Acer truncatum (Sapindaceae) Shantung Maple, Purpleblow Maple, Yuanbao Maple

Acer truncatum, commonly known as the Shantung maple or Yuanbao maple, is a deciduous tree native to northern China, Manchuria, and Korea, now appreciated worldwide as a small ornamental tree for its striking autumn colour and adaptability . It holds a unique position in traditional Chinese culture, valued for its aesthetic beauty and its versatile uses. For centuries, its leaves have been brewed as a healthful tea in northern China, particularly by the Mongolian, Tibetan, and Korean communities, to promote longevity and treat various ailments . Recent scientific investigation is now substantiating these traditional claims, revealing that the tree is a rich source of bioactive compounds that could be vital for brain health and combating age-related diseases. Its seeds are also a source of valuable oil containing nervonic acid, an essential nutrient for nerve cell function .

1. Taxonomic Insights

Species: Acer truncatum Bunge

Family: Sapindaceae (formerly Aceraceae)

The Sapindaceae family, also known as the soapberry family, includes a wide variety of trees, shrubs, and lianas. It is a group of significant economic and ecological importance, encompassing the maples, horse chestnuts, and lychees. The genus Acer, to which this plant belongs, is most famous for its species that produce maple syrup and spectacular autumn foliage. Acer truncatum is a member of the section Platanoidea, a group of maples known for their palmate leaves and distinctive winged seeds .

Taxonomic Note: The species was first described by the Russian botanist Alexander von Bunge in 1833 . The genus name Acer is the classical Latin word for a maple tree. The specific epithet truncatum is derived from the Latin word "truncatus," meaning "cut off square," and refers to the characteristic truncated or squared-off base of the leaf, a key identifying feature . Although frequently described as having a truncate base, the leaf base can occasionally be cordate (heart-shaped) . The plant is a deciduous tree, usually reaching heights of 8-10 metres, and is noted for its pale, exfoliating bark and neat, rounded crown . The leaves have five triangular lobes and exude a milky sap when the petiole is cut, a feature common to some maples .

Related Herbs from the Same Family:

· Acer palmatum (Japanese Maple): Another prized ornamental maple, celebrated for its finely dissected leaves and vibrant autumn colours. It shares a similar cultural significance in landscaping.

· Acer saccharum (Sugar Maple): A North American native known for its sap, which is the primary source of maple syrup. It has a more robust, columnar form and different leaf shape.

· Acer mono (Painted Maple): A species also native to China, often confused with A. truncatum; its leaves are more sharply pointed and its winged seeds have a different shape .

· Aesculus hippocastanum (Horse Chestnut): A member of the Sapindaceae family known for its seeds, which are used in traditional medicine for venous insufficiency.

2. Common Names

Scientific Name: Acer truncatum | English: Shantung Maple, Purpleblow Maple, Shangtung Maple, Yuanbao Maple | Chinese: 元宝槭 (Yuanbao qi), 元宝枫 (Yuanbao feng), 五角枫 (Wujiaofeng) | Korean: San-dan-pung (산단풍).

3. Medicinal Uses

Primary Actions: Anti-aging, Neuroprotective, Hepatoprotective, Anti-inflammatory, Antioxidant

Secondary Actions: Acetylcholinesterase Inhibitory, Antibacterial, Antitumor, Hypolipidemic, Fatty Acid Synthase Inhibitory, Dermatitis Treatment

Medicinal Parts:

The leaves, fruit (samara), and bark are the primary parts used medicinally .

· Leaves: The leaves are the most extensively studied part. They are used to make a traditional tea in northern China. They are rich in phenolic acids and flavonoids and are considered to have potent anti-aging, antioxidant, and anti-inflammatory properties . They have also been used in traditional medicine to treat hyperlipidemia, and skin itching or dry cracks .

· Fruit (Samara): The seeds of the samara are a source of a unique oil rich in nervonic acid, a long-chain fatty acid that is a crucial component for the growth, development, and maintenance of nerve cells and brain tissue . This oil is being studied for its potential in preventing and treating neurodegenerative diseases.

