Abalone (Haliotis spp.): A Comprehensive Encyclopedic Reference
1. Identity, Taxonomy, and Natural Source
Abalone belongs to the phylum Mollusca, class Gastropoda, and family Haliotidae, and is an important marine economic aquaculture shellfish. The genus Haliotis (Greek for "sea ear") encompasses numerous species, all of which are single-shelled marine gastropod molluscs distinguished by their characteristic row of respiratory pores running along the shell's edge.
According to on-site surveys of commercial medicinal materials in China, the shells of abalone consist of nine recognized types, with original animals including Haliotis diversicolor, H. discus hannai, H. ovina, H. asinia, H. ruber, H. laevigata, H. semistrata, H. midae, and H. cracherodii. Three of these — H. semistrata, H. midae, and H. cracherodii — are not included in the Chinese Pharmacopeia, and most shells of abalone currently on the market are H. ruber and H. discus hannai.
Most species are found in the cold waters of New Zealand, South Africa, Australia, Western North America, Japan, and China. Haliotis diversicolor (the nine-hole abalone) is predominantly found along the southern coast of China, particularly in Guangdong and Fujian, while Haliotis discus hannai (the wrinkle-plated abalone) is more common in the cooler northern waters of Shandong and Liaoning.
Haliotis rubra (blacklip abalone) is a single-shelled marine mollusc harvested commercially in many international waters and widely cultured in eastern Asia. Abalone is a commercially important mariculture mollusc due to its nutrient-rich value and extensive market demand, with over 95% of the abalone supply contributed by farming.
Common Names and Synonyms
- English: Abalone, sea ear, ear shell, muttonfish (Australia), perlemoen (South Africa)
- Chinese (TCM): Shí jué míng (石决明) — referring specifically to the shell; "Bào yú" (鲍鱼) — referring to the meat
- Latin pharmacopeial designation (shell): Concha Haliotidis
- Japanese: Awabi (アワビ)
- Korean: Jeonbok (전복)
Common Forms and Preparations as a Dietary Supplement
Marine organisms are increasingly being investigated as sources of bioactive molecules with therapeutic applications as nutraceuticals and pharmaceuticals. In particular, nutraceuticals are gaining popularity worldwide owing to their therapeutic potential and incorporation in functional foods and dietary supplements.
Abalone enters the supplement marketplace in several forms:
- Whole dried meat: The edible foot muscle of abalone is dried (sun-dried or freeze-dried) and ground into powder, which is then encapsulated or sold as a loose powder.
- Shell (calcined or raw): In Traditional Chinese Medicine, the shell is processed by removing the flesh, washing, drying in the sun, and then used either unprocessed or calcined and smashed.
- Hydrolysate / bioactive peptide extracts: Bioactive peptides studied for their pharmaceutical and food industry potential are derived from abalone viscera, which are normally discarded as byproducts and represent a rich source of protein.
- Fermented preparations: Abalone viscera, which accounts for more than 20% of the total weight of abalone, is generally regarded as waste in the food industry; fermentation techniques have been applied to add functionality.
- Polysaccharide extracts: Sulphated polysaccharides isolated from abalone muscle, gonad, or viscera are investigated for nutraceutical applications.
2. Traditional and Historical Use
Traditional Chinese Medicine (TCM)
The shell of Haliotis diversicolor, known as shijueming (SJM), is a type of traditional Chinese medicine that has appeared in historical records as early as the third and fourth centuries, where it had mainly been used to treat eye diseases. After the Qing Dynasty (1757), records emerged detailing the use of SJM for treating skin injuries, particularly for treating poorly managed ulcers or traumatic wounds.
Throughout history, abalone shell has been an important ingredient in many TCM formulations, Korean traditional Hanbang medicine, and Japanese Kampo medicines. In TCM theory, the shell is classified as salty and cold in nature, entering the liver meridian, and is indicated to pacify the liver, subdue yang, clear liver heat, and improve vision.
