|
 
 |
| ORIGINAL ARTICLE |
|
| Year : 2016 | Volume
: 29
| Issue : 2 | Page : 192-197 |
|
A clinical study investigating the impact of adding silymarin to combined therapy (pegylated interferon+ribavirin) on hepatitis C virus viremia
Reda S Badr1, Said S Khamis1, Khalid El-zorkani1, Ahmed M Shakwar2
1 Department of Internal Medicine, Faculty of Medicine, Menoufia University, Menoufia, Egypt
2 Department of Internal Medicine, Berket Elsaba Hospital, Ministry of Health Hospitals, Menoufia, Egypt
| Date of Submission | 15-Jun-2014 |
| Date of Acceptance | 14-Sep-2014 |
| Date of Web Publication | 18-Oct-2016 |
Correspondence Address:
Ahmed M Shakwar
Department of Internal Medicine, Berket Elsaba Hospital, Ministry of Health Hospitals, Menoufia, 32651
Egypt
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/1110-2098.192420
Objectives:
The aim of the study was to evaluate the impact of oral silymarin in hepatitis C virus (HCV) infection when added to conventional treatment [pegylated interferon (IFN)+ribavirin].
Background:
Oral silymarin is widely used for the treatment of HCV as an additive to the conventional therapy but its efficacy is unclear.
Participants and methods:
Sixty consecutive HCV patients referred to our clinic for treatment were recruited. All patients were on combined 180 μg of IFN subcutaneous weekly injection and 800–1200 mg/day ribavirin orally. Patients were randomized into two groups each of 30 patients: the first group received silymarin 140 mg/day orally, whereas the other group did not. Patients had their liver enzymes [aspartate aminotransferase (AST) and alanine aminotransferase (ALT)] and complete blood count checked at baseline and at 12 weeks from the start of treatment. PCR was performed at 12 and 24 weeks from the start of treatment and at 24 weeks after treatment completion.
Results:
The mean age was 37.6 ± 7.9 years, and 23 (38%) patients were female. There was no significant difference between groups regarding their age, sex, AST, ALT, or complete blood count. Compared with patients who did not have silymarin, patients who had silymarin showed significantly lower ALT (29.5 ± 15.7 vs. 44.4 ± 30.4 U/l, P = 0.021), lower AST (26.6 ± 11.5 vs. 40 ± 31 U/l, P = 0.03), similar hemoglobin (11 ± 1.1 vs. 10.6 ± 0.9 g/dl, P = 0.1), higher platelets (170.1 ± 61.9 vs. 133.6 ± 43 × 103/mm3, P = 0.011), and a higher white cell count (3.6 ± 1.1 vs. 2.9 ± 0.8 × 103/mm3, P = 0.011). According to PCR, 24 (80%) patients who received silymarin showed an early virologic response at 12 weeks, whereas only 18 (60%) patients who did not receive silymarin showed early virologic response (P = 0.09). Twenty-four weeks after the completion of therapy, sustained virologic response occurred in all silymarin patients and in only 13 (43%) patients who did not have silymarin (P = 0.003).
Conclusion:
Silymarin may increase the antiviral response and adds a protective benefit against side effects of the conventional IFN/ribavirin therapy in HCV patients. Keywords: hepatitis C infection, pegylated interferon, ribavirin, silymarin
How to cite this article:
Badr RS, Khamis SS, El-zorkani K, Shakwar AM. A clinical study investigating the impact of adding silymarin to combined therapy (pegylated interferon+ribavirin) on hepatitis C virus viremia. Menoufia Med J 2016;29:192-7 |
How to cite this URL:
Badr RS, Khamis SS, El-zorkani K, Shakwar AM. A clinical study investigating the impact of adding silymarin to combined therapy (pegylated interferon+ribavirin) on hepatitis C virus viremia. Menoufia Med J [serial online] 2016 [cited 2023 Oct 2];29:192-7. Available from: http://www.mmj.eg.net/text.asp?2016/29/2/192/192420 |
| Introduction | |  |
Hepatitis C virus (HCV) infection has acute and chronic forms, with most of the morbidity occurring through the development of chronic liver disease. In Egypt, HCV is one of the top five leading causes of death. Most of the infected individuals are not aware of their infective status and are not clinically ill, but they are a source of infection to others [1]. No protective vaccine against HCV is available currently [2]. Treatment is costly, requires long-term medical support and follow-up, and has serious side effects. Modern therapies are not affordable for the majority of the HCV carriers worldwide. In Egypt, the prevalence rate of HCV infections has been reported to be as high as 20%. The annual infection rate is more than 70 000 new cases, of which at least 35 000 would have chronic hepatitis C [3].
