Enhancement of Anticancer Potential of Pterostilbene Derivative by Chalcone Hybridization

Skin delivery of synthetic benzoyl pterostilbenes suppresses atopic dermatitis-like inflammation through the inhibition of keratinocyte and macrophage activation

Atopic dermatitis (AD) is one of the most common skin autoimmune diseases needing continuous anti-inflammatory management. Pterostilbene is reported to exhibit anti-inflammatory activity with higher bioavailability and stability than its parent compound, resveratrol. In this study, a series of synthetic pterostilbene analogs were designed by the hybridization of pterostilbene with chalcones or benzoyl chloride. Seventeen analogs derived from pterostilbene were synthesized with differences in the positions of hydroxyl, methoxyl, or fluoro moieties. These compounds were screened by the inhibitory effect on the overexpressed Th2-associated cytokines/chemokines in the activated human keratinocytes (HaCaT). The anti-IL-5 and anti-CCL5 activity of these compounds led to the identification of three effective compounds: 3a ((E)- 4-(3,5-dimethoxystyryl)phenyl benzoate), 3d ((E)- 4-(3,5-dimethoxystyryl)phenyl 2-methoxybenzoate), and 3g ((E)- 4-(3,5-dimethoxystyryl)phenyl 2-fluorobenzoate). These benzoyl pterostilbenes also significantly decreased Th1/Th17-associated proinflammatory mediators in the activated macrophages (differentiated THP-1). The result showed that the conditioned medium of benzoyl pterostilbene-treated macrophages reduced the phosphorylated STAT3 in the keratinocytes, indicating the blockade of crosstalk between resident and immune cells. Compounds 3d and 3g generally showed greater skin absorption than 3a. The flux of 3g across barrier-defective skins mimicking the AD skin was 3-fold higher than that of across intact skin. The dinitrochlorobenzene (DNCB)-induced AD mouse model manifested that topical delivery with 3g improved the pathological signs through inhibiting cytokines/chemokines (IL-5, TNF-α, CCL17, and CCL22) and macrophage recruitment. The epidermal thickness was reduced from 76 to 55 µm after topical 3g delivery. The therapeutic activity of 3g was comparable to that of tacrolimus (TAC) used as a positive control. The benzoyl pterostilbenes attenuated the inflammation via the MAPK and c-Jun signaling. Furthermore, this study provided experimental evidence of benzoyl pterostilbene analogs for therapeutic potential on AD.

Cinnamic acid hybrids as anticancer agents: A mini-review

Cancer, as a long-lasting and dramatic disease, affects almost one-third of human beings globally. Chemotherapeutics play an important role in cancer treatment, but multidrug resistance and severe adverse effects have already become the main causes of failure in tumor chemotherapy. Therefore, it is an urgent need to develop novel chemotherapeutics. Cinnamic acid contains a ubiquitous α,β-unsaturated acid moiety presenting potential therapeutic effects in the treatment of cancer as these derivatives could act on cancer cells by diverse mechanisms of action. Accordingly, cinnamic acid derivatives are critical scaffolds in discovering novel anticancer agents. This review provides a comprehensive overview of cinnamic acid hybrids as anticancer agents. The structure-activity relationship, as well as the mechanisms of action, are also discussed, covering articles published from 2012 to 2021.