Oleanoic Acid
Also known as: Oleanolic acid, OA, 3β-hydroxyolean-12-en-28-oic acid
Overview
Oleanolic acid (OA) is a naturally occurring pentacyclic triterpenoid compound found in various plants, including olive oil, garlic, and numerous medicinal herbs. It is primarily investigated for its potential antitumour, anti-inflammatory, and metabolic regulatory properties. Chemically, it is classified as 3β-hydroxyolean-12-en-28-oic acid. Despite promising preclinical research, OA exhibits low water solubility and poor bioavailability, which currently limits its direct clinical application. Research on OA is advanced at the preclinical level, with extensive in vitro and animal studies demonstrating its effects. While systematic reviews and meta-analyses of animal studies provide robust evidence for its efficacy in these models, human clinical data remain sparse, indicating a need for further research to translate these findings into clinical practice.
Benefits
Oleanolic acid (OA) has demonstrated significant benefits primarily in preclinical settings. Its most prominent effect is its antitumour activity, where systematic reviews and meta-analyses of randomized controlled animal studies consistently show that OA significantly inhibits tumour growth and reduces tumour weight across various cancer models. This indicates a broad-spectrum antitumour potential, with statistically significant reductions in tumour volume and weight (p < 0.05) observed in animal models. While human data are limited, some research suggests potential secondary benefits related to metabolic health. For instance, meta-analyses on dietary supplementation with oleic acid (a related but distinct compound abundant in olive oil) have indicated improvements in markers of metabolic syndrome, such as lipid profiles and insulin resistance. However, these metabolic benefits may be partly attributable to other components found in olive oil, like hydroxytyrosol, and should not be directly conflated with the effects of oleanolic acid. The strength of evidence for antitumour effects is robust in animal models, but clinical significance in humans is yet to be established.
How it works
Oleanolic acid (OA) exerts its antitumour effects through multiple biological pathways. It primarily induces apoptosis (programmed cell death) and inhibits cell proliferation in cancer cells. OA also demonstrates anti-inflammatory properties and modulates oxidative stress pathways, which are crucial in cancer progression. At a molecular level, OA interacts with and modulates key cellular signaling pathways, including NF-κB and MAPK, and regulates apoptotic proteins such as caspases. These interactions collectively contribute to its ability to suppress tumour growth. However, a significant challenge for OA's therapeutic application is its poor water solubility and low oral bioavailability, which limits its systemic exposure and absorption in the body. Research is ongoing to develop improved formulations to overcome these bioavailability issues.
Side effects
The overall safety assessment of Oleanolic acid (OA) is primarily based on animal studies, where it is generally considered safe at tested doses with minimal reported toxicity. However, human safety data are very limited, and common or uncommon side effects are not well documented in humans. Due to the lack of comprehensive human studies, the full spectrum of potential adverse effects, their severity, and frequency remain largely unknown. There is insufficient data to establish specific drug interactions, but caution is advised, particularly with drugs metabolized by liver enzymes, as OA may potentially interact with these pathways. No specific contraindications have been established for OA in humans due to the limited research. Similarly, data regarding its safety and effects in special populations (e.g., pregnant women, children, individuals with pre-existing conditions) are lacking. Therefore, until more robust human clinical trials are conducted, the safety profile of OA for human supplementation remains largely uncharacterized, and its use should be approached with caution.
Dosage
The minimum effective dose, optimal dosage ranges, and maximum safe dose for Oleanolic acid (OA) in humans have not been established. Current research is predominantly based on animal studies, which utilize variable doses that are not directly translatable to human recommendations. There are no established timing considerations for OA supplementation. Furthermore, specific form-specific recommendations are not available, as improved formulations designed to enhance OA's poor solubility and absorption are still under development. The low water solubility of OA significantly limits its absorption, which is a major factor influencing its potential efficacy and requiring further research into delivery methods. No specific cofactors have been identified as necessary for OA's action. Due to the lack of human clinical data, any self-administration of OA should be approached with extreme caution and under professional medical guidance.
FAQs
Is OA effective for cancer treatment in humans?
Currently, evidence for Oleanolic acid's effectiveness in human cancer treatment is limited to animal models. Clinical efficacy in humans remains unproven, and further research is needed.
Is OA safe for daily supplementation?
The safety of Oleanolic acid for daily human supplementation is not well established due to a lack of comprehensive human clinical trials. Caution is advised until more data are available.
How long does it take to see benefits?
Animal studies show effects of Oleanolic acid over weeks, but human timelines for observing benefits are unknown due to the limited clinical research.
Can OA be combined with other supplements?
There is no specific data on combining Oleanolic acid with other supplements. Potential interactions should be considered, and professional medical advice is recommended.
Research Sources
- https://pmc.ncbi.nlm.nih.gov/articles/PMC11484195/ – This systematic review and meta-analysis by Zeng et al. (2024) assessed the antitumour effects of Oleanolic acid (OA) in randomized controlled animal studies. It found a statistically significant reduction in tumour volume and weight with OA intervention, using rigorous methodology including risk of bias assessment. The study highlights OA's promising antitumour potential in animal models but notes the limitation of lacking human clinical trials.
- https://pubmed.ncbi.nlm.nih.gov/39421313/ – This source, likely related to the Zeng et al. (2024) meta-analysis, reinforces the findings of significant antitumour activity of Oleanolic acid in animal models. It supports the conclusion that OA can reduce tumour volume and weight, emphasizing the need for further research to translate these preclinical findings into human applications.
- https://pubmed.ncbi.nlm.nih.gov/34153478/ – This systematic review and meta-analysis evaluated the effects of olive oil and its components, including oleic acid (a distinct compound from oleanolic acid), on metabolic syndrome parameters in humans. It suggested beneficial effects on lipid metabolism and insulin resistance, but cautioned that these effects might be due to combined components of olive oil rather than oleic acid alone. This source helps differentiate the effects of oleic acid from oleanolic acid.
- https://pubmed.ncbi.nlm.nih.gov/33305589/ – This source likely refers to additional meta-analyses on dietary oleic acid supplementation, indicating potential anti-inflammatory effects. It is crucial for clarifying that these findings pertain to oleic acid (a fatty acid) and not oleanolic acid (a triterpenoid), despite their similar names, thus preventing confusion between the two chemically distinct compounds.