The Egyptian Ministry of Health and Population (MOHP) has a national plan for HCV control and prevention strategies and advices government and private healthcare providers, but does not have an impact on the practices of informal healthcare providers offering services such as wound sutures, abscess drainage, therapeutic injections, teeth extractions, birth attendance, circumcision, and bloodletting [4]. Informal healthcare providers operate outside the government framework and lack safe and hygienic practices. There is an urgent need not only to reduce the transmission of HCV infection but also to avoid chronic liver disease in HCV-infected individuals through appropriate medical management and counseling [4].
Silymarin is an extract of the milk thistle (Silybum marianum) [5]. The tea made of milk thistle was used for the treatment of liver diseases in the ancient times. Dating back to the time of the ancient Greeks (Theophrastus, fourth century BC) and Romans (Pliny the Elder, first century AD), the seeds of milk thistle (also known as St Mary's thistle and lady's thistle) have been used to protect liver health. In the first century AD, Dioskurides used this plant as an emetic as well as a general medicinal herb. It became a favored medicine for hepatobiliary diseases in the 16th century, and the drug was revived again in 1960 in central Europe. Milk thistle grows up to 6 ft tall, especially well on sunny slopes in Mediterranean countries, particularly Spain and Greece. The plant of the milk thistle blooms from June through August, and the shiny black seeds are harvested after the end of the summer to be used for medicinal purposes. Silymarin inhibits HCV by displaying antioxidant, anti-inflammatory, and immunomodulatory actions that contribute to its hepatoprotective effects [6],[7],[8].
The antioxidative properties of silibinin in chronic hepatitis C may improve the response to the conventional pegylated interferon (Peg-IFN)/ribavirin therapy. There are several clinical studies on the use of herbal extracts, especially silymarin, for the treatment of patients with chronic hepatitis C, primarily in the belief that this drug improves the response to antiviral agents and reduces adverse reactions. Oral silymarin is widely used for the treatment of HCV as an additive to conventional therapy, but its efficacy is unclear [6],[7],[8].
Accordingly, the aim of this study was to evaluate the impact of oral silymarin in HCV infection when added to conventional treatment (Peg-IFN/ribavirin).
| Participants and Methods | | |
Sixty consecutive patients, diagnosed to have HCV infection, referred to the outpatient clinic of Menoufia University Hospital, Department of Internal Medicine, were recruited. The study followed a double-blinded design. Patients were recruited and were allocated to the treatment group by an investigator who understood the study design, but was blinded to data collection and outcomes, whereas another investigator who was blinded to the patient allocations did all data collection and analyses. The allocation was performed in a consecutive manner, that is, 60 consecutive patients were recruited, of whom the first 30 were allocated to conventional therapy+silymarin group and followed up and the second 30 were allocated to undergo only conventional dual therapy and were then followed up. Patients were excluded if they had any of the following: advanced liver disease, concomitant hepatitis B or HIV infections, chronic renal disease that required dialysis, any history of previous IFN therapy, history of convulsions, or if pregnant. The study was approved by our institution's local ethics committee, and written informed consent was given by all patients.
Baseline measurements
For all patients, a blood sample was withdrawn to measure serum bilirubin, the liver enzymes aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and the complete blood count (CBC), including the hemoglobin level, the white blood cell count, and the platelet count. In addition, all patients at baseline had an abdominal ultrasonography performed with special emphasis on the liver size, the portal vein size, the presence of liver fibrosis, and the presence of increased liver echogenicity. Finally, a basal PCR for the HCV viral load was performed for all patients.
The hepatitis C virus treatment course
All patients were given combined IFN and ribavirin therapy (IFN: 180 µg subcutaneous weekly injection; ribavirin: weight based at a dose of 15 mg/kg body weight orally in three divided doses). Patients were then randomized into two groups each composed of 30 patients: the first group received silymarin 140 mg/day (Legalon; Madaus GmbH, Cologne, Germany) orally divided into two doses added to the previously described therapy, whereas the other group did not receive additive silymarin. Treatment with either combinations continued for 48 weeks.