· Bark: The bark is used in traditional preparations to treat various conditions, including back pain and as an external application for trauma and bruises .

4. Phytochemicals Specific to the Plant and Their Action

The phytochemical profile of Acer truncatum is remarkably diverse, with a total of 288 compounds identified across the plant .

· Polyphenols and Flavonoids: The aqueous extract of the leaves is abundant in phenolic acids and flavonoids. The most prominent compounds identified are chlorogenic acid, neochlorogenic acid, quercetin, and myricetin . These compounds are potent antioxidants and are responsible for the plant's strong anti-inflammatory, and anti-aging activities.

· Nervonic Acid: Found in the seed oil, nervonic acid is a very long-chain monounsaturated fatty acid (C24:1) that is considered a critical nutrient for the biosynthesis of myelin, the protective sheath surrounding nerve cells. Its presence makes A. truncatum a significant new resource for this valuable compound, which is being explored for its neuroprotective effects .

· Other Compounds: A total of 41 compounds have been isolated from the leaves alone, and over 247 more have been identified in other parts using analytical techniques. These include various other polyphenols, organic acids, and lipids that contribute to the plant's diverse pharmacological effects .

5. Traditional and Ethnobotanical Uses Covering the Medicinal Uses

Aging and Longevity (Anti-aging)

Formulation: Aqueous leaf extract (Maple tea).

Preparation and Use: For generations, the leaves of A. truncatum have been consumed as an herbal tea in northern China, particularly in Inner Mongolia, as a tonic to retard aging and promote a long and healthy life . Modern research using Drosophila melanogaster (fruit fly) as a model has validated this use, demonstrating that supplementation with the leaf extract significantly extends lifespan, improves locomotor activity, and enhances stress resistance .

Reasoning: This anti-aging effect is attributed to the high content of antioxidants like quercetin and myricetin, which combat oxidative stress, a major driver of cellular ageing. Recent research also suggests the extract works by modulating the composition of gut microbiota, promoting beneficial bacteria and reducing harmful ones, thereby influencing metabolic pathways related to longevity .

Cardiovascular and Cerebrovascular Health

Formulation: Leaf extract.

Preparation and Use: Traditional Mongolian, Tibetan, and Korean medicinal practices use the plant to prevent and treat cardiovascular and cerebrovascular diseases, as well as conditions like hyperpiesia (high blood pressure) and hyperlipidemia (high cholesterol) .

Reasoning: The bioactivities of compounds in the leaves, such as antioxidant and fatty acid synthase inhibitory effects, help reduce oxidative damage to blood vessels and lower lipid levels. The presence of nervonic acid in the seeds also plays a role in maintaining brain and nerve health, supporting its use for cerebrovascular disorders .

Skin Trauma and Inflammation

Formulation: Leaf extract (topical or decoction).

Preparation and Use: The leaves are used as a decoction to treat skin trauma, itching, and dry cracks. In vitro studies have shown that an extract of the leaves can protect skin cells (HaCaT cells) from chemically induced inflammation by reducing levels of inflammatory markers like interleukin-6 (IL-6) and prostaglandin E2 (PGE2), and by preventing cell apoptosis .

Reasoning: The anti-inflammatory effects are linked to specific flavonoid compounds like kaempferol-3-O-α-L-rhamnoside and quercetin-3-O-α-L-rhamnopyranoside, which have been isolated from the leaves. These compounds help to calm skin inflammation, making the plant a potential candidate for treating dermatitis .

Waist and Back Pain

Formulation: Bark or root extract.

Preparation and Use: In traditional Chinese medicine, the bark and roots are used to dispel wind and dampness, and they have been employed to treat general aches, back pain, and bruises .

Reasoning: While the specific mechanisms are less studied than the leaf, the anti-inflammatory and analgesic properties of the plant's compounds likely contribute to its effectiveness for pain relief.

6. Healing Recipes, Decoctions, and Preparations

Anti-aging Maple Tea

Purpose: To support overall vitality, combat oxidative stress, and promote longevity.

