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Overexpression of tyrosinase can cause excessive production of melanin and lead to hyperpigmentation disorders, including melasma and freckles. Recently, agents obtained from plants are being used as alternative medicines to downregulate tyrosinase synthesis and decrease melanin production. Phyla nodiflora Greene (Verbenaceae) is used as a folk medicine in Taiwanese for treating and preventing inflammatory diseases such as hepatitis and dermatitis. However, the antimelanogenesis activity and molecular biological mechanism underlying the activity of the methanolic extract of P. nodiflora (PNM) have not been investigated to date. Our results showed that PNM treatment was not cytotoxic and significantly reduced the cellular melanin content and tyrosinase activity in a dose-dependent manner (P < 0.05). Further, PNM exhibited a significant antimelanogenesis effect (P < 0.05) by reducing the levels of phospho-cAMP response element-binding protein and microphthalmia-associated transcription factor (MITF), inhibiting the synthesis of tyrosinase, tyrosinase-related protein-1 (TRP-1), and TRP-2, and decreasing the cellular melanin content. Moreover, PNM significantly activated the phosphorylation of mitogen-activated protein kinases, including phospho-extracellular signal-regulated kinase, c-Jun N-terminal kinase, and phospho-p38, and inhibited the synthesis of MITF, thus decreasing melanogenesis. These properties suggest that PNM could be used as a clinical and cosmetic skin-whitening agent to cure and/or prevent hyperpigmentation.

The preparation of TiO(2) nanocrystallite powders coated with and without 9 mol% ZnO has been studied for cosmetic applications in sunscreens by a co-precipitation process using TiCl(4) and Zn(NO(3))(2)·6H(2)O as starting materials. XRD results show that the phases of anatase TiO(2) and rutile TiO(2) coexist for precursor powders without added ZnO (T-0Z) and calcined at 523 to 973 K for 2 h. When the T-0Z precursor powders are calcined at 1273 K for 2 h, only the rutile TiO(2) appears. In addition, when the TiO(2) precursor powders contain 9 mol% ZnO (T-9Z) are calcined at 873 to 973 K for 2 h, the crystallized samples are composed of the major phase of rutile TiO(2) and the minor phases of anatase TiO(2) and Zn(2)Ti(3)O(8). The analyses of UV/VIS/NIR spectra reveal that the absorption of the T-9Z precursor powders after being calcined has a red-shift effect in the UV range with increasing calcination temperature. Therefore, the TiO(2) nanocrystallite powders coated with 9 mol% ZnO can be used as the attenuate agent in the UV-A region for cosmetic applications in sunscreens.

Kaempferol (KAE) is a strong antioxidant flavonoid compound, but its clinical application is limited by quantity and poor dissolution property. However, the dissolution mechanism of a kaempferol nanoparticle formulation (KAEN) has not yet been elucidated. The aim of the present study was therefore to use a nanoparticle engineering process to resolve the dissolution problem. Our data indicated that KAEN effectively increased the dissolution percentage by particle size reduction, high encapsulation efficiency, amorphous transformation, and hydrogen-bond formation with excipients. In addition, we used several different antioxidant activity assays to evaluate KAE and KAEN. The data indicated that KAEN retained potent antioxidant activity after the nanoparticle engineering process and showed better antioxidant activity than KAE dissolved in water (P < 0.05). According to these findings, we concluded that KAEN could be a low-dose alternative to KAE in health food and future clinical research.

Curcumin (CUR), a natural polyphenol isolated from tumeric ( Curcuma longa ), has been documented to possess antioxidant and anticancer activities. Unfortunately, the compound has poor aqueous solubility, which results in poor bioavailability following high doses by oral administration. To improve the solubility of CUR, we developed a novel curcumin nanoparticle system (CURN) and investigated its physicochemical properties as well as its enhanced dissolution mechanism. Our results indicated that CURN improved the physicochemical properties of CUR, including a reduction in particle size and the formation of an amorphous state with hydrogen bonding, both of which increased the drug release of the compound. Moreover, in vitro studies indicated that CURN significantly enhanced the antioxidant and antihepatoma activities of CUR (P < 0.05). Consequently, we suggest that CURN can be used to reduce the dosage of CUR and improve its bioavailability and merits further investigation for therapeutic applications.