Follow-up
Patients were scheduled for four follow-up visits {12, 24, and 48 weeks from the start of treatment, and 24 weeks after the last visit (completion of treatment courses)}. PCR results were checked during each visit, whereas AST, ALT, and CBC were checked only 12 weeks after the start of the treatment courses. PCR at 24 weeks after treatment completion was performed to detect a sustained virologic response (SVR). All patients reported compliance with the treatment as planned and with the decided doses.
Discontinuation of therapy and relapse
In both study groups, both treatment strategies were discontinued if the decrease in HCV RNA was less than 2 log IU/ml 12 weeks after starting the course of treatment by PCR [early virologic response (EVR)]. Relapse was documented if PCR showed a positive result at the 24-week post-treatment visit after continuing negative results during treatment.
Study endpoints
The primary endpoint of the study was to determine the effect of silymarin on SVR. The secondary endpoints were to determine the effect of silymarin therapy on liver enzymes and bone marrow depression at 12 weeks since the start of treatment compared with basal values.
Statistical analysis
Categorical data were expressed as n (%) and were compared using the c 2-test. Continuous data were expressed as mean ± SD and were compared between groups using the paired Student t-test between results before and after treatment and the unpaired t-test between patients who received silymarin and patients who did not. P-value less than 0.05 was considered statistically significant. Before starting the study, the SVR 24 weeks after treatment completion was checked retrospectively in 10 patients: five of them had already received conventional+silymarin therapy [all (100%) showed SVR] and five had conventional therapy only [four (80%) showed SVR]. A sample of minimum 15 patients on each arm was required to achieve a statistical significance of less than 0.5 and a β-value of 50%. A sample size of 30 patients on each arm was found to have a statistical power of 79% to detect SVR differences between groups. All the analyses were performed with the commercially available software (SPSS version 21.0; SPSS Inc., Chicago, Illinois, USA).
| Results | | |
Basal demographic and laboratory data for all patients
The study included 60 patients: their mean age was 37.6 ± 7.9 years and 23 (38%) patients were female. Eleven (18%) patients had a history of schistosomiasis. The basal serum bilirubin was 37.95 ± 7.9. Abdominal ultrasonography showed an enlarged liver in 13 (22%) patients, increased liver echogenicity in 13 (22%) patients, and liver fibrosis in eight (13%) patients, and their portal vein size was 12.1 ± 1.2 mm ([Table 1]). | Table 1: Basal demographic and laboratory data of all patients and subgroups
Click here to view |
There was no significant difference between patients who received silymarin and patients who did not regarding their age, sex, history of schistosomiasis, or serum bilirubin.
In addition, there was no significant difference between patients who received silymarin and patients who did not regarding the presence of ultrasonography-proven enlarged liver, increased liver echogenicity, liver fibrosis, or portal vein size.
Liver function and complete blood count basally and at 12 weeks from the start of treatment
There was no significant difference between patients who took silymarin and patients who did not regarding their basal ALT, basal AST, basal hemoglobin, basal platelet count, basal white blood cell count, and basal PCR. At 12 weeks from the start of therapy, ALT and AST decreased significantly, and hemoglobin, the platelet count, and the white blood cell count also decreased significantly ([Table 2]). | Table 2: Liver function and complete blood count basally and at 12 weeks from the start of treatment
Click here to view |
Comparisons regarding the response to therapy according to silymarin therapy and the primary endpoint
Overall, 42 patients showed an EVR (confirmed by negative PCR values at 12 weeks), of whom 24 patients received silymarin and 18 patients did not (P = 0.09). Discontinuation of therapy occurred in 18 patients on the basis of the finding of elevated positive PCR values during the 12-week visit after the start of treatment. Six of these patients received silymarin and 12 did not (P = 0.09). It is of note that all patients who showed EVR continued to have undetectable PCR at 24 and 48 weeks after treatment start. At 24 weeks of follow-up after treatment, five (12%) out of the 42 patients had relapse, confirmed by the absence of SVR because of re-elevation of PCR, and all of them did not receive silymarin therapy, which was significantly higher than those who received silymarin (P = 0.02). Finally, the overall number of patients who showed SVR (responders) after completion of treatment was 37 (62%), of whom 28 patients received silymarin and 13 patients did not (P = 0.003) ([Table 3] and [Figure 1]). | Table 3: The primary endpoint and comparisons regarding the response to therapy according to silymarin therapy
Click here to view |
 | Figure 1: Response to therapy at 24 week after treatment. Patients who received silymarin showed less relapse or discontinuation of therapy because of failure to show an early virologic response than patients who did not receive silymarin
Click here to view |
It is worth noting that all patients who received silymarin and had EVR also showed SVR.
