METHODS: We performed a randomized, double-blind, placebo-controlled trial of consecutive adults with biopsy-proven NASH and a NAFLD activity score (NAS) of 4 or more at a tertiary care hospital in Kuala Lumpur, Malaysia, from November 2012 through August 2014. Patients were randomly assigned to groups given silymarin (700 mg; n = 49 patients) or placebo (n = 50 patients) 3 times daily for 48 weeks. After this 48-week period, liver biopsies were repeated. The primary efficacy outcome was a decrease of 30% or more in NAS; findings from 48-week liver biopsies were compared with those from the baseline biopsy. Secondary outcomes included changes in steatosis, lobular inflammation, hepatocyte ballooning, NAS and fibrosis score, and anthropometric measurements, as well as glycemic, lipid, and liver profiles and liver stiffness measurements.
RESULTS: The percentage of patients achieving the primary efficacy outcome did not differ significantly between the groups (32.7% in the silymarin group vs 26.0% in the placebo group; P = .467). A significantly higher proportion of patients in the silymarin group had reductions in fibrosis based on histology (reductions of 1 point or more; 22.4%) than did the placebo group (6.0%; P = .023), and based on liver stiffness measurements (decrease of 30% or more; 24.2%) than did the placebo group (2.3%; P = .002). The silymarin group also had significant reductions in mean aspartate aminotransferase to platelet ratio index (reduction of 0.14, P = .011 compared with baseline), fibrosis-4 score (reduction of 0.20, P = .041 compared with baseline), and NAFLD fibrosis score (reduction of 0.30, P < .001 compared with baseline); these changes were not observed in the placebo group (reduction of 0.07, P = .154; increase of 0.18, P = .389; and reduction of 0.05, P = .845, respectively). There was no significant difference between groups in number of adverse events; adverse events that occurred were not attributed to silymarin.
CONCLUSIONS: In a randomized trial of 99 patients, we found that silymarin (700 mg, given 3 times daily for 48 weeks) did not reduce NAS scores by 30% or more in a significantly larger proportion of patients with NASH than placebo. Silymarin may reduce liver fibrosis but this remains to be confirmed in a larger trial. It appears to be safe and well tolerated. ClinicalTrials.gov: NCT02006498.
PURPOSE: This scoping review aims to describe the effect of lipid-based formulations on the oral bioavailability of herbal compounds.
METHODS: A systematic search was conducted across three electronic databases (Medline, Embase and Cochrane Library) between January 2010 and January 2021 to identify relevant studies. The articles were rigorously screened for eligibility. Data from eligible studies were then extracted and collated for synthesis and descriptive analysis using Covidence.
RESULTS: A total of 109 studies were included in the present review: 105 animal studies and four clinical trials. Among the formulations investigated, 50% were emulsions, 34% lipid particulate systems, 12% vesicular systems, and 4% were other types of lipid-based formulations. Within the emulsion system classification, self-emulsifying drug delivery systems were observed to produce the best improvements in oral bioavailability, followed by mixed micellar formulations. The introduction of composite lipid-based formulations and the use of uncommon surfactants such as sodium oleate in emulsion preparation was shown to consistently enhance the bioavailability of herbal compounds with poor oral absorption. Interestingly, the lipid-based formulations of magnesium lithospermate B and Pulsatilla chinensis produced an absolute bioavailability greater than 100% indicating the possibility of prolonged systemic circulation. With respect to chemical conjugation, D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) was the most frequently used and significantly improved the bioavailability of its phytoconstituents.
CONCLUSION: Our findings suggest that there is no distinct lipid-based formulation superior to the other. Bioavailability improvements were largely dependent on the nature of the phytoconstituents. This scoping review, however, provided a detailed summary of the most up-to-date evidence on phytoconstituents formulated into lipid preparations and their oral bioavailability. We conclude that a systematic review and meta-analysis between bioavailability improvements of individual phytoconstituents (such as kaempferol, morin and myricetin) in various lipid-based formulations will provide a more detailed association. Such a review will be highly beneficial for both researchers and herbal manufacturers.