Why slowing glycation matters

Among the many factors driving skin aging, glycation occupies a distinct place — a process rarely discussed outside specialized literature, though its significance rivals that of photodamage or collagen loss. A review published in Clinical, Cosmetic and Investigational Dermatology [1] systematizes data on how the accumulation of advanced glycation end products affects skin condition and examines the potential of combining hyaluronic acid and trehalose to slow this process.

Glycation involves the non-enzymatic binding of sugars to free amino groups of proteins, lipids, and nucleic acids, forming advanced glycation end products (AGEs)—stable, virtually irreversible molecular complexes. Their formation mechanism, known as the Maillard reaction, unfolds in three stages: glucose first binds to a protein, forming an unstable Schiff base that then rearranges into an Amadori product; this breaks down into highly reactive dicarbonyl compounds, which, in the final stage, form stable, pigmented AGEs [1]. Alongside the classic Maillard pathway, alternative routes of AGE formation have also been described, including the Hodge, Wolff, and acetyl-aldehyde pathways.

Long-lived structural proteins of the dermis—collagen and elastin—are especially prone to glycation: because of their slow turnover, they accumulate modifications over many years, gradually converting into AGEs. Glycation stiffens these fibers, reduces their function, and, importantly, hinders their natural enzymatic degradation and renewal—glycated proteins effectively "drop out" of the normal tissue remodeling cycle and accumulate over the years. Clinically, this manifests as wrinkle formation, decreased skin firmness and elasticity, dullness, and delayed wound healing [1].

The molecular cascade does not end there: by binding to the receptor for AGEs (RAGE), AGEs trigger the NF-κB and MAP kinase signaling pathways, leading to overproduction of pro-inflammatory cytokines (IL-6, IL-1α, TNF-α) and matrix metalloproteinases, as well as increased intracellular production of reactive oxygen species. A self-sustaining vicious cycle forms: glycation provokes oxidative stress, which, by reducing the activity of protective enzymes (superoxide dismutase, catalase) and depleting glutathione stores, in turn accelerates the formation of new AGEs [2]. This mutual escalation makes slowing glycation a distinct and promising target for anti-aging approaches, rather than a secondary addition to combating oxidative stress.

Hyaluronic acid: antioxidant and anti-inflammatory protection

Hyaluronic acid (HA) is a glycosaminoglycan composed of repeating dimers of D-glucuronic acid and D-N-acetylglucosamine. Its biological activity depends on molecular weight: high-molecular-weight HA (HMW-HA, above 1000 kDa) exhibits pronounced protective, anti-inflammatory, and antioxidant properties.

HMW-HA reduces reactive oxygen species (ROS) production and blocks NF-κB activation triggered by AGEs, thereby decreasing production of the pro-inflammatory cytokines interleukin-1α, interleukin-6, and tumor necrosis factor-α [1]. It suppresses cell proliferation, exhibits anti-angiogenic properties, and reduces pro-inflammatory mediator production. In addition, HMW-HA protects cells from death by scavenging free radicals and contributes to extracellular matrix organization.

HMW-HA's role in maintaining tissue water balance deserves particular attention: due to its high hydrophilicity, it retains water molecules in the intercellular space, forms a three-dimensional polymer network within the extracellular matrix, and ensures hydration of the epidermis and dermis [1]. This capacity underlies the moisturizing and volumizing effect of HA-based products used in aesthetic medicine.

Low molecular weight HA fragments (LMW-HA, below 1000 kDa), produced by degradation of the native molecule via enzymes and free radicals, act oppositely: they stimulate production of pro-inflammatory cytokines, enhance NF-κB activation, and promote cell proliferation and angiogenesis [1]. Thus, premature HA degradation not only deprives tissues of its protective properties but also worsens the inflammatory background.

Trehalose: a protector of cellular structures

Trehalose is a naturally occurring disaccharide in which two glucose residues are joined by an atypical α,α-1,1 glycosidic bond, giving the molecule exceptional resistance to heat and acid hydrolysis. This chemical stability underlies its bioprotective functions: trehalose stabilizes cell membranes, activates autophagy, neutralizes reactive oxygen species, and inhibits glycation [1].

Trehalose's inability to undergo glycation stems from the absence of a free reducing hydroxyl group; as a result, the molecule retains its structural integrity even when interacting with human serum albumin and does not form AGEs [1]. Under stress conditions such as heat shock, trehalose protects membranes and macromolecules, partially preserves superoxide dismutase (SOD) activity, and effectively scavenges hydrogen peroxide and superoxide anions [1].

