Evaluation of in vitro Antioxidant Activity of Crude Extracts of Basella alba and Oxalis corniculata and Formulation of a Topical Herbal Gel.

Abstract

Background: Basella alba and Oxalis corniculata belong to Basellacea and Oxalidacea families, respectively. These plants contain a wide variety of natural phytochemicals that demonstrate especially antioxidant properties and have been traditionally utilized in treating different skin disorders in folk medicine and Ayurvedic treatments. Objectives: To explore the phytochemical properties of Basella alba and Oxalis corniculata extracts, evaluate their in vitro antioxidant effects, assess the combined extracts' antioxidant activity, and formulate a topical herbal gel to treat oxidative stress induced topical skin inflammatory conditions due to free radicals

Methods: The study comprised the water extraction of fresh Basella alba leaves employing sonication and centrifugation, and the 70% methanolic extraction of Oxalis corniculata whole plant through maceration for 72 hours. Qualitative phytochemical analysis was performed on these extracts to identify various compounds such as carbohydrates, phenols, flavonoids, and alkaloids. Their antioxidant potential was evaluated spectrophotometrically using the DPPH (2,2-diphenyl-1 picrylhydrazyl) radical scavenging assay at the wavelength of 517 nm, with L-ascorbic acid serving as the positive control. The study entailed the formulation of a topical gel incorporating the two extracts (2%), carbopol 940, carboxymethylcellulose, and disodium EDTA. The final formulation was tested by DPPH assay to evaluate the antioxidant activity and all the formulations were kept at room temperature for 30 days to evaluate the stability.

Results: The phytochemical analysis of both extracts revealed the presence of carbohydrates, phenols, flavonoids, alkaloids, saponins, terpenoids, triterpenoids, and sterols, except tannins and proteins. In the DPPH assay, notable radical scavenging activity was observed for Basella alba, Oxalis corniculata, and the combined extract, with IC50 values of 0.913, 0.581, and 0.311 mg/mL, respectively, compared to ascorbic acid with an IC50 value of 0.042 mg/mL. Formulated herbal gel with an IC50 value of 0.881 mg/mL was stable for 30 days. Conclusions: Basella alba and Oxalis corniculata contain numerous phytochemicals with antioxidant properties, and the combined extract exhibited higher antioxidant activity compared to individual plant extracts. A novel topical formulation with significant antioxidant activity was demonstrated, suggesting potential for further testing and commercial development.