Key Engineering Materials Vol. 819

Abstract: The purpose of this study was to develop the formulation of chitosan-ethylenediaminetetraacetic acid (EDTA)/poloxamer containing GM extract gel. The GM extract with a concentration of 0.5% wt was incorporated into a gel formulation. The physical appearance, pH, viscosity and percentage label amount of GM extract gel were performed. The in vitro antioxidant activity of gel were evaluated using (2,2-diphenyl-1-picrylhydrazyl (DPPH) method. The antibacterial activity against Staphylococcus aureus was evaluated by the zone of inhibition method. The mucoadhesive property was investigated using viscosity technique. The results illustrate that the chitosan-EDTA/poloxamer containing GM extract gel had a yellow colour of GM extract. The pH of a gel was in the range of 4.47 – 6.87. The percentage label amount of gel was in the range of 98.71 – 99.37% and the viscosity of gel were in the range of 14767 – 14784 mPa/s and 9607 – 9641 mPa/s. The TSol-Gel temperature was 35 oC. The antioxidant activities (IC50) which evaluated by DPPH method of all gel was in the range of 13.20 – 13.57 mg/ml. The zone of inhibition of gel against S.aureus was in the range of 8.17 – 10.52 mm. The chitosan-EDTA may improve the mucoadhesive property of gel. In conclusion, the chitosan-EDTA/poloxamer containing GM extract gel may have the potential for pharmaceutical and wound healing application.

Abstract: Bioavailability of orally administered drugs can be influenced by many factors. Poor drug absorption across the intestinal membrane is one of the factors that contribute to low bioavailability of drugs. It has been suggested that the metabolism/active efflux in the small intestine is involved in the poor absorption of many drugs. Intestinal CYP3A4 and P-gp work coordinately to reduce the intracellular concentration of drugs. Recently, bioenhancers have been identified and extensively studied. The aim of this study was to evaluate natural furanocoumarins found in juices of common lime and kaffir lime as the potential enhancers for oral delivery by means of modulating CYP3A4 and/or P-gp activities. The role of isolated furanocoumarins on CYP3A4 was assessed by testosterone 6β-hydroxylation reaction, while the effect on P-gp was investigated using R123 and CAM uptake studies in Caco-2, as well as LLC-PK₁ and LLC-GA5-Col300. In the present study, we demonstrated that isopimpinellin isolated from common lime is the best CYP3A4 inhibitor among 4 isolated furanocoumarins, implying that isopimpinellin would possibly act as a bioenhancer by inhibiting pre-systemic metabolism. 6’,7’-Dihydroxybergamottin found in kaffir lime is a dual inhibitor of CYP3A4 and P-gp, suggest that it could potentially be used as a bioenhancer by inhibiting both pre-systemic metabolism and efflux mechanism. However, in vivo study should be further conducted to confirm these effects in the body.

Abstract: Deer antler velvets (DAVs) contain many growth factors and protein. To extract growth factor from DAV, the suitable method and material properties have to investigate. The aim of this study was to improve the growth factor content in DAV extract for using as a skin rejuvenation compound. Different extraction methods (such as ethanol extract, probe sonication and precipitation method) and material preparations (such as fresh, dried by freeze drier and dried by hot air oven with and without gramma ray) were performed to evaluate the total protein and insulin-like growth factor-1 (IGF-1). The suitable condition was choose to determine the antioxidant activity and effect on the skin properties (such as in vitro skin permeation and in vivo human studies). For the results, fresh DAV extracted by probe sonication method provided the significantly highest total protein (586.31 + 48.17 mg/g) and IGF-1 (31.32 + 10.55 ng/g) contents. At the concentration of 2,000 μg/ml, this extract was completely dissolved in water and exhibited the antioxidant potential nearly 50% inhibition. For skin permeation at 24 h, the skin treated with DAV extract showed 3.83 + 2.04% of protein permeated through skin. The skin elasticity and hydration significantly increased after applying DAV extract for 28 days. In conclusion, the DAV extract by using fresh DAV and probe sonication method exhibited high IGF-1 and protein content as well as an antioxidant potential, leading to improve the skin properties. This extract might play an important role in the skin rejuvenation product.

Abstract: The antioxidant lotion containing 1% mangiferin, which was previously isolated from leaves of mango variety Nam Doc Mai (purity 93.15%, HPTLC analysis), was prepared. The lotion was an o/w type of emulsion with slightly yellow and coconut scent. The viscosity and pH of the lotion were 19,809 centipoise and 5.94, respectively. Stability studies were performed at room temperature (25±5 °C) with 70±10%RH and at high temperature (45±2 °C) with 75%RH. The amount of mangiferin in the lotion was investigated at various time intervals by HPTLC. The results showed that mangiferin in the lotion remained 80.30±1.87%LA after storage for 3 months at room temperature. While it remained less than 80%LA after storage for 2 weeks at high temperature and only 38.51±0.35%LA remained after 3 months of storage. An unknown degradant was detected at the R_f value of 0.24. It was produced increasingly when storage peroid taken longer, especially at the high temperature. UV spectra of the degradant and mangiferin suggested the similarity of their chemical structures. Antioxidant activity of the lotion was evaluated by DPPH radical scavenging method. Interestingly, the activity has not decreased at both temperatures during storage times even if mangiferin degraded. It was possible that the degradant could scavenge DPPH redical and chemical structure of the degradant might be xanthone.

