histidine

Action and Spectrum

Actions and spectrum: 

• Protein Synthesis: histidine is a building block of proteins and is incorporated into polypeptide chains during protein synthesis. 
• Precursor to Histamine: histidine is a precursor to histamine, a compound involved in immune responses, gastric acid secretion, and regulation of allergic reactions. 
• Metal Binding: histidine’s imidazole side chain can bind to metal ions, making it important for the formation of metalloproteins and enzyme catalysis. 
• Enzyme Catalysis: histidine can act as a catalytic residue in enzymes, participating in various chemical reactions and contributing to their activity. 
• pH Buffering: The imidazole side chain of histidine can donate or accept protons, making it useful for pH buffering and helping to maintain cellular pH levels. 
• Neurotransmitter Regulation: Histamine, derived from histidine, acts as a neurotransmitter in the central nervous system, playing a role in wakefulness, appetite regulation, and other functions. 

Drug Interaction

Adverse Reaction

Frequency not defined 

gastrointestinal discomfort 

stomach cramps 

bloating 

nitrogen imbalance 

Allergic Reactions 

Black Box Warning

Black Box Warning: 

There is no specific black box warning associated with the use of histidine. 

Contraindication / Caution

Contraindication/Caution: 

Contraindication: 

• Allergies or Sensitivities: It is important to be aware of food allergies or intolerances and avoid consuming foods that trigger adverse reactions. 
• Metabolic Disorders: While histidine is well-tolerated, individuals with certain metabolic disorders, such as histidinemia, may have difficulty metabolizing histidine properly.  
• Interactions with Medications: If you are taking specific medications, especially those that affect amino acid metabolism or kidney function.

Caution: 

• Supplements: While histidine supplements are available, they are not typically recommended for healthy individuals with a balanced diet. Excessive intake of isolated amino acid supplements could potentially disrupt the balance of other amino acids and nutrients in the body. Always consult a healthcare provider before taking any supplements. 
• Medical Conditions: If you have certain medical conditions, such as kidney disease, liver disease, or certain metabolic disorders, your ability to process amino acids like histidine might be affected.  
• Medication Interactions: High doses of certain amino acid supplements could potentially interact with certain medications. If you are taking any medications, especially those related to amino acid metabolism or kidney function, consult your healthcare provider before using amino acid supplements. 
• Balanced Diet: Instead of focusing solely on one amino acid, it is recommended to obtain amino acids like histidine from a well-rounded, protein-rich diet. Balanced nutrition ensures that your body receives the necessary amino acids along with other essential nutrients.

Comorbidities: 

• Histidinemia: histidinemia is a rare genetic disorder in which the body is unable to properly metabolize histidine. Individuals with histidinemia need to monitor their histidine intake and follow a specialized diet under the guidance of healthcare professionals. 
• Kidney Disorders: People with kidney disorders, such as chronic kidney disease, might need to be cautious about their protein and amino acid intake, including histidine. This is because the kidneys play a role in filtering waste products, including excess amino acids. 
• Metabolic Disorders: Some metabolic disorders can affect amino acid metabolism, potentially impacting the utilization of histidine.  
• Allergies and Sensitivities: While histidine itself is not a common allergen, some individuals might have allergies or sensitivities to certain amino acids. If you suspect an amino acid-related allergy or sensitivity, consult a healthcare professional for proper evaluation. 
• Liver Conditions: Liver health is important for amino acid metabolism. Individuals with liver disorders might have altered amino acid metabolism, potentially affecting the processing of histidine and other amino acids. 

Pregnancy / Lactation

Pregnancy consideration: pregnancy category: not assigned 

Lactation: excreted into breast milk: unknown 

Pregnancy category: 

• Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester. 
• <b>Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 
• Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.   
• Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits. 
• Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women. 
• Category N: There is no data available for the drug under this category. 