Comparisons for secondary endpoints
Interestingly, at 12 weeks from the start of treatment, patients who received silymarin had significantly lower ALT and AST, a higher platelet count, and a higher white blood cell count. The hemoglobin level, despite being relatively higher in patients who received silymarin, did not reach statistical significance ([Table 4]). | Table 4: Comparisons for secondary endpoints according to silymarin therapy
Click here to view |
| Discussion | | |
The present study showed that adding oral silymarin therapy to the conventional combination of IFN/ribavirin therapy increased the response to treatment, decreased the levels of liver enzymes (ALT, AST), and caused less bone marrow depression.
The use of silymarin as an add-on therapy to the conventional combination (Peg-IFN/ribavirin) seemed to be of considerable value in our study. This was noticed early in the course of treatment when we found that patients who received silymarin showed significantly more EVR and that all these patients continued to show SVR (i.e. no relapse) compared with patients who did not receive silymarin, among whom fewer patients showed EVR and five showed relapse. In addition to the lower liver enzymes noticed in all patients treated with silymarin, this clearly shows a possible clinical antiviral benefit of silymarin add-on treatment.
In contrast, our study shows another major benefit of silymarin add-on therapy, which is the taming of bone marrow depression, which is a common side effect of IFN.
The above results of our study might signify that the effect of oral silymarin add-on therapy is beneficial both as a treatment of HCV itself and as a protection against the adverse effects of other conventional therapies.
Oral silymarin is widely used in the treatment of hepatitis C, but its efficacy is unclear. The mechanism of the antiviral effect of silymarin is unknown. The effect might be a direct inhibition of viral replication due in part to the stimulation of the Jak–Stat pathway and the induction of an IFN antiviral response. However, virologic studies suggested that IFN-independent or Jak–Stat-independent mechanisms may be more closely associated with silymarin's anti-HCV effects [9]. Other possible mechanisms could involve Toll-like receptor 7 [0], IFN regulatory factor 3 [1], and p38 mitogen-activated protein kinase pathways [2], all of which can modulate antiviral responses independent of the IFN→Jak–Stat→IFN-stimulated gene paradigm.
It is also important to note that discrepancies in the effect of silymarin in different studies might be due to the effect of the dose and the route of administration of the drug. Because of the complexicity of absorption, metabolism, and the nature of disposition of various flavonoids, it is still largely unclear as to which form of flavonoid (i.e. the parent flavonoid or its metabolites) contributes to the overall effects in the body.
Reportedly, intravenous silymarin infusion (10 mg/kg), administered for 8 days in patients with chronic hepatitis caused by HCV (P < 0.001) reduced the HCV viral load significantly, and thus, it increased the efficacy of Peg-IFN+ribavirin therapy and also reduced ALT levels [3]. The findings of our study reproduce these results; however, in our study, 140 mg/day oral silymarin, and not intravenous silymarin, was used as an add-on treatment to the full course of 48 weeks' conventional therapy. In addition, our study showed that this treatment regimen decreased the known side effect of IFN therapy, which is bone marrow depression.
Nevertheless, these findings oppose clinical studies by Tanamly et al. [4], and Gabbay et al. [5], who found no effect of oral silymarin on HCV in patients with chronic hepatitis C. The main differences between our study and these studies lie in the fact that in the first study, oral silymarin was used for patients who had failure of IFN therapy, whereas in our study, silymarin was added to the therapy, irrespective of the response to IFN.
It is worth noting that in nonresponders (i.e. patients who showed no EVR), the virus load at 12 weeks was not different between patients who received silymarin and patients who did not, which might coincide with the findings of that study; however, among patients who continued therapy for 48 weeks, SVR occurred more in patients who received silymarin. This might signify the importance of a long-term potentiation and antiviral effect in a cohort of patients that showed initial response to IFN therapy. Other studies were more concerned about studying the effect of silymarin monotherapy or the comparison between the effect of oral and intravenous silymarin [14],[15].
