Investigation on pollination approaches, reproductive biology and essential oil variation during floral development in German chamomile (Matricaria chamomilla L.)

German chamomile is an important medicinal and aromatic herb known for its blue essential oil. It lacks studies on anthesis, breeding systems and floral development with their impact on the essential oil. Therefore, the study investigated floral development and divided it into six reproductive stages (RS-1 to RS-6). The first four stages (5–6 days long) were identified as the floral enlargement and differentiation, followed by the fifth stage (10 days long) of three anthesis flushes, i.e., anther dehiscence, ray and disc florets' style branches flush. Anther dehiscence started 1–2 days before style branches flushes showed protandry and overlapped later with style branches flushes. Pollen production started from RS-3 and showed maximum viability (89%) at anther dehiscence (RS-5.1). Pollen showed dispersal through the air up to 0.7 m distance. Seed setting in controlled pollination experiments showed that removing disc florets could be successfully used as the emasculation alternate in German chamomile. The maximum essential oil content (0.40%) at the full blossomed floral stage (RS-4 &-5) suggested the right time for capitula harvesting. The findings on reproductive biology and breeding systems would offer several tools and techniques to support future breeding programs for genetic improvement of German chamomile.

Chamomile and Anise Cultivation in Olive Agroforestry Systems

Agroforestry systems have been practiced for hundreds of years with multiple benefits both environmentally and economically in terms of productivity. Olive cultivation is widespread in the countries of the Mediterranean basin, including Greece. Agroforestry practices are common in olive groves, but little research has been conducted on the productivity of such systems, especially with medicinal–aromatic plants (MAPs) as understory crops. Natural populations of MAPs can be found in various ecosystems, while some of them are cultivated. The purpose of this research was to study the effects of fertilization and shading both on yield and chemical composition of essential oils derived from chamomile (Matricaria recutita L.) and anise (Pimpinella anisum L.), grown in olive silvoarable systems. Fertilization and shading increased the plant height of chamomile and delayed the flowering. In addition, fertilization increased the concentration of α-bisabolol oxide A and (Z)–spiroether, and reduced the α-bisabolone oxide A and hamazulen. Shade also reduced α-bisabolone oxide A and hamazulen but increased the α-bisabolol oxide B. In the case of anise, fertilization increased plant height, decreased the concentration of limonene, and increased the concentration of E-anethole. Shading reduced plant height. Intercropping of olive trees with chamomile and anise yielded essential oils rich in the substances defined by the commercial specifications.

A Comprehensive Review on Biology, Genetic Improvement, Agro and Process Technology of German Chamomile (Matricaria chamomilla L.)

German chamomile (M. chamomilla) is recognized as a star herb due to its medicinal and aromatic properties. This plant is found across a wide range of climatic and soil conditions. Both the flower heads and blue essential oils of German chamomile possess several pharmacological properties of an anti-inflammatory, antimicrobial, antiseptic, antispasmodic and sedative, etc., nature, which makes it a highly sought after herb for use in many pharma and aroma industries. Chamomile tea, prepared from its flower heads, is also a well-known herbal tea for mind and body relaxation. Though it is a high-demand herb, farmers have not adopted this plant for large scale cultivation as a crop, which could improve their livelihood, due to the high cost in flower heads harvesting, loss in over mature and immature flower heads picking during harvesting, unavailability of varieties and agrotechnologies for machine harvesting, a lack of efficient process development of oil extraction and in the lack of improved stable varieties. There are many studies that have reported on the phytochemistry and pharmacological uses of chamomile, which further explore its importance in the medicine industry. Several studies are also present in the literature on its cultivation practices and plant ecology. However, studies on breeding behavior, genetic improvement, varietal development and mechanical harvesting are scarce in German chamomile. Hence, keeping in mind various aspects of farmers' and researchers' interest, earlier reports on taxonomy, floral biology, processing of oil extraction, active constituents, uses, agronomy, breeding challenges and opportunities in German chamomile are summarized in this review.

