Does trigonelline help skin tone? Molecular docking studies of trigonelline on the human tyrosinase, formulation, optimization, and characterization of an emulgel-containing Trigonella foenum-graecum L. fenugreek standardized hydroalcoholic extract

Enhanced Transdermal Delivery of Piroxicam via Nanocarriers, Formulation, Optimization, Characterization, Animal Studies and Randomized Double-Blind Clinical Trial

Piroxicam is a non-steroidal anti-inflammatory drug which is used topically as an adjunctive treatment of knee osteoarthritis and as an option to control joint pain in patients suffering rheumatoid arthritis. In this study, an emulgel containing optimized nano-niosomal piroxicam was formulated and characterized in terms of mean size, polydispersity index, zeta potential, drug entrapment efficiency and capacity, release and transdermal permeation. Also, animal studies including pain level assessment, synovial prostaglandin E2 levels, knee joint swelling degree and histopathologic investigations were conducted. A randomized double-blind clinical trial was also performed to compare the analgesic effect of nano-niosomal piroxicam emulgel with piroxicam gel. The results showed optimized niosome formulation with 142 ± 7nm mean size and 0.23 ± 0.08 PDI, entrapped 99.48 ± 0.79% of added piroxicam with a sustained release pattern. Permeation studies indicated a 3.31-fold transdermal permeation of niosomal piroxicam emulgel compared with the piroxicam gel. The niosomal formulation significantly reduced knee joint swelling and prostaglandin E2 levels. The clinical trial indicated that the painkilling efficiency of the niosomal piroxicam emulgel was 37.30-fold and 3.16-fold greater compared to the placebo and the positive control groups, respectively. In conclusion, the niosomal piroxicam emulgel which may enable the drug to permeate through the skin and accumulate in synovial tissue more efficiently, showed a promising performance in lowering pain and inflammation based on the animal studies and the human clinical trial.

Epigallocatechin Gallate Enzymatic Alpha Glucosylation Potentiates Its Skin-Lightening Activity-Involvement of Skin Microbiota

(1) Background: Ultraviolet radiation takes part in photoaging and pigmentation disorders on skin. Epigallocatechin gallate (EGCG) is a well-known brightening and photoprotective compound but it faces limitations in terms of stability and solubility. (2) Methods: A more stable and water-soluble glucoside called EGCG-G1 was obtained by enzymatic glucosylation of EGCG. In vitro and ex vivo experiments evaluated EGCG-G1 skin penetration, antioxidant activity, and antimelanogenic properties compared to EGCG. This gene expression study characterized the pathways impacted by EGCG-G1. Four clinical studies covering phototypes I to V, at various ages, and different skin areas, using several tools, were conducted to assess the effect of EGCG-G1 on skin hyperpigmentation and tone. The impact of glucoside on skin microbiota, especially Lactobacillus sp., was assessed through in vitro and in vivo investigations. (3) Results: EGCG-G1 better penetrated the epidermis than EGCG due to a possible interaction with GLUT1. EGCG-G1 presented similar antioxidant activity to that of EGCG and decreased melanogenesis through the inhibition of 13 genes, including MITF. The skin Lactobacillus population increased with EGCG-G1, which promoted bacterial growth in vitro as prebiotic, and induced the release of a microbial brightening metabolite. Clinical trials demonstrated EGCG-G1 to decrease hyperpigmented spots and increase skin brightness and homogeneity in a large panel of phototypes, outperforming EGCG and vitamin C. (4) Conclusions: Glucosylation of EGCG maintained its photoprotective antioxidant properties and enhanced penetration across the epidermis. EGCG-G1 demonstrated brightening properties on all skin types by down-regulation of melanogenesis pathways and indirectly by skin microbiota stimulation.

Pharmacological Activities, Therapeutic Effects, and Mechanistic Actions of Trigonelline

Trigonelline (TRG) is a natural polar hydrophilic alkaloid that is found in many plants such as green coffee beans and fenugreek seeds. TRG potentially acts on multiple molecular targets, including nuclear factor erythroid 2-related factor 2 (Nrf2), peroxisome proliferator-activated receptor γ, glycogen synthase kinase, tyrosinase, nerve growth factor, estrogen receptor, amyloid-β peptide, and several neurotransmitter receptors. In this review, we systematically summarize the pharmacological activities, medicinal properties, and mechanistic actions of TRG as a potential therapeutic agent. Mechanistically, TRG can facilitate the maintenance and restoration of the metabolic homeostasis of glucose and lipids. It can counteract inflammatory constituents at multiple levels by hampering pro-inflammatory factor release, alleviating inflammatory propagation, and attenuating tissue injury. It concurrently modulates oxidative stress by the blockage of the detrimental Nrf2 pathway when autophagy is impaired. Therefore, it exerts diverse therapeutic effects on a variety of pathological conditions associated with chronic metabolic diseases and age-related disorders. It shows multidimensional effects, including neuroprotection from neurodegenerative disorders and diabetic peripheral neuropathy, neuromodulation, mitigation of cardiovascular disorders, skin diseases, diabetic mellitus, liver and kidney injuries, and anti-pathogen and anti-tumor activities. Further validations are required to define its specific targeting molecules, dissect the underlying mechanistic networks, and corroborate its efficacy in clinical trials.