ABSTRACT & COMMENTARY
Improved Natural Killer Cell Function with Seaweed Extract New findings on how nori seaweed may enhance the immune system REFERENCE
Jung SJ, Jang HY, Jung ES, et al. Effects of porphyra tenera supplementation on the immune system: A randomized, double-blind, and placebo-controlled clinical trial. Nutrients. 2020;12(6). DESIGN
Randomized, double-blind, placebocontrolled trial of 8-weeks duration OBJECTIVE
To determine if an extract of the seaweed Porphyra tenera (commonly known as nori or laver, and also referred to as Pyropia tenera) has measurable immune-enhancing effects and is safe in humans PARTICIPANTS
A total of 111 participants out of 120 (men=20, women=100) completed the trial. Researchers equally recruited intervention and placebo groups (60 each). All participants were over the age of 50 at the start of the study and all had white blood cell (WBC) counts in the normal range (3,000 to 8,000 cells/µL). Exclusion criteria was extensive and included the following: vaccination for influenza within the prior 3 months, body mass index (BMI) <18 kg/m2 or >35 kg/m2, presence of any acute disease process or chronic disease process, any supplementation with medications or functional foods associated with immune enhancement for the prior month, use of antipsychotic drugs in the prior 3 months, suspected alcoholism or drug abuse, participation in other human tests in the prior 3 months, those who are fertile and
not on contraceptives, and those with abnormal liver or kidney function tests (aspartate aminotransferase [AST] or alanine aminotransferase [ALT] more than 3 times the upper normal limit, serum creatinine >2.0 mg/dL). INTERVENTION
Participants in the intervention group consumed 2.5 g/d of Porphyra tenera extract (PTE) in capsule form. The extraction process began as 100 kg of dried Porphyra tenera in 10% ethanol at 80 ± 2.0 degrees Celsius. The ethanol-extracted fluid was then processed through a 1-µm filter, lyophilized, and concentrated to 10–20 degrees Brix at 65–70 degrees Celsius. The end product contained 68.45 (±20%) mg/g of a specific porphyran called porphyra334 (designating the chemical structure of the porphyran from this species). The placebo was identical in weight, color, and flavor and contained 99.6% microcrystalline cellulose, 0.2% caramel coloring, and 0.2% silicon dioxide. PRIMARY OUTCOME MEASURES
Function of natural killer (NK) cells at week 0 versus week 8. Researchers measured this using CytoTox 96® Non-Radioactive Cytotoxicity Assay kit (Promega Corp, Madison, WI). Cytotoxicity was expressed as a percentage using both natural release and maximal release of lactate dehydrogenase (LDH), using K562 as target cells. K562 is a human leukemia cell line. Tests used effector/ target cell ratios of 50:1, 25:1, and 12.5:1.
10 ©2021 NATURAL MEDICINE JOURNAL. ALL RIGHTS RESERVED. NMJ, MAY 2021 SUPPLEMENT—VOL. 13, NO. 51 (SUPPL)
By Tina Kaczor, ND, FABNO
SECONDARY OUTCOME MEASURES
Researchers compared laboratory markers of immune augmentation from baseline (week 0) and end of study (week 8). This included: cytokines (interleukin-2 [IL-2], IL6, IL-12, interferon-gamma, and tumor necrosis factor-alpha [TNF-alpha]). They assessed the incidence of upper respiratory infection (URI) at baseline (week 0), midway (week 4), and end of study (week 8) using the Wisconsin Upper Respiratory Symptom Survey. All participants had 3 visits total: baseline visit (week 0), midway (week 4), and end of study (week 8). RESULTS
NK-cell activity level in the PTE group increased at every dilution level versus baseline (E:T=12.5:1 P=0.0004; E:T=25:1 P=0.0034; and E:T=50:1 P=0.0055). There was no increase in NK-cell activity in the placebo group. While there was a tendency for improved NK-cell activity in the intervention versus placebo group, this did not reach statistical significance. There were no differences in the secondary outcome measure of cytokine concentrations after 8 weeks between the 2 groups. Safety indicators showed there was no significant difference between the 2 groups in laboratory tests, electrocardiograms, or vital signs. Adverse reactions: abdominal dis comfort=1, heartburn=4, contact dermatitis=1, left knee pain=1, chronic dermatitis=1, trigger finger=1, increased liver enzyme function tests=1, burn on back of hand=1. Of all the