Target and non-target effects of Foeniculum vulgare and Matricaria chamomilla combined extract on Culex pipiens mosquitoes

The present study focused on extracting green larvicides from extracts of the combination of Foeniculum vulgare and Matricaria chamomilla using different solvents of increasing polarity in a Soxhlet extractor and evaluating their ovicidal, larvicidal, and cytotoxic activities. The most promising among all tested extracts was hexane extract. The ovicidal activity of the hexane PH2 extract resulted in a significant (p < 0.05) decrease in egg hatchability from 95.00 ± 6.16% to 15 ± 9.04% at doses ranging from 62.5 to 500 µg/mL. The larval mortality with the hexane extract ranged from 13.33 ± 3.3% to 93.33 ± 3.3% at doses ranging from 31.25 to 250 µg/mL, respectively. The LC₅₀ and LC₉₀ values of the larvicidal activity of the hexane extract were estimated to be 148.3 and 242.17 µg/mL, respectively, after 24 h of exposure. Similarly, the LC₅₀ values after 48 and 72 h of exposure were 124.93 and 100.3 µg/mL, respectively, against the third instar of Cx. pipiens. PH2 treatment of larvae resulted in histopathological changes such as degenerated epithelial cells and destruction of microvilli on the epithelial cells. The PH2 extract achieved a dose-dependent decrease in the rate of cell survival. The IC₅₀ value of PH2-treated HUVECs was 192.07 µg/mL after 24 h of incubation. The cells showed changes in cellular and nuclear morphology. In conclusion, the hexane extract of PH2 could be used in mosquito management programs.

Chemo-Diversity and Antiradical Potential of Twelve Matricaria chamomilla L. Populations from Iran: Proof of Ecological Effects

Matricaria chamomilla L. is a popular medicinal herb that is used for healing various diseases and is widely distributed worldwide in temperate climate zones, and even in the subtropical climate of Southern and Western Iran. This study was aimed at comparing the volatile oil constituents, along with antiradical potential and HPLC analysis of methanolic extracts from twelve plant samples growing in Iran. The present research was carried out for the first time on these populations. Among seventeen identified volatile chemicals evaluated by GC/MS and GC/FID, representing 92.73–97.71% of the total oils, α-bisabolone oxide A (45.64–65.41%) was the major constituent, except in case of “Sarableh” as a new chemotype, where (E)- and (Z)-γ-bisabolene (42.76 and 40.08%, respectively) were the predominant components. Oxygenated sesquiterpenes (53.31–74.52%) were the most abundant compounds in the samples excluding “Sarableh” with 91.3% sesquiterpene hydrocarbons. “Sarableh” also exerted the most potent antioxidant capacity with EC₅₀ = 7.76 ± 0.3 µg/mL and 6.51 ± 0.63 mmol TE (Trolox^® equivalents)/g. In addition, populations “Lali” and “Bagh Malek” contained the highest amounts of apigenin and luteolin with 1.19 ± 0.01 mg/g and 2.20 ± 0.0 mg/g of plant material, respectively. Our findings depict a clear correlation between phytochemical profiles and antiradical potential of M. chamomilla and geographical factors.

Optimization of the process of aromatic and medicinal plant maceration in grape marc distillates to obtain herbal liqueurs and spirits

BACKGROUND

Herbal liqueurs are alcoholic beverages produced by the maceration or distillation of aromatic and medicinal plants in alcohol, and are also highly valued for their medicinal properties. The process conditions, as well as the number and quantity of the plants employed, will have a great influence on the quality of the liqueur obtained. The aim of this research was to optimize these important variables.