Pharmacology

Pharmacology: 

histidine is an essential amino acid with multifaceted roles in the body’s biochemistry. As a precursor to key molecules like histamine and carnosine, it participates in regulatory and buffering processes. histidine also serves as a vital component of protein synthesis and enzymatic reactions.

Its imidazole side chain allows metal binding, making it important for metalloproteins and enzymes. Although it does not have a direct pharmacological use like drugs, histidine’s dynamic functions contribute to various physiological processes that support overall health and well-being.  

Pharmacodynamics: 

• Histamine Production: histidine serves as a precursor for histamine, a neurotransmitter involved in immune responses, allergic reactions, and gastric acid secretion. 
• Buffering: The imidazole side chain of histidine allows it to act as a pH buffer, helping to maintain the body’s acid-base balance. 
• Metal Binding: The imidazole group in histidine can coordinate with metal ions, contributing to the formation of metalloproteins and enzyme activity. 
• Protein Synthesis: histidine is a fundamental component of protein synthesis, contributing to the formation of polypeptide chains and the structure of proteins. 
• Enzymatic Catalysis: In enzymes, histidine residues can play crucial roles in catalyzing chemical reactions due to their specific chemical properties. 
• Neurotransmitter Regulation: Histamine, derived from histidine, acts as a neurotransmitter in the central nervous system, influencing various physiological functions including wakefulness and appetite regulation. 
• Immune System: histidine is involved in immune responses and contributes to the formation of antibodies and immune cell function. 

Pharmacokinetics: 

Absorption 

histidine is absorbed in the small intestine, primarily through active transport mechanisms. Its uptake can be influenced by dietary factors and the presence of other amino acids. 

Distribution 

Once absorbed, histidine is transported via the bloodstream to various tissues and cells throughout the body. It is utilized for protein synthesis, enzymatic reactions, and the formation of important molecules like histamine and carnosine. 

Metabolism 

histidine undergoes various metabolic pathways in the body. It serves as a precursor for histamine, which plays a role in immune responses and neurotransmission. Additionally, histidine contributes to the synthesis of carnosine, a dipeptide with antioxidant properties. 

Elimination and excretion 

The breakdown products of histidine metabolism are excreted from the body primarily through the kidneys. Any excess or unutilized histidine is eliminated in the urine. 

Adminstartion

Administration: 

histidine is the essential amino acid that is obtained through the diet, primarily from protein-rich foods. It is not typically administered as a standalone supplement or medication.  

• Protein-Rich Foods: histidine is found in foods that are rich in protein, such as meats (beef, poultry, pork), fish, eggs, dairy products (milk, cheese, yogurt), and plant-based protein sources (soy, legumes, nuts, seeds). 
• Whole Grains: Whole grains like wheat, rice, and oats also contain moderate amounts of histidine. 
• Certain Vegetables: Some vegetables, including spinach and peas, also contain histidine, although in lower amounts compared to protein-rich foods. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: histidine 

Pronounced: (HISS-ti-deen)  

Why do we use histidine? 

• Protein Synthesis: histidine is a fundamental building block for protein synthesis in the body. It is incorporated into proteins, enzymes, and other functional molecules that are essential for cellular structure and function. 
• Histamine Production: histidine serves as a precursor for histamine, a neurotransmitter and signalling molecule involved in allergic responses, immune reactions, gastric acid secretion, and regulation of certain physiological processes. 
• Carnosine Formation: histidine is also a component of carnosine, a dipeptide found in skeletal muscles and brain tissues. Carnosine has antioxidant properties and is involved in buffering acid levels in muscle tissues. 
• Metal Binding: The imidazole side chain of histidine allows it to bind with metal ions, contributing to the formation of metalloproteins and enzymes that are crucial for various biochemical reactions. 
• Enzymatic Reactions: histidine residues in enzymes can act as catalytic sites, facilitating specific chemical reactions essential for metabolism and cellular function. 
• pH Regulation: histidine’s imidazole group can act as a buffer, helping to regulate the body’s pH balance and maintain appropriate acid-base levels.