Ginsenoside Rb₁ (or Ginsenoside Rb1 or GRb₁ or GRb1) is a chemical compound belonging to the

ginsenoside Ginsenosides or panaxosides are a class of natural product steroid glycosides and triterpene saponins. Compounds in this family are found almost exclusively in the plant genus '' Panax'' (ginseng), which has a long history of use in traditional m ...

family. Like other ginsenosides, it is found in the plant genus ''

Panax The ''Panax'' (ginseng) genus belongs to the ''Araliaceae'' (ivy) family. ''Panax'' species are characterized by the presence of ginsenosides and gintonin. ''Panax'' is one of approximately 60 plant genera with a classical disjunct east Asian and ...

'' (

ginseng Ginseng () is the root of plants in the genus '' Panax'', such as Korean ginseng ('' P. ginseng''), South China ginseng ('' P. notoginseng''), and American ginseng ('' P. quinquefolius''), typically characterized by the presence of ginsenosides ...

), and has a variety of potential health effects including anticarcinogenic,

immunomodulatory Immunotherapy or biological therapy is the treatment of disease by activating or suppressing the immune system. Immunotherapies designed to elicit or amplify an immune response are classified as ''activation immunotherapies,'' while immunotherap ...

, anti‐inflammatory,

antiallergic An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies. In technical terms ...

, antiatherosclerotic,

antihypertensive Antihypertensives are a class of drugs that are used to treat hypertension (high blood pressure). Antihypertensive therapy seeks to prevent the complications of high blood pressure, such as stroke and myocardial infarction. Evidence suggests tha ...

, and antidiabetic effects as well as

antistress Stress management is a wide spectrum of techniques and psychotherapies aimed at controlling a person's level of stress, especially chronic stress, usually for the purpose of and for the motive of improving everyday functioning. Stress produces nu ...

activity and effects on the

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all p ...

Pharmacological effects

A 1998 study by Seoul National University reported that GRb₁ and GRg₃ (ginsenosides Rb₁ and Rg₃) significantly attenuated glutamate-induced neurotoxicity by inhibiting the overproduction of

nitric oxide synthase Nitric oxide synthases () (NOSs) are a family of enzymes catalyzing the production of nitric oxide (NO) from L-arginine. NO is an important cellular signaling molecule. It helps modulate vascular tone, insulin secretion, airway tone, and p ...

among some other findings regarding their

neuroprotective Neuroprotection refers to the relative preservation of neuronal structure and/or function. In the case of an ongoing insult (a neurodegenerative insult) the relative preservation of neuronal integrity implies a reduction in the rate of neuronal los ...

properties. In 2002, the Laboratory for Cancer Research in

Rutgers University Rutgers University (; RU), officially Rutgers, The State University of New Jersey, is a public land-grant research university consisting of four campuses in New Jersey. Chartered in 1766, Rutgers was originally called Queen's College, and was ...

showed that GRb₁ and GRg₁ have neuroprotective effect for

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the sp ...

neuron A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. ...

s, while ginsenoside Re did not exhibit any activity. GRb₁ and GRg₁ are proposed to represent potentially effective

therapeutic agents A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to medical diagnosis, diagnose, cure, treat, or preventive medicine, prevent disease. Drug therapy (pharmacotherapy) is an imp ...

for

spinal cord injuries A spinal cord injury (SCI) is damage to the spinal cord that causes temporary or permanent changes in its function. Symptoms may include loss of muscle function, sensation, or autonomic function in the parts of the body served by the spinal cor ...

. The protection that GRg₁ (ginsenoside Rg₁) and GRb₁ offer against

Alzheimer’s disease Alzheimer's disease (AD) is a neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in remembering recent events. As t ...

symptoms in mice was first published by researchers in 2015. The GRg₁ affected three metabolic pathways: the

metabolism Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run c ...

of lecithin,

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha a ...

s and

sphingolipid Sphingolipids are a class of lipids containing a backbone of sphingoid bases, a set of aliphatic amino alcohols that includes sphingosine. They were discovered in brain extracts in the 1870s and were named after the mythological sphinx because o ...

s, while GRb₁ treatment affected lecithin and amino acid metabolism. It was reported in 2017 that GRb₁ improved cardiac function and remodelling in heart failure in mice. The treatment of H-ginsenoside Rb₁ potentially attenuated cardiac hypertrophy and

myocardial fibrosis Cardiac fibrosis commonly refers to the excess deposition of extracellular matrix in the cardiac muscle, but the term may also refer to an abnormal thickening of the heart valves due to inappropriate proliferation of cardiac fibroblasts. Fibrotic c ...

Proposed biosynthesis

The biosynthesis of GRb₁ in ''Panax ginseng'' starts from farnesyl diphosphate (FPP), which is converted to

squalene Squalene is an organic compound. It is a triterpenoid with the formula C30H50. It is a colourless oil, although impure samples appear yellow. It was originally obtained from shark liver oil (hence its name, as ''Squalus'' is a genus of sharks). A ...

with

squalene synthase Squalene synthase (SQS) or farnesyl-diphosphate:farnesyl-diphosphate farnesyl transferase is an enzyme localized to the membrane of the endoplasmic reticulum. SQS participates in the isoprenoid biosynthetic pathway, catalyzing a two-step react ...

(SQS), then to 2,3-oxidosqualene with

squalene epoxidase Squalene monooxygenase (also called squalene epoxidase) is a eukaryotic enzyme that uses NADPH and diatomic oxygen to oxidize squalene to 2,3-oxidosqualene (squalene epoxide). Squalene epoxidase catalyzes the first oxygenation step in sterol b ...

(SE). The 2,3-oxidasqualene is then converted to dammarenediol-II by

cyclization A cyclic compound (or ring compound) is a term for a compound in the field of chemistry in which one or more series of atoms in the compound is connected to form a ring. Rings may vary in size from three to many atoms, and include examples where ...

, with dammarenediol-II synthase (DS) as the

catalyst Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

. The dammarenediol-II is converted to

protopanaxadiol Protopanaxadiol (PPD) is an organic compound characterizing a group of ginsenosides. It is a dammarane-type tetracyclic terpene sapogenin found in ginseng (''Panax ginseng'') and in notoginseng (''Panax pseudoginseng''). Just what protopanaxadi ...

and then to ginsenoside Rd. Finally, GRb₁ is synthesized from ginsenoside Rd, catalysed by UDPG:ginsenoside Rd

glucosyltransferase Glucosyltransferases are a type of glycosyltransferase that enable the transfer of glucose. Examples include: * glycogen synthase * glycogen phosphorylase Glycogen phosphorylase is one of the phosphorylase enzymes (). Glycogen phosphorylase c ...

(UGRdGT), a biosynthetic

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...

of GRb₁ first discovered in 2005.''''

References

{{reflist Pharmacology Biosynthesis