In Traditional Chinese Medicine, the shell is recognized for its ability to treat a wide variety of eye disorders, including glaucoma, conjunctivitis, night blindness, and cataracts, and is also known to help calm anxiety and soothe headaches caused by what the Chinese call excessive Liver Heat.
The most prized TCM form is the "nine-hole" variety (Jiu Kong Shi Jue Ming, 九孔石决明) from Haliotis diversicolor, which should have 7 to 9 clearly visible open respiratory holes along the shell edge.
Food and Culinary Traditions in Asia
For thousands of years, different cultures have used abalone as a traditional functional food, believing consumption provides health benefits. Abalone meat is one of the most precious commodities in Asian markets, where it is considered a culinary delicacy. The abalone fishery is highly valued as a seafood delicacy in many parts of the world, especially in Asia.
Indigenous and Other Traditional Uses
Abalone shells have been used in Traditional Chinese Medicine as medicine and by Native Americans as sacred containers used for holding sage and other sacred herbs for smudging the environment.
3. Key Constituents and Active Compounds
Proximate Nutritional Composition
Abalone contains a number of bioactive compounds, including phenolic compounds, glycogen, carbohydrates, protein, amino acids, fatty acids, and minerals, all of which offer health-promoting effects beyond basic nutrition. Nutritional analyses revealed that 100 g of the edible portion of abalone contains approximately 20 grams of high-quality protein.
The protein, carbohydrate, lipid, and ash contents of abalone muscle (H. discus hannai) have been measured at 15.87, 6.36, 0.22, and 1.36 g/100 g respectively. Most of the carbohydrates in the abalone muscle are released easily into water, and potassium is the most abundant mineral.
In hybrid abalone (H. discus hannai ♀ × H. fulgens ♂), the adductor muscle showed a protein content of 20.42% and total carbohydrate content of 4.14%. All three muscle parts were rich in polyunsaturated fatty acids, and the mineral elements were rich in variety, with high K, P, Mg, and Zn contents.
Amino Acids
The protein profile of abalone is determined by the type of amino acids available in the body. Abalone meat contains all essential amino acids — arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine — as well as nonessential amino acids including alanine, aspartic acid, cystine, glutamic acid, glycine, proline, serine, and tyrosine. Abalone muscle protein is notably high in leucine and arginine, and the water-soluble fraction is rich in essential and umami amino acids.
In extracts of abalone viscera obtained via ultrasonication, protein content was measured at 39.01% and polysaccharide content at 8.63%. For essential amino acid analysis, the extract showed especially high contents of alanine (65%), arginine (7%), and glycine (6%).
Fatty Acids
According to Mulvaney et al. (2015), 100 g of abalone contains 94 mg of n-3 long-chain polyunsaturated fatty acids (LC-PUFA), which is higher than the 70, 26, and 50 mg of PUFA found in beef, pork, and chicken, respectively.
Polysaccharides
Recent research has revealed that abalone is composed of many vital moieties like polysaccharides, proteins, and fatty acids that provide health benefits beyond basic nutrition. Two antioxidative substances have been extracted from the abalone (H. discus hannai) shell: a homogeneous polysaccharide (abalone shell polysaccharide, ASP-1) and a non-polysaccharide compound (ACS-2). ASP-1 is a heteropolysaccharide comprising 9.3% uronic acid and 86.4% saccharide, the latter including mannose, ribose, rhamnose, glucose, galactose, arabinose, and two unknown monosaccharides.
Bioactive Peptides
An anti-inflammatory peptide (AAIP, abalone anti-inflammatory peptide) was purified from abalone intestines. Tandem MS analysis identified the AAIP sequence as Pro-Phe-Asn-Glu-Gly-Thr-Phe-Ala-Ser (1175.2 Da), with nitric oxide inhibitory activity at an IC50 of 55.8 μM.
