Sang Ye

Sang Ye (Mulberry Leaf) is the dried leaf of Morus alba L., a fast-growing deciduous tree in the family Moraceae. In the traditional TCM classification system, Sang Ye is considered sweet and bitter in flavor with a cold nature. It enters the Lung and Liver meridians, giving it a central role in formulas that address Wind-Heat patterns, Lung dryness, and Liver Heat.

Botanical description: Morus alba is a medium-sized deciduous tree reaching 10–20 m in height, with a spreading crown and a short, stout trunk. The leaves are simple, alternate, and broadly ovate to heart-shaped (cordate), 5–15 cm long and 4–12 cm wide, with serrated margins and a pointed tip. The leaf base is often asymmetrical. The leaves are pale green and smooth on the upper surface, with a slightly paler, pubescent lower surface. The leaf blade is palmately veined with 3–5 basal veins. The tree produces small, unisexual catkins in spring, followed by the well-known aggregate fruits (mulberries), which are white, pink, or purple-black when ripe, depending on the cultivar.

Habitat and cultivation: M. alba is native to China and has been cultivated for thousands of years, primarily for sericulture (silkworm rearing). In China, the primary producing regions include Jiangsu, Zhejiang, Sichuan, and Anhui provinces. The tree prefers full sun and well-drained, fertile soils, tolerating a wide range of climatic conditions. The leaves are traditionally harvested after the first frost in autumn (a practice known as "frost-descent mulberry leaf" or shuang sang ye), when the active constituents are believed to be at their peak. The leaves are cleaned, dried in the sun or by artificial drying, and cut into pieces for medicinal use.

Quality markers: The Chinese Pharmacopoeia specifies that high-quality Sang Ye should have intact leaves that are pale greenish-yellow to brownish-green, with a characteristic mild odor and a slightly bitter taste. Premium-grade material is described as being large, complete, and pale greenish-yellow, free from mold or insect damage. Chemical markers including rutin content are specified in pharmacopoeial standards for quality control of commercial Sang Ye preparations.

In the traditional Chinese medicine theoretical framework, Sang Ye is understood in terms of its effects on specific patterns of disharmony (zheng). Because Sang Ye enters the Lung and Liver meridians and has a sweet, bitter, and cold quality, it is traditionally indicated for a range of patterns involving Wind-Heat, Lung dryness, and Liver Fire.

Dispersing Wind-Heat: Sang Ye is considered one of the most important herbs in TCM for dispersing Wind-Heat from the upper body. In TCM theory, when Wind-Heat invades the exterior, it may manifest as fever, mild chills, headache, sore throat, red eyes, and a thin yellow tongue coating. Sang Ye is traditionally used to release the exterior and clear Heat, particularly when the symptoms are concentrated in the head and upper respiratory tract. It is commonly combined with Ju Hua (chrysanthemum) and Bo He (peppermint) in classic Wind-Heat dispersing formulas.

Clearing the Lung and moistening dryness: Sang Ye is traditionally used as a key herb for Lung Heat and Lung dryness patterns, which may manifest as a dry cough with scanty yellow sputum, sore throat, and thirst. By clearing Lung Heat and moistening Lung dryness, Sang Ye is believed to restore the Lung's normal descending and diffusing functions. It is frequently combined withHuang Qin (Scutellaria) to clear Lung Heat, and with Xing Ren (apricot seed) and Jie Geng (Platycodon) to regulate Lung Qi.

Clearing the Liver and brightening the eyes: Sang Ye enters the Liver meridian and is traditionally used to clear Liver Heat and brighten the eyes. It is indicated for patterns of Liver Fire or Liver Yang rising presenting as red, swollen, and painful eyes, blurred vision, dizziness, photophobia, and excessive tearing. In TCM theory, the Liver opens into the eyes, and when Liver Fire or Liver Yin deficiency with Heat affects the eyes, Sang Ye is believed to clear the Heat and restore normal vision. It is commonly combined with Ju Hua, Jue Ming Zi (Cassia seed), and Gou Qi Zi (goji berry) for eye-related patterns.

Cooling Blood and stopping bleeding: Sang Ye is traditionally used for Heat in the Blood patterns, which may manifest as various types of bleeding, including hemoptysis, epistaxis, and hematemesis. By clearing Heat from the Blood level, Sang Ye is believed to cool the Blood and stop bleeding. In classical practice, it is often used in combination with fresh Sheng Di Huang (Rehmannia root) and Ce Bai Ye (Platycladus leaf) for Blood-Heat bleeding patterns.

Classical literature references: The Shen Nong Ben Cao Jing (Divine Farmer's Materia Medica Classic, circa 200 CE) classified Sang Ye as a middle-grade herb and recorded its traditional use for "expelling Wind-Heat, clearing the eyes, and brightening the vision." The Ben Cao Gang Mu (Compendium of Materia Medica, 1596 CE) by Li Shizhen noted Sang Ye's ability to "clear the Lung, moisten the dry, and pacify the Liver and brighten the eyes" and described its traditional roles in treating Wind-Heat common cold, cough, red eyes, and dizziness.

