Antioxidant and Neuroprotective Properties of Sour Tea (Hibiscus sabdariffa, calyx) and Green Tea (Camellia sinensis) on some Pro-oxidant-induced Lipid Peroxidation in Brain in vitro

Oxidative stress is the cause of neurodegenerative disorders such as Lou Gehrig’s disease, Parkinson’s disease, and Huntington’s disease; one practical way to prevent and manage neurodegenerative diseases is through the eating of food rich in antioxidants (dietary means). This present study sought to compare the ability of aqueous extract of sour tea (Hibiscus sabdariffa, calyx) and green tea (Camellia sinensis) to prevent some pro-oxidant [Fe (II), sodium nitroprusside, quinolinic acid]-induced lipid peroxidation in rat’s brain in vitro. Aqueous extracts of both teas were prepared (1 g tea in 100 ml of hot water). Thereafter, the ability of the extracts to prevent 25 μM FeSO₄, 7 μM sodium nitroprusside, and 1 mM quinolinic acid-induced lipid peroxidation in isolated rat’s brain tissue preparation was determined in vitro. Subsequently, the total phenol content, reducing power, Fe (II) chelating and OH radical scavenging ability were determined. The results of the study revealed that both teas significantly (P < 0.05) inhibit lipid peroxidation in basal and pro-oxidant-induced lipid peroxidation in the rat’s brain homogenates in a dose-dependent manner. Also, the teas had high total phenol content [sour (13.3 mg/g); green (24.5 mg/g)], reducing power, and Fe (II) chelating and OH radical scavenging ability (except sour tea). However, green tea had a significantly higher (P < 0.05) ability to inhibit lipid peroxidation in both the basal and pro-oxidant-induced lipid peroxidation in rat’s brain homogenates in vitro. Therefore, it is obvious from the study that both teas had high antioxidant properties and could inhibit Fe²⁺, sodium nitroprusside, and quinolinic acid-induced lipid peroxidation in brain. However, green tea had a higher inhibitory effect, which may probably be due to its high total phenol content, reducing power, Fe (II) chelating ability, and OH radical scavenging ability.     

Effectiveness and pesticide susceptibility of the pyrethroid-resistant predatory mite Amblyseius womersleyi in the integrated pest management of tea pests

To prevent the resurgence of the Kanzawa spider mite, Tetranychus kanzawai Kishida, on tea plants caused by the application of synthetic pyrethroid insecticides (SP), an SP-resistant strain of the predatory mite Amblyseius womersleyi Schicha was released onto tea bushes under SP (permethrin) application. The released predators successfully survived and may be able to suppress T. kanzawai. In the plot where A. womersleyi was released, the damage to new leaves was less severe than in the control plot and the predators remained resistant to the permethrin in the bushes. The selective use of pesticides that are harmless against natural enemies is necessary to achieve a program of integrated tea pest management. Although mortality of adult females of the tested strain in response to SP was from 6.5 to 89.3%, and mortality was more than 95% in response to several carbamate and organophosphate insecticides, usefulness of A. womersleyi as an agent of biological control was successfully demonstrated in the present study.     

Microwave‐assisted water extraction of green tea polyphenols

Introduction – Green tea, a popular drink with beneficial health properties, is a rich source of specific flavanols (polyphenols). There is a special interest in the water extraction of green tea polyphenols since the composition of the corresponding extracts is expected to reflect the one of green tea infusions consumed worldwide. Objective – To develop a microwave‐assisted water extraction (MWE) of green tea polyphenols. Methodology – MWE of green tea polyphenols has been investigated as an alternative to water extraction under conventional heating (CWE). The experimental conditions were selected after consideration of both temperature and extraction time. The efficiency and selectivity of the process were determined in terms of extraction time, total phenolic content, chemical composition (HPLC‐MS analysis) and antioxidant activity of the extracts. Results – By MWE (80°C, 30 min), the flavanol content of the extract reached 97.46 (± 0.08) mg of catechin equivalent/g of green tea extract, vs. only 83.06 (± 0.08) by CWE (80°C, 45 min). In particular, the concentration of the most bioactive flavanol EGCG was 77.14 (± 0.26) mg of catechin equivalent/g of green tea extract obtained by MWE, vs 64.18 (± 0.26) mg/g by CWE. Conclusion – MWE appears more efficient than CWE at both 80 and 100°C, particularly for the extraction of flavanols and hydroxycinnamic acids. Although MWE at 100°C typically affords higher yields in total phenols, MWE at 80°C appears more convenient for the extraction of the green tea‐specific and chemically sensitive flavanols. Copyright © 2009 John Wiley & Sons, Ltd.     

