Comprehensive metabolic fingerprinting of Withania somnifera leaf and root extracts

Profiling of metabolites is a rapidly expanding area of research for resolving metabolic pathways. Metabolic fingerprinting in medicinally important plants is critical to establishing the quality of herbal medicines. In the present study, metabolic profiling of crude extracts of leaf and root of Withania somnifera (Ashwagandha), an important medicinal plant of Indian system of medicine (ISM) was carried out using NMR and chromatographic (HPLC and GC-MS) techniques. A total of 62 major and minor primary and secondary metabolites from leaves and 48 from roots were unambiguously identified. Twenty-nine of these were common to the two tissues. These included fatty acids, organic acids, amino acids, sugars and sterol based compounds. Eleven bioactive sterol-lactone molecules were also identified. Twenty-seven of the identified metabolites were quantified. Highly significant qualitative and quantitative differences were noticed between the leaf and root tissues, particularly with respect to the secondary metabolites.     

Molecular basis for cytokinin biosynthesis

Cytokinins (CKs) are a group of phytohormones that play a crucial role in the regulation of plant growth and development. Identification of the enzymes and the corresponding genes that are involved in CK metabolism allowed us to understand how plants synthesize CKs and adjust CK activity to optimal levels. A major accomplishment toward these goals was the identification of genes for the first enzyme in the CK biosynthetic pathway, adenosine phosphate-isopentenyltransferase (IPT). In Arabidopsis thaliana and Agrobacterium tumefaciens, detailed analyses of IPTs were conducted through not only enzymatic characterization but also molecular structural approaches. These studies revealed the molecular basis for the Agrobacterium-origin of IPT used for the efficient biosynthesis of trans-zeatin that promotes tumorigenesis in host plants. Another landmark in CK research was the identification of CYP735A as an enzyme that converts iP-nucleotide to tZ-nucleotide. Furthermore, the identification of a CK-activating enzyme, LOG, which catalyzes a novel activation pathway, is a remarkable recent achievement in CK research. Collectively, these advances have revealed the complexity of the entire metabolic scheme for CK biosynthesis.     

Ajuga remota Benth.: from ethnopharmacology to phytomedical perspective in the treatment of malaria

Treatment and control of malaria have become more difficult with the spread of drug-resistant parasites and insecticide-resistant mosquito vectors. In the search for new antimalarial drugs, ethnopharmacological sources should merit more attention. Establishing the safety of traditional herbal medicines, along with identifying their active principles, are essential steps in the production of a properly standardized and accessible herbal medicine. Phytochemical characterization could also serve as a base for the development of new chemical compounds. The genus of Ajuga belongs to the family Lamiaceae and contains at least 301 species. Many of these plants have been used in traditional medicine. Ajuga remota in particular is traditionally used as a herbal remedy for fever and infections, and is prescribed for malaria by 66% of the Kenyan herbalists. A large number of compounds have already been isolated from A. remota, including ergosterol-5,8-endoperoxide (6), ajugarin-I (1), 8-O-acetylharpagide (5) and several phytoecdysteroids. In vitro pharmacological studies have been conducted on constituents of A. remota of which some of them displayed a concentration-dependent inhibition of chloroquine-sensitive and -resistant Plasmodium falciparum and Mycobacterium tuberculosis. Inhibition of parasitaemia was demonstrated in mouse models with P. berghei, supporting the traditional use of the plant against malaria. In this state-of-the-art review, A. remota as a possible therapeutic tool for malaria is discussed.     

Ethnobotany,phytochemistry and pharmacology of Podocarpus sensu latissimo (s.l.)

