Development of an Antibacterial Herbal Cream Combining Carica papaya Leaf Extract and Ascorbic Acid.

Abstract

Background: Carica papaya (Papaya) exhibits medicinal properties such as antibacterial and anti-inflammatory effects while, ascorbic acid also possesses significant antimicrobial and antioxidant properties. The combination of papaya extract with vitamin C is used to check the enhancement of antibacterial activity while development of topical formulation will be beneficial for the consumers offering a potential solution for various skincare needs.

Objective: To evaluate the in vitro antibacterial and antioxidant activity of C. papaya leaf extract and ascorbic acid, and develop an antibacterial cream

Methods: The ethanolic leaf extract (18 g) was obtained by maceration method and preliminary phytochemical identification was performed. In vitro antioxidant activity was evaluated using DPPH assay. Antibacterial activity was evaluated for the extract (25, 50, 100, 125, 250, and 500 mg/mL), ascorbic acid (1.5, 3.0, 6.0, 7.5, 15.0, 30.0 mg/mL), and combination of the extract and ascorbic acid (50:3 mg/mL), using agar well diffusion method against Staphylococcus aureus and Pseudomonas aeruginosa. Ciprofloxacin (2 mg/mL) was used as the positive control. Two herbal cream formulations (2.5% and 5%) were developed using effective concentrations in 50:3 ratio (extract: ascorbic acid), and stability and antibacterial activities were evaluated. Results: Alkaloids, phenolic compounds, tannins, diterpenes, amino acids, cardiac glycosides, carbohydrates, and flavonoids were present in the ethanolic extract. C. papaya extract showed free radical scavenging activity at IC50= 900 µg/mL in the DPPH assay compared to the IC50 value of ascorbic acid (IC50= 8 µg/mL). The highest concentration of C. papaya extract exhibited 18.76±0.53 mm zone of inhibition against S. aureus and 16.51±2.55 mm against P. aeruginosa. 10.18±0.13 mm and 9.74±0.32 mm zone of inhibitions were observed in the highest concentration of ascorbic acid against S.aureus and P. aeruginosa, respectively. Combining papaya extract with ascorbic acid enhanced antibacterial activity resulting in 25.94±2.73 mm zone of inhibition against S. Aureus and 23.54±3.74 mm against P. aeruginosa in the highest concentration (500+30 mg/mL) which showed a significant difference (p<0.05), compared to each ascorbic acid and papaya extract. Both formulated creams F1 and F2 exhibited 12.04±0.74 mm and 22.22±1.03 mm against S. aureus and 9.94±0.64 mm and 14.83±0.13 mm against P. aeruginosa. They were stable under tested parameters like organoleptic test, homogeneity, viscosity, pH, spreadability, and phase separation. Conclusion: This study shows that C. papaya has antioxidant and antibacterial activity, and ascorbic acid enhances the antibacterial activity of the C. papaya crude extract against S. aureus and P. aeruginosa which can be used to develop an antibacterial cream.