Topical treatment of cutaneous herpes simplex virus-1 infection in mice with a specially formulated caffeine gel (Cafon)

Experimental Study on the Effect of Caffeine Hydrogel on the Expression of TGF -β1, α-SMA and Collagen in Hypertrophic Scar of Rabbit Ears

This study evaluated the effects of topical use of caffeine hydrogel on hypertrophic scar in a rabbit ear wound model. Nine rabbits were randomly divided into three groups: control group, caffeine hydrogel group, and matrix group. Punched defects were established on each rabbit's ear which resulted in a hypertrophic scar. When the wound epithelialization and scar hyperplasia could be seen, control group did not do any treatment, while caffeine hydrogel group and matrix group were treated with caffeine hydrogel and hydrogel matrix, respectively. After 3 weeks of administration, the general morphological changes of scar were observed, and the scar tissue of rabbit ears was stained with HE and Masson. The relative expressions of TGF β-1, α-SMA, type I collagen, and type III collagen in scar tissue were detected by Western blot. In all three groups, findings showed that caffeine hydrogel can inhibit scar growth by reducing the expression of TGF β-1, reducing the proliferation of fibroblasts, improving collagen arrangement and reducing collagen deposition. The overall study shows efficacy and mechanism of caffeine. It concluded that caffeine could be an effective therapeutic agent for hypertrophicscars.

Caffeine and Its Pharmacological Benefits in the Management of Androgenetic Alopecia: A Review

Caffeine, particularly after ingestion, is well known to exert various pharmacological effects. A growing body of evidence implicates the ingestion of caffeine with beneficial effects on several diseases. The easy penetration of caffeine across the skin barrier and into human skin makes caffeine an ideal compound for topical application. Hair loss is known to negatively affect the quality of life and predispose to depression and anxiety. Androgenetic alopecia (AGA) is the most common type of hair loss in both men and women. To date, only few approved drug-based treatments for AGA exist, and these are inevitably associated with side effects. Therefore, the development of topical treatments based on well-tolerated natural ingredients such as caffeine to alleviate hair loss may provide a much-needed alternative to drug-based approaches.

Caffeine improves barrier function in male skin

The influence of androgens, especially testosterone and its effector dihydrotestosterone, results in a constitutive disadvantage for male skin, e.g. reduced viability of hair at the scalp and reduced epidermal permeability barrier repair capacity. Dihydrotestosterone can act, among others, as an adenyl cyclase inhibitor. Caffeine on the other hand is an inexpensive and (in regular doses) harmless substance used in various cosmetic products, which can act as a phosphodiesterase inhibitor. To prove the hypothesis that caffeine as a phosphodiesterase inhibitor is able to override testosterone-induced effects on barrier function, we performed a double-blind placebo controlled study with healthy volunteers. In this study, 0.5% caffeine in a hydroxyethylcellulose gel preparation (HEC) was applied on one forearm, HEC without caffeine on the other forearm of male and female volunteers for 7 days and transepidermal water loss (TEWL) was measured before and at the end of the treatment period. Basal TEWL did not differ significantly between male and female subjects but the application of caffeine significantly reduced TEWL in male skin compared with female skin. We conclude that caffeine is beneficial for barrier function in male skin.

Short-term iontophoretic and post-iontophoretic transport of model penetrants across excised human epidermis

The effect of short-term current application (0.4mA for 10min) on the epidermal transport of two model penetrants (butyl paraben, BP; caffeine, CF) of differing lipohilicity was investigated and compared to that produced by employing an established method of skin penetration enhancement (delipidisation). The aim was to investigate the mechanism of enhancement and route of skin permeation associated with each penetrant and mode of treatment. Franz cell diffusion experiments were conducted using human epidermal sheets and a saturated buffer solution (pH 7.4) of the respective penetrant, at a pseudo-finite dose. The effects of electrode type (anodal or cathodal) and current treatment protocol (iontophoresis or post-iontophoresis) on solute permeation was found not to be significantly different (p>0.05). However, in contrast to BP, a significant increase in CF transport (3-5-fold) relative to untreated skin was observed when iontophoretic/post-iontophoretic treatment protocols were employed. The use of delipidised skin was found to enhance the permeation of both model penetrants to an extent greater than iontophoresis (BP: 3-fold; CF: 24-fold). Results from this study suggest that the permeation of the more hydrophilic CF across the skin, unlike BP, may involve multiple pathways. Electroperturbation of the epidermis was confirmed as the mechanism responsible for enhancing CF transport when electrical current was applied. Iontophoretic and post-iontophoretic enhancement may serve as a potential approach to enhance the topical delivery of CF in cosmetic or dermatological treatments (anti-cellulite, viral infections and psoriasis).

Caffeine inhibits paresthesia induced by herpes simplex virus through action on primary sensory neurons in rats

Herpetic infection causes paresthesia, including hypoalgesia, in humans and hypoalgesia in rats. This study was conducted to examine the effect of caffeine, which inhibits replication of herpes simplex virus type-1 (HSV) and affects several neuronal functions, on HSV-induced paresthesia in rats. HSV-induced hypoalgesia was suppressed by repeated treatment of unilateral hindpaw with 10% caffeine gel regardless of when the treatment was started. Repeated treatment with acyclovir, an anti-HSV agent, suppressed HSV-induced hypoalgesia only when started before inoculation; acyclovir did not produce therapeutic effects on the HSV-induced sensory abnormality. Many dorsal root ganglion neurons were positive for HSV antigen following HSV inoculation of the hindpaw. Repeated treatment with caffeine and acyclovir markedly decreased HSV antigen-positive neurons in the dorsal root ganglia when started before, but not 2 or 4 days after, infection. These results suggest that topical caffeine inhibited HSV-induced paresthesia through direct action on sensory neurons, and that not only antiviral activity but also direct alteration of neural functions are involved in the caffeine sensory actions.

Efficacy of Cafon gel on cutaneous infection with herpes simplex virus (HSV)-2 and acyclovir-resistant HSV in mice

Caffeine is known to inhibit replication of herpes simplex virus (HSV)-1 and the therapeutic efficacy of caffeine (Cafon) gel has been shown in a mouse model cutaneously infected with HSV-1. In this study we examined the inhibitory effect of caffeine on infection with HSV-2 and acyclovir-resistant HSV-1 strains, thymidine kinase (TK)-deficient and phosphonoacetic acid (PAA)-resistant HSV-1 in vitro and in vivo. Caffeine inhibited plaque formation of HSV-2 and acyclovir-resistant HSV-1 strains and their EC50 values ranged from 0.42 to 1.11 mg/ml. Topical treatment with Cafon gel was significantly effective in retarding the development of skin lesions caused by cutaneous infection with HSV-2 and PAA-resistant HSV-1 and in reducing the virus yield of the skin infected with TK-deficient HSV-1. The results suggested that Cafon gel would be useful for the topical treatment of cutaneous infection with HSV-2 and acyclovir-resistant HSV strains.