Study limitations
Unfortunately, this study suffered from some important limitations. First, the study included a small number of patients; second, there was no placebo given in the control group; finally, different doses and routes of administration of silymarin were not compared.
As the study suffers from these limitations, the study can only provide preliminary data regarding the benefits of adding silymarin to the regimen. Therefore, a larger randomized controlled trial is required to confirm the results.
| Conclusion | | |
From the results of this study, it was concluded that the addition of silymarin to the conventional therapy of IFN/ribavirin might increase the antiviral response to the conventional therapy as it potentiates the response to treatment, produces a better SVR, causes less relapse after treatment, and decreases liver enzymes (ALT, AST). Addition of silymarin might also provide protection against the side effects of the conventional therapy as it decreases bone marrow depression.
Conflicts of interest
There are no conflicts of interest.
| References | | |
| 1. | |
| 2. | Simmonds P. Genetic diversity and evolution of hepatitis C virus – 15 years on. J Gen Virol 2004; 85:3173–3188.  |
| 3. | El-Ahmady O, Halim AB, Mansour O, Salman T. Incidence of hepatitis C virus in Egyptians. J Hepatol 1994; 21:687. |
| 4. | |
| 5. | Lee DY, Liu Y. Molecular structure and stereochemistry of silybin A, silybin B, isosilybin A, and isosilybin B, isolated from Silybum marianum (milk thistle). J Nat Prod 2003; 66:1171–1174. |
| 6. | Pietrangelo A, Borella F, Casalgrandi G, Montosi G, Ceccarelli D, Gallesi D, et al. Antioxidant activity of silybin in vivo during long-term iron overload in rats. Gastroenterology 1995; 109:1941–1949. |
| 7. | Lucena MI, Andrade RJ, de la Cruz JP, Rodriguez-Mendizabal M, Blanco E, Sánchez de la Cuesta F. Effects of Silymarin MZ-80 on oxidative stress in patients with alcoholic cirrhosis. Results of a randomized, double-blind, placebo-controlled clinical study. Int J Clin Pharmacol Ther 2002; 40:2–8. |
| 8. | Mira L, Silva M, Manso CF. Scavenging of reactive oxygen species by silibinin dihemisuccinate. Biochem Pharmacol 1994; 48:753–759. |
| 9. | Polyak SJ, Morishima C, Shuhart MC, Wang CC, Liu Y, Lee DY. Inhibition of T-cell inflammatory cytokines, hepatocyte NF-kappaB signaling, and HCV infection by standardized Silymarin. Gastroenterology 2007; 132:1925–1936. |
| 10. | Lee J, Wu CC, Lee KJ, Chuang TH, Katakura K, Liu YT, et al. Activation of anti-hepatitis C virus responses via Toll-like receptor 7. Proc Natl Acad Sci USA 2006; 103:1828–1833. |
| 11. | Grandvaux N, Gaboriau F, Harris J, ten Oever BR, Lin R, Hiscott J. Regulation of arginase II by interferon regulatory factor 3 and the involvement of polyamines in the antiviral response. FEBS J 2005; 272:3120–3131. |
| 12. | Platanias LC. The p38 mitogen-activated protein kinase pathway and its role in interferon signaling. Pharmacol Ther 2003; 98:129–142. |
| 13. | Ferenci P, Laferl H, Scherzer TM, Gschwantler M, Maieron A, Brunner H, et al. Austrian Hepatitis Study Group Peginterferon alfa-2a and ribavirin for 24 weeks in hepatitis C type 1 and 4 patients with rapid virological response. Gastroenterology 2008; 135:451–458. |
| 14. | Tanamly MD, Tadros F, Labeeb S, Makld H, Shehata M, Mikhail N, et al. Randomised double-blinded trial evaluating silymarin for chronic hepatitis C in an Egyptian village: study description and 12-month results. Dig Liver Dis 2004; 36:752–759. |
| 15. | Gabbay E, Zigmond E, Pappo O, Hemed N, Rowe M, Zabrecky G, et al. Antioxidant therapy for chronic hepatitis C after failure of interferon: results of phase II randomized, double-blind placebo controlled clinical trial. World J Gastroenterol 2007; 13:5317–5323. |
[Figure 1]
[Table 1], [Table 2], [Table 3], [Table 4]
|
Search Pubmed for