Development and evaluation of topical formulations that contain hydroethanolic extract from Schinus terebinthifolia against HSV-1 infection

Abstract The therapeutic drugs to treat Herpes simplex virus (HSV) infections have toxic side effects and there has been an emergence of drug-resistant strains. Therefore, the search for new treatments for HSV infections is mounting. In the present study, semi-solid formulations containing a crude hydroethanolic extract (CHE) from Schinus terebinthifolia were developed. Skin irritation, cutaneous permeation, and in vivo therapeutic efficacy of the formulations were investigated. Treatment with the ointment formulations did not result in any signs of skin irritation while the emulsions increased the thickness of the epidermis in Swiss mice. The cutaneous permeation test indicated that the CHE incorporated in the formulations permeated through the skin layers and was present in the epidermis and dermis even 3 h after topical application. In vivo antiviral activity in BALB/c mice treated with the CHE ointments was better than those treated with the CHE emulsions and did not significantly differ from an acyclovir-treated group. Taken together, this suggests that the incorporation of CHE in the ointment may be a potential candidate for the alternative topical treatment of herpetic lesions.

One-step synthesis of site-specific antibody-drug conjugates by reprograming IgG glycoengineering with LacNAc-based substrates

Glycosite-specific antibody‒drug conjugatess (gsADCs), harnessing Asn297 N-glycan of IgG Fc as the conjugation site for drug payloads, usually require multi-step glycoengineering with two or more enzymes, which limits the substrate diversification and complicates the preparation process. Herein, we report a series of novel disaccharide-based substrates, which reprogram the IgG glycoengineering to one-step synthesis of gsADCs, catalyzed by an endo-N-acetylglucosaminidase (ENGase) of Endo-S2. IgG glycoengineering via ENGases usually has two steps: deglycosylation by wild-type (WT) ENGases and transglycosylation by mutated ENGases. But in the current method, we have found that disaccharide LacNAc oxazoline can be efficiently assembled onto IgG by WT Endo-S2 without hydrolysis of the product, which enables the one-step glycoengineering directly from native antibodies. Further studies on substrate specificity revealed that this approach has excellent tolerance on various modification of 6-Gal motif of LacNAc. Within 1 h, one-step synthesis of gsADC was achieved using the LacNAc-toxin substrates including structures free of bioorthogonal groups. These gsADCs demonstrated good homogeneity, buffer stability, in vitro and in vivo anti-tumor activity. This work presents a novel strategy using LacNAc-based substrates to reprogram the multi-step IgG glycoengineering to a one-step manner for highly efficient synthesis of gsADCs.

The in vivo effect of L-arginine on skin elasticity in mice

ABSTRACT The human skin aging process is a complex mechanism that can be induced both by intrinsic and extrinsic factors. Observations include a decrease in the biosynthetic and proliferative capacity of cells, increased expression of matrix metalloproteinases, reduction in collagen type I expression, and the progressive disappearance of elastic tissue in the papillary dermis. L-arginine, the substrate of nitric oxide synthesis, is involved in angiogenesis and cell proliferation, as well as an indirect precursor of collagen synthesis via the proline pathway. The aim of this study was to examine the tensile strength, histology, and immunohistochemistry of female and male mice skin receiving different concentrations of topically applied L-arginine, in order to evaluate the possibility of using L-arginine as an active cosmetic ingredient in antiaging products. The results suggest that the application of L-arginine improves the mechanical resistance of skin from older female mice (20 weeks old) and promotes the formation of a larger amount of collagen and elastic fibers in the skin when applied at a concentration of 15%.