Phytochemical Characterisation and Antiinflammatory Evaluation of a Dual Extract In-situ Gel from Sesamum indicum and Rubus idaeus: An In-vitro Study

Abstract

Introduction: Rubus idaeus and Sesamum indicum have antiinflammatory and antioxidant qualities because they contain bioactive substances such as polyphenols, anthocyanins, tocopherols, and lignans. By reducing systemic adverse effects, combining these extracts in a topical (mucous membrane) in-situ gel may provide a safer substitute for traditional antiinflammatory medications. The study was undertaken with the rationale of exploring a natural therapeutic approach for managing inflammation. Aim: To develop, characterise, and evaluate a dual herbal insitu gel with extracts of sesame and raspberry for its potential to reduce inflammation in-vitro. Materials and Methods: This in-vitro study was conducted in the Institutional Research Laboratory, Nanobiomedicine lab, Saveetha Medical College and Hospital, Chennai, Tamil Nadu, India, from March to June 2025. Before biological evaluation, the herbal components were subjected to phytochemical characterisation to confirm the presence of bioactive constituents associated with anti-inflammatory activity. The formulated gel, prepared using a Carbopol-CMC gel base, was assessed at five concentrations (10-50 µg/mL). Anti-inflammatory activity was analysed using three standard in-vitro assays, namely the Bovine Serum Albumin (BSA) denaturation assay, Egg albumin denaturation assay, and Human Red Blood Cell (HRBC) membrane stabilisation assay, with diclofenac sodium serving as the standard reference drug. All experiments were performed in triplicate, resulting in a total sample size of 18, divided into two main groups based on the formulation, Group I (standard - diclofenac sodium) and Group II (sesame + raspberry gel). The data obtained were statistically analysed using Statistical Package for Social Sciences (SPSS) version 23.0. Normality of distribution across concentrations (10-50 µg/mL) was assessed using the Shapiro-Wilk test. For normally distributed data, parametric tests including One-way Analysis of Variance (ANOVA) were used for within-group comparisons, followed by Tukey’s post-hoc test for multiple pairwise comparisons, and the Independent samples t-test for between-group analysis. Statistical significance was set at p<0.05. Results: The herbal gel showed uniform appearance, good homogeneity, suitable viscosity, pH=3.58, and 25 mm spreadability. It exhibited anti-inflammatory activity in all invitro assays, with significant differences (p<0.05) at most concentrations, and the highest inhibition observed in the membrane stabilisation assay. Low variability indicated reliable results. Conclusion: The raspberry-sesame dual herbal in-situ gel demonstrated favourable physicochemical properties and appreciable in-vitro anti-inflammatory activity, suggesting its potential as a safe topical herbal alternative.