Purpose: A novel naringenin-loaded nanoparticles system (NARN) was developed to resolve the restricted bioavailability of naringenin (NAR) and to enhance its hepatoprotective effects in vivo on oral administration., Materials and Methods: Physicochemical characterizations of NARN included assessment of particle size and morphology, powder X-ray diffraction, fourier transform infrared spectroscopy, and dissolution study. In addition, to evaluate its bioactivities and its oral treatment potential against liver injuries, we compared the hepatoprotective, antioxidant, and antiapoptotic effects of NARN and NAR on carbon tetrachloride (CCl(4))-induced hepatotoxicity in rats., Results: NARN had a significantly higher release rate than NAR and improved its solubility. NARN also exhibited more liver-protective effects compared to NAR with considerable reduction in liver function index and lipid peroxidation, in conjunction to a substantial increase in the levels of the antioxidant enzymes (P < 0.05). Moreover, NARN was able to significantly inhibit the activation of caspase-3, -8, and -9 signaling, whereas NAR only markedly inhibited caspase-3 and -9 (P < 0.05)., Conclusion: NARN effectively improved the release of NAR which resulted in more hepatoprotective effects mediated by its antioxidant and antiapoptotic properties. These observations also suggest that nanoformulation can improve the free drug's bioactivity on oral administration.

Chinese herbs employed in traditional Chinese medicine (TCM) have been used for centuries in the practice of medicated diet and dietetic therapy. The seed of Cuscuta chinensis Lam. (Convolvulaceae), a commonly used traditional Chinese herb, is frequently added in Chinese cooking and preparation of refreshments, including porridge and alcoholic beverages, to nourish the human body. In the present study, we compared the antioxidant activities of water and ethanol extracts from the seeds C. chinensis and also of its different organic fractions, including n-hexane, ethyl acetate, n-butanol and organic water, by assessing their DPPH (1,1-diphenyl-2-picryl hydrazine) free radical-scavenging, superoxide anion scavenging, anti-superoxide anion formation and anti-lipid peroxidation abilities. The flavonol contents of all test samples were analyzed by high-performance liquid chromatography with an ultraviolet (HPLC-UV) detector. The results showed that there is a direct correlation of the flavonol content with the antioxidant activities from the extracts and fractions of C. chinensis. Moreover, the ethyl acetate fraction demonstrated significantly better and higher antioxidant effects, and also had a higher flavonol content than had the remaining samples (P<0.05). The water fractions, however, exhibited the weakest antioxidant activity, and had low concentrations of flavonols. Thus, we suggest that the ethanol extract of C. chinensis, but not its water extract, could be used as a dietary nutritional supplement to promote human health and prevent oxidation-related diseases, due to its antioxidant properties., (Copyright © 2007 Elsevier Ltd. All rights reserved.)

Cuscuta chinensis is a commonly used traditional Chinese medicine to nourish the liver and kidney. Due to the poor water solubility of its major constituents such as flavonoids and lignans, its absorption upon oral administration could be limited. The purpose of the present study was to use the nanosuspension method to prepare C. chinensis nanoparticles (CN), and to compare the hepatoprotective and antioxidant effects of C. chinensis ethanolic extract (CE) and CN on acetaminophen-induced hepatotoxicity in rats. An oral dose of CE at 125 and 250 mg/kg and CN at 25 and 50mg/kg showed a significant hepatoprotective effect relatively to the same extent (P<0.05) by reducing levels of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase. These biochemical assessments were supported by rat hepatic biopsy examinations. In addition, the antioxidant activities of CE and CN both significantly increased superoxide dismutase, catalase, glutathione peroxidase, and reduced malondialdehyde (P<0.05). Moreover, the results also indicated that the hepatoprotective and antioxidant effects of 50 mg/kg CN was effectively better than 125 mg/kg CE (P<0.05), and an oral dose of CN that is five times as less as CE could exhibit similar levels of outcomes. In conclusion, we suggest that the nanoparticles system can be applied to overcome other water poorly soluble herbal medicines and furthermore to decrease the treatment dosage.

