Unveiling the future reservoir of anti-cancer molecule—Combretastatin A4 from callus and cell aggregate suspension culture of flame creeper (Combretum microphyllum): growth, exudation and elicitation studies

Abstract

Combretastatin A4 (CA4), a natural stilbenoid molecule, has currently gained noticeable prominence for holding outstanding anti-angiogenic and selective vascular-targeting competency combined with renowned potential to prevent tumour metastasis. Efficacious preclinical insights against several types of cancer revealed better druggability potentials of specialized derivative(s) of this molecule. Considering such therapeutic significance and scanty natural availability, the competence of callus and compact cell aggregates (CCA)—suspension cultures of Combretum microphyllum had been explored revealing their untouched potentials as effective production alternatives for CA4. The CCA-suspension culture accumulated the highest amount of the CA4 (2.29 ± 0.04 mg/g DW) at 12 weeks cultivation period, which was 2.26 fold higher over that in 3 years old in-vivo plant leaves (1.01 ± 0.05 mg/g DW). In comparison, the calli (grown with TDZ) showed 1.89 fold lesser yield of CA4 (1.21 ± 0.05 mg/g DW) than the CCA-suspension culture. Exudation of CA4 in CCA-suspension cultures was evident throughout culture duration with the highest level (70.03%) at the maximum production phase. Compared to untreated control CCA-suspension culture, methyl-jasmonate (MeJ) elicitation first time ascertained 2.26 fold improvement of CA4 yield with noticeable stimulation of exudation. Observably, the longer duration (48hrs) and the higher dose (200 µm) of MeJ treatment proved optimum for the maximum enhancement of CA4 yield in CCA-suspension cultures. Present findings unveiled an unprecedented avenue towards fulfilling the rising commercial requirement of CA4 for future anti-cancer drug development processes through strategic implementation of in-vitro cultures options in C. microphyllum including MeJ elicitation and exudation. First report of a leading anti-cancer molecule- Combretastatin A4 synthesis in Combretum microphyllum through calli and compact cell aggregate-suspension cultures with promising yield improvement benefits through exudation and MeJ elicitation.