Grindelia Herb Extract
Also known as: Grindelia robusta Nutt., Grindelia squarrosa (Pursh) Dunal, Grindelia humilis Hook. et Arn., Grindelia camporum Greene, Grindelia herb, gumweed, Grindelia robusta
Overview
Grindelia herb extract is derived from several species of the Grindelia genus, primarily G. robusta and G. squarrosa. It is a traditional medicinal plant known for its content of saponins, polyphenols, and grindelic acid, which are considered its key bioactive compounds. Historically, it has been used for respiratory conditions such as cough, bronchitis, and cold symptoms, owing to its perceived anti-inflammatory and expectorant properties. While some in vitro and in vivo studies support these traditional uses, comprehensive systematic reviews or meta-analyses specifically on Grindelia herb extract are limited. The European Medicines Agency (EMA) has acknowledged the anti-inflammatory potential and traditional use of Grindelia robusta extracts in respiratory ailments.
Benefits
Grindelia herb extract exhibits significant anti-inflammatory effects. Methanolic extracts of G. robusta have been shown to inhibit nitric oxide production and reduce pro-inflammatory cytokines (IL-1β, IL-12) and enzymes (iNOS, COX-2) in macrophage cell lines without causing cytotoxicity. In animal studies, oral administration of G. robusta dry extract dose-dependently reduced carrageenan-induced paw edema by up to 63%, a result comparable to the standard anti-inflammatory drug indomethacin. Furthermore, G. squarrosa extract has been observed to decrease TLR-4 expression and NF-κB activity in LPS-stimulated nasal and bronchial epithelial cells, leading to a reduction in pro-inflammatory cytokines (IL-8, TNF-α, IL-1β, IL-6). While traditionally used as an expectorant for cough and cold, systematic reviews classify it as a traditional adjunct rather than a primary treatment, and high-quality randomized controlled trials (RCTs) specifically isolating Grindelia herb extract for respiratory conditions in humans are currently lacking.
How it works
The anti-inflammatory effects of Grindelia herb extract are primarily mediated through the inhibition of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), which are key enzymes in inflammatory pathways. It also suppresses the nuclear factor kappa B (NF-κB) translocation, a critical regulator of inflammatory gene expression, and reduces the production of various pro-inflammatory cytokines. Grindelic acid, a prominent compound in G. squarrosa, contributes to these effects, suggesting a synergistic action of multiple phytochemicals within the extract. The extract also modulates Toll-like receptor 4 (TLR-4) signaling pathways in respiratory epithelial cells, thereby reducing inflammatory responses triggered by bacterial lipopolysaccharide (LPS). Although bioavailability data are limited, oral administration in animal models demonstrates systemic anti-inflammatory effects.
Side effects
Grindelia herb extracts generally appear safe when used in traditional doses, with no cytotoxicity observed in vitro at tested concentrations. However, there are important contraindications and safety considerations. It is contraindicated in individuals with hypersensitivity to the plant. Due to a lack of sufficient safety data and potential risks, Grindelia herb extract is not recommended for children under 18 years of age, pregnant women, or lactating women. While no significant adverse effects or drug interactions have been widely reported in the reviewed literature, the overall clinical safety data for human use are limited. Therefore, caution is advised, especially given the absence of robust human clinical trials and regulatory restrictions concerning pediatric and pregnant populations.
Dosage
Standardized human dosing guidelines for Grindelia herb extract are not well-established due to the lack of robust clinical trials. Animal studies have utilized oral doses of 100–200 mg/kg of dry extract to achieve anti-inflammatory effects. In traditional use, herbal preparations are often standardized based on their saponin content. However, specific recommendations for timing, formulation, and optimal dosage for various conditions remain undefined in a clinical context. There are no clearly defined upper limits or safety thresholds for human consumption, underscoring the need for further research to establish safe and effective dosing regimens.
FAQs
Is Grindelia herb extract effective for cough and cold?
Traditional use and preclinical studies suggest anti-inflammatory and expectorant properties. However, high-quality human randomized controlled trials are currently lacking to confirm its efficacy for cough and cold.
Is Grindelia herb extract safe for children?
No, Grindelia herb extract is contraindicated in children under 18 years of age, as well as during pregnancy and lactation, due to insufficient safety data and potential risks.
How fast does Grindelia herb extract work?
Animal studies have shown effects within hours to days of administration. However, human data on the onset of action are currently unavailable, making it difficult to predict how quickly it would work in people.
Are there known drug interactions with Grindelia herb extract?
No significant drug interactions have been reported in the reviewed literature. However, due to limited clinical data, caution is warranted, and consultation with a healthcare professional is advisable.
Research Sources
- https://www.ema.europa.eu/en/documents/herbal-report/final-assessment-report-grindelia-robusta-nutt-grindelia-squarrosa-pursh-dunal-grindelia-humilis-hook-et-arn-grindelia-camporum-greene-herba_en.pdf – This EMA assessment report recognizes the traditional use of Grindelia robusta extracts for respiratory ailments and acknowledges their anti-inflammatory potential. It provides a regulatory perspective on the herb's traditional medicinal product status, highlighting the available evidence and safety considerations.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC7848105/ – This study investigated the anti-inflammatory activity of Grindelia robusta extract. It demonstrated that the extract inhibited nitric oxide production and reduced pro-inflammatory cytokines and enzymes in macrophage cells, and significantly reduced carrageenan-induced paw edema in rats, suggesting potent anti-inflammatory effects.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC10220542/ – This research explored the effects of Grindelia squarrosa extract on respiratory inflammation. It found that the extract decreased TLR-4 expression and NF-κB activity in LPS-stimulated human nasal and bronchial epithelial cells, leading to a reduction in various pro-inflammatory cytokines, indicating its potential to modulate inflammatory responses in the respiratory tract.
- http://www.agricultforest.ac.me/data/20220929-17%20Petrovic%20et%20al%20.pdf – This systematic review on herbal expectorants, including Grindelia, highlights its traditional use as an adjunct expectorant. It notes the lack of high-quality randomized controlled trial evidence for Grindelia alone and emphasizes contraindications for children and pregnant women due to insufficient safety data.