The ACE inhibitory peptide Ala-Met-Asn has been reported to be produced by enzymatic hydrolysis in abalone gonads.
Shell Composition
The shell of abalone (Concha Haliotidis) is composed primarily of calcium carbonate in the aragonite polymorph, interlayered with a protein matrix that creates the distinctive nacreous (mother-of-pearl) structure. In vitro and in vivo models have demonstrated that the shell decreases inducible nitric oxide synthase (iNOS) expression in macrophages and, in a rat burn injury model, decreases neutrophil infiltration, promotes wound healing by increasing collagen I content, and promotes the expression of transforming growth factor-beta 1 (TGF-β1).
Taurine
Researchers have discovered a free amino acid from Haliotis discus water named taurine, which has demonstrated anti-inflammatory and antioxidant potentials in zebrafish models.
4. Scientific Evidence by Health Area
4.1 Antioxidant Activity
Abalone, a marine gastropod, contains a variety of bioactive compounds with anti-oxidant, anti-thrombotic, anti-inflammatory, anti-microbial, and anti-cancer activities.
In vitro and preclinical evidence: Antioxidant activity assays indicated that 5.0 mg/mL of abalone shell polysaccharide (ASP-1) has significant scavenging effects on superoxide radicals (86.2%), compared to the positive control of ascorbic acid (95.6%). The antioxidant activity of abalone visceral polysaccharide may provide health benefits in reducing the risk of atherosclerosis because its ability to lower cholesterol levels is combined with antioxidative stress effects.
Evidence strength: Antioxidant data for abalone and its extracts are primarily in vitro (cell-free radical scavenging assays) and in animal models. These polysaccharides must be investigated further in humans to ascertain if they are effective and whether they have any side effects. No published randomized controlled trials in humans were identified for antioxidant outcomes specifically attributed to abalone supplementation.
4.2 Anti-inflammatory Effects
In vitro evidence: The anti-inflammatory potential of mucus-secreting gland by-products from H. discus hannai was evaluated using the RAW 264.7 mouse macrophage cell model. Results indicated that the mucosubstance by-products significantly lowered nitric oxide (NO) production along with expressional suppression of inflammatory mediators such as cytokines TNF-α, IL-1β, and IL-6 and enzymes iNOS and COX-2.
Investigation of the anti-inflammatory effect of AAIP on LPS-stimulated RAW 264.7 macrophages showed that the AAIP peptide suppresses LPS-induced production of nitric oxide via inducible nitric oxide synthase (iNOS) expression in a dose-dependent manner.
Animal model evidence: Sulfated polysaccharide from Pacific abalone (AGSP) reduced the level of lipopolysaccharides and increased the production of short chain fatty acids in the colon of mice, and reduced the levels of interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α while increasing the IL-10 level in in vitro cell models, suggesting its potential use as a probiotic agent to inhibit intestinal inflammation.
Recent studies have demonstrated that collagen peptides derived from abalone viscera exhibit anti-inflammatory properties, which may be achieved by regulating the gut microbiota and alleviating oxidative stress.
Evidence strength: Anti-inflammatory evidence remains at the preclinical (in vitro and animal) stage. No human clinical trials evaluating abalone supplementation specifically for inflammatory biomarkers were identified in the literature searched.
4.3 Wound Healing (Shell / Concha Haliotidis)
Preclinical study (in vitro and animal model): A study applied in vitro and in vivo models, tissue section analysis, and western blotting to evaluate the effect of SJM on wound healing. RAW 264.7 cells were used in anti-inflammatory activity assays, and male Wistar rats were subjected to a full-thickness burn injury created by a copper block preheated to 165 °C applied to the skin for 10 seconds. The results revealed that in the in vitro model, the presence of SJM decreased iNOS expression and enhanced macrophage functions. In the rat burn injury model, SJM decreased neutrophil infiltration, promoted wound healing by increasing collagen I content, and promoted the expression of TGF-β1. The effect and mechanism of SJM on promoting wound healing is speculated to be related to macrophage activation.
