The geranium genus: A comprehensive study on ethnomedicinal uses, phytochemical compounds, and pharmacological importance

The geranium genus consists of about 400 species, which have been utilized for a long time in ancient medical practices throughout the world. As a result, herbal medications based on species are commonly utilized to treat a range of illnesses. This investigation aims to provide an extensive assessment of the literature on the phytochemistry, ethnomedicinal and pharmacological importance of the genus Geranium. Data were collected through systemic computer searches among the most reputable scientific databases, Web of Science, Google Scholar, and Scopus. Occasionally, information published as peer-reviewed literature was added to data from sources that these databases do not include. This review includes all published works through the end of 2022. The assessment of the biological characteristics of medicinal plant species in the genus Geranium has received a great deal of attention, primarily in the last 20 years, in tandem with the growing interest in herbal remedies in general. The detailed and systematic comparative analysis presented here provides valuable information on the current Geranium species. It paves the way for other beneficial species of Geranium to be studied in the fields of ethnobotany, phytochemistry, and new drug discovery.

Botany, ethnopharmacology, phytochemistry and pharmacology of Erodii Herba Geranii Herba-An review

ETHNOPHARMACOLOGICAL RELEVANCE

As a commonly used traditional Chinese herbal medicine, Erodii Herba Geranii Herba (Geranium wilfordii Maxim., Geranium carolinianum L. and Erodium stephanianum Willd.), which was known as Laoguancao (Chinese:), has high medicinal value. It has been used to dispel rheumatism, dredge the meridians, activate blood circulation, remove blood stasis, clear heat and detoxify, and stop diarrhea and dysentery. It's also used to treat eczema, sores, carbuncles, boils caused by accumulation of damp toxin.

AIM OF THE REVIEW

This review aimed to provide a systematic and comprehensive analysis of the current research progress in terms of the botany, ethnopharmacology, phytochemistry and pharmacological activities of Erodii Herba Geranii Herba, and discuss expectations for prospective research and implementation about this herb.

MATERIALS AND METHODS

Information on Erodii Herba Geranii Herba was gathered via the Internet (using Google Scholar, Baidu Scholar, Pubmed, Elsevier, ACS, Medline Plus, CNKI and Web of Science) and libraries. Additionally, information was also obtained from local books and brilliant scholars in ethnopharmacology.

RESULTS

More than isolated 240 chemical compounds were recorded, and main compositions are tannins, flavones, organic acids and volatile oil. The pharmacoactives of Erodii Herba Geranii Herba and its active constituents are diverse, including antibacterial, antiviral, antioxidant, liver and kidney protection, anti-inflammatory and analgesic, other activities. Among them, the antibacterial, antiviral, anti-inflammatory, analgesic, antidiarrheal and other pharmacological activities of it are consistent with traditional applications.

CONCLUSIONS

All kinds of research conducted on Erodii Herba Geranii Herba, especially in field of ethnopharmacological use, phytochemicals and pharmacology have been reviewed. There are plenty of active compounds with varied effects in Erodii Herba Geranii Herba. However, some traditional applications and pharmacological activities of Erodii Herba Geranii Herba have not been scientifically evaluated or convincing due to incomplete methods and ambiguous results, as well as the lack of clinical data. In order to verify the pharmacological activity, clinical efficacy and safety of it, a systematic and comprehensive research evaluation is also required. As an important traditional Chinese medicine, Erodii Herba Geranii Herba should be further explored to promote the development of new drugs and therapeutics for various diseases. How to make better use of it should be paid more attention to.

Pollen-feeding behavior of diverse insects on Geranium delavayi, a flower with large, accessible pollen grains

PREMISE

Why have pollen grains evolved to be exceptionally large in some species? Pollen-feeding hypothesis suggests that if the proportion of pollen amounts for feeding is reduced in a flower, the low allocation to pollen number would allow pollen grains to be larger.

METHODS

To examine whether species with large pollen grains experience low pollen consumption, the behavior of insects feeding on nectar and pollen was observed and pollen transfer efficiency was estimated for four visitor types in Geranium delavayi. To see whether bees actively collected pollen, the numbers of grains in pollen baskets and on the body were compared. Both nutritional value (total protein and lipid) and chemical defense (phenolic metabolites) in pollen against pollen feeders were measured.

RESULTS

Bumblebees and honeybees foraged for nectar, rarely groomed pollen into corbiculae, and had >5× higher pollen transfer efficiency than smaller solitary bees and flies, which were pollen eaters that removed more pollen but deposited less. Pollen grains were characterized by low protein and high lipid content with a low protein-lipid ratio, an unfavorable combination for bumblebees. Three secondary metabolites were significantly higher in pollen grains (7.77 mg/g) than in petals (1.08 mg/g) or in nectar (0.44 mg/g), suggesting stronger chemical defense in pollen.