The genus Podocarpus sensu latissimo (s.l.) was initially subdivided into eight sections. However, based on new information from different morphological and anatomical studies, these sections were recognised as new genera. This change in nomenclature sometimes is problematic when consulting ethnobotanical data especially when selecting plants for pharmacological screening, thus there is a need to clear any ambiguity with the nomenclature. Species of Podocarpus s.l. are important timber trees in their native areas. They have been used by many communities in traditional medicine and as a source of income. Podocarpus s.l. is used in the treatment of fevers, asthma, coughs, cholera, distemper, chest complaints and venereal diseases. Other uses include timber, food, wax, tannin and as ornamental trees. Although extensive research has been carried out on species of Podocarpus s.l over the last decade, relatively little is known about the African species compared to those of New Zealand, Australia, China and Japan. Phytochemical studies have led to the isolation and elucidation of various terpenoids and nor- and bis-norditerpenoid dilactones. Biflavonoids of the amentoflavone and hinokiflavone types have also been isolated. Nor- and bis-norditerpenes are said to be taxonomic markers for this genus. Recent in vitro and in vivo studies have shown antitumor, antimicrobial, anti-inflammatory, antioxidant, larvicidal, plant and insect growth regulation activities. Various studies have yielded important natural bioactive products and two of them are worth mentioning. Taxol, a significant anticancer agent has been isolated from Podocarpus gracilior and totarol, a diterpenoid isolated from various species and now commercially produced as a potent antibacterial and antioxidant agent. Findings from this review supports the use of an ethnobotanical and chemotaxonomical approach in selecting plants for pharmacological screening since most of the species in the different morphological groups have similar uses. Also the isolated compounds have chemotaxonomic value amongst the groups. Some of the biological activities identified from extracts and compounds isolated from Podocarpus s.l. support the rationale behind the medicinal uses of these species.     

A novel insight into the cost–benefit model for the evolution of botanical carnivory

Background The cost–benefit model for the evolution of botanical carnivory provides a conceptual framework for interpreting a wide range of comparative and experimental studies on carnivorous plants. This model assumes that the modified leaves called traps represent a significant cost for the plant, and this cost is outweighed by the benefits from increased nutrient uptake from prey, in terms of enhancing the rate of photosynthesis per unit leaf mass or area (A_N) in the microsites inhabited by carnivorous plants.Scope This review summarizes results from the classical interpretation of the cost–benefit model for evolution of botanical carnivory and highlights the costs and benefits of active trapping mechanisms, including water pumping, electrical signalling and accumulation of jasmonates. Novel alternative sequestration strategies (utilization of leaf litter and faeces) in carnivorous plants are also discussed in the context of the cost–benefit model.Conclusions Traps of carnivorous plants have lower A_N than leaves, and the leaves have higher A_N after feeding. Prey digestion, water pumping and electrical signalling represent a significant carbon cost (as an increased rate of respiration, R_D) for carnivorous plants. On the other hand, jasmonate accumulation during the digestive period and reprogramming of gene expression from growth and photosynthesis to prey digestion optimizes enzyme production in comparison with constitutive secretion. This inducibility may have evolved as a cost-saving strategy beneficial for carnivorous plants. The similarities between plant defence mechanisms and botanical carnivory are highlighted.     

Battle and balance at mucosal surfaces - The story of Shigella and antimicrobial peptides

Shigella is a major cause of morbidity and mortality for children in many developing countries. Emergence of antibiotic-resistance among Shigella demands the development of effective medicines. Antimicrobial peptides (AMPs) are expressed in phagocytes and at epithelial surfaces and are important effector molecules of innate immunity. We have found that pathogens are able to turn off the endogenous expression of AMPs, resulting in serious infections such as shigellosis. A therapeutic rationale to prevent microbial invasion would be to strengthen the epithelial line of defence through enhancing AMP expression. We have identified several inducers of AMP-production, including butyrate, phenylbutyrate and vitamin D, which have been investigated in animal models of shigellosis as well as in clinical trials. We believe that the conceptual framework presented here can be applied to additional clinical entities and that this novel approach can be an alternative or complement to traditional antibiotics in the future.     

Prenylated flavanones and flavanonols as chemical markers in Glycosmis species (Rutaceae)

Fifteen prenylated or geranylated flavanones and flavanonols were isolated from the leaf extracts of different Glycosmis species collected in Thailand and Malaysia. All structures were elucidated by spectroscopic methods, especially 1D and 2D NMR. Six compounds were described for the first time and two were only known so far as synthetic products. The chemotaxonomic significance of flavanoid accumulation within the genus Glycosmis is highlighted.     

A Novel Cell Death Gene Acts to Repair Patterning Defects in Drosophila melanogaster

Cell death is a mechanism utilized by organisms to eliminate excess cells during development. Here, we describe a novel regulator of caspase-independent cell death, Mabiki (Mabi), that is involved in the repair of the head patterning defects caused by extra copies of bicoid in Drosophila melanogaster. Mabiki functions together with caspase-dependent cell death mechanisms to provide robustness during development.     