Preparation and Use:

1. Take one to two teaspoons of dried Acer truncatum leaves.

2. Place the leaves in a cup and pour over 250 ml of freshly boiled water.

3. Steep for 5-10 minutes, allowing the active compounds to infuse.

4. Strain and drink this tea once or twice daily. This traditional preparation is now supported by research demonstrating its anti-aging effects .

Cardiovascular Support Infusion

Purpose: To help manage blood pressure and cholesterol levels.

Preparation and Use:

1. Boil a handful of dried leaves in 500 ml of water for about 15 minutes.

2. Allow the decoction to cool, strain, and drink 100 ml twice daily.

3. This practice is rooted in traditional use for preventing cardiovascular disease . It should be used as a complementary measure and not as a substitute for prescribed medication.

Topical Skin Soother

Purpose: To help soothe inflammation, itching, and dry skin.

Preparation and Use:

1. Crush fresh or dried Acer truncatum leaves to make a paste.

2. Mix a small amount with a carrier oil like coconut or olive oil.

3. Apply this mixture topically to the affected area of skin to help calm irritation .

Culinary Uses

· Young Leaves: The young leaves can be consumed as a vegetable or used to wrap foods, though they are most famous as a tea .

· Seeds: The seeds (samaras) are a valuable source of edible oil. The oil is rich in nervonic acid and has a pleasant flavour. It can be used in salads, cooking, or as a dietary supplement. In traditional communities, the seeds were sometimes eaten directly after being fried .

7. In-Depth Phytochemical Profile and Clinical Significance

Introduction

Acer truncatum, while renowned for its ornamental value, is a species of immense therapeutic potential. Its use as a longevity tonic and a remedy for various inflammatory and metabolic conditions in traditional Chinese medicine is being powerfully validated by modern scientific research. The therapeutic potential of A. truncatum is grounded in its unique phytochemical synergy: the potent antioxidant polyphenols and flavonoids (quercetin, chlorogenic acid) in its leaves, and the neuroprotective nervonic acid concentrated in its seed oil. The discovery that the leaf extract can significantly extend lifespan in animal models and protect skin cells from inflammation provides a strong mechanistic basis for its traditional application in gerontology, dermatology, and cardiovascular health.

1. Polyphenols and Flavonoids: The Antioxidant and Anti-Aging Arm

Key Compounds: Chlorogenic acid, Neochlorogenic acid, Quercetin, Myricetin, Kaempferol glycosides, Esculin .

Quantitative Profile: An aqueous extract of the leaves was found to contain a high concentration of phenolic acids (32.45% of identified compounds) and flavonoids (28.13%). Quantitatively, this included neochlorogenic acid (17.94 mg/g), myricetin (3.44 mg/g), chlorogenic acid (2.902 mg/g), and quercetin (1.197 mg/g) .

Actions and Clinical Relevance:

· Anti-aging: The extract has demonstrated a significant ability to extend the lifespan of Drosophila melanogaster . This effect is attributed to the powerful antioxidant properties of quercetin and myricetin, which are known to reduce cellular oxidative stress. Furthermore, the extract positively modulates the gut microbiome in aged flies, reducing the prevalence of detrimental bacteria (like Enterococcus) and increasing beneficial ones (like Lactococcus), which is linked to improved metabolic health and longevity .

· Anti-inflammatory: The polyphenols, particularly compounds like kaempferol-3,7-di-O-α-L-rhamnoside, exert potent anti-inflammatory effects by reducing the production of key inflammatory cytokines such as IL-6 and PGE2. This supports the traditional use of the leaves for treating skin inflammation and other inflammatory conditions .

2. Nervonic Acid: The Neuroprotective Lipid

Key Compound: Nervonic acid (cis-15-tetracosenoic acid).

Pharmacological Profile: This very-long-chain monounsaturated fatty acid is a major component of the seed oil. It is a vital structural component of sphingolipids, which are abundant in the myelin sheath of nerve cells .

