Telocinobufagin

The effects of telocinobufagin isolated from Chan Su on the activation and cytokine secretion of immunocytes in vitro.[Pubmed: 19709323]

Fundam Clin Pharmacol. 2009 Aug;23(4):457-64.

Many traditional Chinese medicines have been used as immunomodulators that act as either immunosuppressants or immunostimulators. Recently, our lab successfully isolated a monomer Telocinobufagin (TCB) from the chloroform extract of Chan Su (Venenum Bufonis). In the present paper, we evaluated the immunomodulatory effects of this compound in vitro.
METHODS AND RESULTS:
We found that TCB significantly stimulates splenocyte proliferation when administered alone or in combination with polyclonal T-cell mitogens concanavalin A (Con A) and lipopolysaccharide. Telocinobufagin markedly enhances natural killer cell and peritoneal macrophage activation. Telocinobufagin increases the percentage of CD4, CD8 positive cells within a population of splenocytes. Moreover, we found that the level of several Th1 cytokines, including interleukin-2 (IL-2), interleukin-12 (IL-12), interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha), are significantly increased after TCB treatment, while the level of the Th2 cytokine interleukin-4 (IL-4) is significantly decreased. As a result, the ratio of Th1/Th2 is significantly increased.
CONCLUSIONS:
Taken together, these results indicate that TCB has potential immune system regulatory effects and suggest that this compound could be developed as a novel immunotherapeutic agent to treat cancer and other immune-mediated diseases, and it may become a new immunomodulatory agent in many regions.

Antimicrobial activity of the bufadienolides marinobufagin and telocinobufagin isolated as major components from skin secretion of the toad Bufo rubescens.[Pubmed: 15804527]

Toxicon. 2005 May;45(6):777-82.

The increase in the emergence of antibiotic-resistant microorganisms and difficult to treat infections caused by these pathogens stimulate research aiming the identification of novel antimicrobials. Skin secretion of amphibian contains a large number of biologically active compounds, including compounds that performance defense mechanisms against microorganisms.
METHODS AND RESULTS:
In the present work, two antimicrobial bufadienolides, Telocinobufagin (402.1609 Da) and marinobufagin (400.1515 Da), were isolated from skin secretions of the Brazilian toad Bufo rubescens. The specimens were collected in Brasilia (Distrito Federal, Brazil), the skin secretions extracted by electric stimulation, and submitted to purification by RP-HPLC. The molecular structure and mass determination were done by (1)H and (13)C NMR and mass spectrometry data, respectively. The antimicrobial activity was performed by liquid growth inhibition against Staphylococcus aureus and Escherichia coli. The minimum inhibitory concentrations of Telocinobufagin and marinobufagin were, respectively, 64.0 and 16.0 microg/mL for E. coli and both 128 microg/mL for S. aureus.
CONCLUSIONS:
Besides the antimicrobial activity both bufadienolides promoted an increase of the contraction force in isolated frog ventricle strips.

Pharmacological effects of telocinobufagin, a bufodienolide originated from the parotoid glands of Bufo paracnemis: comparative study with local anesthetic bupivacaine.[Reference: WebLink]

Universidade Federal do Ceará, 2004.5.26.

The pharmacological effects of Telocinobufagin (TCB), a bufadienolide extracted from Bufo paracnemis parotoid glands by HPLC, were compared to that induced by bupivacaine (BUPI).
METHODS AND RESULTS:
On guinea-pig isolated ileum, TCB (10-8 to 10-4 M) inhibited both, the electrical field stimulation (EFS)-induced contraction (with a value of 0.9 ± 0.9 % of the control response at 6x10-4 M), and the contractions elicited by ACh, in a concentration-dependent manner. BUPI (10-7 to 10-3 M) also inhibited both, the EFS- and the ACh-induced contractions on guinea-pig isolated ileum, in a concentration-dependent manner. On rat isolated sciatic nerve, TCB (1 mM) reduced the compound action potential (CAP) peak-to-peak amplitude (PPA) to 64.9±7.2 % and 12.9±4.4 % of the control amplitude after 15 min and 30 min, respectively; withdrawal of Telocinobufagin reversed to 83.2±17.5% after 45 min. TCB reduced the CAP conduction velocity (CV) to 15.0±15.0 % of the control after 30 min; wash reversed to 78.7±7.2 % of the control. BUPI (1 mM) inhibited the CAP PPA to 46.7±14,4 % and 11.8.±6.5 % of the control after 15 min and 30 min, respectively; it recovered partially to 29.7±8.3 % after 45 min of wash. BUPI inhibited the CAP CV to 17.4±11.2 % of the control after 30 min; it recovered partially to 44.8±14.5 % after 45 min of wash. On rat isolated atrium, TCB (10-6 to 10-4 M) did not alter the spontaneous inotropism, which was abolished by BUPI.
CONCLUSIONS:
Thus, TCB showed a reversible local anesthetic action, similar to BUPI, however, without cardiac toxicity in vitro. This study shows perspectives to research of new molecules for local anesthetic activity with therapeutic interest.