Dynamics of progestogenic activity in serum following administration of Ligusticum chuanxiong

Many women are using botanical alternatives for menopausal hormone replacement therapy (HRT) because current progestins, compounds with progesterone activity, have adverse risk profiles. However the development of phyto-progestins for HRT is hampered by the absence of basic pharmacokinetic/pharmacodynamic (PK/PD) data due to the lack of methods to capture summated effects of the numerous compounds that contribute to bioactivity in vivo. In this study, we explored the utility of progesterone receptor (PR)-driven bioassays to track changes in serum progestogenic activity following administration of traditional Chinese medicinal herb, Ligusticum chuanxiong, with potent progestogenic activity. Sensitive and specific (>300-fold) increases in progestogenic activity were observed when HeLa cells transfected with PR and a PR-driven promoter were exposed to the progestogenic drug, medroxy-progesterone acetate (MPA), suggesting the utility of the bioassay to measure progestogenic effects for PK/PD studies. Progestogens were administered to male Sprague-Dawley rats and serum extracted for measurement of progestogenic activity. Effect-time studies indicate that injection of MPA and L. chuanxiong extract raised area-under-curve of progestogenic activity in sera by 8.2-fold (p<0.001) and 4.5-fold (p<0.01) respectively, compared to sera from rats administered vehicle only. Administration of MPA and L. chuanxiong extract by the oral route resulted in a 5.4 (p<0.001) and 2.3-fold (p=0.07) increase respectively. Our data suggest that PR-responsive reporter gene bioassays can measure bioavailability of compounds, known and unknown, of complex botanicals for hormone replacement therapy. L. chuanxiong extracts exert progestogenic activity in vivo, and may have utility for progesterone-replacement therapy.     

Qualitative and quantitative determination of major saponins in Paris and Trillium by HPLC-ELSD and HPLC–MS/MS

High-performance liquid chromatographic (HPLC) with evaporative light scattering detection (ELSD) and HPLC with electrospray ionization multistage tandem mass spectrometry (HPLC–ESI-MSⁿ) were used to identify and quantify steroid saponins in Paris and Trillium plants. The content of the known saponins such as Paris I, II, III, V, VI, VII, H, gracillin and protodioscin in Paris and Trillium plants was determined simultaneously using the developed HPLC-ELSD method. Furthermore, other 12 steroid saponins were identified by HPLC–ESI(+/−)-MSⁿ detection. In the end, a developed analytical procedure was proved to be a reliable and rapid method for the quality control of Paris and Trillium plants. In addition, the alternative resources for Paris yunnanensis used as a traditional Chinese medicine were discovered according to the hierarchical clustering analysis of the saponin fraction of these plants.     

Presence of polygodial and drimenol in Drimys populations from Chile

Drimys winteri (Winteraceae) is a tree with medicinal properties native to Chile. Its bark contains polygodial and drimenol in unknown quantities, with antimicrobial and antinociceptive activity. The purpose of the present study was to quantify polygodial and drimenol concentrations in leaves of five populations of D. winteri and one of Drimys andina from different regions of Chile, by GC analysis of the hexane extract. The concentration of these compounds was also determined in the bark of one of the D. winteri populations. In dried leaves mean concentrations of 0.99% for polygodial and 0.011% for drimenol could be observed, both differing significantly among the studied populations. It is concluded that polygodial and drimenol are present in the leaves and the bark of D. winteri and in D. andina leaves, this being the first report of the presence of these compounds in the latter species.     

Ethnoveterinary medicines used for horses in Trinidad and in British Columbia, Canada

This paper investigates the commonalities in ethnoveterinary medicine used for horses between Trinidad (West Indies) and British Columbia (Canada). These research areas are part of a common market in pharmaceuticals and are both involved in the North American racing circuit. There has been very little research conducted on medicinal plants used for horses although their use is widespread. The data on ethnoveterinary medicines used for horses was obtained through key informant interviews with horse owners, trainers, breeders, jockeys, grooms and animal care specialists in two research areas: Trinidad and British Columbia (BC). A participatory validation workshop was held in BC. An extensive literature review and botanical identification of the plants was also done. In all, 20 plants were found to be used in treating racehorses in Trinidad and 97 in BC. Of these the most-evidently effective plants 19 of the plants used in Trinidad and 66 of those used in BC are described and evaluated in this paper. Aloe vera, Curcuma longaand Ricinus communisare used in both research areas. More research is needed in Trinidad to identify plants that respondents claimed were used in the past. Far more studies have been conducted on the temperate and Chinese medicinal plants used in BC and therefore these ethnoveterinary remedies reflect stronger evidence of efficacy.     

