Shah Alam Khan

The study aimes to investigate the physicochemical properties of seven honey samples to assess their quality as per GCC Standardization Organization (GSO) and international standard parameters. Seven honey samples, four marketed honey samples, and three locally produced Omani honey were collected and analysed for the pH, acidic content, % of insoluble matter, moisture content, proline, hydroxyl methyl furfural (HMF) and total reducing sugar contents. The results showed that pH of the tested honey samples are within the limit however acidity of the three samples did not comply with the prescribed limits. The moisture, proline, and hydroxy methyl furfural (HMF) contents of the honey samples tested are found to be within the acceptable range. However, the % of insoluble matter expressed for locally produced Sidr, Sumer, and Zah’r honey samples was below the maximum limit (0.5%) while marketed honey samples exceeded the limits of GSO (0.1%). The total reducing sugar concentration was below the limit in terms of four samples. Most of the tested honey samples meet the International/GSO standards for quality while a few failed to comply with acidity limits, the total reducing sugars content, and % of insoluble matter.

Euphorbia larica Boiss is a wild plant of Oman that grows in gravel plains, mountain areas, desert and forest edges. Traditionally, Omani herbalists use the Euphorbia larica plant extract, resins, latex and juice to treat a wide range of ailments such as wounds, burns, insect bites, intestinal parasites, gonorrhea, eye infections, migraines and warts. In an attempt to scientifically validate the traditional uses and to unlock its hidden therapeutic potential, in this work, the chemical composition of E. larica essential oil (ELEO) along with its potential antioxidant, antimicrobial and hemolytic activities is studied. In a GC-MS analysis of the extracted ELEO, 29 chemicals were found, with α-pinene (27.36%) and limonene (11.5%) being the two most abundant volatile components. ELEO exhibited moderate inhibition of DPPH radicals (17.74-40.96%; IC50 = 48.97 μg/mL). It showed antimicrobial activity against S. aureus, B. subtilis, S. pyogenes, E. coli, P. aeruginosa and P. vulgaris but was ineffective against K. pneumoniae bacterial strain however, exhibited the maximum antibacterial activity against S. aureus (11 ± 1.3 and 15 ± 2.3 mm at 5 and 10 μL concentrations, respectively) comparable to positive antibiotic ampicillin (15 mm at 5 μg). Moreover, ELEO exhibited a very low hemolytic activity (0.12 to 1.1% at doses of 50-500 μg) suggesting it to be non-toxic to human or animal cells. Thus, it can be concluded that E. larica plant holds significant potential as a source of bioactive agents for the development of novel therapeutics.