Assessment of the antioxidant and antimicrobial activities of Caralluma deflersiana growing in the South of Saudi Arabia

Reactive oxygen species and oxidative stress are related to a large number of human degenerative diseases. Consequently, plants have been investigated across the world to exploit their potential antioxidant and antimicrobial activities. In the current study, Caralluma deflersiana is native to Saudi Arabia and was screened to assess its antioxidant and antimicrobial potential activities as well as the phenolic content/phytochemicals. Subsequently, the collected aerial parts were extracted by maceration with different solvents. The antioxidant activity was investigated using the total antioxidant capacity, diphenylpicryl hydrazine (DPPH)- radical scavenging assay, ABTS radical scavenging assay, and Ferric reducing antioxidant power assay (FRAP). Regarding the antimicrobial activity, the Minimum Inhibitory Concentration (MIC) assays were used. The total phenolic content of C. deflersiana extracts was quantified using standard methods. As a result, the water extract of C. deflersiana displayed a strong antioxidant activity in all tested methods compared to other plant extracts. Moreover, it was also noted that water and methanolic extracts exhibited approximately similar bacterial and fungal growth inhibition. Additionally, the water extract of C. deflersiana also demonstrated the highest phenol content among other plant extracts, consistent with the higher antioxidant activity found in C. deflersiana. In conclusion, Caralluma species could be a promising source of antioxidant and antimicrobial agents. Key words: Caralluma deflersiana, antioxidant, antimicrobial.