CONCLUSIONS

Our results indicated that large bees took nectar but little of the nutritionally poor and highly toxic pollen. These data support one prediction of the pollen-feeding hypothesis, that species with few and large pollen grains would also have low pollen-consumption rates.

An automated pipeline for supervised classification of petal color from citizen science photographs

PREMISE

Petal color is an ecologically important trait, and uncovering color variation over a geographic range, particularly in species with large distributions and/or short bloom times, requires extensive fieldwork. We have developed an alternative method that segments images from citizen science repositories using Python and k-means clustering in the hue-saturation-value (HSV) color space.

METHODS

Our method uses k-means clustering to aggregate like-color pixels in sample images to generate the HSV color space encapsulating the color range of petals. Using the HSV values, our method isolates photographs containing clusters in that range and bins them into a classification scheme based on user-defined categories.

RESULTS

We demonstrate the application of this method using two species: one with a continuous range of variation of pink-purple petals in Geranium maculatum, and one with a binary classification of white versus blue in Linanthus parryae. We demonstrate results that are repeatable and accurate.

DISCUSSION

This method provides a flexible, robust, and easily adjustable approach for the classification of color images from citizen science repositories. By using color to classify images, this pipeline sidesteps many of the issues encountered using more traditional computer vision applications. This approach provides a tool for making use of large citizen scientist data sets.

Anti-mosquito properties of Pelargonium roseum (Geraniaceae) and Juniperus virginiana (Cupressaceae) essential oils against dominant malaria vectors in Africa

Background

More than 90% of malaria cases occur in Africa where the disease is transmitted by Anopheles gambiae and Anopheles arabiensis. This study evaluated the anti-mosquito properties of Juniperus virginiana (JVO) and Pelargonium roseum (PRO) essential oils (EOs) against larvae and adults of An. gambiae sensu lato (s.l.) from East Africa in laboratory and semi-field conditions.

Methods

EOs was extracted from the aerial green parts of Asian herbs by hydrodistillation. Their constituents were characterized by gas chromatography-mass spectrometry (GC-MS). Larvicidal activities of JVO, PRO, and PRO components [citronellol (CO), linalool (LO), and geraniol (GO)] were investigated against An. gambiae sensu stricto (s.s.). The percentage of knockdown effects and mortality rates of all oils were also evaluated in the adults of susceptible An. gambiae s.s. and permethrin-resistant An. arabiensis.

Results

GC-MS analyses identified major constituents of JVO (sabinene, dl-limonene, β-myrcene, bornyl acetate, and terpinen-4-ol) and PRO (citronellol, citronellyl formate, L-menthone, linalool, and geraniol). Oils showed higher larvicidal activity in the laboratory than semi-field trials. The LC₅₀ values for JVO/PRO were computed as 10.82–2.89/7.13–0.9 ppm and 10.75–9.06/13.63–8.98 ppm in laboratory and semi-field environments, respectively at exposure time of 24–72 h. The percentage of knockdown effects of the oils were also greater in An. gambiae s.s. than in An. arabiensis. Filter papers impregnated with JVO (100 ppm) and PRO (25 ppm) displayed 100% mortality rates for An. gambiae s.s. and 3.75% and 90% mortality rates, for An. arabiensis populations, respectively. Each component of CO, LO, and GO exhibited 98.13%, 97.81%, and 87.5%, respectively, and a mixture of the PRO components indicated 94.69% adult mortality to permethrin-resistant An. arabiensis.

Conclusions

The findings of this study show that PRO and its main constituents, compared to JVO, have higher anti-mosquito properties in terms of larvicidal, knockdown, and mortality when applied against susceptible laboratory and resistant wild populations of An. gambiae s.l. Consequently, these oils have the potential for the development of new, efficient, safe, and affordable agents for mosquito control.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-022-04220-8.