Abstract: Propionibacterium acnes (P. acnes) is one of skin bacteria that induce acne comedone formation. Previous studies reported that P. acnes was susceptible to alcoholic seed husk extract of Tamarindus indica L. (T. indica), no studies have been reported about the susceptibility of water extract from tamarind seed husk to P. acnes. Therefore, the objectives of this investigation were to explore the antibacterial activity of water and ethanolic seed husk extracts from T. indica (wTSH and eTSH) against P. acnes and to compare antibacterial activity of hydrogels containing wTSH and eTSH extracts against P. acnes. wTSH and eTSH extracts were reddish brown powder, and oligomeric proanthocyanidin was identified by UV-Vis spectroscopy and high performance liquid chromatography as the main ingredient in the extracts. wTSH and eTSH extracts showed the average of total phenolic compounds of 408.3±0.01 and 385.5±0.02 mg GAE/g and exhibited very strong free radical scavenging ability by DPPH assay with IC50 value of 19.6±0.2 µg/ml and 18.8±0.2 µg/ml, respectively. In addition, wTSH and eTSH extracts showed good activity against P. acnes. The minimum inhibitory concentration (MIC) of wTSH and eTSH extracts was 500 and 250 µg/ml, and the minimum bactericidal concentration (MBC) of both extracts was 500 µg/ml. In conclusion, the hydrogels which composed of 0.1% wTSH or eTSH extracts, 2% HPMC, 15% glycerin and 1% paraben concentrate, exhibited weak acid with pH 5±2, good physical stability, i.e. good spreadability with pseudoplastic flow, and also exhibited noticeable anti P. acnes activity in fluorescent resazurin assay after storage in the accelerated conditions for 3 months.

Abstract: The purpose of this study was to develop micromeulsion consisting of Carthamus tinctorius floret extract (CT) as an ingredient to inhibit 5α-reductase activity. CT was extracted using a simple maceration technique with ethanol and inhibition of 5α-reductase activities was determined. Solutions of 2% CT extract were loaded into four microemulsion (ME) formulas (F1, F2, F3 and F4) and investigated for their physical properties, skin permeation and stability. Results showed that crude CT extract had no toxic effects on DU145 cells at concentrations of 0.0001-1.0 mg/mL. For reduction of 5α-reductase activities, concentration of CT extract at 0.05 mg/mL exhibited highest 5-reductase type-1 inhibition activity on the DU-145 cell line at 89.96% of the control, higher than standard finasteride (31.39%) and dutasteride (38.58%). The results indicated that a thermodynamically stable microemulsion improved the stability and permeation rate of CT extract. Among the ME formula, F3 was most appropriate for ME formulation with highest permeation rate and good stability during 30 days of storage. Therefore, using nanotechnology for stable transdermal delivery systems of bioactive compounds from Thai medicinal plants is one approach to improve skin and hair follicle permeation.

Abstract: The market of hair gel products in Thailand steadily grows with the changing trend of fashion every year. The main component of the hair gel products is the fixative polymer, which plays a role in hair styling properties including stiffness and curl retention. Properties of the hair styling product depending on hair types and climates must be suitably improved for Thai hair. In this study, 10 %w/w gel solutions of polyacrylic acid, polyquaternium-86, polyvinylpyrrolidone (PVP), acrylates copolymer, and vinylpyrrolidone (VP) copolymers were cast as polymeric thin films. The film properties such as mechanical properties, wettability, and crystallinity were characterized afterwards. As a result, the highest puncture strength of 2.2 N/mm² was found from PVP-K90 film (500-700 μm thick). Whereas, VP/vinyl acetate (VA) copolymer film was the most flexible with 42.5% elongation. For water contact angle analysis, it was noticed that VP copolymers had the angle of ~50^o indicating the moderate wettability. The x-ray patterns of raw materials, polymeric films, and humidified films were varied especially for PVP-K30. Morphologies of the Thai hair samples coated with the fixative polymers were visualized through SEM. After storing coated hair samples in the humidified atmosphere (95±2% Relative humidity), acrylates copolymer, VP/Methacrylamide/Vinyl Imidazole copolymer, and VP/VA copolymer appeared the humidity resistance suitable for Thai hair styling gel.

