Phytochemical analysis, antioxidant, and antibacterial activities of Cyperus rotundus L. rhizomes

Cyperus rotundus L. is a ubiquitous weed, commonly found in tropical, subtropical, and temperate regions around the world, belonging to the Cyperaceae family. This slender, erect, perennial sedge propagates through a fibrous root system, enabling it to thrive in diverse habitats. The rhizomes initially appear black, transitioning to a darker shade as they mature. This plant is a traditional medicinal herb renowned for treating stomach ailments, nausea, vomiting, intestinal parasites, food poisoning, indigestion, and bowel irritation. Phytochemical screening of the ethanolic crude extract of C. rotundus L. rhizomes was conducted, revealing the presence of flavonoids, polyphenols, terpenoids, tannins, steroids, carbohydrates, and fixed oils. The total phenolic content was measured at 51.48 ± 1.77 mg GAE/g, 159.63 ± 2.28 mg GAE/g, and 17.90 ± 2.64 mg GAE/g in the ethanolic crude extract, ethyl acetate, and hexane fractions, respectively. Similarly, the total flavonoid content in the ethanolic crude extract, ethyl acetate, and hexane fractions was determined as (21.00 ± 1.51), (118.07 ± 5.06), and (10.67 ± 2.53) mg GAE/g, respectively. The ethyl acetate fraction of C. rotundus L. rhizomes exhibited significant antioxidant activity with an IC50 value of 27.11 ± 1.46 µg/mL. Furthermore, the ethanolic crude extract of C. rotundus L. rhizomes displayed effective antibacterial activity against gram-positive bacteria Staphylococcus aureus, with a zone of inhibition (ZOI) of 8 mm.