Trehalose also shows photoprotective properties: it reduces UVB-induced keratinocyte damage, suppresses UVB-induced matrix metalloproteinase expression, and simultaneously enhances type I procollagen synthesis, thereby counteracting skin photoaging [1]. In addition, trehalose can improve skin flap survival in reconstructive procedures by stimulating angiogenesis and reducing apoptosis [1].

Its use has long extended beyond laboratory research — trehalose is approved by the FDA for a range of medical applications, reflecting a strong safety profile for this compound [3].

HA + Trehalose: the secret behind the synergy

The combined action of trehalose and HA is not additive but mutually reinforcing: trehalose acts as a molecular "shield" for hyaluronic acid, slowing its enzymatic and non-enzymatic degradation. By preserving HA's structural integrity, this pairing sustains tissue water-electrolyte balance longer and prolongs the antioxidant and anti-inflammatory effect compared with either component used alone. As a result, the combination not only inhibits AGE formation more effectively but also forms a more pronounced, reparative-oriented defense against oxidative stress than monotherapy [1].

Direct clinical data specific to dermatology remain limited, but accumulated experience from related medical fields is compelling. In knee osteoarthritis, combining trehalose with hyaluronate provided sustained tissue improvement over six months of follow-up, whereas the effect of standard HA-only therapy diminished as early as the third month [4]. In ophthalmology, a trehalose-HA combination in eye drops for dry eye disease improved tear film stability, reduced ocular surface damage, and supported goblet cell recovery [5]. These findings were not obtained in skin, but they demonstrate a general principle: trehalose prolongs and enhances the biological activity of hyaluronic acid across diverse tissues, providing solid grounds for extending this approach to aesthetic medicine.

Limitations and safety considerations

The source does not provide specific data on adverse events for the HA-trehalose combination in dermatological products — the review's authors limit themselves to noting trehalose's generally favorable safety profile.

An important caveat concerns the staged nature of the aging process: the effectiveness of any anti-glycation approach naturally declines in later stages of aging, when structural damage to collagen and elastin has already accumulated and is difficult to correct.

The authors explicitly point to the need for further research—both to clarify the molecular mechanisms underlying the differing effects of HA at different molecular weights and to more fully reveal trehalose's therapeutic potential in clinical practice [1].

Conclusion

Glycation and AGE accumulation represent a significant yet modifiable mechanism of skin aging, closely intertwined with oxidative stress and chronic subclinical inflammation. Hyaluronic acid and trehalose, with their complementary properties, demonstrate a more pronounced protective effect in combination than either alone: trehalose extends the "functional lifespan" of hyaluronic acid in tissues, protecting it from rapid degradation while reducing the glycation and oxidative stress burden on the dermis. For practitioners, this supports a specific approach to product selection—incorporating trehalose into HA-based skin boosters and injectable products is justified not only by its moisturizing effect but also by its potential to develop more stable, longer-lasting formulations aimed at preventing one of the fundamental mechanisms of skin aging.

Direct clinical data on the use of this duo in aesthetic medicine remain limited, but findings from related fields appear compelling enough to consider the approach promising. Further research should clarify optimal concentrations, formulations, and clinical indications for incorporating this combination into anti-aging dermatocosmetology practice.

References

1. Chmielewski R., Lesiak A. Mitigating glycation and oxidative stress in aesthetic medicine: hyaluronic acid and trehalose synergy for anti-AGEs action in skin aging treatment. Clin Cosmet Investig Dermatol  2024; 17: 2701–2712.
2. Umbayev B., Askarova S., Almabayeva A. et al. Galactose-induced skin aging: the role of oxidative stress. Oxid Med Cell Longev 2020; 17: 7145656.
3. Chen A., Gibney P.A. Non-nutritive effects of trehalose on physiology and pathophysiology. Nutrients 2023; 15(6): 1393.
4. Gobbi A., Karnatzikos G., Sankineani S.R. et al. New trehalose hyaluronate for knee osteoarthritis. J Cartil Jt Preserv 2022; 2(3): 100043.
5. Mencucci R., Boccalini C., Caputo R., Favuzza E. A new formulation of trehalose hyaluronate for the management of dry eye disease. J Clin Med 2021; 10(20): 4699.