Inspired by vitamin A for anti‐ageing: Searching for plant‐derived functional retinoid analogues

Secondary Terpenes in Cannabis sativa L.: Synthesis and Synergy

Cannabis is a complex biosynthetic plant, with a long history of medicinal use. While cannabinoids have received the majority of the attention for their psychoactive and pharmacological activities, cannabis produces a diverse array of phytochemicals, such as terpenes. These compounds are known to play a role in the aroma and flavor of cannabis but are potent biologically active molecules that exert effects on infectious as well as chronic diseases. Furthermore, terpenes have the potential to play important roles, such as synergistic and/or entourage compounds that modulate the activity of the cannabinoids. This review highlights the diversity and bioactivities of terpenes in cannabis, especially minor or secondary terpenes that are less concentrated in cannabis on a by-mass basis. We also explore the question of the entourage effect in cannabis, which studies to date have supported or refuted the concept of synergy in cannabis, and where synergy experimentation is headed, to better understand the interplay between phytochemicals within Cannabis sativa L.

Multidirectional activity of bakuchiol against cellular mechanisms of facial aging - Experimental evidence for a holistic treatment approach

Objective

Skin ageing is a multifactorial process involving formation of reactive oxygen species, consecutive inflammation with reduced epidermal and dermal cell viability and resulting damage to the extracellular matrix. Effective dermocosmetic treatment modalities should ideally address these hallmarks in a holistic approach. Here, we determined the corresponding activity profile of bakuchiol, a plant‐derived meroterpene, in an array of in vitro, ex vivo and in vivo studies and compared it to retinol, currently considered as gold standard in topical antiageing cosmetics.

Methods

The antioxidative capacity and power of bakuchiol and retinol were analysed by measuring 2,2′‐diphenyl‐1‐picrylhydrazyl (DPPH) reduction via its absorption decay and electron spin resonance spectroscopy, respectively. Effects on prostaglandin E2 (PGE2), macrophage migration inhibitory factor (MIF), fibroblast growth factor 7 (FGF7), collagen type I and VII (COL1A1, COL7A1), fibronectin (FN) levels as well as the metabolization of water‐soluble tetrazolium 1 (WST‐1) were determined in human dermal fibroblasts. Epidermal regeneration was assessed utilizing an in vitro wound healing model. FN protein levels were analysed ex vivo after treatment with a formulation containing bakuchiol, retinol or vehicle using suction blister fluid. Skin condition improvement was determined in vivo in a split‐face comparison study after application of bakuchiol or vehicle.

Results

In contrast to retinol, bakuchiol demonstrated high antioxidative efficacy. Levels of PGE2 and MIF were significantly decreased by both bakuchiol and retinol. Bakuchiol but not retinol significantly increased FGF7 protein levels. WST‐1 metabolization levels were significantly augmented by bakuchiol and retinol. Bakuchiol and retinol application led to a significant augmentation of COL1A1, COL7A1 and FN protein levels. Wounds supplemented with bakuchiol but not retinol displayed a significant increase in epidermis regeneration. Clinically, areas treated with a bakuchiol‐containing formulation showed a statistically significant increase in FN protein values after a 4‐week application compared to untreated areas and areas treated with vehicle.

Conclusion

These data provide evidence for the multidirectional efficacy of bakuchiol against cellular hallmarks of skin ageing. Its activity profile shares some common features with retinol but demonstrates several hitherto unknown biopositive effects in our studies, namely stimulation of the critical extracellular matrix component FN, and accelerated epidermal regeneration and wound healing.

A Harungana madagascariensis extract with retinol-like properties - Gene upregulations and protein expressions in human fibroblasts and skin explants

OBJECTIVE

Because they limit, even reverse, age-induced skin alterations, retinoids became a staple in cosmetology. However, their use can result in undesired secondary effects and there is a demand for natural sources of compounds with retinoid like effects. A preliminary screening identified a Harungana madagascariensis plant extract (HME) as possibly inducing genes stimulated by retinol. We analysed its effect on gene and protein expression, comparing it to retinoids.

METHODS

Gene expression was analysed by real-time qPCR on RNA from isolated fibroblasts subjected to retinol or the plant extract for 6, 48 or 96 hours. Skin markers were quantified in fibroblasts cultured with retinol or extract containing medium, and UV-aged skin explants subjected to topical applications of creams containing retinol, retinaldehyde or HME.

RESULTS

Real-time qPCR show that the extract induced all RARs and RXRs, even RXRγ that was not induced by retinol. Eighty-eight percent of the 25 early retinoid reaction genes induced by a concentration of retinol are induced by the extract. In fibroblasts, only the extract increased collagen III labelling, while collagen I and fibronectin labelling are increased by retinol and the extract, with higher levels for the extract. When topically applied to UV-aged skin explants, only the cream containing the HME led to increased labelling of CRABP1 in the epidermis. CRABP2 and Ki67 are induced by all three creams and no effect was detected on RXRs. In the dermis the extract containing cream increased CRABP2, total collagen, procollagen I and collagen I while creams with retinol or retinaldehyde only affected some of these proteins.

CONCLUSIONS

The HME induces an overall retinol-like gene induction profile in isolated fibroblasts and retinoid-like stimulation of protein synthesis in both isolated fibroblasts and photoaged skin explants.