Get Your Personalized Supplement StackSupplement Stack Quiz

terpenoids

Also known as: Isoprenoids, Terpenes, Terpenoids

Overview

Terpenoids, also known as isoprenoids, are a large and diverse class of naturally occurring organic chemicals derived from five-carbon isoprene units. They are secondary metabolites found abundantly in plants, fungi, and some marine organisms, contributing to aroma, flavor, and defense mechanisms. Common sources include essential oils from herbs, spices, and conifers. Terpenoids are studied for their potential antioxidant, anti-inflammatory, antimicrobial, and anticancer properties, and are often used as dietary supplements. While preclinical evidence is moderate to advanced, clinical research in humans is still emerging, with most current evidence derived from animal and in vitro studies.

Benefits

Terpenoids exhibit significant antioxidant effects, improving cell viability and reducing oxidative stress markers like ROS, NO, and MDA, while increasing antioxidant enzymes (SOD, CAT, GPx) in preclinical models, as shown in a meta-analysis of 39 studies. They also demonstrate anti-inflammatory properties by decreasing pro-inflammatory cytokines (IL-6, IL-1β, TNF-α, NF-κB) and increasing anti-inflammatory IL-10 in animal models. Specific diterpenoids and triterpenoids have shown protective effects in acute lung injury (ALI) by reducing pulmonary edema in animal models. Furthermore, certain terpenoids act as bacterial efflux pump inhibitors, enhancing antibiotic efficacy against resistant strains like Staphylococcus aureus. Secondary benefits observed in preclinical studies include anti-apoptotic, genoprotective, liver and renal function improvement, reproductive function enhancement, lipid profile improvement, and downregulation of carcinogenesis biomarkers. While these effects are statistically significant in preclinical settings, their clinical relevance to humans requires further validation.

How it works

Terpenoids exert their effects primarily by modulating oxidative stress pathways through scavenging reactive oxygen species (ROS) and enhancing endogenous antioxidant enzymes such as SOD, CAT, and GPx. Their anti-inflammatory action involves the downregulation of the NF-κB pathway and pro-inflammatory cytokines, while promoting anti-inflammatory mediators. They also demonstrate anti-apoptotic effects by regulating key proteins like Bax, caspase-3, caspase-9, and Bcl-2. In the context of antimicrobial activity, some terpenoids act as inhibitors of bacterial efflux pumps, thereby enhancing the effectiveness of antibiotics against resistant bacterial strains. Their lipophilic nature suggests variable oral bioavailability, with specific pharmacokinetics depending on the terpenoid subclass and formulation.

Side effects

Preclinical studies on terpenoids have not reported major toxicity, and there is currently insufficient clinical data to establish common, uncommon, or rare side effects in humans. Therefore, the overall safety profile in humans is not yet well-defined. Potential drug interactions may exist, particularly through the modulation of drug efflux pumps, which could alter the efficacy of co-administered antibiotics or other medications. Due to the limited human clinical data, no specific contraindications have been established. Caution is advised for special populations, as there is no available data regarding their safety or efficacy in these groups.

Dosage

Optimal dosage ranges for terpenoids in humans are not yet defined, as most research is preclinical. In animal models, low doses of diterpenoids and triterpenoids have shown efficacy in acute lung injury, but human equivalent doses have not been established. The maximum safe dose for human consumption is also unknown. Timing considerations vary; acute administration has shown effects in lung injury models, while chronic dosing effects are unclear. Different terpenoid subclasses, such as monoterpenoids and tetraterpenoids, have demonstrated strong antioxidant effects, while diterpenoids and triterpenoids were effective in lung injury models. The lipophilicity of terpenoids may influence absorption, but specific data on this is lacking, and no required cofactors have been reported.

FAQs

Are terpenoids safe for human consumption?

Preclinical data suggest safety, but human clinical trials are lacking, so definitive safety for human consumption is not yet established.

Can terpenoids be used to treat inflammation or oxidative stress?

Animal and in vitro studies support anti-inflammatory and antioxidant effects; however, clinical evidence in humans is currently limited.

Do terpenoids enhance antibiotic effectiveness?

Yes, some terpenoids can inhibit bacterial efflux pumps, which enhances the efficacy of antibiotics against resistant bacterial strains.

What forms of terpenoids are most effective?

Monoterpenoids and tetraterpenoids show strong antioxidant effects, while diterpenoids and triterpenoids are effective in lung injury models.

How quickly do benefits appear?

In animal models, effects can be acute (hours to days), especially in lung injury; chronic effects require further study.

Research Sources

https://pubmed.ncbi.nlm.nih.gov/39477689/ – This meta-analysis of 39 preclinical studies found that terpenoids significantly improved oxidative stress, inflammation, apoptosis, and organ function in various animal and cell models exposed to nanomaterials. The study highlights robust statistical effects, though it notes the lack of human data.
https://pmc.ncbi.nlm.nih.gov/articles/PMC9401633/ – This systematic review and meta-analysis of animal studies demonstrated that low doses of diterpenoids and triterpenoids significantly reduced pulmonary edema in animal models of acute lung injury. The research provides strong evidence for the protective effects of these specific terpenoid subclasses in an acute setting.
https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2022.953982/full – This systematic review focused on terpenes as bacterial efflux pump inhibitors, concluding that they synergistically enhanced antibiotic efficacy against resistant Staphylococcus aureus strains in in vitro settings. The study suggests a promising role for terpenoids in combating antibiotic resistance.
https://analyticalsciencejournals.onlinelibrary.wiley.com/doi/abs/10.1002/jat.4716 – This source, while not explicitly summarized in the provided text, is cited in relation to the meta-analysis on oxidative stress. It likely contributes to the understanding of terpenoid effects on oxidative stress markers and antioxidant enzymes, reinforcing the findings of the primary meta-analysis.