A phase I single-blind clinical trial to evaluate the safety of oil palm phenolics (OPP) supplementation in healthy volunteers

Syed Fairus, Soon-Sen Leow, Isa Naina Mohamed, Yew-Ai Tan, Kalyana Sundram, Ravigadevi Sambanthamurthi, Syed Fairus, Soon-Sen Leow, Isa Naina Mohamed, Yew-Ai Tan, Kalyana Sundram, Ravigadevi Sambanthamurthi

Abstract

Plant phenolics are being increasingly consumed globally with limited scientific and clinical evidence pertaining to safety and efficacy. The oil palm fruit contains a cocktail of phenolics, and palm oil production results in high volumes of aqueous by-products enriched in phenolics and bioactives. Several lines of evidence from in vitro and in vivo animal studies confirmed that the aqueous extract enriched in phenolics and other bioactives collectively known as oil palm phenolics (OPP) is safe and has potent bioactivity. A phase one clinical trial was conducted to evaluate the safety and effects of OPP in healthy volunteers. In this single-blind trial, 25 healthy human volunteers were supplemented with 450 mg gallic acid equivalent (GAE)/day of OPP or control treatments for a 60-day period. Fasting blood and urine samples were collected at days 1, 30 and 60. Medical examination was performed during these trial interventions. All clinical biochemistry profiles observed throughout the control and OPP treatment period were in the normal range with no major adverse effect (AE) or serious adverse effect (SAE) observed. Additionally, OPP supplementation resulted in improvement of total cholesterol and LDL-C levels, compared to the control treatment. The outcomes support our previous observations that OPP is safe and may have a protective role in reducing cholesterol levels.

Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1
Figure 1
Total cholesterol level in plasma following OPP and control treatments for 60 days. #Time × treatment interaction was significant, p = 0.001 (2-factor repeated measures ANOVA). Based on Wilcoxon signed rank test, TC was significantly lower for OPP treatment compared to control treatment (at day 60), p = 0.025. However, following Bonferroni correction, no significant difference of total cholesterol level was found between OPP and control treatments at day 1, 30 and 60.
Figure 2
Figure 2
LDL-C level following OPP and control treatments for 60 days. #Time × treatment interaction was significant, p = 0.018 (2-factor repeated measures ANOVA). Based on Wilcoxon signed rank test, LDL-C was significantly lower after OPP compared to control treatment (at day 60), p = 0.04. However, following Bonferroni correction, no significant difference of LDL-C level was found between OPP and control treatments at day 1, 30 and 60.
Figure 3
Figure 3
HDL-C level following OPP and control treatments for 60 days. *Baseline HDL-C level was significantly different between treatments, p = 0.038 (Wilcoxon’s signed-rank test). Value was further used as covariates in repeated measures. Although the time × treatment analysis was significant, p = 0.011 (2-factor repeated measures ANOVA), no significant difference of HDL-C level was found between treatments at day 30 and 60 (Wilcoxon signed rank test). Similarly, no significant difference of HDL-C level was found between treatments at day 30 and 60 after Bonferroni correction.

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