空心莲子草响应南方菟丝子寄生的生长-防御权衡

为探讨全寄生植物南方菟丝子(Cuscuta australis)防治入侵植物空心莲子草(Alternanthera philoxeroides)的可行性,以二者野外天然生长的种群为研究对象,分析南方菟丝子寄生对空心莲子草生长及防御的影响,阐明空心莲子草在受到寄生胁迫时如何权衡自身生长与防御的关系,进而发展出一套应对南方菟丝子寄生的生长-防御策略。结果显示:(1)南方菟丝子寄生显著改变空心莲子草茎的形态,茎直径和平均节间长均增加,茎直径变化极显著(P0.01);(2)南方菟丝子寄生显著减少空心莲子草叶片数,但同时显著增加后者茎的分枝数,而茎上的节是潜在的无性繁殖体,故有利于空心莲子草的克隆繁殖;此外,南方菟丝子寄生显著降低了空心莲子草的根、茎、叶生物量和总生物量,抑制空心莲子草的生长;(3)南方菟丝子寄生显著增加空心莲子草茎的单宁、总酚、三萜皂苷含量,增强其防御能力;(4)南方菟丝子寄生的空心莲子草的生物量与茎部木质素、三萜皂苷、单宁和总酚含量均呈现显著负相关性(P0.01),对照组则不存在相关性;且寄生组较对照组相比,生物量的相对百分比显著低于对照组(P0.01),而用于防御的次生代谢产物总含量的相对百分比显著高于对照组(P0.01)。以上结果表明,受到南方菟丝子寄生胁迫后,空心莲子草改变自身的生长-防御策略,减少营养生长投入而将更多的资源投向克隆繁殖,同时增强对"防御"物质的投入,增强其防御能力,以利于后代生存和繁衍。     

Flower removal increases rhizome mass in natural populations of Alstroemeria aurea (Alstroemeriaceae)

Plant architecture and phenotypic plasticity under natural conditions remain little known for many rhizomatous species. This study evaluates, in situ, the plastic responses of Alstroemeria aurea plants from three Patagonian populations to flower or flowering-shoot removal. The size and architecture of treated and untreated plants were assessed. Nutrient contents (N, P and K) were evaluated for rhizomes and roots developed in two successive years. Those plants that were deprived of their inflorescences developed, on average, a heavier rhizome than both control plants and plants from which flowering shoots had been removed. Neither of the two treatments applied altered the number of metamers or the branching pattern of the rhizomes. The contents of N, P and K were higher in rhizomes than in roots. In summer, nutrients were more concentrated in inflorescences and the new rhizome segment than in the rhizome segment developed in the previous year. The idea that fruiting failure in A. aurea promotes resource re-assignment from aerial shoots to rhizomes without altering the architecture of plants is supported. The development of the underground portion of aerial shoots in late summer-autumn allows A. aurea plants to take full advantage of short growth periods, but would impose a limit to plasticity.     

Isolation of anti-Candida albicans compounds from Markhamia obtusifolia (Baker) Sprague (Bignoniaceae)

An increase in clinical cases of Candidiosis globally as well as fungal resistance to drugs prompted the search for novel anti-Candida albicans agents from plant sources. Leaf extracts of Markhamia obtusifolia were screened for activity against C. albicans in vitro. An acetone extract obtained following serial exhaustive extraction contained mainly the active components with at least four active zones on the bioautogram. Bioassay guided fractionation of this extract led to the isolation of three compounds which inhibited the growth of three C. albicans strains. Based on spectroscopy studies (NMR and MS), the compounds were identified as 3β-hydroxyurs-12-en-28-oic acid, ursolic acid (1) 3β, 19α-dihydroxyurs-12-en-28-oic acid, pomolic acid (2) and 2β, 3β, 19α -trihydroxy-urs-12-en-28-oic acid, 2-epi-tormentic acid (3). The most active compound was 3β, 19α-dihydroxy-12-ursen-28-oic acid (2) with a minimum inhibitory concentration (MIC) value of 12.5 µg/mL for C. albicans isolated from dog and 25.0 µg/mL for C. albicans from cat and ATCC 90028 at 24 h following incubation. However, at 48 h of incubation MICs were > 400 µg/mL for all the three compounds isolated. This study indicated that M. obtusifolia could be a potential source of active principles against C. albicans.