Comprehensive In Vitro Evaluation of Antibacterial, Antioxidant, and Computational Insights into Blepharis ciliaris (L.) B. L. Burtt from Hail Mountains, Saudi Arabia

The arid mountainous region of Hail in Saudi Arabia has a variety of desert vegetation, some of which are conventionally used in Bedouin traditional medicine. These plants need scientific examination. This research seeks to examine Blepharis ciliaris using a thorough multi-analytical methodology that includes antibacterial and antioxidant assessments as well as computational modeling. GC-MS analysis of the methanolic extract revealed 17 organic compounds, including pentadecanoic acid, ethyl methyl ester (2.63%); hexadecanoic acid, methyl ester (1.00%); 9,12-octadecadienoic acid (Z,Z)-, methyl ester (2.74%); 9-octadecenoic acid, methyl ester (E) (2.78%); octadecanoic acid (5.88%); 9-tetradecenoic acid (Z) (3.22%); and undec-10-enoic acid, undec-2-n-1-yl ester (5.67%). The DPPH test evaluated antioxidant activity, revealing a notable increase with higher concentrations of the methanolic extract, achieving maximum inhibition of 81.54% at 1000 µg/mL. The methanolic extract exhibited moderate antibacterial activity, with average inhibition zones of 10.33 ± 1.53 mm, 13.33 ± 1.53 mm, 10.67 ± 1.53 mm, and 10.00 ± 2.00 mm against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Serratia marcescens, respectively, as determined by the disk diffusion method. The minimum inhibitory concentration (MIC) values were 500 µg/mL for S. aureus and B. subtilis, whereas E. coli and S. marcescens showed susceptibility at 1000 µg/mL. Computational simulations were employed to assess the toxicity, drug-likeness, and ADMET profiles of compounds derived from Blepharis ciliaris. Thirteen bioactive compounds were assessed in silico against Staphylococcus aureus sortase A (PDB: 1T2O), Bacillus subtilis BsFabHb (PDB: 8VDB), Escherichia coli LPS assembly protein (LptD) (PDB: 4RHB), and a modeled Serratia marcescens outer-membrane protein TolC, focusing on cell wall and membrane structures. Compound 3, (+)-Ascorbic acid 2,6-dihexadecanoate, shown significant binding affinities to B. subtilis BsFabHb, E. coli LPS assembly protein, and S. marcescens TolC.