Myrmecodia tuberosa Jack (Rubiaceae) has been used as part of traditional Indonesian remedies for a wide range of therapeutic usages in West Papua. Our preliminary study revealed the significant potency of these plant extracts and fractions as an immunomodulator by an in vitro technique on Balb/c mice. This study explored the effect of M. tuberosa hypocotyl ethanol extract on the TCD4+ and TCD8+ cell profiles of doxorubicin (Dox)-induced immune-suppressed Sprague Dawley (SD) rats by an in vivo method. Dried powder of M. tuberosa hypocotyl was macerated in 95% ethanol. Following solvent evaporation in a vacuum, the ethanol extract (EE) was partitioned to yield an n-hexane fraction (FH) and residue (FNH). FNH was further partitioned to yield ethyl acetate (FEtOAc) and water fractions (FW). The extract and fractions in the concentrations 10, 20, 50, and 100 μg/mL were tested on macrophage cells by the latex bead method, while the proliferation of lymphocyte cells was evaluated by the MTT assay. The total phenolic and flavonoid contents of those fractions were evaluated. The active fraction was administrated orally on Dox-induced SD rats for 28 days by an in vivo method to observe the TCD4+ and TCD8+ cell profiles. The in vivo assay showed that the FNH could maintain the number of TCD4+ cells, but not the number of TCD8+ cells. The ED50 observed was 24.24 mg/kg BW. Steroid/terpenoid compounds were detected in this fraction along with the phenolics and flavonoids. The FNH contained 3.548 ± 0.058% GAE of total phenolics and 0.656 ± 0.026% QE of total flavonoids. M. tuberosa hypocotyl extract is a potent immunomodulatory agent and may act as co-chemotherapy in Dox use.
Keywords: Ant plant; Doxorubicin; Myrmecodia tuberosa hypocotyl; TCD4+; TCD8+.