Enhanced production of anticancer triterpenoids in optimized Pistacia lentiscus L. callus cultures via methyl jasmonate and silver nitrate elicitation

Abstract

Pistacia lentiscus L. is a traditional medicinal plant from the Mediterranean region with a long history of use. Elicitor-based strategies have proven effective in enhancing the production of secondary metabolites (SMs) with therapeutic potential in callus cultures. In addition, optimizing callus cultures is crucial for the synthesis and stability of SMs production. In this study, we have successfully established practical and optimized callus cultures from the leaves and roots of the mastic tree. Full-strength Murashige and Skoog (MS) medium gave the highest callus growth, with the combination of 2,4-dichlorophenoxyacetic acid and kinetin (each at 1 mg/l) giving the most favourable results for both explant types (80 % and 84 % callus induction, respectively). Optimal culture conditions were determined to be a sucrose concentration of 15 g/l, a pH of 5.8, a temperature of 25 °C and light intensities of 20 μmol m−2 s−1 for roots and 80 μmol m−2 s−1 for leaves. It is interesting to note that methyl jasmonate (MeJA) positively affected callus biomass, whereas silver nitrate (AgNO3) had the opposite effect. Elicitation with AgNO3 and MeJA significantly enhanced the biosynthesis of anticancer triterpenoids, particularly ursonic acid (UA), ursolic acid (ULA), masticadienolic acid (MDLA), and oleanonic acid (ONNA). Liquid Chromatography-Mass Spectrometry (LC-MS/MS) analysis revealed a remarkable 26.71-fold and 3.4-fold increase in UA content in leaf and root calli treated with AgNO3, respectively. It is noteworthy that ULA, MDLA and ONNA were not present prior to elicitation but were detected after elicitation. The accumulation of anticancer triterpenoids in callus cultures generated from various P. lentiscus L. explants is first demonstrated in our research. In addition, this research demonstrates a structured methodology for the enhancement of the accumulation of anticancer triterpenoids during callus culture.