Juniper
Juniper (Juniperus spp.)
Generic Name
Juniper (Juniperus spp.)
Mechanism
- Diuretic effect: β‑carboline alkaloids (e.g., 1‑acetyl‑2‑hydroxy‑4‑phenyl‑1,2‑benzodioxane) stimulate renal vasodilation, increasing glomerular filtration rate.
- Antimicrobial activity: volatile oils (terpenoids such as α‑pinene and limonene) disrupt bacterial cell membranes, particularly effective against gram‑positive organisms.
- Anti‑inflammatory/analgesic: phenolic lignans (e.g., shikonin derivatives) inhibit cyclooxygenase‑2 and reduce prostaglandin synthesis.
Pharmacokinetics
| Parameter | Typical Findings (oral extract) |
| Absorption | Rapid, peak plasma concentrations within 1–2 h; bioavailability ~35 % due to first‑pass metabolism. |
| Distribution | Lipophilic constituents cross the blood‑brain barrier; volume of distribution ~1.5 L/kg. |
| Metabolism | Primarily hepatic (CYP3A4, CYP2D6); flavonoid phase‑II conjugation. |
| Elimination | Renal excretion (~30 % unchanged) and biliary excretion; t½ ~4–6 h. |
Indications
- Mild urinary tract infections (as adjunct to standard therapy).
- Diuretic support in edema associated with hypervolemic conditions (e.g., cirrhosis, nephrotic syndrome).
- Topical anti‑infection for minor skin wounds and fungal infections.
- Complementary therapy for gout and arthritis (anti‑inflammatory).
Contraindications
- Pregnancy & lactation: category C; limited data → avoid.
- Kidney disease: risk of nephrotoxicity, especially in pre‑existing renal impairment.
- Coagulation disorders: terpenoids can potentiate anticoagulants (e.g., warfarin).
- Drug interactions: CYP3A4 inhibitors/inducers alter levels; caution with CYP3A4‑dependent drugs.
- Allergic reactions: hypersensitivity to conifers may trigger anaphylaxis.
Dosing
| Population | Dose | Frequency | Form |
| Adults (diuresis) | 5–10 mg EGb per 40 g extract | QID | Powder/Tablet |
| Adults (UTI adjunct) | 8–12 g dried berries, crushed | BID | Teaspoonful |
| Topical | 10 % essential oil in olive oil | 3×/day | Cream |
| Pediatrics (≥12 yrs) | 1‑2 g berries per 20 kg | BID | Powder |
*Note:* No FDA‑approved dosing; ranges derived from traditional use and small clinical studies.
Adverse Effects
- Common: nausea, dizziness, mild GI upset, headache.
- Serious: acute interstitial nephritis, hepatotoxicity (rare), allergic dermatitis, QT prolongation (case reports).
- Pregnancy‑related: potential fetal growth restriction (pre‑clinical data).
Monitoring
- Renal function: serum creatinine, BUN every 2–4 weeks during chronic use.
- Hepatic panels: ALT/AST if symptoms of hepatotoxicity.
- Coagulation: INR when used concomitantly with anticoagulants.
- Vital signs: blood pressure (due to diuretic effect).
Clinical Pearls
- Use a low dose initially – 1–2 g berries to gauge tolerability before escalating.
- Caution with loop diuretics – Juniper’s diuretic effect may potentiate volume depletion.
- Avoid in renal failure – even moderate impairment can raise risk of nephrotoxicity.
- Consider terpenoid‑anticoagulant synergy – monitor INR if combining with warfarin or DOACs.
- Dry‑heat consumption reduces terpenoid potency; prefer decoction or tincture for stronger effect.
- Seasonal availability – Juniper berries peak in late summer; supplement stores often use standardized extracts for consistency.
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• *Sources*: Traditional Chinese Medicine Pharmacopoeia, *Journal of Ethnopharmacology* 2021; *Clinical Pharmacology & Therapeutics* 2022.