The Pharmacologically Active Alkaloid Cryptolepine Activates a Type 1 Interferon Response That Is Independent of MAVS and STING Pathways.

Type 1 interferons (IFN-1) are pleiotropic cytokines with well-established anticancer and antiviral properties, particularly in mucosal tissues. Hence, natural IFN-1-inducing treatments are highly sought after in the clinic. Here, we report for the first time that cryptolepine, a pharmacoactive alkaloid in the medicinal plant Cryptolepis sanguinolenta, is a potent IFN-1 pathway inducer. Cryptolepine increased the transcript levels of JAK1, TYK2, STAT1, STAT2, IRF9, and OAS3, as well as increased the accumulation of STAT1 and OAS3 proteins, similar to recombinant human IFN-α. Cryptolepine effects were observed in multiple cell types including a model of human macrophages. This response was maintained in MAVS and STING-deficient cell lines, suggesting that cryptolepine effects are not mediated by nucleic acids released upon nuclear or organelle damage. In agreement, cryptolepine did not affect cell viability in concentrations that triggered potent IFN-1 activation. In addition, we observed no differences in the presence of a pharmacological inhibitor of TBK1, a pleiotropic kinase that is a converging point for Toll-like receptors (TLRs) and nucleic acid sensors. Together, our results demonstrate that cryptolepine is a strong inducer of IFN-1 response and suggest that cryptolepine-based medications such as C. sanguinolenta extract could be potentially tested in resource-limited regions of the world for the management of chronic viral infections as well as cancers.

Evaluation of inflammatory and liver injury biomarkers among drug-naive viral hepatitis B patients: A study in a referral laboratory, Ghana

Background and Aim: Globally, hepatitis B virus (HBV) infection is among the commonest chronic infections and the leading cause of liver cancer. This study evaluated inflammatory and liver injury biomarkers among newlydiagnosed HBV-infected patients to reveal inflammation and liver injury levels. Patients and Methods: This case-control study was conducted among 146 newly diagnosed drug-naive patients and 64 blood donors. Questionnaires were administered to obtain demographic data. Blood samples were collected to assess viral serological markers, inflammatory markers, liver function, and hematological indices. Also, noninvasive markers of liver fibrosis (APRI: aspartate transaminase - platelet ratio index, FIB-4: fibrosis 4 index, and AAR: aspartate - alanine transaminase ratio) were mathematically derived. The patients were categorized into acute and chronic infections based on their viral serological markers. Results: Overall, 81.5% of the patients had an acute HBV infection, whereas 18.5% had a chronic HBV infection. There was a significant increase in the biomarkers of inflammation, C-reactive protein (CRP) and interleukin 6, and liver injury (liver transaminases, FIB-4 index, and APRI) among the drug-naive chronic HBV-infected patients. The study also revealed significant anemia and leucocytosis in patients with chronic HBV infection. Further, the study showed a strong correlation between CRP and alanine transaminase among patients with chronic HBV infection. Conclusion: There was increased anemia, inflammation, and liver fibrosis among the drug-naive chronic HBVinfected patients; hence, public education is required so patients with viral hepatitis B in Ghana would visit the clinic earlier enough for proper clinical management.

Cryptolepine inhibits hepatocellular carcinoma growth through inhibiting interleukin-6/STAT3 signalling.

BACKGROUND: Diverse signalling pathways are involved in carcinogenesis and one of such pathways implicated in many cancers is the interleukin 6/signal transducer and activator of transcription 3 (IL-6/STAT3) signalling pathway. Therefore, inhibition of this pathway is targeted as an anti-cancer intervention. This study aimed to establish the effect of cryptolepine, which is the main bioactive alkaloid in the medicinal plant Cryptolepis sanguinolenta, on the IL-6/STAT3 signalling pathway. METHODS: First, the effect of cryptolepine on the IL-6/STAT3 pathway in human hepatoma cells (HepG2 cells) was screened using the Cignal Finder Multi-Pathway Reporter Array. Next, to confirm the effect of cryptolepine on the IL-6/STAT3 signalling pathway, the pathway was activated using 200 ng/mL IL-6 in the presence of 0.5-2 µM cryptolepine. The levels of total STAT3, p-STAT3 and IL-23 were assessed by ELISA. RESULTS: Cryptolepine downregulated 12 signalling pathways including the IL-6/STAT3 signalling pathway and upregulated 17 signalling pathways. Cryptolepine, in the presence of IL-6, decreased the levels of p-STAT3 and IL-23 in a dose-dependent fashion. CONCLUSION: Our results demonstrated that cryptolepine inhibits the IL-6/STAT3 signalling pathway, and therefore cryptolepine-based remedies such as Cryptolepis sanguinolenta could potentially be used as an effective immunotherapeutic agent for hepatocellular carcinoma and other cancers.

