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In addition to its high nutritional value, alfalfa (Medicago sativa L.) has several health benefits including antioxidant, neuroprotective, antimicrobial, antiulcer, hypocholesterolemic, hypolipidemic, and estrogenic effects. We aimed to assess the nutritional value and antioxidant capacity of alfalfa leaves at different times of the year in arid regions. Alfalfa was harvested in autumn, winter, spring, and summer and fresh yield and leaf:stem ratio were measured. Leaves were collected to determine their nutritional value and antioxidant capacity using two different extracts viz.: absolute ethanol or distilled water. Fresh yield and leaf:stem ratio were highest in spring (20 t ha-1 and 57.6%, respectively), followed equally by winter and autumn, and were lowest in summer (10.75 t ha-1 and 51.6%, respectively). The autumn cut had the highest crude protein (33.52%) and crude fat content (3.79%) and the lowest content of crude fiber (13.95%) and acid detergent fiber (16.55%), which are good indicators of suitability for human nourishment. However, leaves collected in autumn were characterized by lower digestibility values (86.2%) compared to the other cuts. Antioxidant capacity of leaves harvested in autumns and extracted with either ethanol or distilled water was examined in terms of total polyphenols, total flavonoids, DPPH scavenging capacity, and reducing power. Ethanol extract showed higher antioxidant capacity in terms of total phenol and total flavonoid contents (6.41 and 4.88 mg gallic acid equivalents g-1 DW, respectively). These results suggest that autumn is the most appropriate season to cut alfalfa leaves for human nutritional purposes. [ABSTRACT FROM AUTHOR]

Increased problems associated with side effects and bacterial resistance of chemical drugs has prompted the research focus on herbal medicines in the past few decades. In the present investigation, the antimicrobial activity of the various parts of Avicennia marina (AM), a mangrove plant, has been evaluated. The plants were collected from the Jazan area of the Kingdom of Saudi Arabia. Primary extracts of roots, stem, leaves, fruits, and seeds were made in ethanol and fractioned in ethanol, ethyl acetate, petroleum ether, chloroform, and water. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the extracts were determined against Bacillussubtilis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. It has been observed that the chloroform extract of roots of the AM exhibited inhibitory effects against both S. aureus (MIC = 1.5 ± 0.03 mg/mL) and E. coli (MIC = 1.7 ± 0.01 mg/mL). The ethanolic extract of the AM roots has shown antibacterial activity against Pseudomonas aeruginosa (MIC = 10.8 ± 0.78 mg/mL), Bacillussubtilis (MIC = 6.1 ± 0.27 mg/mL), Staphylococcus aureus (MIC = 2.3 ± 0.08 mg/mL), and Escherichia coli (MIC = 6.3 ± 0.28 mg/mL). The leaf extract of the AM in ethyl acetate showed antibacterial activity against S. aureus and E. coli. Antifungal activity of these extracts was also investigated against Aspergillus fumigatus and Candida albicans. Ethanolic extract of roots and seeds of the AM has shown antifungal activity against Aspergillus fumigatus when applied individually. Ethanolic extract of the AM fruits has shown an inhibitory effect on the growth of Aspergillus fumigatus and Candida albicans. It is suggested that the plant extracts of AM have tremendous antimicrobial activity against a group of microbes, and this effect depends on both the plant part and the solvent used for extraction. Therefore, this plant can be considered to treat various diseases caused by antibiotic-resistant bacteria. [ABSTRACT FROM AUTHOR]