Pulegone (5-methyl-2-(1-methylethylidene)cyclohexanone)

Pulegone is a monoterpene compound found in pennyroyal and other mint plants that exhibits significant hepatotoxicity in humans. This bioactive compound lacks established therapeutic benefits and poses serious safety concerns due to its liver-damaging metabolites.

Origin & History

Pulegone is a naturally occurring monoterpenoid ketone (C₁₀H₁₆O) appearing as a colorless oil, primarily sourced from plants in the mint family (Lamiaceae), particularly pennyroyal (Mentha pulegium) where it can constitute up to 61.11% of essential oils. It is typically extracted through steam distillation of plant leaves followed by fractional distillation or chemical synthesis for pure forms.

Historical & Cultural Context

Limited traditional medicinal use documentation beyond its presence in pennyroyal and mint plants. The compound has been noted for insecticidal properties in plant extracts, but no specific traditional medicine systems (Ayurveda, TCM) or historical durations of use are mentioned in the research.

Health Benefits

• No therapeutic health benefits established - the research dossier contains no human clinical trials demonstrating efficacy
• Insecticidal properties noted in plant extracts (traditional use evidence only)
• Flavoring agent applications documented (regulatory evaluation only)
• Hepatotoxic effects identified in animal models through metabolism to menthofuran
• Rapid metabolism in human hepatic microsomes observed (toxicology data only)

How It Works

Pulegone undergoes hepatic metabolism via cytochrome P450 enzymes, particularly CYP1A2 and CYP2E1, producing reactive metabolites including menthofuran and pulegone epoxide. These metabolites deplete hepatic glutathione stores and form protein adducts, leading to oxidative stress and hepatocellular damage. The compound also demonstrates insecticidal activity through disruption of insect nervous system function.

Scientific Research

No human clinical trials, RCTs, or meta-analyses were identified in the available research for pulegone's biomedical applications. The existing literature focuses exclusively on toxicity studies in animal models and metabolic pathway characterization, with no PMIDs provided for therapeutic efficacy studies.

Clinical Summary

No human clinical trials have established therapeutic benefits for pulegone supplementation. Case reports document severe hepatotoxicity following pennyroyal oil ingestion, with doses as low as 10mL causing liver failure in adults. Animal studies demonstrate dose-dependent hepatic necrosis, with LD50 values ranging from 150-470 mg/kg in rodents. The limited research focuses primarily on toxicological rather than therapeutic outcomes.

Nutritional Profile

Pulegone (5-methyl-2-(1-methylethylidene)cyclohexanone) is a pure monoterpenoid ketone compound (C10H16O, molecular weight 152.23 g/mol) with no meaningful nutritional profile in the conventional sense. It contains no protein, carbohydrates, dietary fiber, vitamins, or minerals. Macronutrient breakdown by structure: carbon 78.9%, hydrogen 10.6%, oxygen 10.5%. As a lipophilic monoterpene ketone, it is essentially 100% fat-soluble with negligible water solubility (~1 g/L at 25°C), conferring high bioavailability via lipid absorption pathways. Caloric contribution is theoretically ~7.6 kcal/g (estimated from hydrocarbon ketone structure) but is consumed only in trace flavoring quantities (typically <1 mg per serving), rendering caloric contribution nutritionally insignificant. Bioactive compound concentration in its pure form is 100% pulegone. In pennyroyal oil (primary natural source), pulegone constitutes 60–90% of total composition. It possesses no fiber, no amino acids, and no micronutrient content. Its biological activity is driven entirely by its metabolic conversion: hepatic CYP2E1 and CYP1A2 enzymes convert pulegone to the reactive intermediate menthofuran and further to cis- and trans-pulegone epoxides, which are the primary hepatotoxic species identified in animal models at doses >400 mg/kg body weight.

Preparation & Dosage

No clinically studied dosage ranges are available as human therapeutic trials are lacking. The compound is noted in flavoring evaluations without therapeutic standardization, and is contraindicated in high doses based on rodent hepatotoxicity data. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

No synergistic ingredients identified due to toxicity concerns and lack of therapeutic applications

Safety & Interactions

Pulegone exhibits significant hepatotoxicity with reported cases of acute liver failure and death following ingestion of pulegone-containing products. The compound is contraindicated during pregnancy due to abortifacient properties and teratogenic potential. Drug interactions may occur with medications metabolized by CYP1A2 and CYP2E1 enzymes. The FDA prohibits pulegone in dietary supplements due to safety concerns established in 2018.