Avocado/Soybean Unsaponifiables
Common Name(s): A1S2, Arthrocen, ASU, Avocado/soybean unsaponifiables, Piascledine
Medically reviewed by Drugs.com. Last updated on Nov 30, 2022.
Clinical Overview
Use
Clinical studies are largely supportive of a place in therapy for avocado/
Dosing
Dosages of ASU 300 or 600 mg/day (typical duration, 6 months) have been studied for the treatment of osteoarthritis.
Contraindications
Contraindications have not been identified.
Pregnancy/Lactation
Information regarding efficacy and safety of ASU during pregnancy and lactation is lacking. Avocado fruit and soybean are both considered generally recognized as safe (GRAS) when used as food.
Interactions
None well documented.
Adverse Reactions
No clinically important adverse effects have been reported. Infrequent mild GI complaints have been documented in reviews, at a similar rate to the comparator or placebo.
Toxicology
No data.
Scientific Family
- Fabaceae (bean)
- Lauraceae
Botany
ASU is derived from avocado (Laurus persea L. or Persea americana Mill.) and soy (Glycine max L. Merr.) plants (see individual Avocado and Soy monographs).
History
Clinical studies evaluating ASU, primarily conducted by French researchers, first appeared in the literature in the 1970s. Published findings remained limited to a few groups of researchers. Interest in veterinary applications has been growing.Henrotin 2005, Henrotin 1998, Kawcak 2007 ASU has been studied in in vitro and in vivo animal models of experimental arthrosis. A commercial ASU product (Piascledine) has been widely used in Europe (eg, France) for osteoarthritis and has been evaluated as an alternative or adjunctive therapy to standard nonsteroidal anti-inflammatory drugs (NSAIDs).Frondoza 2018, Gluszko 2016, Henroitin 2017
Chemistry
ASU is made up of unsaponifiable fractions of avocado and soybean extracts.Gluszko 2016 Portions of avocado and soybean oils (approximately 1%) are unsaponifiable (ie, cannot be hydrolyzed or made into soap), and are combined to form ASU, generally in a ratio of 1:2 (one-third avocado and two-thirds soybean unsaponifiables).Christiansen 2015, Gluszko 2016, Henrotin 1998, Lippiello 2008 Other ratios of avocado:soybean unsaponifiables have been evaluated.Henrotin 1998
The major components of ASU are the phytosterols beta-sitosterol, campesterol, and stigmasterol, as well as saturated hydrocarbons, squalene, tocopherols, and alcohols.Henrotin 1998, Lippiello 2008
Uses and Pharmacology
Anti-inflammatory effects
Animal and in vitro data
Anti-inflammatory effects have been demonstrated in vitro and in animal studies.(Al-Afify 2018, Christensen 2008, Goudarzi 2018, Henrotin 1998, Kawcak 2007, Lippiello 2008, Oliveira 2016) Several possible mechanisms of action have been described.(Frondoza 2018, Gluszko 2016, Henrotin 2017)
In a murine model of osteoarthritis of the knee, ASU 27.5 mg/kg administered orally daily for 3 weeks attenuated degeneration of the synovium, cartilage, and subchondral bone, as well as decreased the expression of inflammatory mediators such as tumor necrosis factor alpha and matrix metalloproteinase-13, suggesting beneficial structural modifying effects in osteoarthritis.(Al-Afify 2018, Ernst 2003) Additionally, in a rat model of arthritis, ASU administration improved osseointegration, as measured by bone-to-implant contact and bone area between the threads.(dePaula 2018)
In a small study in horses (N=16) with induced osteoarthritis, ASU supplementation did not improve outcomes of pain or lameness; however, the researchers reported reductions in the severity of articular cartilage erosion and synovial hemorrhage, as well as increased articular cartilage glycosaminoglycan synthesis.(Kawcak 2007)
Clinical data
Clinical studies largely support a role for ASU in the treatment of osteoarthritis, due to its anti-inflammatory effects; however, methodological limitations and sponsorship bias exist among studies.(Christiansen 2015, Cornblatt 2016, Ernst 2003) Pain reduction has been reported; however, effectiveness of ASU on structural disease-modifying properties have not been confirmed by radiographic evidence in independent trials.