The purpose of this study was to develop quercetin-loaded nanoparticles (QUEN) by a nanoprecipitation technique with Eudragit E (EE) and polyvinyl alcohol (PVA) as carriers, and to evaluate the antioxidant effects of quercetin (QU) and of its nanoparticles. The novel QUEN systems were characterized by particle size and morphology, yield and encapsulation efficiency, differential scanning calorimetry (DSC), powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), (1)H nuclear magnetic resonance ((1)H NMR), and dissolution study. It was observed that the weight ratio of QU:EE:PVA at 1:10:10 carried a particle size of <85 nm, a particle distribution with polydispersity index <0.3, and its yield and encapsulation efficiency were over 99%. The results from XRD and DSC of the QUEN showed that the crystal of the drug might be converted to an amorphous state. The FT-IR and (1)H NMR demonstrated that QU formed intermolecular hydrogen bonding with carriers. The release of the drug from the QUEN was 74-fold higher compared with the pure drug. In addition, the antioxidant activity of the QUEN was more effective than pure QU on DPPH scavenging, anti-superoxide formation, superoxide anion scavenging, and anti-lipid peroxidation.

Tu-Si-Zi, the seeds of Cuscuta chinensis Lam. (Convolvulaceae), is a traditional Chinese medicine that is commonly used to nourish and improve the liver and kidney conditions in China and other Asian countries. As oxidative stress promotes the development of acetaminophen (APAP)-induced hepatotoxicity, the aim of the present study was to evaluate and compare the hepatoprotective effect and antioxidant activities of the aqueous and ethanolic extracts of C chinensis on APAP-induced hepatotoxicity in rats. The C chinensis ethanolic extract at an oral dose of both 125 and 250mg/kg showed a significant hepatoprotective effect relatively to the same extent (P<0.05) by reducing levels of glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), and alkaline phosphatase (ALP). In addition, the same ethanolic extract prevented the hepatotoxicity induced by APAP-intoxicated treatment as observed when assessing the liver histopathology. Regarding the antioxidant activity, C chinensis ethanolic extract exhibited a significant effect (P<0.05) by increasing levels of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), and by reducing malondialdehyde (MDA) levels. In contrast, the same doses of the aqueous extract of C chinensis did not present any hepatoprotective effect as seen in the ethanolic extract, and resulted in further liver deterioration. In conclusion, these data suggest that the ethanolic extract of Cuscuta chinensis can prevent hepatic injuries from APAP-induced hepatotoxicity in rats and this is likely mediated through its antioxidant activities.

Nuzhenzi, the fruit of Ligustrum lucidum Ait. (Oleaceae), is commonly used as tonic for kidney and liver in the traditional Chinese medicine prescription. The present study aimed to investigate the antioxidant activities of ethanol extract of Ligustrum lucidum fruits (ELL) and its effects on butylated hydroxytoluene (BHT)-induced oxidative stress in rats. Results showed that ELL possesses weak antioxidant activities. Compared to the BHT (1000mg/kg)-treated group, results showed that ELL at 250, 500 and 1000mg/kg significantly reduced the levels of blood urea nitrogen (BUN), serum glutamic pyruvic transaminase (sGPT), glutamic oxaloacetic transaminase (sGOT), alkaline phosphatase (sALP), lactate dehydrogenase (LDH), triglyceride (TG) and creatinine (Cr), as well as LDH in bronchoalveolar lavage fluid (BALF). It also significantly decreased the level of lipid peroxides in liver and lung. In addition, ELL significantly enhanced the levels of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) in these organs. Histopathological evaluation of the tissues revealed that ELL reduced the incidence of lung lesions, while the liver and kidney tissues were not affected by BHT administration. Taken together, the protective effect of ELL against acute BHT-induced oxidative stress in rats could be through the upregulation of antioxidant enzymes.

Yin-Chiao-San (YCS), a kampo medicine, is widely used for patients with pulmonary disease and was applied for the treatment of SARS in Asia countries in 2003. For this reason, the present study investigated the preventive effect of YCS on bleomycin (BLM)-induced pulmonary fibrosis (PF) in rats. Animals were divided into four groups: (1) saline control group; (2) BLM-induced group, in which 15 mg/kg BLM was intraperitoneally injected three times per week for a period of 5 weeks; (3) BLM + vitamin E (10 mg/kg/day) as a positive group; (4) and BLM + YCS (1000 mg/kg/day). After 35 days, the rats were anesthetized, killed and then the lungs and bronchoalveolar lavage fluids (BALFs) were collected. The attenuation of pulmonary fibrosis was estimated according to the lung index, malondialdehyde (MDA), catalase (CAT), hydroxyproline (HP) and tumor necrosis factor-alpha (TNF-alpha) level in lung tissue and BALF. The serial sections of lung were stained with haematoxylin-eosin and Masson trichrome for histopathological observation of pulmonary fibrosis. The results indicated that YCS significantly reduced the lung index, MDA, HP and TNF-alpha, but YCS significantly enhanced the CAT level when compared with the BLM-induced group (p < 0.05). Additionally, the BLM group displayed severe histopathological change in the lung tissue, but YCS treatment could attenuate the BLM-induced PF. In conclusion, the results demonstrated that YCS possesses antioxidant and antiinflammatory activities and also inhibited collagen formation. Thus, YCS exhibited a preventive effect in BLM-induced PF and it is suggested that YCS may be applied to attenuate the side effects of BLM in chemotherapy.

