Advancement in Medicinal Plant Research

85-90

Authors: Sleman Kadan, Yoel Sasson and Hilal Zaid

Portulaca oleracea L. is a grassy plant with a fleshy stem, succulent leaves, yellow or white small flowers and small black seeds. P. oleracea used as a medicinal plant in many countries, as a diuretic, febrifuge, vermifuge, antiseptic, anti-spasmodic, anti-bacterial, anti-inflammatory and anti-oxidant. It is in use also as anti-diabetic medicinal herb. The aim of this study was to evaluate the effect of the aerial parts of P. oleracea 50% ethanol/50% water and methanol based extracts on the glucose transporter-4 (GLUT4) translocation to the plasma membrane of muscle cells. Anti-diabetic activity of the extracts was examined by measuring the relative amount of GLUT4 translocation to the plasma membrane in the presence and absence of insulin. L6 muscle cells, stably expressing myc-tagged GLUT4, repeatedly shown to display insulin regulated GLUT4 traffic, were used as a model in this project. L6 myoblasts were pre-treated with increasing concentrations of P. oleracea extracts for 20 h, followed by 3 h serum-deprivation and insulin stimulation for 20 min and then GLUT4myc levels at the plasma membrane was determined. Toxicity of the extracts was determined by MTT assay and LDH leakage assay. Results obtained show no cytotoxic effects in cells treated for 24 h with 50% ethanol and methanol P. oleracea extract up to 1 mg/ml and 0.5 mg/ml extract respectively as measured with MTT and LDH-leakage assays. GLUT4 translocation to the plasma membrane was elevated by 2.6 and 4 folds (-/+ insulin) after treatment for 20 h with 1 mg/ml P. oleracea 50% ethanol extract and 1.7 and 3 folds (-/+ insulin) when treated with 0.5 mg/ml methanol extract. These results indicate that P. oleracea anti-diabetic proporties are mediated in part by increasing GLUT4 distribution in the muscle plasma membrane.

97-106

Authors: Mashael Al-Mutarrafi, Nagwa Thabet Elsharawy, Aisha Al-Ayafi, Ahmed Almatrafi and Hayam Abdelkader

The Kingdom of Saudi Arabia is considered one of the major dates producing zones in the world, contributing 13% of the total world production. Most of the dates are delivered to local markets without any treatment thus, may be leading to microbial contamination which may increase the incidence of microbial growth. Some pathogenic fungi associated with soft dates (Phoenix dactylifera, Linn.) collected from Almadinah Almunawarah, local markets, was isolated and molecularly identified during summer 2019. Contaminated date samples (Sukkary, Ajwa, Shalabi madinah, Barni and Sogea) were placed on PDA plates and incubated at 26°C for 5 days. Morphological and molecular identification of the resulting fungi were investigated. Molecular identification of fungal isolates was conducted using the internal transcribed spacer (ITS) region of the ribosomal DNA (rDNA). Fungal DNAs were amplified by PCR using ITS1-F (5’-TCCGTAGGTGAACCTGCGG-3’) and ITS4 (5’-TCCTCCGCTTATTGATATGC-3’). The purified PCR products were sequenced and the obtained nucleotide sequences were submitted to GenBank on the NCBI. The results showed that the most dominant isolated fungi were Aspergillus niger (100%) associated with “Sogea”, followed by Aspergillus tubingensis (66%) isolated from “Shalabi Almadinah” (40%), Rhizopus stolonifer (36.3%) associated with “Ajwa”, Talaromyces minioluteus (14.2%) isolated from “Sukkary”, respectively. Soft dates are most likely contaminated due to the artificial rise in moisture content and the related inappropriate storage conditions. In conclusion, the study has declared that Aspergillus spp. considered the most fungal contamination of date fruits. Fungal contamination may have an effect on the public health by their mycotoxins which may lead to severe poisoning, diarrhea, emesis, and death. Most date fruits sold and marketed are neither covered nor protected in any way from environmental contamination. If these dates are consumed without thoroughly washing that may induce imminent mycotic infection. The study recommended that prevention of dates fruit mold spoilage should be avoided by application of hazard analysis, critical control point programs and adherence to hygienic good manufacturing practices.