RESULTS

A Box-Benhken experimental design was used to evaluate the independent variables: alcohol content, amount of plant and time during the experimental maceration of plants in grape marc distillate. Four plants were assessed, with the main compound of each plant representing the dependent variable evaluated with respect to following the evolution of the maceration process. Bisabolol oxide A in Matricaria recutita L., linalool in Coriander sativum L. and eucalyptol in Eucalyptus globulus Labill. were quantified using a gas chromatography-flame ionization detector. Glycyrrhizic acid in Glycyrrhiza glabra L was determined using a high-performance liquid chromatography-diode array detector. Other dependent variables were also evaluated: total phenolic content, color parameters and consumer preference (i.e. appearance).

CONCLUSION

The experimental designs allowed the selection of the optimal maceration conditions for each parameter, including the preference score of consumers: 70% (v/v) of ethanol, 40 g L^-1 plant concentration and a maceration process of 3 weeks. © 2016 Society of Chemical Industry.

Increase of Chamazulene and α-Bisabolol Contents of the Essential Oil of German Chamomile (Matricaria chamomilla L.) Using Salicylic Acid Treatments under Normal and Heat Stress Conditions

The chamazulene and α-(-)-bisabolol contents and quality of the chamomile oil are affected by genetic background and environmental conditions. Salicylic acid (SA), as a signaling molecule, plays a significant role in the plant physiological processes. The aim of this study was to evaluate the chemical profile, quantity, and improve the essential oil quality as a consequence of the increase of chamazulene and α-(-)-bisabol using salicylic acid under normal and heat stress conditions by the gas chromatography-mass spectrometry (GC-MS) technique. The factorial experiments were carried out during the 2011-2012 hot season using a randomized complete block design with three replications. The factors include four salicylic acid concentrations (0 (control), 10, 25 and 100 mg·L^-1), and three chamomile cultivars (Bushehr, Bona, Bodegold) were sown on two different planting dates under field conditions. Fourteen compounds were identified from the extracted oil of the samples treated with salicylic acid under normal and heat stress conditions. The major identified oil compositions from chamomile cultivars treated with salicylic acid were chamazulene, α-(-)-bisabolol, bisabolone oxide, β-farnesene, en-yn-dicycloether, and bisabolol oxide A and B. Analysis of variance showed that the simple effects (environmental conditions, cultivar and salicylic acid) and their interaction were significant on all identified compounds, but the environmental conditions had no significant effect on bisabolol oxide A. The greatest amount of chamazulene obtained was 6.66% at the concentration of 10 mg·L^-1 SA for the Bona cultivar under heat stress conditions, whereas the highest α-(-)-bisabolol amount attained was 3.41% at the concentration of 100 mg·L^-1 SA for the Bona cultivar under normal conditions. The results demonstrated that the application of exogenous salicylic acid increases the quantity and essential oil quality as a consequence of the increase of chamazulene and α-(-)-bisabolol under normal and heat stress conditions.

Himalayan Aromatic Medicinal Plants: A Review of their Ethnopharmacology, Volatile Phytochemistry, and Biological Activities

Aromatic plants have played key roles in the lives of tribal peoples living in the Himalaya by providing products for both food and medicine. This review presents a summary of aromatic medicinal plants from the Indian Himalaya, Nepal, and Bhutan, focusing on plant species for which volatile compositions have been described. The review summarizes 116 aromatic plant species distributed over 26 families.

Composition and Bioactivities of an (E)-β-Farnesene Chemotype of Chamomile (Matricaria Chamomilla) Essential Oil from Nepal

The essential oil of Matricaria chamomilla, collected from Nepal, was obtained by hydrodistillation and analyzed by gas chromatography – mass spectrometry. The major components in Nepalese chamomile oil were ( E)-β-farnesene (42.2%), α-bisabolol oxide A (22.3%), ( E,E)-α-farnesene (8.3%), cis-bicycloether (5.0%), α-bisabolol oxide B (4.5%), and α-bisabolone oxide A (4.0%). A cluster analysis based on the chemical compositions of 48 samples of chamomile oil reported in the literature has revealed seven chemotypes, and the oil from Nepal represents the ( E)-β-farnesene chemotype. The chamomile oil was screened for antimicrobial activity against Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, and Aspergillus niger, and toxicity toward MCF-7 breast tumor cells, Artemia salina, Chaoborus plumicornis, Caenorhabditis elegans, and Drosophila melanogaster.

