Oxidative Stress and Inflammation Probes

1 Ginkgo biloba (EGb 761)

Ginkgo enhances cerebral blood flow (vasodilation, improved microvascular perfusion), antagonizes platelet-activating factor (PAF, reducing neuroinflammation), and provides antioxidant support. It probes whether cerebral hypoperfusion is limiting cognitive function.

1.1 If Ginkgo works

Finding: Cerebral hypoperfusion was limiting cognition

Improvement means reduced cerebral blood flow was constraining cognitive function; enhancing perfusion helped.

Certainty: Low — cognitive benefits are documented in dementia, not ME/CFS.
Does NOT tell us: the cause of the hypoperfusion (autonomic vasoregulation, microvascular dysfunction, low cardiac output).
Action: Supports investigating cerebral perfusion as a contributor.
Level of action: Symptom management.

1.2 What a positive response does NOT reveal

The cause of the hypoperfusion.
Whether the benefit is from perfusion, PAF antagonism, or antioxidant effect — these are confounded within one extract.

1.3 If Ginkgo does NOT work

The cognitive deficit may arise from neurotransmitter insufficiency, not perfusion.
Neuronal mitochondrial failure may limit cognition independently of blood flow.
Glymphatic dysfunction may be the driver.

1.4 Key caveat

Ginkgo inhibits platelet aggregation — avoid it with anticoagulants (warfarin, aspirin) and before surgery. Use the standardized EGb 761 extract only.

1.5 How Ginkgo combines with other medications

Ginkgo + pyridostigmine both work → cerebral perfusion improved by both vasodilation and increased cardiac output.
Ginkgo works + low-dose aripiprazole (LDA) does not → the cognitive deficit is perfusion-limited, not neurotransmitter-limited.
Ginkgo + NAC both work → cerebral hypoperfusion and oxidative stress are co-present.

1.6 Compendium

The full pharmacodiagnostic entry — including mechanism-exclusion logic, dose-specific side-effect diagnostic patterns, combination diagnostics, and worsening risk profiles — is at Mechanistic Cascade Tracing: From Hypothesis to Clinical Probe (sec-12, Ginkgo Biloba entry).

2 NAC (N-Acetylcysteine)

NAC is a glutathione precursor (antioxidant), glutamate modulator (cystine-glutamate antiporter), and potentially reduces HSAT2 retroelement activation (ROS → HSF1 → HSAT2).

2.1 If NAC works

Finding: Oxidative stress was a significant contributor.

NAC → glutathione synthesis → antioxidant capacity increased → oxidative damage reduced.

Certainty: Low to Medium.
Does NOT tell us: the source of oxidative stress (mitochondrial electron leak, NADPH oxidase, ischemia-reperfusion).
Level of action: Partial root cause — reduces damage without eliminating source.

Finding: Glutamate excitotoxicity was contributing (if brain fog and sensory sensitivity improve).

NAC normalizes extrasynaptic glutamate via cystine-glutamate antiporter.

Certainty: Low — glutamate modulation established in addiction/OCD, not ME/CFS.
Level of action: Symptom management.

Finding: HSAT2 retroelement activation may be reduced.

NAC reduces ROS → reduces HSF1 → reduces HSAT2 transcription.

Certainty: Low — HSAT2 cascade anchored in single Ewing sarcoma preprint.
Level of action: Partial root cause (if HSAT2 contributes to disease maintenance).

2.2 What a positive response does NOT reveal

A positive NAC response confirms that oxidative stress was a significant contributor but does not identify its source (mitochondrial electron leak, NADPH oxidase, or ischemia-reperfusion remain indistinguishable). It cannot separate the glutathione-antioxidant effect from the glutamate-modulating and putative HSAT2-reducing effects, since NAC acts through all three. The glutamate and HSAT2 inferences rest on evidence from outside ME/CFS (addiction/OCD and a single Ewing sarcoma preprint), so their relevance to any given patient is uncertain, and a genuine effect cannot be cleanly separated from placebo.

2.3 If NAC does NOT work

Oxidative stress not a dominant contributor — damage may be driven by inflammation, receptor dysfunction, or hypoperfusion rather than reactive oxygen species.
Glutathione synthesis rate-limited by other factors — iron or selenium deficiency can cap glutathione production regardless of cysteine supply.
HSAT2 driven by HSF1 independently of ROS — reducing oxidative stress would not lower HSAT2 in that case.
Dose insufficient — oral NAC has poor bioavailability; intravenous NAC has a different pharmacokinetic profile and may reach targets oral dosing cannot.

2.4 Key caveat

Non-response does not exclude oxidative stress. Glutathione synthesis can be rate-limited by cofactors other than cysteine (iron, selenium), and oral NAC’s poor bioavailability means non-response may reflect insufficient target exposure rather than absence of the mechanism. Non-response is weaker evidence than response.

