Synergistic anti-tumor activity of a novel immunomodulator, BCH-1393, in combination with cyclophosphamide

The ethanolic extract of Rhaphidophora peepla prevents inflammation by inhibiting the activation of Syk/AKT/NF-κB and TAK1/MAPK/AP-1

BACKGROUND

Inflammation is the body's innate reaction to foreign pathogens and serves as a self-regulating mechanism. However, the immune system can mistakenly target the body's own tissues, triggering unnecessary inflammation. For millennia, medicinal plants have been employed for the treatment of diseases. One such plant, Rhaphidophora peepla, has demonstrated potential anti-inflammatory properties. However, the precise mechanism underlying its anti-inflammatory effects remains elusive.

STUDY DESIGN

For this study, validation of target molecules by different experimental approaches and employing two different in vivo experiments were tried to improve the immunopharmacological value of Rhaphidophora peepla.

PURPOSE

Our goal is to elucidate the mechanism through which the ethanol extract of Rhaphidophora peepla (Rp-EE) demonstrates anti-inflammatory properties, both in vivo and in vitro.

METHOD

Rp-EE was phytochemically analyzed with gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC). Bioinformatic analysis with protein-protein interaction (PPI) networks and Kyoto Encyclopedia of Genes and Genomes (KEGG), nitric oxide (NO) assay, MTT assay, RT-PCR, ELISA, luciferase assay, CETSA, hematoxylin and eosin (H&E) staining, and Western blotting analysis were used to evaluate anti-inflammatory activity of Rp-EE and its mechanism.

RESULTS

Rp-EE significantly reduced inflammatory responses including nitric oxide (NO) release induced by lipopolysaccharide (LPS) at the non-cytotoxic concentrations in vitro, and HCl/EtOH-induced gastritis and LPS-induced acute lung injury models in vivo. Mechanistically, it was revealed that Rp-EE can specifically target spleen tyrosine kinase (Syk) and transforming growth factor β-activated kinase 1 (TAK1) to suppress the phosphorylation levels of nuclear factor (NF)-κB subunits (p65 and p50) and activator protein (AP)-1 subunits (c-Jun and c-Fos).

CONCLUSION

Rp-EE can inhibit inflammatory reactions managed by Syk and TAK1, resulting in suppressing the Syk/AKT/NF-κB and TAK1/MAPK/AP-1 signaling pathways. These findings lead us to a possibility that Rp-EE can be developed as a promising anti-gastric ulcer and anti-lung injury remedy.

Synergistic Anti-cancer Activity of MH-30 in a Murine Melanoma Model Treated With Cisplatin and its Alleviated Effects Against Cisplatin-induced Toxicity in Mice

BACKGROUND/AIM

Although cisplatin is an effective anticancer drug, its toxic effects on normal tissues limit its use. We developed a herbal formula, MH-30, with increased fat-soluble polyphenols by improving the manufacturing method of HemoHIM. In this study, we examined whether the combination of MH-30 with cisplatin exerts synergistic antitumor effect while it reduces cisplatin-induced toxicities.

MATERIALS AND METHODS

MH-30 was produced by adding the ethanol-insoluble fraction to its extract after decocting herbs in 30% ethanol and water. We used a melanoma-bearing mice model to investigate synergistic anticancer effects. The NK cell activity and cytokine levels were measured by Cr⁵¹-release assay and ELISA. The AST, ALT, BUN, and creatinine levels were estimated in the serum.

RESULTS

MH-30 effectively inhibited melanoma growth in vitro. Furthermore, MH-30 had a synergistic effect in combination with cisplatin on melanoma growth inhibition in vitro and in vivo. In melanoma-bearing mice, cisplatin alone decreased the activity of NK cells and the levels of IL-2 and IFN-γ, which were effectively restored by the combination of MH-30 with cisplatin. Combined treatment with MH-30 and cisplatin significantly inhibited the cisplatin-induced increase in the levels of AST, ALT, BUN, and creatinine.

CONCLUSION

Combination of MH-30 with cisplatin may be a beneficial anticancer treatment with reduced adverse effects.

Immunomodulatory Effect of Rhaphidophora korthalsii on Natural Killer Cell Cytotoxicity

The in vivo immunomodulatory effect of ethanolic extracts from leaves of Rhaphidophora korthalsii was determined via immune cell proliferation, T/NK cell phenotyping, and splenocyte cytotoxicity of BALB/c mice after 5 consecutive days of i.p. administration at various concentrations. Splenocyte proliferation index, cytotoxicity, peripheral blood T/NK cell population, and plasma cytokine (IL-2 and IFN-γ) in mice were assessed on day 5 and day 15. High concentration of extract (350 μg/mice/day for 5 consecutive days) was able to stimulate immune cell proliferation, peripheral blood NK cell population, IL-2, and IFN- γ cytokines, as well as splenocyte cytotoxicity against Yac-1 cell line. Unlike rIL-2 which degraded rapidly, the stimulatory effect from the extract managed to last until day 15. These results suggested the potential of this extract as an alternative immunostimulator, and they encourage further study on guided fractionation and purification to identify the active ingredients that contribute to this in vitro and in vivo immunomodulatory activity.

Enhancement of Th1 type cytokine production and primary T cell activation by PBI-1393

In previous reports, we have shown that PBI-1393 (formerly BCH-1393), N,N-Dimethylaminopurine pentoxycarbonyl D-arginine, stimulates cytotoxic T-lymphocyte (CTL) responses both in vitro and in vivo in normal immune status and immunosuppressed mice. Additionally, PBI-1393 was tested for anticancer activity in syngeneic mouse experimental tumor models and it displayed significant inhibition of tumor outgrowths when given in combination with sub-therapeutic doses of cytotoxic drugs (cyclophosphamide, 5-fluorouracil, doxorubicin and cis-platinum). However, the mechanism of action of PBI-1393 was still unknown. Here, we report that PBI-1393 enhances IL-2 and IFN-gamma production in human activated T cells by 51% and 46% respectively. PBI-1393 increases also IL-2 and IFN-gamma mRNA expression as shown by RT-PCR. The physiological relevance of IL-2 and IFN-gamma gene modulation by PBI-1393 is illustrated by the advantageous increase of T cell proliferation (39+/-0.3% above control) and human CTL response against prostate (PC-3) cancer cells (42+/-0.03%). The enhancement of human T cell proliferation and CTL activation by PBI-1393 demonstrates that this compound potentiates the immune response and in this regard, it could be used as an alternative approach to IL-2 and/or IFN-gamma therapy against cancer.