PFS.22.02 to P.F.-S.), Quito, Ecuador, under the project titled “Evaluation of the antimicrobial activity of natural extracts from Andean plants contained in horchata against WHO prioritized pathogens”, and partially supported by the Collaboration Grants 2021 to A.M. of the Research Office funded by the Universidad San Francisco de Quito (USFQ), under the Project ID: 17577 titled “The antibiofilm potential of lactobacilli biosurfactants against multi-drug-resistant pathogens”. The funders had no role in the study design, data collection, analysis, decision to publish, or preparation of the manuscript.