Evidence strength: Wound healing evidence is limited to in vitro and rodent models. No human clinical trial data were identified for this application.
4.4 Cardiovascular Effects — Antihypertensive Activity
Fermented abalone viscera has exhibited increased angiotensin I-converting enzyme (ACE) inhibitory activity and enhanced inhibition of blood pressure elevation in spontaneously hypertensive rats (SHRs).
Aspergillus oryzae fermented viscera study (animal model): In a study where viscera were fermented with Aspergillus oryzae 001, fermented abalone viscera exhibited increased ACE inhibitory activity and enhanced inhibition of blood pressure elevation in SHRs. Abalone viscera administration had no significant effect on body weight, food intake, liver and kidney weights, or serum components in SHRs. The identified substance was L-m-tyrosine, which non-competitively inhibited ACE and, in a single oral administration, significantly reduced blood pressure in SHRs. L-m-tyrosine was isolated for the first time from fermented abalone viscera as a single ACE-inhibitory amino acid.
Lactiplantibacillus pentosus fermented viscera study (animal model): The effects of abalone viscera fermented with Lactiplantibacillus pentosus SN001 on ACE activity and blood pressure were evaluated in spontaneously hypertensive rats. The fermented product significantly reduced systolic blood pressure compared with the control. There were no significant differences in blood glucose, triglyceride, total cholesterol, or HDL cholesterol levels between groups. Uracil was isolated and identified from the fermented product as the probable active component. Overall, L. pentosus SN001-fermented abalone viscera showed sustained inhibitory effects on blood pressure elevation but did not alter blood components after long-term intake.
Previous studies have confirmed that abalone viscera fermented with Lacticaseibacillus casei 001 and Lactiplantibacillus pentosus SN001 also showed ACE-inhibitory activity.
Evidence strength: Antihypertensive evidence is confined to spontaneously hypertensive rat (SHR) models with fermented abalone viscera preparations. No human clinical trials were identified for this endpoint.
4.5 Hypolipidemic / Cardiovascular Lipid Effects
A study evaluated the hypolipidemic and anti-atherogenic activities of crude polysaccharides extracted from abalone viscera (AVCP). Abalone viscera oil (AVO) was extracted via multistage countercurrent extraction, and its oil quality, fatty acid composition, in vitro antioxidant activity, and anti-hyperlipidemic effects on high-fat-diet (HFD)-induced hyperlipidemia mice were evaluated.
Evidence strength: Hypolipidemic data are from animal (rodent) and in vitro models only. Compared to the peptides and polysaccharides in abalone viscera, research on the extraction and functional evaluation of abalone viscera lipids is relatively scarce. No human clinical trial data were identified.
4.6 Antimicrobial Activity
A study explored the potential bioactivity of peptides derived from abalone viscera (Haliotis fulgens and Haliotis corrugata) after hydrolysis with a commercial mixture of enzymes. The hydrolysates were fractionated and investigated for antimicrobial and cytotoxic activities. Results showed antimicrobial activity for protein fractions of H. corrugata against Proteus mirabilis and Pseudomonas aeruginosa (66.2–116.25 kDa), Bacillus subtilis (6.5–21.5 kDa), and Aspergillus niger (97.4–116.25 kDa).
Evidence strength: Antimicrobial evidence is entirely in vitro. Translation to clinical efficacy has not been demonstrated in human studies.
4.7 Anticancer / Cytotoxic Activity
Hydrolysate fractions from abalone viscera were investigated for their cytotoxic activities, including the expression of gelatinases MMP-2 and MMP-9 in human prostate cancer cell lines (PC3). The discovery of novel bioactive peptides from marine origins with specific cellular targets may complement the search for promising drug candidates. During the last decade, hundreds of marine-based bioactive molecules have been discovered, with several undergoing clinical trials.
