<b>Exploring the Phytochemical Profile and Antibacterial Potential of <i>Helianthus annuus</i> and <i>Rosa indica</i></b>

Background: Medicinal plants are important sources of bioactive compounds with antioxidant and antimicrobial potential, offering safer alternatives to synthetic agents that often cause side effects and resistance. Helianthus annuus (sunflower) and Rosa indica (rose) are widely cultivated plants known for diverse phytochemicals and traditional therapeutic uses. Objective: To analyze the phytochemical composition, antioxidant capacity, and antibacterial potential of H. annuus and R. indica leaf extracts prepared with solvents of varying polarity. Methods: Leaves were collected from Lahore, Pakistan, dried, powdered, and extracted using aqueous, ethanol, and petroleum ether solvents. Qualitative and quantitative phytochemical screenings were performed using standard biochemical assays. Antioxidant activity was assessed using the DPPH radical scavenging method, while antibacterial efficacy against Staphylococcus aureus and Klebsiella pneumoniae was evaluated using the agar well diffusion assay. Results: Extract yields varied across solvents, with ethanol extracts of H. annuus showing the highest recovery (~38%). Quantitative assays revealed higher alkaloid content in R. indica (5.35%) compared with H. annuus (4.09%). Carbohydrate concentration was maximal in aqueous R. indica (14.7 ± 0.81 mg/g), whereas petroleum ether H. annuus extract showed the highest protein content (14.37 ± 0.52 mg/g). Antioxidant activity peaked in aqueous H. annuus (85.2 ± 2.1%), exceeding aqueous R. indica (72.5 ± 1.4%). Antibacterial testing demonstrated that ethanol R. indica extract exhibited the strongest activity, producing inhibition zones of 16 ± 2 mm against S. aureus and 14 ± 1 mm against K. pneumoniae, while petroleum ether R. indica maintained moderate activity (12–14 mm). In contrast, H. annuus showed minimal antibacterial activity, with only the aqueous extract inhibiting K. pneumoniae (10 ± 2 mm). Conclusion: Both plants contain abundant phytochemicals with strong antioxidant and antibacterial activities. R. indica exhibited greater alkaloid content and antibacterial potential, whereas H. annuus demonstrated superior antioxidant capacity. These complementary roles highlight their potential as natural alternatives to synthetic agents.