Context Phyllanthus emblica L. (Euphorbiaceae) (amla), Manilkara zapota L.P. Royen (Sapotaceae) (sapota) and silymarin are reported to contain antioxidant effects. However, information on other biological activities relating to the anti-aging properties is limited. Objective To compare in vitro antioxidants, anti-collagenase (MMP-1 and MMP-2) and anti-elastase properties as well as the phenolic and flavonoid contents of amla, sapota and silymarin as potential anti-aging ingredients. Materials and methods The ethanol amla and sapota fruit extracts were prepared by three cycles of maceration with 24 h duration each. The total phenolic (TPC) and flavonoid (TFC) contents were determined. The antioxidant capacity was evaluated by DPPH and ABTS assays. The effects of MMP-1, MMP-2 and elastase inhibitions were determined by using the EnzChek Õ assay kits (Molecular-Probes, Eugene, OR). Results Amla exhibited the highest in TPC (362.43 ± 11.2 mg GAE/g) while silymarin showed the highest in TFC (21.04 ± 0.67 mg QE/g). Results of antioxidant activity by DPPH and ABTS methods showed that amla possessed the most potent capacity with IC 50 values of 1.70 ± 0.07 and 4.45 ± 0.10 mg/mL, respectively. Highest inhibitions against MMP-1, MMP-2 and elastase were detected for sapota with IC 50 values of 89.61 ± 0.96, 86.47 ± 3.04 and 35.73 ± 0.61 mg/mL, respectively. Discussion and conclusion Test extracts offered anti-aging properties in different mechanisms. Amla showed the highest phenolic content and antioxidant property with moderate anticollagenase. Silymarin exhibited measurable flavonoid content with anti-elastase effect. Sapota showed the highest collagenase and elastase inhibitions with moderate antioxidant effect. Thus, extracts might be added as a mixture to gain the overall anti-aging effects.ARTICLE HISTORY

Abstract. Silymarin is a standardized extract from Silybum marianum seeds, known for its many skin benefits such as antioxidant, anti-inflammatory, and immunomodulatory properties. In this study, the potential of several microemulsion formulations for dermal delivery of silymarin was evaluated. The pseudo-ternary phase diagrams were constructed for the various microemulsion formulations which were prepared using glyceryl monooleate, oleic acid, ethyl oleate, or isopropyl myristate as the oily phase; a mixture of Tween 20®, Labrasol®, or Span 20® with HCO-40® (1:1 ratio) as surfactants; and Transcutol® as a cosurfactant. Oil-inwater microemulsions were selected to incorporate 2% w/w silymarin. After six heating-cooling cycles, physical appearances of all microemulsions were unchanged and no drug precipitation occurred. Chemical stability studies showed that microemulsion containing Labrasol® and isopropyl myristate stored at 40°C for 6 months showed the highest silybin remaining among others. The silybin remainings depended on the type of surfactant and were sequenced in the order of: Labrasol®>Tween 20®>Span 20®. In vitro release studies showed prolonged release for microemulsions when compared to silymarin solution. All release profiles showed the best fits with Higuchi kinetics. Non-occlusive in vitro skin permeation studies showed absence of transdermal delivery of silybin. The percentages of silybin in skin extracts were not significantly different among the different formulations (p>0.05). Nevertheless, some silybin was detected in the receiver fluid when performing occlusive experiments. Microemulsions containing Labrasol® also were found to enhance silymarin solubility. Other drug delivery systems with occlusive effect could be further developed for dermal delivery of silymarin.

Context Psidium guajava L. (Myrtaceae) leaf contains a wide variety of bioactive compounds that contribute valuable effects on human well-being. Objective This study investigates the influence of guava leaf extract-menthol toner on thermoregulation, including perspiration, skin temperature, and recovery heart rate. Materials and methods This randomised, placebo-controlled clinical trial assessed the effects of the guava leaf extract-menthol toner and placebo with a 1-week washout period. Sixty-four participants were enrolled. The participants exercised on a treadmill until a 75% heart rate reserve was achieved for 5 min, followed by a 5 min post-exercise rest period. The skin temperature and heart rate were then measured before 5 mL of the testing product was sprayed to specific areas of the body, left it for 30 sec before wiped off. Post-exercise perspiration and skin temperatures were collected by sweat patches and measured by the Skin-thermometer ST500, respectively. A 20 min heart rate monitoring period started 10 min after the exercise and measured every 2 min intervals. Results Use of the toner significantly reduced post-exercise perspiration to approximately half of the baseline and placebo use values ( p < 0.05). Furthermore, relative heart rate changes showed no significant differences among the tests ( p > 0.05). Skin temperature was also unaffected ( p > 0.05). Discussion and Conclusion Guava leaf extract-menthol toner reduced perspiration by astringent effects but did not influence heat dissipation and did not affect cardiovascular mechanism compared to the controls. Additional cleaning with guava leaf extract-menthol toner could offer better hygiene after a workout.

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