Abstract: Gac fruit (Momordica cochinchinensis Spreng) is mostly found in southeast Asian countries. Previous studies have demonstrated that gac fruit is a major source of β-carotene, lycopene, and α-tocopherol. This study aimed to develop the extraction of Thai gac fruit as a potential active ingredient for antioxidant, melanogenesis, and collagen stimulating activities. In the present study, different parts of ripe Thai gac fruit, the peel, pulp, and seed membrane, were extracted using the accelerated solvent extraction (ASE) technique, an innovative plant extraction method. DPPH radical-scavenging activity, ABTS radical scavenging activity, and ferric reducing/antioxidant power (FRAP) assay were performed to compare the antioxidant activity derived from each part of the fruit. The effect of Thai gac fruit on melanogenesis and collagen stimulating activities was investigated using B16F1 and human fibroblast cell lines, respectively. The results demonstrate that the pulp (EC₅₀ value of 7.42 ± 0.81 mg/mL) and the seed membrane (EC₅₀ value of 76.43 ± 2.66 μg/mL) showed the strongest antioxidant activities in DPPH and ABTS assay, respectively. The peel clearly displayed the strongest antioxidant activity and significantly increased the FRAP value (247.67 ± 19.73 μM/mg). Furthermore, the peel showed the lowest melanin content (76.56 ± 7.13 % of control) in the B16F1 cell line, and clearly increased the most amount of collagen (21.87 ± 3.12%) in the human fibroblast cell line in comparison to the other fractions. Therefore, Thai gac fruit peel revealed the biological effects, including antioxidant, melanogenesis, and collagen stimulating activities. In conclusion, Thai gac fruit extracted using the ASE technique exhibited several effects that could be used as a potential active ingredient for cosmeceutical products, due to its antioxidant, melanogenesis, and collagen stimulating activities. Our findings provide potential uses of Thai gac fruit as a multifunctional cosmeceutical ingredient to be further explored in future studies.

Abstract: Excessive of ultraviolet light causes abnormality of melanin production. Antioxidants and antityrosinase agents are able to reduce hyperpigmentation by interrupting the process of melanin production. The purpose of this study is to examine the antioxidant and antityrosinase activities as well as toxicity of both 80% ethanol and aqueous extracts of Alpinia nigra by DPPH free radical scavenging assay, mushroom tyrosinase assay and brine shrimp lethality bioassay. Alpinia nigra extracts showed positive result on antioxidant and antityrosinase activities. We found that extract of A. nigra’s leaf has the most effective activity of antioxidant and antityrosinase among other parts of this plant. The ethanol and aqueous extracts from the leaf of A. nigra at the concentration of 125 μg/mL showed % inhibition for free radical scavenging as 94.97% and 93.35%, respectively. The IC₅₀ values of antioxidant were 39.83±16.21 and 46.33±15.22 μg/mL, respectively. In addition, ethanol extract of the leaf from A. nigra at the concentration of 1,000 μg/mL produced 92.61% inhibition of mushroom tyrosinase activity, whereas aqueous extract of A. nigra’s leaf at the same concentration produced 74.47% inhibition. The IC₅₀ of antityrosinase activities were 142.81±13.32 and 406.88±66.43 μg/mL for ethanol and aqueous extracts, respectively. Moreover, the brine shrimp lethality bioassay showed that all extracts were non-toxic (LC₅₀ >1,000 μg/mL). In conclusion, the ethanol extract of A. nigra’s leaf may be beneficial and provide the novel and safe source for antioxidant and whitening agent.

Abstract: Melanin is cutaneous pigment which level of its production determines skin complexion. Overproduction of melanin, frequently promoted by UV rays, results in darkening of the skin. Inhibition of tyrosinase activity, a core component in melanin biosynthesis, is one of the mechanisms of depigmenting agents. Hydroquinone and kojic acid are the examples of well-known whitening agents widely used in both pharmaceutical and cosmetic products. However, their adverse effect issues still needed to be overcome. A recent study showed that p-chlorophenyl benzyl ether (Cl-benz), a new synthetic compound, more strongly inhibited mushroom tyrosinase than kojic acid. In the current study, cytotoxicity, anti-melanogenic activity and anti-tyrosinase activity of Cl-benz were performed in mouse B16F10 melanoma cells compared to kojic acid. After 24 h of treatment on B16F10 cells, the cytotoxicity was not observed with Cl-benz and kojic acid. However, after incubation for 48 h, kojic acid at a concentration of 500 μM reduced cell viability less than 50%, whereas Cl-benz-treated cells showed negligible cytotoxicity. For cell-based assay, Cl-benz exhibited inhibitory effect similar to kojic acid. Melanin production in B16F10 cells was suppressed by Cl-benz in a dose dependent manner. One hundred micrograms of Cl-benz decreased melanin content in α-MSH by 66%. Moreover, the percentage of cellular tyrosinase activity of Cl-benz showed positive association with its corresponding melanin content. These results revealed that Cl-benz could inhibit melanogenesis via the mechanism of cellular tyrosinase inhibition. Accordingly, Cl-benz has potential to become a novel skin whitening agent in terms of efficacy and safety.