Ampa Jimtaisong

Natural products as photoprotection

The rise in solar ultraviolet radiation on the earths surface has led to a depletion of stratospheric ozone over recent decades, thus accelerating the need to protect human skin against the harmful effects of UV radiation such as erythema, edema, hyperpigmentation, photoaging, and skin cancer. There are many different ways to protect skin against UV radiations harmful effects. The most popular way to reduce the amount of UV radiation penetrating the skin is topical application of sunscreen products that contain UV absorbing or reflecting active molecules. Based on their protection mechanism, the active molecules in sunscreens are broadly divided into inorganic and organic agents. Inorganic sunscreens reflect and scatter UV and visible radiation, while organic sunscreens absorb UV radiation and then re‐emit energy as heat or light. These synthetic molecules have limited concentration according to regulation concern. Several natural compounds with UV absorption property have been used to substitute for or to reduce the quantity of synthetic sunscreen agents. In addition to UV absorption property, most natural compounds were found to act as antioxidants, anti‐inflammatory, and immunomodulatory agents, which provide further protection against the damaging effects of UV radiation exposure. Compounds derived from natural sources have gained considerable attention for use in sunscreen products and have bolstered the market trend toward natural cosmetics. This adds to the importance of there being a wide selection of active molecules in sunscreen formulations. This paper summarizes a number of natural products derived from propolis, plants, algae, and lichens that have shown potential photoprotection properties against UV radiation exposure‐induced skin damage.

Novel biocomposite of carboxymethyl chitosan and pineapple peel carboxymethylcellulose as sunscreen carrier

This study aims to prepare of biocomposite of carboxymethyl chitosan (CM-chitosan) and carboxymethylcellulose (CMC) from Ananas comosus (pineapple) peel for use as broad spectrum sunscreen carrier. Biocomposite was produced by using ferulic acid (FA), a plant extract, as crosslinker with the optimal ratio of CMC: CM-chitosan: FA at 1:2:4%w. FT-IR technique demonstrated that crosslinking may occur at amine group of CM-chitosan and carboxyl group of FA and hydrogen bonding between hydroxyl group of CMC and carboxyl group of FA. Biocomposite is pale yellow powder and present fibre bundle-like surface in the SEM image. DSC, TGA and XRD results indicated that new compound was formed. The particle size of biocomposite is 626nm determined by using Zetasizer. Hydrophilic TiO2 and phenylbenzimidazole sulphonic acid (PBSA) were used as sunscreen agent at ratio of TiO2: PBSA at 2:1%w. The biocomposite sunscreen possesses the SPF value of 2.47 with boost star rating of 3 at 2% compound. The results obtained indicate that the biocomposite was successfully prepared from CM-chitosan and pineapple peel CMC and the system can be used as matrix delivery system for hydrophilic sunscreens.

In vitro antioxidant activities of laccaic acids and its aluminum lake

Antioxidant activities of laccaic acids and its aluminum lake were investigated by DPPH assay, reducing power, and thiocyanate method. The DPPH assay, which used for the reaction kinetic of samples by measuring the ability of antioxidants on reacting with DPPH in a function of time, showed that 0.1, 0.2, and 0.5 mg/mL laccaic acids and 0.5 and 1.25 mg/mL aluminum lake possessed intermediate behavior since they reacted slowly and reach a steady state within 30 min. Laccaic acids of 1.0 mg/mL and aluminum lac lake at concentrations of 2.5 and 5.0 mg/mL reacted much slower and took longer time to reach a steady state thus possessed a slow kinetic behavior. The DPPH assay also showed that antioxidative activity of laccaic acids (EC50=0.38mg/mL) is higher than the aluminum lake (EC50=1.63 mg/mL) and butylated hydroxytoluene (EC50=0.57 mg/mL) but lower than ascorbic acid (EC50= 0.14 mg/mL), and gallic acid (EC50=0.05 mg/mL). The reducing power assay indicated that laccaic acids had greater reducing power than aluminum lake. While, % inhibition of lipid peroxidation of laccaic acids (29.9%) was lower than the lac lake (43.8%).

Inclusion Complex of Plai Oil and β-Cyclodextrin

Inclusion complex of β-cyclodextrin (β-CD) and Plai (Zingiber cassumunar) oil was prepared using a simple co-precipitation method at β-CD to Plai oil in different ratios. The inclusion complexes were characterized using Fourier transform-infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). The FT-IR absorption bands of inclusion complex at 3600-3200 cm-1 were broader and shifted toward lower frequencies compared with that of pure β-CD (3359 cm-1). DSC of the inclusion complexes showed two endothermic peaks shifted to lower temperatures (90-100°C and 295-300°C) compared to that of β-CD. The different physicochemical characteristic could be an indication of an embedded guest molecule in the β-CD cavities in the inclusion complex preparation.

Preparation of Porous Ceramic and its Utilization as Spa Compress Ball

Herbal compress ball has been traditionally used in Thai spa industry. The major limitations of the product are microbial contamination and a short reuse-cycle. Thus, this work attempts to develop the ceramics in the form of compress ball. The porosity of the prepared porcelain ceramics, which affects the different absorption and vaporization of essential oils, was studied by the variation of Al2O3 quantities and firing temperatures. The absorption and vaporization on water and essential oils of the developed ceramics were studied at ambient temperature (24-27 °C), 50 °C and 100 °C. The ceramic product fried at 1150 °C possessed a higher absorption and evaporation than that fired at 1230 °C in all evaporated temperatures. Moreover, in term of the absorption property, water absorption raised as the Al2O3 content increased however; at 1150 °C of firing temperature, water absorption increased to maximum at 4% Al2O3 content but decreased at higher content. In addition, ceramic compress ball with the optimal properties (fired at 1150 °C, 4% Al2O3) was prepared and 60 mg of mixture of Plai oil, Lemongrass oil and Kaffir lime oil were added into the compress ball. The product was then tested by 10 volunteers and it showed that 80% of volunteers were highly satisfied with the product. Even though, the ceramic compress ball product tends to have volunteer’s positive satisfaction, there are some issues for further improvement such as rough and hard feeling, shape and usability of the product.

Green Synthesis of Silver Nanoparticles Using a Vitamin C Rich Phyllanthus emblica Extract

Silver nanoparticles were prepared by treating a solution of AgNO3 dissolved in deionized water with Emblica (Phyllanthus emblica) extract as reducing agent. The factors that affect the synthesis of silver nanoparticles (time, temperature and concentration of silver nitrate and reducing agent) were investigated. The high concentration of silver nitrate and reducing agent showed the higher in concentration of silver nanoparticles. The heating temperature help increase the yield of silver nanoparticles at shorter reaction time. Their structure, shape and size distribution were characterized by UV-vis spectrophotometer, SEM and TEM technique. The UV-vis spectrophotometer show peaks located of silver-Emblica nanoparticle at 430 nm and the particle size of silver-Emblica is 41.2 nm in average diameter determined by TEM.