Antibacterial effects and microbial quality of commonly consumed herbs in Dubai, United Arab Emirates

© All Rights Reserved. Herbal plants are traditionally known to exhibit antimicrobial properties and used in several countries as an alternative to modern pharmaceutical drugs. This study investigated the antibacterial properties and microbial quality of common herbs used in the United Arab Emirates (UAE). In total, 20 herb samples of parsley (Petroselinum crispum), basil (Ocimum basilicum), sage (Salvia officinalis), mint (Mentha spicata), and thyme (Thymus vulgaris) were randomly collected and analysed for the total aerobic bacteria count, yeasts and molds, Escherichia coli, Staphylococcus aureus, Salmonella and Pseudomonas aeruginosa by standard plate counting method using selective and differential culture media. Antibacterial effects of herbs on E.coli, S. aureus, Salmonella and P. aeruginosa were tested by disk diffusion method. The microbial analysis of herbs revealed that 50% of herb samples exceeded the world health organization (WHO) limit for the total aerobic bacteria count, and 75% exceeded the permissible limit for total molds and yeast count. 75% of herb samples were found contaminated with Escherichia coli and Salmonella spp, 65% with Shigella, and 10% exceeded the WHO permissible limit for Pseudomonas aeruginosa. However, all herb samples were found to be within the WHO acceptable limit for Staphylococcus aureus. All herbal extracts exhibited some form of antibacterial activity against E. coli, S. aureus, Salmonella and P. aeruginosa except for parsley, which had no inhibitory effect on S. aureus. However, the results of microbial quality suggest that most of the analysed herbs had unsafe microbial contamination that exceeded the World Health Organization permissible limits. Therefore, strict measures to reduce the risk of microbial contamination by applying Hazard Analysis and Critical Control Point (HACCP) need to be implemented on local and imported herbs prior to consumption

Simplified HPLC method for identification of gingerol and mangiferin in herbal extracts

Quantification of bioactive compounds through modern analytical techniques is essential for proving authenticity, credibility, and safe use of herbal products in Ayurvedic medicine. In this study, we describe the development of a simplified method for the identification of key bioactive compounds in six commercial herbal products of various forms using High Performance Liquid Chromatography (HPLC). Marker compounds such as mangiferin 1 and [6]-gingerol 2 were examined in various extracts of mango leaves and ginger, respectively. The compounds were extracted by sonication with methanol at room temperature and were analyzed by HPLC with 0.1% acetic acid buffer (pH = 3.00)/methanol mixture used as gradient mobile phase. Eluents were monitored by a photo diode array (PDA) detector and UV detection fixed at 280/320 nm. Further characterization of each extract was performed using FTIR and UV-Vis. Mangiferin 1 eluted at 6 min (320 nm) and gingerol 2 at 16.9 min (280 nm). The proposed method provides a good resolution of the selected marker compounds in herbal products and dietary supplements that could be further used for their quantification and standardization in routine analysis and quality control. © EuroJournals Publishing, Inc. 2011