The present study aimed to examine the antioxidant properties of Houttuynia cordata (HC) and its protective effect on bleomycin-induced pulmonary fibrosis in rats. Results showed that aqueous extract of HC exhibited a different magnitude of antioxidant activities in all model systems tested. Although HC showed weaker free radical scavenging and xanthine oxidase inhibitory activity than vitamin E, its anti-lipid peroxidation activity in rat liver homogenate was close to that of vitamin E. In animal studies, HC significantly decreased the levels of superoxide dismutase, malondialdehyde, hydroxyproline, interferon-gamma, and tumor necrosis factor-alpha. However, an increase in the concentration of catalase was noted in the bronchoalveolar lavage fluid. HC also remarkably improved the morphological appearance of the lung of bleomycin-treated rats. These results suggest that HC possesses a protective effect against bleomycin-induced pulmonary fibrosis. Interestingly, this protective effect was more pronounced than that of vitamin E. In conclusion, the protective effect of HC on pulmonary fibrosis could be partly associated with the reduction of oxidative damage caused by bleomycin.

Chai-Hu-Ching-Kan-Tang (CHCKT) is one of the traditional Chinese medicine prescriptions commonly used to treat liver diseases. In this study, we evaluated the hepatoprotective effects of aqueous CHCKT extract at various concentrations (125, 250 and 500 mg/kg body weight) on acetaminophen (APAP)-induced acute liver injury in rats. Results showed that CHCKT treatments significantly decreased the level of serum glutamic oxaloacetic transaminase (sGOT) and glutamic pyruvic transaminase (sGPT) in APAP-treated groups. CHCKT also significantly decreased the level of lipid peroxides and increased the activity of antioxidant enzymes (i.e. SOD and GPx). Histopathological observation further confirmed the hepatoprotective activity of CHCKT as indicated by the amelioration in the central necrosis and fatty changes of the liver after APAP induction. Interestingly, the hepatoprotective activity of CHCKT at concentrations 125~500 mg/kg appeared to be as good as 12.5 mg/kg silymarin (a commercial hepatoprotective agent). Taken together, these results suggest that aqueous extract of CHCKT possesses potent hepatoprotective effects agianst APAP-induced liver injury in rats.

The generation of oxygen radicals and lipid peroxidation may be factors in the cerebral damage secondary to ischaemia of the cerebrovascular disease, as in stroke. Five traditional Chinese medicinal prescriptions were investigated for their antioxidant activity: Shiee Fuu Jwu Iu Tang (TCMP1), Oh Yaw Shuen Chin Saan (TCMP2), Buu Yang Hwan Wuu Tang (TCMP3), Sheau Shiuh Ming Tang (TCMP4), and Chir Hwu Jia Long Guu Muu Lih Tang (TCMP5). Anti-lipid peroxidation, anti-superoxide formation and free radical scavenger activity were determined by the FeCl2--ascorbic acid-induced lipid peroxidation effects on lipids in-vitro, xanthine oxidase inhibition, cytochrome C system and an electron spin resonance spectrometer, respectively. The results showed that TCMP5 had greater anti-lipid peroxidation and anti-superoxide formation activity than the other prescriptions. TCMP4 had the greatest free radical scavenging effect, TCMP5 showed the greatest superoxide radical scavenger activity and TCMP3 showed the greatest hydroxyl radical scavenger activity. Tests were also performed to evaluate the effects of the five prescriptions on blood lipid in-vivo. The test showed that the prescriptions decreased the level of total cholesterol and LDL-cholesterol in serum in high cholesterol-fed rats. From these results, it seems probable that these prescriptions may be effective in the prevention and therapy of stroke and ischaemia.