Telocinobufagin enhances the Th1 immune response and protects against Salmonella typhimurium infection.[Pubmed: 25687199]

Int Immunopharmacol. 2015 Apr;25(2):353-62.

Ideal potential vaccine adjuvants to stimulate a Th1 immune response are urgently needed to control intracellular infections in clinical applications. Telocinobufagin (TBG), an active component of Venenum bufonis, exhibits immunomodulatory activity. Therefore, we investigated whether TBG enhances the Th1 immune response to ovalbumin (OVA) and formalin-inactivated Salmonella typhimurium (FIST) in mice.
METHODS AND RESULTS:
TBG augmented serum OVA- and FIST-specific IgG and IgG2a and the production of IFNγ by antigen-restimulated splenocytes. TBG also dramatically enhanced splenocyte proliferative responses to concanavalin A, lipopolysaccharide, and OVA and substantially increased T-bet mRNA levels and the CD3(+)/CD3(+)CD4(+)/CD3(+)CD8(+) phenotype in splenocytes from OVA-immunized mice. In in vivo protection studies, TBG significantly decreased the bacterial burdens in the spleen and prolonged the survival time of FIST-immunized mice challenged with live S. typhimurium. In vivo neutralization of IFNγ with anti-IFNγ mAbs led to a significant reduction in FIST-specific IgG2a and IFNγ levels and in anti-Salmonella effect in TBG/FIST-immunized mice.
CONCLUSIONS:
In conclusion, these results suggest that TBG enhances a Th1 immune response to control intracellular infections.

Mechanism of colon cancer cell apoptosis induced by telocinobufagin: role of oxidative stress and apoptosis pathway.[Pubmed: 27435769]

Nan Fang Yi Ke Da Xue Xue Bao. 2016 Jun 20;36(7):921-6.

To investigate the effects of Telocinobufagin on viability and apoptosis of colorectal cancer (CRC) cells and explore the mechanism of Telocinobufagin-induced apoptosis.
METHODS AND RESULTS:
MTT assay was performed to detect the viability of CRC cells exposed to Telocinobufagin. Nuclear staining with Hoechst 33342 and flow cytometry were used to analyze the cell death of CRC cells. Expressions of proteins related with cell apoptosis and oxidative stress were determined with Western blotting. Telocinobufagin decreased the viability of CRC cells in a time- and dose-dependent manner. The presence of karyopycnosis and apoptotic bodies together with the results of flow cytometry suggested that Telocinobufagin induced cell apoptosis to cause cell death. Western blotting showed that Telocinobufagin exposure of the cells resulted in upregulated p53 and Bax protein expressions and promoted cleavage of caspase 9 and PARP. Telocinobufagin induced phosphorylation of Bad and PARP cleavage, and suppressed phosphorylation of IKBα and TAK1 and expression of survivin in the cells.
CONCLUSIONS:
Telocinobufagin can decrease the viability of CRC cells by inducing cell apoptosis, which involves p53-mediated Bax activation and inhibition of the IAP pathway.

Clin Biochem. 2005 Jan;38(1):36-45.

A novel endogenous digitalis, telocinobufagin, exhibits elevated plasma levels in patients with terminal renal failure.[Pubmed: 15607315]

There are several potential endogenous digitalis-like factors (EDLF) in mammalian body fluids, and marinobufagenin (MBG) may be the most potent EDLF. Improved assays are needed to confirm the potency of these metabolites. In the present study, we have identified MBG and Telocinobufagin (TCB) in human plasma by high-resolution mass spectrometry (MS) and nuclear magnetic resonance (NMR).
METHODS AND RESULTS:
The high-resolution MS analysis revealed the molecular masses of TCB and MBG to be the same as their respective theoretical values. Using a tandem mass spectrometer, the mass-charge ratio for TCB was determined to be 403.2 for the parent ion and 349.2 for the daughter ion. The mass-charge ratio for MBG was m/z 383.2 and m/z 401.2. The NMR study revealed that the signals for MBG and TCB were the same as those obtained by MS analysis. In human blood, MBG and TCB were also identified by liquid chromatography (LC) as well as MS. In the LC/MS assay, proscillaridin A was used as an internal standard. The plasma was pretreated with Sep-Pak C18, and then 50 microL was applied to the C8 high-performance liquid chromatography (HPLC) column. The mean plasma concentration of MBG in healthy volunteers (0.94 +/- 0.28 ng/mL) was significantly lower than that in patients undergoing regular hemodialysis (3.81 +/- 1.92 ng/mL). The concentration of TCB in the healthy volunteers (1.80 +/- 0.55 ng/mL) was also significantly lower than that in patients with terminal renal failure (6.86 +/- 4.30 ng/mL).
CONCLUSIONS:
These results indicate that the major EDLF is TCB because its plasma concentration is the highest among the reported endogenous digitalis candidates.