Sang Ye contains a range of bioactive compounds that have been the subject of pharmacological investigation. The following overview summarizes the major chemical constituents identified in the leaves of Morus alba and what is currently known about them from published research.

Rutin and quercetin: Rutin (quercetin-3-O-rutinoside) and its aglycone quercetin are among the principal flavonoid constituents identified in Sang Ye. They have been studied in pre-clinical research for a range of potential pharmacological activities, including antioxidant, anti-inflammatory, vasoprotective, and capillary-stabilizing effects. Some animal studies suggest that rutin and quercetin may help protect against oxidative stress-induced cellular damage, reduce inflammation through modulation of NF-κB signaling, and improve microvascular integrity. However, most evidence comes from animal and in-vitro studies; robust human clinical data confirming the clinical relevance of these effects from whole-herb Sang Ye preparations are limited.

1-Deoxynojirimycin (DNJ): DNJ is a polyhydroxylated alkaloid and one of the most distinctive bioactive constituents of Sang Ye. It is a potent competitive inhibitor of alpha-glucosidase enzymes in the small intestine, which break down complex carbohydrates into absorbable monosaccharides. By inhibiting these enzymes, DNJ can delay carbohydrate digestion and absorption, leading to a reduction in postprandial blood glucose spikes. Some small-scale human studies have investigated the effects of DNJ-enriched mulberry leaf extracts on postprandial blood glucose, with mixed but generally modest results. The clinical significance of DNJ in the overall pharmacological profile of whole-herb Sang Ye preparations is an active area of research.

GABA (gamma-aminobutyric acid): Sang Ye contains significant amounts of GABA, a non-protein amino acid that functions as an inhibitory neurotransmitter in the central nervous system. Some pre-clinical and small-scale human studies have investigated the potential hypotensive effects of GABA-enriched mulberry leaf preparations, with preliminary evidence suggesting modest blood pressure-lowering effects in individuals with mild hypertension. The clinical relevance of GABA from whole-herb Sang Ye preparations is not well established.

Other constituents: Sang Ye also contains chlorogenic acid, polysaccharides, sterols, coumarins, and various other secondary metabolites. Chlorogenic acid is a phenolic compound with antioxidant and anti-inflammatory properties studied in pre-clinical research. Mulberry leaf polysaccharides have been investigated for their potential immunomodulatory and prebiotic effects. Most research on these secondary compounds remains at the pre-clinical stage, and their specific contributions to the pharmacological profile of whole-herb Sang Ye are not fully understood.

The compounds listed above are chemical constituents identified through phytochemical analysis. Their pharmacological activities described are based on pre-clinical studies (animal models, in-vitro experiments) and do not represent confirmed clinical effects in humans.

Sang Ye is a core ingredient in several important classical formulas in the TCM tradition for dispersing Wind-Heat and clearing the Lung. Below are three key formulas that feature Sang Ye as a primary or significant component, along with their traditional indications and the role Sang Ye plays in each composition.

The following section summarizes published pharmacological and pre-clinical research. Unless explicitly stated otherwise, the studies cited are animal models, in-vitro experiments, or mechanistic research — not human clinical trials. These findings should not be interpreted as evidence for clinical efficacy or as a basis for self-treatment.

Anti-diabetic effects of DNJ and mulberry leaf extracts: The most extensively studied property of Sang Ye is its potential anti-diabetic activity, primarily attributed to the alpha-glucosidase inhibitory effect of DNJ. A systematic review by Morales Ramos et al. published in F1000Research (2021, PMID: 34912543) evaluated 29 studies on Morus alba leaves for type 2 diabetes control and reported that the phytochemical constituents (chlorogenic acid, isoquercitrin, and quercitrin) improve glucose uptake and exert antihyperglycemic and antihyperlipidemic activities. A review by Tang et al. published in Journal of Ethnopharmacology (2023, PMID: 36632855) discussed the mechanistic insights of mulberry leaves in managing T2DM, focusing on gut microbiota modulation, inflammation, and metabolism. Zhang et al. (2022, PMID: 34896248) reviewed the potential of mulberry leaf in metabolic diseases, highlighting mechanisms of action. Most of this evidence comes from pre-clinical and early-phase clinical studies; large-scale, randomized human trials confirming these effects are lacking.

Antioxidant and anti-inflammatory effects: Multiple pre-clinical studies have reported that Sang Ye extracts and isolated constituents (including rutin, quercetin, and chlorogenic acid) exhibit antioxidant and anti-inflammatory activities. In animal models of inflammation, Sang Ye extracts have been reported to reduce levels of pro-inflammatory cytokines such as TNF-α and IL-6, and to enhance antioxidant enzyme activity. A comprehensive review by Batiha et al. published in Naunyn-Schmiedeberg's Archives of Pharmacology (2023, PMID: 36877269) summarized the phytochemical and pharmacological profile of Morus alba, including its antioxidant, anti-inflammatory, antimicrobial, and neuroprotective activities. While these findings are scientifically interesting, their clinical significance for human inflammatory conditions has not been established.

