Exploration of Long-Chain Vitamin E Metabolites for the Discovery of a Highly Potent, Orally Effective, and Metabolically Stable 5-LOX Inhibitor that Limits Inflammation

Abstract

Endogenous long-chain metabolites of vitamin E (LCMs) mediate immune functions by targeting 5-lipoxygenase (5-LOX) and increasing the systemic concentrations of resolvin E3, a specialized proresolving lipid mediator. SAR studies on semisynthesized analogues highlight α-amplexichromanol ( 27a ), which allosterically inhibits 5-LOX, being considerably more potent than endogenous LCMs in human primary immune cells and blood. Other enzymes within lipid mediator biosynthesis were not substantially inhibited, except for microsomal prostaglandin E 2 synthase-1. Compound 27a is metabolized by sulfation and β-oxidation in human liver-on-chips and exhibits superior metabolic stability in mice over LCMs. Pharmacokinetic studies show distribution of 27a from plasma to the inflamed peritoneal cavity and lung. In parallel, 5-LOX-derived leukotriene levels decrease, and the inflammatory reaction is suppressed in reconstructed human epidermis, murine peritonitis, and experimental asthma in mice. Our study highlights 27a as an orally active, LCM-inspired drug candidate that limits inflammation with superior potency and metabolic stability to the endogenous lead.

Mitochondria-targeted antioxidant SkQ1 inhibits leukotriene synthesis in human neutrophils

“…In support of this possibility, a non-targeted antioxidant, a water-soluble analogue of vitamin E (Trolox), also inhibited the synthesis of leukotrienes, although at much higher concentration than SkQ1 ( Figures 1D–F ). Long-chain vitamin E analogs and metabolites have previously been reported to be effective inhibitors of 5-LOX ( Neukirch et al, 2021 ). However, short-chain analogs like Trolox were ineffective, so direct inhibition of 5-LOX by Trolox can be ruled out.…”

A vitamin E long-chain metabolite and the inspired drug candidate α-amplexichromanol relieve asthma features in an experimental model of allergen sensitization

“…α-T-13'-COOH also effectively modulates allergen-induced hyperreactivity [13]. Starting from endogenous LCMs as lead structures, many semisynthetic compounds have been synthesized [16,17], and 12α′,13′-dihydroxylated α-tocotrienol (α-amplexichromanol, α-AC) has been identified as a highly potent allosteric 5-LOX inhibitor with prominent in vitro and in vivo anti-inflammatory activity [16]. Based on this evidence we have here investigated the effects of α-T-13'-COOH and α-AC in an experimental mouse model of asthma.…”

Reorganization of innate immune cell lipid profiles by bioinspired meroterpenoids to limit inflammation

“…SACM was obtained by culturing Staphylococcus aureus (LS1 strain) in Brain Heart Infusion (BHI) medium for 18 h followed by sterile filtration of the supernatant (3,400 × g, 10 min, RT) through a Rotilabo ® -syringe filter (PVDF, 0.22 µm, Roth, Karlsruhe, Germany). [73-74] Alternatively, M2 cells were incubated with vehicle (DMSO, 0.1%) or test compounds for 195 min without further stimulation to investigate lipid mediator profiles in resting macrophages.…”

“…Freshly isolated PBMCs consisting predominantly of CD14 + /CD16 + and CD14 Germany). [73][74] eicosatetraenoic-5,6,8,9,11,12,14,15-d8 acid, 5S,12R-dihydroxy-6Z,8E,10E,14Z-eicosatetraenoic-6,7,14,15-d4 acid, 9-oxo-11α,15S-dihydroxy-prosta- 19,19,20,20,20-d5 acid, and 7S,16R,17S-trihydroxy-4Z,8E,10Z,12E,14E,19Z-21,21',22,22,22-d5 docosahexaenoic acid, and 2000 pg 5Z,8Z,11Z,14Zeicosatetraenoic-5,6,8,9,11,12,14,15-d8 acid. For 9)-epoxy-5Z,8Z, 14Z-eicosatrienoic-16,16,17,17,18,18,19,19,20,20,20-d11 5,6,8,9,11,12,14,15-d8 µM AA (20:4). The reaction was terminated after 15 min at 37 °C by addition of 1 mL ice-cold methanol containing 200 pg 5S-hydroxy-6E,8Z,11Z,14Zeicosatetraenoic -5,6,8,9,11,12,14,15-d8 acid as internal standard.…”