Comparative evaluation of anti-inflammatory and antioxidant properties of Globularia alypum L. extracts and gels from Northern Tunisia

Abstract

Background

Globularia alypum
L. is frequently used in traditional medicine to treat skin diseases and abscesses; however, there is no scientific evidence indicating the main organ of this plant responsible for its biological activity.

Methods

The present study aimed to assess the total phenolic and flavonoid contents, as well as the antioxidant properties and anti-inflammatory activity (AIA) of various parts (leaves, flowers, stems, and roots) of
Globularia alypum
L. collected from three regions in Tunisia. Additionally, hydrogels were formulated using aqueous leaf extracts to evaluate their rheological properties and the retention of bioactive compounds. Antioxidant capacity was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays, and AIA was determined using the enzyme lipoxygenase-5 (LOX-5).

Results

High levels of total phenolic content (TPC) were detected in both the leaf and flower extracts, with 451.97 ± 11.24 and 421.95 ± 15.38 mg gallic acid equivalents per gram of dry material (mg GAE/g DM). The leaf extract exhibited a high total flavonoid content (TFC), with a concentration of 35.17 ± 0.82 mg catechin equivalents per gram of dry material (mg EQ/g DM) and showed the strongest antioxidant activity, with an inhibitory concentration of 50% (IC
50
) was 0.149 mg/mL) and a significant LOX-5 inhibition (IC
50
 = 0.15 mg/mL). Hydrogels made with aqueous extracts from leaves retained 57% of polyphenols and maintained 58.6% of antioxidant activities. A rheological analysis of these hydrogels confirmed that the gel formulations are suitable for skincare applications, highlighting their potential for dermatological and anti-inflammatory treatments.

Conclusion
This comparative study offers a scientific basis for the traditional use of this local plant's leaves, emphasising their potential as natural antioxidants and sources of bioactive compounds with anti-inflammatory properties.