Actions and Clinical Relevance:

· Neuroprotective: Nervonic acid is considered an essential nutrient for brain development and function. It plays a critical role in the synthesis of myelin, and its deficiency has been linked to neurodegenerative diseases and cognitive decline. The high yield of nervonic acid from A. truncatum seeds positions this plant as a key new resource for developing nutraceuticals aimed at delaying brain aging and treating conditions like multiple sclerosis and Alzheimer's disease .

An Integrated View of Healing in Acer truncatum

· For Healthy Aging: The combination of potent antioxidants and gut-microbiome modulating effects from the leaf extract positions A. truncatum as a powerful natural agent for promoting longevity and maintaining health in old age .

· For Brain and Nerve Health: A. truncatum is a rare and valuable source of nervonic acid, making it a promising candidate for dietary interventions to support brain function and prevent neurological decline .

· For Metabolic and Skin Health: Its traditional uses for cardiovascular ailments and skin trauma are backed by its anti-inflammatory and lipid-lowering bioactivities, offering a natural approach to these common health concerns .

Toxicological Profile and Quality Control

Safety Profile: Acer truncatum is generally considered safe, and its leaves are approved as a food raw material in China . However, comprehensive toxicological data for concentrated extracts is still being gathered. As with any medicinal plant, it should be used with caution. Pregnant or nursing women should consult a healthcare provider before use.

Quality Control Parameters: The identification of the specific chemical profile of the leaves provides a basis for standardising extracts. Key marker compounds like chlorogenic acid, neochlorogenic acid, quercetin, and myricetin can be used to ensure the quality, consistency, and potency of commercial extracts and teas .

Conclusion: Acer truncatum is a prime example of a plant where ancient wisdom and modern science converge. Once simply a beautiful ornamental tree, it has emerged as a promising source of compounds with significant potential for promoting longevity, protecting the brain, and fighting inflammation. Its nervonic acid-rich seed oil offers hope in the fight against neurodegenerative diseases, while its antioxidant-rich leaf tea provides a simple and effective way to support overall health. As research continues, Acer truncatum is poised to become an increasingly important player in the fields of nutraceuticals and anti-aging medicine.

Disclaimer:

Acer truncatum is generally considered safe for traditional uses. However, comprehensive safety data, particularly for concentrated extracts and long-term use, are still emerging. Pregnant or nursing women should consult a qualified healthcare professional before use. This information is for educational use only and is not a substitute for professional medical advice.

8. Reference Books, Books for In-depth Study

· Journal of Ethnopharmacology - for comprehensive review on ethnobotany, phytochemistry, and pharmacology .

· Scientific Reports - for anti-aging and gut microbiota research .

· Frontiers in Pharmacology - for skin inflammation and dermatitis treatment research .

· Trees and Shrubs Online - for horticultural and botanical details .

· Missouri Botanical Garden Plant Finder - for general plant characteristics .

· Flora of China - for botanical description and distribution.

9. Further Study: Plants That Might Interest You Due to Similar Medicinal Properties

10. Ginkgo biloba (Maidenhair Tree)

· Species: Ginkgo biloba | Family: Ginkgoaceae

· Similarities: A living fossil tree renowned for its neuroprotective properties, particularly for improving cognitive function and cerebral circulation. Like A. truncatum, it is a focus of research for brain health and anti-aging.

11. Camellia sinensis (Tea Plant)

· Species: Camellia sinensis | Family: Theaceae

· Similarities: The source of green, black, and oolong tea. It is famous for its rich polyphenol content, particularly catechins, which provide powerful antioxidant and health-promoting benefits comparable to those found in A. truncatum leaves.

12. Hippophae rhamnoides (Sea Buckthorn)

· Species: Hippophae rhamnoides | Family: Elaeagnaceae

· Similarities: A plant whose berries produce a unique oil rich in omega fatty acids (like nervonic acid) and antioxidants. It is used for its cardioprotective, anti-inflammatory, and skin-healing properties.

-x-xEnd-x-x