Enhancing anti-inflammatory activity of Eucalyptus camaldulensis by upregulating secondary metabolites using suspension cultures techniques

Abstract

Eucalyptus camaldulensis Dehn (Family Myrtaceae) is among the most prominent Eucalyptus species, extensively exploited for its anti-inflammatory efficacy. The present study undertakes a comparative phytochemical and pharmacological evaluation of leaf and tissue culture (callus) extracts and their corresponding volatile oils. Methanolic extracts from both plant sources were subjected to liquid chromatography–mass spectrometry (LC/MS), revealing 32 phytoconstituents in leaf extracts and 54 in callus extracts. Identified chemical classes included flavonoids, tannins, coumarins, and phenolic acids, with higher relative abundance in callus-derived extracts. Volatile oil analysis using gas chromatography–mass spectrometry (GC/MS) identified 58 compounds in leaf oil and 52 in callus oil. Quantitative profiling demonstrated a significant elevation in bioactive volatiles within callus oil: 1,8-cineole content showed a 2.1-fold increase compared to leaf oil, and both α-terpineol and sabinene exhibited approximately fourfold increases relative to leaf oil. Bioassays further indicated that callus extracts and volatile oils possess enhanced anti-inflammatory and antioxidant activities, exhibiting higher potency than leaf-derived counterparts. Remarkably, the anti-inflammatory activity of callus volatile oil exceeded that of the standard pharmaceutical agent indomethacin. These findings underscore the potential of in vitro tissue culture as a biotechnological tool for amplifying the yield and bioactivity of secondary metabolites in E. camaldulensis.