Guaianolides and volatile compounds in chamomile tea

Chamomile (German Chamomile, Matricaria recutita L., Asteraceae) is one of the most popular medicinal plants in use as an herbal tea for food purposes and in folk medicine. Qualitative and semi-quantitative analyses of the volatile fraction of chamomile herbal tea were performed. Volatile constituents of the infusion were isolated by two different methods, namely hydrodistillation and solid phase extraction (SPE), and analysed by GC-MS. The relative proportions of particular chemical classes, present in the essential oil and volatile fractions of the infusion showed remarkable differences. The proportion of mono- and sesquiterpene hydrocarbons in the infusion, as compared to the essential oil, was significantly lower. Strikingly, the dichloromethane extract of the infusion contained a lower amount of bisabolol oxides and chamazulene, but higher amounts of spiroethers, sesquiterpene lactones and coumarins, as compared to the hydrodistillates of the herbal drug and the infusion. In addition to the previously known guaianolides matricarin and achillin, acetoxyachillin and leucodin (= desacetoxymatricarin), corresponding C-11 stereoisomers with various biological activities typically occurring in Achillea species, were identified in the dichloromethane extract of chamomile tea for the first time.

Psychopharmacological profile of Chamomile (Matricaria recutita L.) essential oil in mice

In this study, the effect of Matricaria recutita L. essential oil (MEO) on the central nervous system (CNS) of mice was investigated using some behavioral methods. Chemical profiling both by GC and GC-MS analyses of the hydrodistilled essential oil of M. recutita revealed α-bisabolol oxide A (28%), α-bisabolol oxide B (17.1%), (Z)-β-Farnesene (15.9%) and α-bisabolol (6.8%) as the main components. Changes induced by MEO (25, 50 and 100 mg/kg) and reference drug caffeine (25 mg/kg) in spontaneous locomotor activities and motor coordinations of mice were investigated by activity cage measurements and Rota-Rod tests, respectively. Open field, social interaction and elevated plus-maze tests were applied to assess the emotional state of the animals. Further, tail-suspension test was performed for evaluating the effect of MEO on depression levels of mice. As a result, at 50 and 100 mg/kg, MEO significantly increased the numbers of spontaneous locomotor activities, exhibited anxiogenic effect in the open field, elevated plus-maze and social interaction tests and decreased the immobility times of animals in tail suspension tests. The falling latencies in Rota-Rod tests did not change. This activity profile of MEO was similar to the typical psychostimulant caffeine. The exact mechanism of action underlying this stimulant-like effect should be clarified with further detailed studies.

Content and composition of the essential oil of Chamomilla recutita (L.) Rauschert from some European countries

Variations in the essential oil composition of Chamomilla recutita (L.) Rauschert from different European countries were determined. A total of 39 components were identified, representing over 92% of the total oil yield. The principal biologically active compounds in chamomile oils were bisabolol oxide A (3.1-56.0%), alpha-bisabolol (0.1-44.2%), bisabolol oxide B (3.9-27.2%), cis-enyne-bicycloether (8.8-26.1%), bisabolon oxide A (0.5-24.8%), chamazulene (0.7-15.3%), spathulenol (1.7-4.8%) and (E)-beta-farnesene (2.3-6.6%). In 8 chamomile samples from 13, bisabolol oxide A (27.5-56.0%) was predominant (among them in three Estonian samples). alpha-Bisabolol (23.9-44.2%) was predominant in the samples from Moldova, Russia and the Czech Republic. The sample from Armenia was rich in bisabolol oxide B (27.2%) and chamazulene (15.3%). The oils were obtained in yields of 0.7-6.7 mL kg(-1) and the minimum limit of 4 mL kg(-1) stated by the European Pharmacopoeia was exceeded only in 13 samples from 13 analysed drugs.