Phenolic Composition and Antimicrobial Activity of Different Emirati Date (Phoenix dactylifera L.) Pits: A Comparative Study

Abstract

The biochemical composition, secondary metabolites (phenolic compounds, flavonoids) and antimicrobial potential of different varieties of Emirati date (Phoenix dactylifera L.) pits were investigated. Total phenolic acids (TPC) and total flavonoid contents (TFC) of the different date pits were measured using a Folin–Ciocalteau reagent. Different organic solvents [(n-hexane; H2O: EtOH (1:1); ethyl acetate; acetone: Water (1:1); and methanol: Chloroform (1:1)] were compared to evaluate the phytotoxicity of Ajwa, Fard, Khalas, Khodari, Abu Maan, Lulu, and Mabroom date pits. The antimicrobial activity of the date pit extracts were evaluated by means of agar-well diffusion assay on Staphylococcus aureus (ATCC 29123), Escherichia coli (ATCC 25922) and Candida albicans (ATCC 66027). Minimum inhibitory concentrations (MICs) were measured following clinical laboratory standardization institute (CLSI) protocol. The biochemical analyses of date pits indicate that TPC were ranged from 7.80 mg of equivalent gallic acid⁄100 g dry weight in Ajwa to 4.65 mg in Mabroom. The TFC were ranged between 1.6–4.54 mg of equivalent catechin⁄100 g dry weight. Ajwa pit extract showed good quality traits (higher protein, lower ash content, and intermediate dietary fiber). The results indicate that the ethyl acetate extract of Khalas and Khodari inhibited S. aureus with an inhibition zone diameter of 20 mm and MIC of 10 mg/mL. Abu Mann pit extract inhibited the S. aureus and also decreased the population of E. coli. The diameter of inhibition zone was 15, 16, and 18 mm after treatment with Ajwa extracts, while the MICs were 7.5 and 5 mg/mL. The MeOH: CFM extract of Abu Mann and Ajwa was more potent against E. coli bacteria than any other extract. This work demonstrates that the Emirati date pits extract has antimicrobial (antibacterial, antifungal) potential and can be used as phytotoxic natural compounds.

Date Palm Extract (Phoenix dactylifera) PEGylated Nanoemulsion: Development, Optimization and Cytotoxicity Evaluation

“…Some previous investigations showed that the total flavonoid contents were estimated for Algerian cultivars (15–299 mg QE/100 g dried weight), Iranian cultivars (1–81 mg CE/100 g dried weight), and Tunisian cultivars (6–54 mg QE/100 g fresh weight) [ 6 , 30 ]. These variations and differences could be because of various parameters such as age, location, applied agricultural practices, climatic conditions, storage, or even genetic factors [ 3 , 4 , 5 , 6 ].…”

“…One of the most famous types of edible fruit is date fruit. Date fruits are cheap and rich source of carbohydrates, proteins, amino acids, and essential minerals (zinc, copper, selenium, potassium, calcium, magnesium, phosphorus, manganese, and iron), fiber, vitamins (C and E), carotenoids, fatty acids, polyphenols and flavonoids [ 3 , 4 , 5 , 6 ].…”

“…Although date pits represent around 11-18% of date fruit, they are considered of low market value due to their hard texture and contamination by fungi or insects during the processing of date fruits [18,19]. Despite several reports demonstrating the presence of high amounts of phenolic and flavonoid constituents in both the fruits and the pits of date palm, the fruits (edible and safe) are easier and cheaper to deal with comparable to pits [4,18].…”

Secondary Metabolites, Ferulic Acid and p-Hydroxybenzoic Acid Induced Toxic Effects on Photosynthetic Process in Rumex acetosa L.

“…The much great diversity of identified allelopathic compounds in nature implies a high variability in their mode of action. Works found in literature show that allelochemicals interfere with several and diverse metabolic processes in plants [ 38 , 39 , 40 ]. Application of cinnamic acid (100 μM) caused significant reduction in photosynthetic rate but there was no effect on efficiency and quantum yield of ΦPSII [ 41 ].…”

Anticancer activities of selected Emirati Date (Phoenix dactylifera L.) varieties pits in human triple negative breast cancer MDA-MB-231 cells

“…It is supporting the idea that these mentioned extracts are affecting cell cycle, apoptosis and proliferation individually or all the three processes together. The use of crude extracts that are rich in phenolic and flavonoid contents ( Hussain et al, 2019 ) in addition to dietary constituents like fats, proteins, carbohydrates and dietary fibers might be the possible reason for the multi-effects of the extracts. Abu-Maan and Khalas varieties are sharing antibacterial and antifungal activities as well as anti-proliferative activities, where Khodari and Ajwa showed good antimicrobial potential, however inconsistent anti-proliferative activity.…”