Alternaria tenuis
Also known as: Alternaria tenuis, Alternaria species, Alternaria alternata
Overview
Alternaria tenuis is a fungal species within the genus Alternaria, commonly found as a plant pathogen and environmental mold. While not a traditional dietary supplement, research focuses on its secondary metabolites, such as altenuene and alternariol, for potential antiviral and anti-inflammatory properties. These metabolites have shown promise in inhibiting SARS-CoV-2 spike protein binding to the ACE-2 receptor in laboratory studies. However, it's crucial to note that Alternaria species are known environmental molds and can be opportunistic pathogens, particularly in immunocompromised individuals. Therefore, the current research is in early stages, primarily in vitro and in silico, with no established clinical trials on humans for supplementation. The quality of available evidence is limited, and no high-quality randomized controlled trials (RCTs) or systematic reviews support its use as a supplement ingredient.
Benefits
Secondary metabolites from Alternaria species, including compounds identified from Alternaria alternata (closely related to A. tenuis), have demonstrated potential antiviral and anti-inflammatory effects in preclinical studies. Specifically, these metabolites have shown inhibition of SARS-CoV-2 spike protein binding to the human ACE-2 receptor, suggesting antiviral potential. Additionally, they exhibit anti-inflammatory effects via downregulation of proinflammatory cytokines TNF-α and IL-6 in macrophage cell models. However, it's important to emphasize that these benefits are based on laboratory findings, and no clinical data are available to support these effects in humans. The evidence is currently considered preclinical, and no clinical effect sizes have been reported.
How it works
The antiviral activity of Alternaria metabolites is believed to occur via the inhibition of the SARS-CoV-2 spike protein's interaction with the ACE-2 receptor, preventing viral entry into host cells. The anti-inflammatory activity is thought to be mediated through the inhibition of TNF-α:TNFR2 signaling and the reduction of proinflammatory cytokines. These mechanisms suggest a potential modulation of the immune response and viral entry pathways in lung endothelial and immune cells. However, the absorption, bioavailability, and pharmacokinetics of these metabolites have not been studied in vivo, and the precise molecular targets and interactions within the body remain largely unknown.
Side effects
No clinical safety data are available for Alternaria tenuis or its metabolites as supplements. Alternaria species are known environmental molds and can be opportunistic pathogens in immunocompromised individuals. Invasive infections have been reported in immunocompromised patients, including those with AIDS, indicating potential pathogenicity. Therefore, caution is advised, especially for individuals with compromised immune systems. Drug interactions are currently unknown. Due to the potential for pathogenicity, Alternaria species are contraindicated in immunocompromised individuals. Further research is needed to fully assess the safety profile of Alternaria tenuis and its metabolites.
Dosage
No established dosing guidelines exist for Alternaria tenuis or its metabolites as supplements due to the lack of clinical trials. Therefore, no recommended dosage ranges, timing considerations, or upper limits can be provided. The absence of clinical data also means that form and absorption factors are unknown. Until further research is conducted, it is not possible to determine a safe and effective dosage for human supplementation.
FAQs
Is Alternaria tenuis safe to consume as a supplement?
There is no evidence supporting safe human consumption. The fungus is primarily studied for its metabolites in vitro, and Alternaria species can be opportunistic pathogens, especially in immunocompromised individuals.
Are there proven health benefits?
Only preliminary laboratory evidence suggests antiviral and anti-inflammatory potential. No clinical proof exists to support these benefits in humans.
Can it cause infections?
Yes, Alternaria species can cause opportunistic infections in immunocompromised individuals. This is a significant safety concern.
Is it used in allergen immunotherapy?
Some Alternaria species are allergens, but A. tenuis is not established in allergen immunotherapy.
Research Sources
- https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0313616 – Althunian et al. (2023) identified secondary metabolites from *Alternaria alternata* with inhibitory activity against SARS-CoV-2 spike protein binding to ACE-2 receptor and anti-inflammatory effects in vitro. The study used molecular docking, immunoblotting, and cell-based assays to demonstrate potential antiviral and anti-inflammatory mechanisms, but lacks in vivo or clinical data.
- https://www.mdpi.com/2073-4395/15/6/1343 – This systematic review on plant protection products against *Alternaria* brown spot (caused by *Alternaria* species) summarized empirical evidence on controlling the fungus in agriculture. The review focuses on agricultural applications and does not address human health or supplementation.
- https://academic.oup.com/cid/article-abstract/9/4/799/279490 – This clinical case report and review from 1987 documented invasive *Alternaria* infections in immunocompromised patients, including AIDS patients, highlighting the pathogenic potential of *Alternaria* species. The report underscores safety concerns in vulnerable populations.
- https://www.jstor.org/stable/26895018 – This source provides general information about Alternaria species, their characteristics, and their role as plant pathogens. It offers a foundational understanding of the fungus but does not specifically address its use as a supplement or its effects on human health.
- https://onlinelibrary.wiley.com/doi/10.1111/all.13201 – This source discusses Alternaria species as allergens and their role in allergic diseases. It provides insights into the allergenic properties of certain Alternaria species but does not focus on Alternaria tenuis as a supplement or its potential benefits.