Cardiovascular and hypotensive effects: Some pre-clinical and small-scale human studies have investigated the potential cardiovascular and hypotensive effects of Sang Ye. The GABA content in mulberry leaves has been studied for its potential blood pressure-lowering effects, with some preliminary evidence suggesting modest reductions in systolic and diastolic blood pressure in individuals with mild hypertension. The flavonoid constituents (rutin, quercetin) have been studied for their vasoprotective and capillary-stabilizing properties in pre-clinical models. A review by Trimarco et al. (2025, PMID: 40732887) examined the effects of white mulberry plant extracts in cardiovascular prevention, summarizing both preclinical and clinical findings. However, robust clinical evidence for cardiovascular indications is limited.

Neuroprotective effects: Some pre-clinical studies have investigated the potential neuroprotective effects of Sang Ye constituents, particularly rutin and quercetin, in models of neurodegenerative diseases. These studies have suggested that these flavonoids may protect neuronal cells from oxidative stress, reduce neuroinflammation, and modulate neurotransmitter systems. The clinical relevance of these findings for human neurodegenerative conditions such as Alzheimer's or Parkinson's disease has not been established, and no robust clinical trials support the use of Sang Ye for these indications.

What the research does NOT show: Despite promising pre-clinical signals, the research on Sang Ye and its active compounds does NOT demonstrate conclusive clinical efficacy for any specific disease in humans. There is no robust evidence from large-scale, randomized, placebo-controlled clinical trials that Sang Ye can treat, cure, or prevent diabetes, cardiovascular disease, inflammatory disorders, or any other medical condition. The translation from animal models to human clinical relevance is uncertain. This page does not endorse Sang Ye as a treatment for any condition.

Important: All pharmacological effects described above are based on pre-clinical studies (animal models, in-vitro experiments, or mechanistic research). They do not constitute evidence of clinical efficacy in humans. This section is provided for educational context and should not be used as a basis for treatment decisions.

General safety profile: Sang Ye is widely used in TCM practice and is generally considered to have a favorable safety profile when used appropriately in formula combinations. It is also approved as a "medicine and food homology" substance in China, meaning it has a history of safe use in both medicinal and culinary contexts. However, like all herbal products, it is not free of risk. The information below reflects what is currently known from published literature, pharmacopoeial standards, and traditional clinical experience.

Spleen deficiency-cold patterns: In traditional TCM theory, Sang Ye is cold in nature. Individuals with Spleen deficiency-cold constitutions — characterized by abdominal distension, loose stools, sluggish digestion, poor appetite, a pale tongue with white coating, and a weak pulse — should generally avoid Sang Ye or use it with caution. Its cold nature may theoretically worsen Spleen Yang deficiency and digestive function. Sang Ye should only be used under professional guidance with appropriate warming herbs when Spleen deficiency coexists with other indications.

Exterior Wind-Cold conditions: In TCM theory, Sang Ye's cold nature is considered inappropriate during early-stage exterior Wind-Cold conditions (characterized by severe chills, mild fever, no sweating, body aches, and a thin white tongue coating). Its use in such circumstances may theoretically trap the exterior pathogen. Sang Ye is traditionally reserved for Wind-Heat patterns rather than Wind-Cold conditions.

Pregnancy and lactation: Sang Ye does not have a specific traditional contraindication during pregnancy when used in formula combinations under professional guidance. However, because of its cold nature, it is traditionally considered that pregnant women with significant Spleen deficiency-cold should use it with caution. Modern pre-clinical data on Sang Ye constituents in pregnancy are insufficient to fully establish safety. Do not use Sang Ye during pregnancy without direct supervision from a qualified healthcare professional.

Drug interactions: Pre-clinical data suggest that DNJ in Sang Ye may have alpha-glucosidase inhibitory effects, which could theoretically enhance the effects of anti-diabetic medications (including insulin and oral hypoglycemic agents) and increase the risk of hypoglycemia. The flavonoid constituents (rutin, quercetin) may affect the activity of hepatic cytochrome P450 enzymes, which could theoretically alter the metabolism of drugs processed through these pathways. There is also theoretical potential for additive effects when combined with antihypertensive medications, given the GABA content in Sang Ye. Clinical interaction data for whole-herb Sang Ye are very limited. Consult a qualified healthcare professional before combining Sang Ye with any prescription medications.

Reported side effects: Based on available reports, side effects associated with Sang Ye are generally rare and mild when used at appropriate doses. Occasional reports include mild gastrointestinal discomfort (nausea, bloating, or loose stools, particularly in individuals with pre-existing Spleen weakness), dizziness, or allergic reactions (skin rash) in sensitive individuals. Any suspected adverse effects should be reported to a healthcare professional.

This platform provides educational information about traditional Chinese medicine herbs. It does not recommend, endorse, or prescribe the use of Sang Ye or any other herbal product for the treatment of any medical condition. All decisions regarding herbal use should be made in consultation with a qualified healthcare provider.