2.5 How NAC combines with other medications

NAC + mitochondrial supplements both work → oxidative stress arising from mitochondrial electron leak; the two mechanisms are linked (a leaking electron transport chain generates the reactive oxygen species NAC neutralizes).
NAC + LDN both work → neuroinflammation plus oxidative damage, a common co-occurrence in which inflammatory signaling and oxidative stress reinforce each other.
NAC works alone (LDN does not) → peripheral oxidative stress without a dominant neuroinflammatory component.

2.6 Compendium

3 Omega-3 Fatty Acids (EPA/DHA)

Omega-3s probe failed resolution of inflammation. EPA and DHA are precursors for resolvins, protectins, and maresins (specialized pro-resolving mediators, or SPMs) that actively terminate inflammation. Supplementation tests whether inflammation persists because the resolution off-switch is broken rather than because the on-switch is stuck.

3.1 If omega-3s work

Finding: Resolution failure may be contributing

Improvement means inflammation was persisting because resolution was inadequate; supplying SPM precursors helped switch it off.

Certainty: Low for the SPM mechanism in ME/CFS — SPMs have never been measured in this population.
Does NOT tell us: whether SPM synthesis is actually restored, since SPM levels are not measured clinically.
Action: Supports resolution support as a contributor; use therapeutic doses.
Level of action: Partial root cause — provides precursors for resolution.

3.2 What a positive response does NOT reveal

Whether SPMs are genuinely being synthesized or the benefit is a general anti-inflammatory effect.
Whether resolution failure is primary or downstream of a persistent trigger.

3.3 If omega-3s do NOT work

The inflammation may not be the resolution-failure type.
EPA/DHA conversion to SPMs may be impaired.
The dose may have been insufficient — therapeutic doses are 2–4 g EPA+DHA/day, well above standard supplement doses.

3.4 Key caveat

Aspirin at doses above 100 mg inhibits COX-2 and blocks the EPA→SPM conversion — aspirin and omega-3 should not be combined at standard analgesic doses. The triglyceride form absorbs better than the ethyl ester form.

3.5 How omega-3s combine with other medications

Omega-3 + PEA both work → resolution failure plus mast cell activation (complementary).
Omega-3 + NAC both work → oxidative stress and resolution failure are co-present.
Omega-3 work + antihistamines do not → inflammation from resolution failure, not acute mast cell mediators.

3.6 Compendium

4 PEA (Palmitoylethanolamide)

PEA activates PPAR-α, suppressing inflammatory gene transcription upstream of mediator release. It also stabilizes mast cells and modulates microglia. A meta-analysis of 11 RCTs (n=774) supports its use for pain (Lang-Ilievich et al. 2023). Because it acts at the nuclear-receptor level, it probes a distinct arm of inflammation from receptor-blocking or TLR4-targeting drugs.

4.1 If PEA works

Finding: Mast cell or microglial inflammation was contributing

Improvement means PPAR-α-responsive inflammatory cells were driving symptoms; suppressing their transcription helped. The mechanism is distinct from LDN (TLR4) and antihistamines (receptor blockade) — PEA suppresses at the nuclear-receptor level, upstream of mediator release.

Certainty: Low to Medium — RCT support for pain; no ME/CFS-specific trials.
Does NOT tell us: whether the inflammatory driver is peripheral (mast cell) or central (microglial).
Action: Supports upstream anti-inflammatory strategies; distinguishes transcription-level from receptor-level intervention.
Level of action: Symptom management.

4.2 What a positive response does NOT reveal

Whether the responsive cells are mast cells, microglia, or both.
Whether the inflammation is primary or secondary to another driver.

4.3 If PEA does NOT work

The inflammatory pathology may not be driven by PPAR-α-responsive cells.
The mechanism may be autoantibody-driven (humoral) or T-cell/NK-cell mediated.
A dose or formulation issue — micronized or ultramicronized PEA is required for adequate absorption.

4.4 Key caveat

Standard PEA has poor oral bioavailability; only ultramicronized or micronized formulations achieve adequate plasma levels. Effects typically require a minimum of 4–8 weeks.

4.5 How PEA combines with other medications

PEA + LDN both work → peripheral mast cell plus CNS microglial involvement.
PEA works + antihistamines do not → upstream PPAR-α suppression is more effective than receptor blockade.
PEA does not work + LDN works → microglia (the TLR4 pathway), not the PPAR-α pathway, is the primary neuroinflammatory driver.

4.6 Compendium

References

Lang-Ilievich, Kristina, Christopher Klivinyi, Mischa Grill, and Helmar Bornemann-Cimenti. 2023. “Palmitoylethanolamide in the Treatment of Chronic Pain: A Systematic Review and Meta-Analysis.” Pain Physician 26 (1): E31–40.