Hops: 8-PN Absorbs Better Than 6-PN in Human Study

observational-study PMID: 29363261

Hops: 8-PN Absorbs Better Than 6-PN in Human Study

Quick Summary: Scientists tested two compounds from hops—8-prenylnaringenin (8-PN) and 6-prenylnaringenin (6-PN)—to see how well the body absorbs them after eating. They found that 8-PN gets into the bloodstream much more easily than 6-PN in healthy adults. Even so, both compounds boosted the health of certain immune cells about the same way, with no side effects reported.

What The Research Found

Researchers compared how hops compounds 8-PN and 6-PN work in the body, focusing on absorption (bioavailability) and their effects on immune cells. Hops come from the Humulus lupulus plant, often used in beer, but these compounds are studied for potential health perks like fighting cancer or reducing inflammation.

Key discoveries include:
- Better Absorption for 8-PN: When people took 8-PN, it reached peak blood levels of 16.1 ng/mL, compared to just 1.2 ng/mL for 6-PN. Overall exposure (measured as area under the curve) was 107 ng·h/mL for 8-PN versus 12.3 ng·h/mL for 6-PN—about 9 times higher.
- Immune Cell Boost: Both compounds improved the survival rate of peripheral blood mononuclear cells (PBMCs), which are key immune cells. Surprisingly, 6-PN worked just as well as 8-PN here, even though less of it entered the blood.
- Gender Note: Women absorbed more 8-PN initially (20.1 ng/mL peak vs. 12.1 ng/mL in men), but this difference vanished when adjusting for body weight.
- Safe and Tolerable: No bad reactions occurred from either compound or the placebo.

These findings show how tiny changes in a molecule's structure (8-PN and 6-PN are isomers, like close cousins) can make a big difference in how the body uses them.

Study Details

This was a careful science experiment designed to be fair and unbiased.

Who was studied: 16 healthy adults—8 women and 8 men—with no health issues.
How long: Participants took one dose at a time, with a 7-day break (washout) between tests to clear the body. Blood and cell effects were tracked for up to 28 days total.
What they took: A single oral dose of 500 mg of either 6-PN, 8-PN, or a fake pill (placebo). They got each one in random order, without knowing which was which (double-blind setup). Blood levels were measured with high-tech tools, and immune cell health was tested in a lab.

What This Means For You

If you're interested in hops supplements for health reasons—like supporting immunity or exploring natural anti-cancer options—this study highlights why 8-PN might be the smarter pick. It absorbs better, so your body gets more of it from the same dose, potentially leading to stronger benefits from things like antioxidant effects.

Supplement Shoppers: Look for products rich in 8-PN if you want better absorption. Both compounds seem safe for short-term use, but they're not a cure-all—talk to a doctor before trying.
Beer Lovers: Hops in beer contain these compounds, but brewing processes might change how much you absorb. This research is more about pure extracts than your pint.
Health Enthusiasts: The equal immune boost from 6-PN suggests it could still help locally (like in the gut), even if less reaches your bloodstream. For overall wellness, prioritize 8-PN for efficiency.

Bottom line: This could guide better supplement formulas, making hops-based products more effective for everyday health support.

Study Limitations

No study is perfect, and this one has some caveats to consider.

Small Group: Only 16 people took part, so results might not apply to everyone—more diverse or larger groups are needed.
One-Time Doses: They tested single doses, not daily use over months. Long-term effects on absorption or health are unknown.
Unclear Details: It's not specified if participants ate before dosing, which could affect results. Also, why 6-PN worked as well on cells despite low absorption isn't explained.
No Broader Comparisons: They didn't test against other hops compounds or real foods, so real-world use might differ.

Keep these in mind—more research will build on this to confirm benefits for conditions like menopause relief or cancer prevention, where these compounds show promise in lab tests.

Key Findings

The study found that 8-prenylnaringenin (8-PN) exhibited significantly greater oral bioavailability compared to its positional isomer 6-prenylnaringenin (6-PN) in healthy humans. Despite this difference, both compounds showed similar efficacy in enhancing peripheral blood mononuclear cell (PBMC) viability.

Study Design

Type: Double-blind, placebo-controlled, randomized crossover trial.
Sample Size: 16 healthy volunteers (8 women, 8 men; age range not specified).
Duration: Participants received single doses of 6-PN, 8-PN, or placebo in random order, with a 7-day washout period between interventions. Plasma concentrations and PBMC effects were measured over 28 days.
Methodology: Plasma levels of 6-PN and 8-PN were quantified using HPLC-MS/MS. PBMC viability was assessed via MTT assay.

Dosage & Administration

Dose: 500 mg of either 6-PN or 8-PN administered orally as a single dose.
Placebo: Inert substance matched to the test compounds.
Administration: Single oral dose under fasting conditions (as inferred from standard pharmacokinetic protocols, though not explicitly stated in the summary).

Results & Efficacy

Bioavailability:
C_max: 8-PN reached 16.1 ng/mL vs. 1.2 ng/mL for 6-PN (p < 0.001).
AUC (area under the curve): 8-PN showed 107 ng·h/mL vs. 12.3 ng·h/mL for 6-PN (p < 0.001).
Gender Differences: Women had higher 8-PN C_max than men (20.1 vs. 12.1 ng/mL, p = 0.02), but this was not significant after adjusting for body weight.
PBMC Viability: Both 6-PN and 8-PN increased PBMC viability compared to placebo (exact values not provided), with no significant difference between the two isomers.
Safety: No adverse effects reported for either compound.

Limitations

Small Sample Size: Only 16 participants, limiting generalizability.
Single-Dose Design: Results reflect acute effects; long-term bioavailability or efficacy unknown.
Lack of Mechanistic Data: The similar PBMC effects despite differing bioavailability were not explained mechanistically.
Unspecified Dosing Context: Whether compounds were taken with food or fasting is unclear.
No Active Control: Placebo was inert, but comparisons to other flavonoids or interventions were absent.

Clinical Relevance

Formulation Implications: 8-PN’s superior bioavailability suggests it may be more effective for systemic health benefits (e.g., antioxidant or anticancer effects) at equivalent doses.
PBMC Viability: 6-PN’s comparable impact on PBMC viability despite lower absorption highlights potential localized or dose-independent mechanisms.
Safety: Both compounds were well-tolerated, supporting their use in dietary supplements.
Gender Considerations: Initial gender differences in 8-PN absorption may warrant further investigation, though adjustments for body weight negated significance.

Takeaway: This study underscores the importance of structural differences in flavonoid bioavailability and suggests that supplement formulations prioritizing 8-PN could optimize systemic exposure. However, the similar PBMC effects of 6-PN indicate both isomers may hold therapeutic value, depending on the target outcome.