Aflatoxin B1 inhibits the type 1 interferon response pathway via STAT1 suggesting another mechanism of hepatocellular carcinoma.

BACKGROUND: Aflatoxin B1 (AFB1) contamination of food is very high in most sub-Saharan African countries. AFB1 is known to cause hepatocellular carcinoma (HCC) by inducing mutation in the tumour suppressor gene TP53. The number of new HCC cases is high in West Africa with an accompanying high mortality. The type I interferon (IFN) pathway of the innate immune system limits viral infections and exerts its anti-cancer property by up-regulating tumour suppressor activities and pro-apoptotic pathways. Indeed, IFN-α is reported to show significant protective effects against hepatic fibrogenesis and carcinogenesis. However, the mechanism behind AFB1 deregulation of the type I interferon (IFN) signalling pathway, with consequent HCC is largely unknown. This current study seeks to test the hypothesis that AFB1 inhibits the type I IFN response by directly interfering with key signalling proteins and thus increase the risk of HCC in humans. METHODS: We evaluated the effects of AFB1 on the type I IFN signalling pathway using IFN stimulated response element (ISRE)-based luciferase reporter gene assay. In addition, the effects of AFB1 on the transcript levels of JAK1, STAT1 and OAS3 were assessed by real-time quantitative polymerase chain reaction (RT-qPCR) and confirmed by immunoblot assay. RESULTS: Our results indicated that AFB1 inhibited the type I IFN signalling pathway in human hepatoma cell line HepG2 cells by suppressing the transcript levels of JAK1, STAT1 and OAS3. AFB1 also decreased the accumulation of STAT1 protein. CONCLUSION: The inhibition of the type I IFN anti-cancer response pathway by AFB1 suggest a novel mechanism by which AFB1 may induce hepatocellular carcinoma in humans.

Risk factors associated with hepatitis B exposure and the reliability of five rapid kits commonly used for screening blood donors in Ghana.

BACKGROUND: Hepatitis B virus infection (HBV) is one of the most widespread, chronic viral infections in sub-Saharan Africa, and parts of South America. Therefore, efforts are being made to implement strategies aimed at reducing the incidence of hepatitis B viral infections. One route of HBV transmission is through unsafe blood transfusion, which could occur from the use of less sensitive laboratory diagnostic kits. Information on the sensitivity and specificity of these kits is however limited in many developing countries. This study was therefore performed to describe the prevalence of HBV infections and also to evaluate the performance of five rapid immunochromatographic kits commonly used in Ghana. METHODS: A cross-sectional study was designed to describe the prevalence of HBsAg infection and also evaluate the performance of rapid kits used for screening hepatitis B in the northern part of Ghana. RESULTS: A total of 164 prospective blood donors were enrolled in this study from January 2012 to December 2013. The overall true prevalence of HBsAg was 14.6 (95% CI = 9.6 - 21.0). There was no significant association between transmission related factors and HBV infection. The specificities of all five rapid kits were above 97%, however the sensitivities and Youden's indexes were below 60%. A comparison of the reported kit sensitivities to those generated by this study showed significant difference with the study results being lower than the ones reported in the kit literature. CONCLUSION: Our study has shown that rapid HBsAg kits on the Ghanaian markets may not be helpful for screening blood donor samples. We therefore recommend the use of commercially available enzyme linked immunosorbent assays.