Formulation and Biomedical Activity of Oil-in-Water Nanoemulsion Combining Tinospora smilacina Water Extract and Calophyllum inophyllum Seeds Oil

Elnaz Saki; Vinuthaa Murthy; Hao Wang; Roshanak Khandanlou; Johanna Wapling; Richard Weir

doi:10.2147/CCID.S405427

Formulation and Biomedical Activity of Oil-in-Water Nanoemulsion Combining Tinospora smilacina Water Extract and Calophyllum inophyllum Seeds Oil

Clin Cosmet Investig Dermatol. 2023 May 1:16:1159-1174. doi: 10.2147/CCID.S405427. eCollection 2023.

Authors

Elnaz Saki¹, Vinuthaa Murthy¹, Hao Wang¹, Roshanak Khandanlou¹, Johanna Wapling², Richard Weir³

Affiliations

¹ Faculty of Science and Technology, Charles Darwin University, Darwin, Northern Territory, Australia.
² Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia.
³ Department of Industry, Tourism and Trade, Berrimah Veterinary Laboratory, Darwin, Northern Territory, Australia.

Abstract

Introduction: Tinospora smilacina is a native plant used in traditional medicine by First Nations peoples in Australia to treat inflammation. In our previous study, an optimised Calophyllum inophyllum seed oil (CSO) nanoemulsion (NE) showed improved biomedical activities such as antimicrobial, antioxidant activity, cell viability and in vitro wound healing efficacy compared to CSO.

Methods: In this study, a stable NE formulation combining T. smilacina water extract (TSWE) and CSO in a nanoemulsion (CTNE) was prepared to integrate the bioactive compounds in both native plants and improve wound healing efficacy. D-optimal mixture design was used to optimise the physicochemical characteristics of the CTNE, including droplet size and polydispersity index (PDI). Cell viability and in vitro wound healing studies were done in the presence of CTNE, TSWE and CSO against a clone of baby hamster kidney fibroblasts (BHK-21 cell clone BSR-T7/5).

Results: The optimised CTNE had a 24 ± 5 nm particle size and 0.21± 0.02 PDI value and was stable after four weeks each at 4 °C and room temperature. According to the results, incorporating TSWE into CTNE improved its antioxidant activity, cell viability, and ability to promote wound healing. The study also revealed that TSWE has >6% higher antioxidant activity than CSO. While CTNE did not significantly impact mammalian cell viability, it exhibited wound-healing properties in the BSR cell line during in vitro testing. These findings suggest that adding TSWE may enhance CTNE's potential as a wound-healing treatment.

Conclusion: This is the first study demonstrating NE formulation in which two different plant extracts were used in the aqueous and oil phases with improved biomedical activities.

Keywords: RSM; in vitro; medicinal plants; nanoemulsion; wound healing.

Grants and funding

The authors would like to acknowledge Charles Darwin University for its financial support. Charles Darwin University had no role in the design of the study and collection, analysis, and interpretation of data and in writing this manuscript.