福安三种不同茶园节肢动物群落的消长动态调查

根据对福建福安的3种不同茶园（天香有机茶园、北门高山茶园和溪柄平地茶园）的节肢动物群落消长动态调查。并经多样性分析,结果获知：福安3种茶园节肢动物群落的物种丰富度（s）和多样性指数（H）的大小顺序依次为：天香（S=19．64,H=2．537）〉北门（S=18．01,H=2．502）〉溪柄（S=17．59,H=2．297）;而均匀度指数的大小顺序是：北门（J=0．621）〉天香（J=0．595）〉溪柄（J=0．559）。表明植被比较丰富、人为干扰较少的茶园,节肢动物群落的物种丰富度、多样性指数和均匀度指数较高,害、益虫群落易于保持较好的平衡状态,有利于减少（或不使用）化学农药、发展绿色无公害茶叶生产。     

Production of phenolic compounds in callus cultures of tea plant under the effect of 2,4-D and NAA

The effect of hormone-like compounds at different concentrations: 2,4-D (2 × 10^?6; 2 × 10^?5; and 2 × 10^?4M) and 1-NAA (2 × 10^?7; 2 × 10^?6; 2 × 10^?5; 4 × 10^?5, and 6 × 10^?5 M) on the growth and production of phenolic compounds, including flavans and lignin, was investigated in callus culture of tea plant (Camellia sinensis L., a highly productive strain IFR ChS-2). The growth of the culture was vigorous, and production of phenolic compounds therein was efficient in the medium containing 2 × 10^?5 M 2,4-D. Substitution of 1-NAA for 2,4-D in all the cases decelerated the growth of the culture. These changes were more pronounced when 2 × 10^?7 and 2 × 10^?6 M 1-NAA was used; in this case, biomass accumulation decreased by 1.5–2.0 times as compared with control material growing on the medium with 2 × 10^?5 M 2,4-D. In the presence of 1-NAA, the content of total soluble phenolic compounds and flavans in the calli rose by 30% on the average as compared with control material. Accumulation of lignin remained essentially the same. Therefore, the replacement of 2,4-D with 1-NAA in the nutrient medium used for the growing of highly productive strain of tea plant callus did not induce considerable changes in its ability to produce phenolic compounds.     

Altitudinal distribution of territorial Pallas’s Leaf Warblers (Phylloscopus proregulus) in Korea and its disruption by fir (Abies)-planting

Pallas’s Leaf Warbler (Phylloscopus proregulus) is a common breeding bird above 700 m in the forests of the Myohyang range, Korea. Within the largely natural forest are several temple gardens, four of which at 140–520 m held territorial Pallas’s Leaf Warblers. All had mature planted firs (Abies), which occur naturally in the area only over 1,000 m. The planted firs evidently stimulated the warblers to settle below their natural altitudinal range, but cannot be the only stimulus because the natural lower distribution of the warbler is 300 m below that of the tree.     

Rethinking the common garden in invasion research

In common garden experiments, a number of genotypes are raised in a common environment in order to quantify the genetic component of phenotypic variation. Common gardens are thus ideally suited for disentangling how genetic and environmental factors contribute to the success of invasive species in their new non-native range. Although common garden experiments are increasingly employed in the study of invasive species, there has been little discussion about how these experiments should be designed for greatest utility. We argue that this has delayed progress in developing a general theory of invasion biology. We suggest a minimum optimal design (MOD) for common garden studies that target the ecological and evolutionary processes leading to phenotypic differentiation between native and invasive ranges. This involves four elements: (A) multiple, strategically sited garden locations, involving at the very least four gardens (2 in the native range and 2 in the invaded range); (B) careful consideration of the genetic design of the experiment; (C) standardization of experimental protocols across all gardens; and (D) care to ensure the biosafety of the experiment. Our understanding of the evolutionary ecology of biological invasions will be greatly enhanced by common garden studies, if and only if they are designed in a more systematic fashion, incorporating at the very least the MOD suggested here.     

逆相蒸发法制备茶多酚脂质体及质量评价

采用逆相蒸发法制备茶多酚脂质体并进行质量评价。通过二次回归旋转组合设计优化茶多酚脂质体制备工艺及配方,对其形态、结构、粒径分布等性质进行考察。研究结果表明,最佳配方为m（大豆卵磷脂）：m（胆固醇）=3：1、茶多酚质量浓度为7mg／mL、V（有机相）：V（水相）=4：1、磷酸盐缓冲液浓度15mmoL／L,此条件下包封率为50．37％;所制备的茶多酚脂质体形态呈圆球形或椭球形,为大单室脂质体,有效粒径为165．3nm,Zeta电位为-69．3mV。逆相蒸发法制备茶多酚脂质体方法简单可行,所制备的脂质体具有一定缓释性。