Mecobalamin

Methylcobalamin (MeCbl) can mediate its analgesic effect in chronic peripheral neuropathic pain by: 1) offering neuroprotection by maintaining intra-epidermal nerve fiber density and protecting mitochondria from abnormalities; 2) its strong anti-inflammatory activity by inhibiting NF-κB activation, reducing NADPH oxidase expression, lowering pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) and increasing production of anti-inflammatory IL-10; 3) inhibiting neuronal hyperexcitability by decreasing expression of voltage gated sodium channels and reducing spontaneous activity of dorsal root ganglion neurons and downregulating nociceptors TRPA1 and TRPM8; and finally 4) encouraging neurotrophic activity by methylating Ras to activate ERK/Akt/mTOR, aiding neurite outgrowth and neuronal survival. MeCbl also encourages nerve regeneration/reparation by inhibiting Erk1/2 signaling in Schwann cells, which increases expression of myelin basic protein and synthesis of lipids needed for remyelination of nerves, as well as promoting axonal regeneration through upregulation of βIII tubulin and faster regeneration of damaged nerves through improved Schwann cell response to neuronal debris clearance.

Fig. 1 The action of MeCbl in modulating peripheral neuropathic pain. (Ramadhani A, et al. 2024)

Researchers explore methylcobalamin (MeCbl) encapsulated in ultra-flexible liposomes as a novel treatment for hyperpigmentation. The liposomes, prepared with soy phosphatidylcholine and sodium cholate via thin-film hydration, exhibited a particle size of ~124 nm, a negative surface charge, and stability for four weeks. Encapsulation efficiency was ~42%, with 70% drug release within 24 hours. These deformable liposomes penetrated deeper into porcine skin layers compared to free MeCbl, enhancing transdermal delivery. Biocompatibility tests confirmed no cytotoxicity and high cellular uptake in human fibroblasts and melanocytes. In melanocytes, MeCbl-loaded liposomes significantly reduced melanin synthesis, tyrosinase activity, and reactive oxygen species (ROS) levels, demonstrating antioxidant potential. The findings suggest these liposomes are promising nanocarriers for targeted hyperpigmentation therapy.

Fig. 2 Preparation of blank and drug loaded ultra-flexible liposomes by TFH method. (Erkut T S, et al. 2025)