METHYLENE BLUE

Properties of Methylene Blue

Uses of Methylene Blue

Pharmaceutical Uses of Methylene Blue

• Methemoglobinemia: Methylene blue is a medication used in the optimization and treatment of methemoglobinemia, a condition in which hemoglobin decreases its ability to carry oxygen.
• Cyanide Poisoning: Methylene blue is an effective antidote against cyanide poisoning as it binds to the cyanide ions in the body averting the harm by converting hemoglobin into methemoglobin which is excreted through urine.
• Ifosfamide toxicity: Methylene Blue acts as a preventive measure to reduce the risk & toxicity of encephalopathy for the patients getting the ifosfamide treatment.
• Alzheimer’s Disease: Methylene blue reduces tau and amyloid beta levels and promotes autophagy, which improves cognition.
• Anti-malaria: It is regarded as a positive shield against Malaria Tropica. It shows in vitro activity against P. falciparum. Further, when combined with artemisinin, it exhibits synergic activities and kills the parasite.
• Anti-cancer: Methylene blue with Photodynamic therapy (PDT) is active against a broad range of cancers such as colorectal tumors, carcinoma, and melanoma. When combined with nanopharmaceuticals, its efficacy as anti-cancer therapy increases significantly.
• Anti-oxidant: Methylene blue enhances mitochondrial functions and reduces oxidative stress making it a versatile compound in several therapeutic applications. It supports ATP production and contributes to cell health & durability.
• Bipolar disorder: It exhibits antidepressant, anti-anxiety, and neuroprotective effects. It stabilizes mood and supports mitochondrial functions by reducing oxidative stress, depriving the risk of mania.
• Priapism: Methylene Blue is used to treat priapism. It acts as a guanylate cyclase inhibitor and prevents the reproduction of cyclic GMP. It can be used to treat both ischemic priapism (low blood flow to the penis) and, in some cases, high-flow priapism (excessive blood flow to the penis).
• Mapping of parathyroid gland: It is used to dye parathyroid glands during thyroidectomy as it absorbs the dye faster than thyroid tissue aiding difference & reducing the risk of postoperative hypocalcemia.
• Septic shock: It helps in septic shock by inhibiting guanylate cyclase and blocking nitric oxide production, which increases blood pressure reducing the need for other medications.
• Acne vulgaris: Methylene blue, in a nanoformulation with salicylic acid and oleic acid, is initiated by light to target Cutibacterium acnes. This reduces acne lesions and sebum production, making it effective in the photodynamic treatment of mild-to-moderate acne.
• Diagnostics & Biomedical Imaging: It is used as a dye in biomedical imaging & diagnostic to visualize specific tissue, nodes and blood vessels. It is also used in microbiology to stain microbes.
• Hepatopulmonary syndrome (HPS): Hepatopulmonary syndrome is a rare condition of dilated blood vessels in lungs with liver disease. Methylene blue helps in blocking the stimulation of soluble guanylate cyclase by nitric oxide, which helps to constrict dilated blood vessels of the lungs, leading to better oxygenation.

Methylene Blue for Skin

Methylene Blue slows down the aging effects of skin as it has antioxidant property. It stimulates fibroblast proliferation & promotes wound healing. It also increases the skin thickness and hydration. Studies are undergoing to check the potential of methylene blue in treatment progeria (Hutchinson-Gilford Progeria Syndrome).

Other Uses of Methylene Blue

• Eosin Methylene blue (EMB) agar: Methylene Blue in EMB agar, inhibits Gram+ve bacteria making it selective for Gram-ve bacteria. Lactose fermentation by bacteria like E. coli results in blue-black colonies with a green metallic sheen.
• Aquaculture Industry: MB is used as an aquarium disinfectant as it treats the toxicity caused by ammonium and nitrate. It’s also primarily used to prevent fungal growth on fish eggs and is further active against parasitic protozoa and fungal infections.
• Disinfectant: It acts as a disinfectant by deactivating viruses & pathogens when exposed to light. Through the COVID-19 epidemic, it was discovered that treating PPE with light and methylene blue for 5 to 30 min could disinfect the coronaviruses.
• Redox Indicator: Methylene blue is used as a redox indicator as it changes to blue when oxidised and colourless when reduced. 
• Water testing: It is an indirect indication of dissolved oxygen content. When there is oxygen present, the indicator becomes blue. It is also used to detect biological contamination.
• Biological staining: Methylene Blue is a positively charged stain ( blue dye) that binds to negatively charged components of cells such as the nucleus (DNA) and RNA in the cytoplasm. It allows to view tiny life in vivid color. It may also be used to assess whether eukaryotic cells like yeast are alive or dead.
• Dairy Industry: Methylene blue dye reduction test is the most effective, economical & efficient way to determine the microbiological quality of raw and pasteurized milk. This test is based on the fact that the blue colour of the dye solution added to the milk get decolourized when the oxygen present in the milk get exhausted due to microbial activity. The sooner the decolourization, more inferior is the bacteriological quality of milk assumed to be.

Side Effects of Methylene Blue

There are different side effects associated with the use of Methylene Blue depending upon the route of administration.

Methylene blue oral side effects

• Headache
• Diarrhea
• Dizziness
• Vomiting
• Nausea
• Dilated pupils
• Increased sensitivity to sunlight

Methylene blue injection side effects

• Nails & Lips turn Bluish-colored
• Sore throat & Coughing
• Black Urine
• Fever with Rapid Heartbeat
• Palms agitation 
• Severe headache
• Massive hive-like swelling on the face, eyelids, lips, tongue, neck, hands, legs, feet
• Hyperactive reflexes resulting in poor coordination in working
• Shivering with extreme sweating
• Altered sense of taste

Methylene blue side effects on skin​

Itching & Rashes are common side effects of Methylene Blue. Redness and swelling may occur at the injection site. Skin turns bluish or greenish in color, mainly around the site of application. It also induces photosensitivity in the skin.

Methylene blue long-term side effects

Prolonged use of methylene blue increases the chances of Hemolytic anemia, hepatotoxicity, and nephrotoxicity. Neurological effects like serotonin syndrome and cognitive impairment also have been reported.