Evidence strength: Anti-cancer data related to abalone-derived compounds are at the in vitro and early preclinical stage. No human clinical trials of abalone-specific anticancer preparations were identified in the sources reviewed.
4.8 Skin Health
The skin health effects of abalone viscera ultrasonic extract (AVU) have been confirmed in human dermal fibroblast (HDF) and HaCaT keratinocyte cell models. Ultrasonication technology is used as an environmentally friendly method to efficiently extract bioactive compounds such as proteins from animal tissues. After extraction, AVU showed high protein content and suitability for functional food or cosmetics production.
Abalone (Haliotis asinina) extracts derived from the hypobranchial gland and gills have been evaluated for cell protective effects on HaCaT cells following UV-B exposure. Abalone, as a gastropod, could possibly have similar, yet unexplored advantageous attributes to land snail mucus in skin anti-aging and wound healing.
Evidence strength: All skin health data are in vitro (cell culture). No human clinical trials of abalone-derived preparations for dermatological endpoints were identified.
4.9 Gut / Intestinal Health
Sulfated polysaccharide from Pacific abalone (AGSP) reduced LPS levels and increased the production of short-chain fatty acids in the colon of mice, and reduced pro-inflammatory cytokine levels (IL-6, IL-1β, TNF-α) while increasing the anti-inflammatory IL-10 level in in vitro models.
Evidence strength: Intestinal health evidence is limited to mouse models and in vitro systems. Clinical human data are absent.
5. Body Systems Associated with Abalone
- Cardiovascular system: ACE inhibitory peptides and polysaccharides, LC-PUFA content relevant to lipid management.
- Ocular/visual system: In TCM, the shell is recognized for treating a wide variety of eye disorders, including glaucoma, conjunctivitis, night blindness, and cataracts.
- Integumentary system (skin): Bioactive protein and polysaccharide extracts investigated for wound healing and anti-inflammatory effects on skin cells.
- Gastrointestinal tract: Sulfated polysaccharides studied for modulation of intestinal inflammation and microbiota.
- Immune system: Abalone possesses anti-microbial, anti-thrombotic, anti-cancer activities, and anti-inflammatory properties.
- Musculoskeletal: High essential amino acid content and glycine/proline profile relevant to collagen and connective tissue; in TCM theory, the shell is associated with the liver meridian and calming of yang hyperactivity, which encompasses headache and musculoskeletal tension.
6. Dosage Forms and Dosages Reported in Studies
Because abalone research is primarily preclinical (animal and in vitro), standardized human dosages have not been established. The following dosages appear in peer-reviewed sources and are reported descriptively as found in those studies:
- Abalone shell polysaccharide (ASP-1) — in vitro antioxidant: A concentration of 5.0 mg/mL ASP-1 produced significant scavenging effects on superoxide radicals (86.2%) in cell-free assays.
- Abalone anti-inflammatory peptide (AAIP) — in vitro: The AAIP peptide (Pro-Phe-Asn-Glu-Gly-Thr-Phe-Ala-Ser, 1175.2 Da) demonstrated nitric oxide inhibitory activity at an IC50 of 55.8 μM in LPS-stimulated RAW 264.7 macrophages.
- Fermented abalone viscera (A. oryzae 001) — animal model: In a single oral administration in SHRs, L-m-tyrosine isolated from fermented abalone viscera significantly reduced blood pressure compared to control.
- Fermented abalone viscera (L. pentosus SN001) — animal model: The effects of fermented abalone viscera on ACE activity and blood pressure elevation were evaluated in spontaneously hypertensive rats, and the fermented product significantly reduced systolic blood pressure compared to control, with no significant differences in blood lipids or liver enzyme markers.
No standardized clinical dosages for human supplementation with abalone or its extracts could be identified in the peer-reviewed sources reviewed. Effective human doses, if any, remain undetermined pending controlled clinical trials.