In a meta-analysis of 4 industry-funded clinical trials conducted prior to 2002 (664 patients with knee and/or hip osteoarthritis), supplemental ASU resulted in improvements in pain scores and functional indices, especially in those with osteoarthritis of the knee.(Christiansen 2008, Ernst 2003)
Further studies similarly report improvements in pain and function. A 6-month multicenter clinical study comparing ASU (ie, Piascledine) with chondroitin in patients with osteoarthritis of the knee (N=364) suggests equivalent efficacy, with decreases in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Lequesne Index scores noted for both groups. No adverse effects were documented in the study.(Pavelka 2010)
A 3-year, industry-sponsored clinical trial in patients with hip osteoarthritis (N=399) receiving ASU 300 mg/day or placebo suggested a protective effect on the joint with ASU therapy, as measured by change in joint space width over the length of the trial. A lower rate of progression (deterioration) was found in the ASU group (40% vs 50%; P=0.04), but no difference in mean joint space width loss was determined. No differences were found for secondary outcomes of Lequesne Index score, WOMAC pain score, or analgesic or NSAID use.(Maheu 2014)
In an open-label study of 4,822 patients with knee osteoarthritis, the effects of ASU 300 mg daily for 6 months were assessed. The proportion of patients taking NSAIDs or other analgesics decreased from 58.8% at baseline to 24.9% after 6 months of therapy (P<0.001). Additionally, functional impairment, as measured using the Lequesne index, significantly improved from baseline to the final visit (median decrease in score from 8 to 4 points [P<0.001]). ASU was also associated with a significant improvement from baseline in pain intensity (P<0.001).(Gluszko 2016)
In a 6-month clinical study evaluating ASU 300 mg daily versus placebo in patients with osteoarthritis of the temporomandibular joint (N=14), decreases in pain and use of rescue analgesic medication were reported among those receiving ASU.(Catunda 2016)
The European League Against Rheumatism's updated recommendations for the management of hand osteoarthritis (2018) indicated that no evidence for clinical efficacy exists for use of avocado-soybean unsaponifiables.(Kloppenburg 2018)
Antimicrobial effects
Animal data
Coadministration of ASU with praziquantel increased elimination of Schistosoma mansoni in mice.(Soliman 2012)
Metabolic syndrome
Clinical data
ASU did not modify insulin sensitivity in a small clinical study of obese adults (N=7).(Martinez-Abundis 2013)
Wound healing
Animal data
A study in rats suggests anti-inflammatory effects of ASU may be responsible for observed increased collagen synthesis and decreased inflammation during wound healing.(de Oliveira 2013, Oryan 2015)
Dosing
ASU (eg, Piascledine) dosages of 300 or 600 mg/day (typical duration, 6 months) have been studied for the treatment of osteoarthritis (eg, osteoarthritis of the knee, hip, or temporomandibular joint).Catunda 2016, Gluszko 2016, Maheu 2014, Pavelka 2010
Pregnancy / Lactation
Information regarding use of ASU during pregnancy and lactation is lacking. Avocado fruit and soybean are both considered GRAS when used as food.
Interactions
None well documented.
Adverse Reactions
No clinically important adverse effects have been reported in clinical studies.Catunda 2016, Pavelka 2010 Infrequent mild GI complaints have been documented in reviews, at a similar rate to the comparator or placebo.Christensen 2008, Ernst 2003 In a safety meta-analysis, the adverse effect profile of ASU was similar to that of placebo.Honvo 2019
Toxicology
Information is limited. A lack of short-term toxicity was reported in in vitro studies of unsaponifiable mixtures.Henrotin 1998 See individual Avocado and Soy monographs.
References
Disclaimer
This information relates to an herbal, vitamin, mineral or other dietary supplement. This product has not been reviewed by the FDA to determine whether it is safe or effective and is not subject to the quality standards and safety information collection standards that are applicable to most prescription drugs. This information should not be used to decide whether or not to take this product. This information does not endorse this product as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this product. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this product. This information is not specific medical advice and does not replace information you receive from your health care provider. You should talk with your health care provider for complete information about the risks and benefits of using this product.
This product may adversely interact with certain health and medical conditions, other prescription and over-the-counter drugs, foods, or other dietary supplements. This product may be unsafe when used before surgery or other medical procedures. It is important to fully inform your doctor about the herbal, vitamins, mineral or any other supplements you are taking before any kind of surgery or medical procedure. With the exception of certain products that are generally recognized as safe in normal quantities, including use of folic acid and prenatal vitamins during pregnancy, this product has not been sufficiently studied to determine whether it is safe to use during pregnancy or nursing or by persons younger than 2 years of age.
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