Gambogic Acid and Piperine Synergistically Induce Apoptosis in Human Cholangiocarcinoma Cell via Caspase and Mitochondria-Mediated Pathway

Most cholangiocarcinoma (CCA) patients undergo chemotherapy as a therapeutic approach due to the disease's frequently late diagnosis. However, because CCA is resistant to currently available treatments, the prognosis for this cancer is still quite poor. Combination therapy has emerged as a novel and promising strategy in cancer treatment, as monotherapy frequently results in tumor recurrence and drug resistance. Gambogic acid has been shown to have a synergism with other compounds in combating certain cancer cells. Moreover, piperine has been shown to improve the efficacy of numerous chemotherapy drugs and other anticancer natural substances. However, no research has been done on the combination of these two compounds in the treatment of bile duct cancer. In this study, the cytotoxic activity was determined by using the MTT assay, and then, the combined effect was assessed by using the combination index (CI). We found that the combination of gambogic acid and piperine inhibited cell viability more effectively than either treatment alone, and it also demonstrated a synergistically cytotoxic effect against CCA cells. Interestingly, the findings allowed the use of lower concentrations of gambogic acid in cancer treatment when combined with piperine, which could reduce its adverse effect on normal cholangiocytes. Furthermore, the combination of the two compounds increased CCA cell death by inducing apoptosis via both the extrinsic and intrinsic or mitochondria-mediated pathways, as determined by caspase-3, -8, and -9 activity and the reduction of mitochondrial transmembrane potential (ΔΨm). It is possible that the use of these two natural compounds together could be a promising strategy for the treatment of bile duct cancer.

Coronavirus Infection-Associated Cell Death Signaling and Potential Therapeutic Targets

COVID-19 is the name of the disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection that occurred in 2019. The virus-host-specific interactions, molecular targets on host cell deaths, and the involved signaling are crucial issues, which become potential targets for treatment. Spike protein, angiotensin-converting enzyme 2 (ACE2), cathepsin L-cysteine peptidase, transmembrane protease serine 2 (TMPRSS2), nonstructural protein 1 (Nsp1), open reading frame 7a (ORF7a), viral main protease (3C-like protease (3CLpro) or Mpro), RNA dependent RNA polymerase (RdRp) (Nsp12), non-structural protein 13 (Nsp13) helicase, and papain-like proteinase (PLpro) are molecules associated with SARS-CoV infection and propagation. SARS-CoV-2 can induce host cell death via five kinds of regulated cell death, i.e., apoptosis, necroptosis, pyroptosis, autophagy, and PANoptosis. The mechanisms of these cell deaths are well established and can be disrupted by synthetic small molecules or natural products. There are a variety of compounds proven to play roles in the cell death inhibition, such as pan-caspase inhibitor (z-VAD-fmk) for apoptosis, necrostatin-1 for necroptosis, MCC950, a potent and specific inhibitor of the NLRP3 inflammasome in pyroptosis, and chloroquine/hydroxychloroquine, which can mitigate the corresponding cell death pathways. However, NF-κB signaling is another critical anti-apoptotic or survival route mediated by SARS-CoV-2. Such signaling promotes viral survival, proliferation, and inflammation by inducing the expression of apoptosis inhibitors such as Bcl-2 and XIAP, as well as cytokines, e.g., TNF. As a result, tiny natural compounds functioning as proteasome inhibitors such as celastrol and curcumin can be used to modify NF-κB signaling, providing a responsible method for treating SARS-CoV-2-infected patients. The natural constituents that aid in inhibiting viral infection, progression, and amplification of coronaviruses are also emphasized, which are in the groups of alkaloids, flavonoids, terpenoids, diarylheptanoids, and anthraquinones. Natural constituents derived from medicinal herbs have anti-inflammatory and antiviral properties, as well as inhibitory effects, on the viral life cycle, including viral entry, replication, assembly, and release of COVID-19 virions. The phytochemicals contain a high potential for COVID-19 treatment. As a result, SARS-CoV-2-infected cell death processes and signaling might be of high efficacy for therapeutic targeting effects and yielding encouraging outcomes.

Anticancer effects of a traditional Thai herbal recipe Benja Amarit extracts against human hepatocellular carcinoma and colon cancer cell by targeting apoptosis pathways

ETHNOPHARMACOLOGICAL RELEVANCE

A preparation of Benja Amarit (BJA) has been effectively used in folk medicine to treat diseases related to the liver and colon and forms of cancer for hundreds of years in Thailand. However, there has not been any research on BJA with regard to its anticancer activity against human hepatocellular carcinoma and colon cancer cells.

AIM OF THE STUDY

This study was to obtain the scientific supports for the traditional usage in anticancer potential of BJA extracts on hepatocellular carcinoma and colon cancer.

MATERIALS AND METHODS

The cytotoxic effects were determined using MTT assay. Apoptosis was quantitated by annexin V-FITC/PI staining. Caspases activities were measured by using specific substrates and colorimetric analysis. The protein expressions were determined by Western blot analysis. Reactive oxygen species (ROS) generation, mitochondrial transmembrane potential, and calcium ion levels were measured by specific fluorescence probes and flow cytometry. The chick embryo chorioallantoic membrane model has been used to study the in vivo anticancer activity. The phytochemical identification was performed by GC-MS and LC-MS.

RESULTS

Notably, 95% (BJA-95) and 50% (BJA-50) ethanolic extract of BJA inhibited hepatocellular carcinoma and colon cancer cell viability in a dose-dependent manner. While, the water extract of BJA (BJA-W) was not found to be toxic to both kinds of cancer cell lines. BJA extract induced both the extrinsic and intrinsic or mitochondria-mediated apoptosis pathways. Moreover, BJA-95 caused ROS generation and endoplasmic reticulum stress-mediated apoptosis. The extract exhibited the growth inhibitory effects on cancer cells in vivo. Phytochemical analysis revealed that the major active compounds were piperine, xanthotoxol and dihydrogambogic acid.

CONCLUSION

This study is the first to demonstrate anticancer efficiency of BJA extracts on human cancer cells. We consider BJA extract to be a potentially alternative cancer treatment and to be a promising candidate in the future development of antitumor agents.