7. Safety Considerations and Interactions
Allergic Reactions
Abalone belongs to the mollusk family of shellfish, classified as gastropods alongside snails and whelks. Allergies to mollusks (such as abalone, clams, and oysters) are less common than allergies to crustaceans (like shrimp). However, reactions can be serious: as with most food allergies, symptoms are usually mild such as oral allergy syndrome, but severe symptoms such as anaphylactic shock can also occur after consumption.
A report of anaphylaxis in adults referred to a Singapore clinic found that ingestion of mollusks (abalone and limpet) was the most common cause of food-related anaphylaxis (11 of 30 cases). A South African study of individuals with self-reported hypersensitivity to seafood reported that reaction to abalone was the third most common reaction to seafood after shrimp and crayfish, with 38 of 105 patients reacting to abalone.
Cross-Reactivity
Allergy to abalone is most commonly associated with allergy to other related shellfish such as limpet, snails, winkles, and whelks (gastropods). Reactions can also be triggered by eating more distantly related mollusks such as clams, mussels, oysters, and scallops (bivalves) or cuttlefish, octopus, and squid (cephalopods). After a diagnosis of allergy to one mollusk, patients are normally advised to avoid all mollusks.
In the United States, crustacean shellfish are required to be listed on labels per FALCPA, but mollusks (including abalone) are not, making abalone a potential hidden allergen. Abalone is not currently listed in Annex IIIa of the EU directive on labelling of foods, and thus individuals allergic to mollusks must be alert to the possibility of abalone or other mollusks as hidden allergens.
Heavy Metal Contamination
Generally speaking, mercury and other heavy metal contamination is not a significant issue with abalone; however, research suggests there are some areas of the world where heavy metal contamination might be more of a concern. Specifically, the bioaccumulation of heavy metals in abalone appears to be a problem for some Chinese abalone farms, primarily involving cadmium, mercury, and silver.
Shellfish Toxins and Food Safety
Shellfish poisoning can frequently masquerade as an allergic reaction. Ingestion of contaminated shellfish results in a wide variety of symptoms depending on the concentration of toxins and amount consumed, with five types of shellfish poisoning identified. Paralytic shellfish poisoning is the best known and is caused by saxitoxins; it is the most severe, with neurological symptoms predominating.
Animal Safety Data from Fermented Preparations
In spontaneously hypertensive rat studies, abalone viscera administration had no significant effect on body weight, food intake, liver and kidney weights, or serum components, indicating an absence of overt organ toxicity at the doses tested in animals.
Regulatory Status
As of the sources reviewed, there are no published WHO monographs, ESCOP monographs, European Pharmacopoeia monographs, or NIH Office of Dietary Supplements fact sheets specifically evaluating abalone as a dietary supplement for human health. The Chinese Pharmacopeia recognizes six of the nine identified commercial species of abalone shell as official medicinal materials, while three species are not included in the Pharmacopeia. The overall evidence base for abalone as a human dietary supplement is primarily preclinical, and no major regulatory body has approved specific health claims.
8. Overall Evidence Assessment
Abalone contains a variety of bioactive compounds with anti-oxidant, anti-thrombotic, anti-inflammatory, anti-microbial, and anti-cancer activities, and different cultures have used abalone as a traditional functional food for thousands of years, believing consumption provides health benefits. Recent research has revealed that abalone is composed of many vital moieties like polysaccharides, proteins, and fatty acids that provide health benefits beyond basic nutrition.
Nonetheless, the overwhelming majority of evidence for specific bioactivities remains at the in vitro and animal model stage. The biological activity of most marine compounds is still unclear and under investigation. Robust, randomized, placebo-controlled human clinical trials evaluating specific health endpoints of abalone supplementation are, as of the sources reviewed, absent from the published literature. The most evidence-supported traditional use — the shell for ocular and liver-related conditions in TCM — is supported by historical textual records and limited preclinical anti-inflammatory and wound healing studies, but lacks human clinical trial validation.
References
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