f.: A Good Gift from the Natural Treasure

This study focused on the biological evaluation and chemical characterization of Geranium pyrenaicum Burm. f. Different solvent extracts (hexane, ethyl acetate, methanol, and water extracts) were prepared. The phytochemical profile, antioxidant, and enzyme inhibitory activity were investigated. Cytotoxicity was assessed using VERO, FaDu, HeLa and RKO cells. The antiviral activity was carried out against HSV-1 (Herpes simplex virus 1) propagated in VERO cell line. The aqueous extract, possessing high phenolic content (170.50 mg gallic acid equivalent/g extract), showed the highest reducing capacity (613.27 and 364.10 mg Trolox equivalent/g extract, for cupric reducing antioxidant capacity and ferric reducing antioxidant power, respectively), radical scavenging potential (469.82 mg Trolox equivalent/g extract, against 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), metal chelating ability (52.39 mg ethylenediaminetetraacetic acid equivalent/g extract) and total antioxidant capacity (3.15 mmol Trolox equivalent/g extract). Liquid chromatography-electrospray ionization-quadrupole time-of-flight-mass spectrometry (LC-ESI-QTOF-MS/MS) alloved to tentatively identify a total of 56 compounds in the extracts, including ellagitannins, gallic acid and galloyl derivatives amongst others. The ethyl acetate extracts substantially depressed cholinesterase enzymes (4.49 and 12.26 mg galantamine equivalent/g extract against AChE and BChE, respectively) and α-amylase enzyme (1.04 mmol acarbose equivalent/g extract). On the other hand, the methanolic extract inhibited tyrosinase (121.42 mg kojic acid equivalent/g extract) and α-glucosidase (2.39 mmol acarbose equivalent/g extract) activities. The highest selectivity towards all cancer cell lines (SI 4.5-10.8) was observed with aqueous extract with the FaDu cells being the most sensitive (CC50 40.22 µg/mL). It can be concluded that the presence of certain bioactive antiviral molecules may be related to the high anti HSV-1 activity of the methanolic extract. This work has generated vital scientific data on this medicinal plant, which is a prospective candidate for the creation of innovative phyto-pharmaceuticals.

Identification of a novel endornavirus in Geranium carolinianum and occurrence within three agroecosystems

A putative endornavirus was detected in Carolina geranium (Geranium carolinianum) in Louisiana, USA. The virus was provisionally named Geranium carolinianum endornavirus 1 (GcEV1). The viral RNA was sequenced, and it consisted of 14,625 nt containing a single ORF coding a putative polyprotein of 4815 aa with conserved domains for a helicase 1, peptidase C97, glycosyl transferase GTB-type, and RNA-dependent RNA polymerase 2. The 5'end consisted of 130 nt while the 3'end consisted of 54 nt ending in nine cytosine residues. The closest relative to GcEV1 was Phaseolus vulgaris endornavirus 3. In phylogenetic analyses, GcEV1 clustered with members of the genus Alphaendornavirus. GcEV1 was detected in 57 of 60 G. carolinianum plants collected from three distinct agroecosystems. The virus was not detected in eight other species of the genus Geranium. There was no association of a particular phenotypic trait of the host with the presence or absence of the virus. GcEV1 was transmitted at a rate of 100% in seeds of a self-pollinated G. carolinianum plant.

Neurobehavioral, apoptotic, and DNA damaging effects of sub-chronic profenofos exposure on the brain tissue of Cyprinus carpio L.: Antagonistic role of Geranium essential oil

Currently, the contamination of water with different insecticides like profenofos (PFF) is a critical concern in the aquatic ecosystem. There are limited studies available on the negative impacts of PFF on common carp fish (Cyprinus carpio L.). Therefore, the existing study was designed to investigate the effect of PFF exposure (1/10 of the 96 h-LC50) on the neurobehavior, growth performance, chemical composition, oxidative status, DNA damage, apoptotic status and histological indices of the brain and gill tissues. In addition, this study seeks to detect the ability of geranium essential oil (GEO) dietary supplementation to mitigate the negative impacts of PFF. Accordingly, a total of 120 healthy fish were divided into four groups: the control group, fed on basal diet only; the other groups were fed on a basal diet supplemented with 400 mg kg^-1 GEO, basal diet and PFF in water (PFF group), and supplemented diet with GEO and PFF in water (GEO + PFF), respectively, for 60 days. The results showed that PFF significantly reduced fish growth performance, crude protein, and lipid contents. It caused several behavioral alterations including spiral movement, decreased activeness, and changes in feeding behavior. Moreover, PFF increased the DNA tail length, tail moment, and the level of 8-hydroxy-2'-deoxyguanosine. Histologically, PFF induced a wide array of circulatory, inflammatory, regressive and progressive alterations in the brain and gill tissues. PFF significantly downregulated Bcl-2 and upregulated caspase-3 immuno-expression in both organs. Further, it considerably depleted the antioxidant enzymes, including superoxide dismutase, catalase, and glutathione peroxidase. The GEO supplementation did not reach the respective control values but markedly improved most of the behavioral, physical, biochemical, oxidative, apoptotic, and inflammatory markers, altered by PFF exposure. It also protected the gill and brain tissues from the branchial and encephalopathic effects of PFF. These findings suggest that GEO dietary supplements could be advantageous for mitigating PFF negative impacts and presenting a promising feed additive for common carp in aquaculture.

Species from Vlasina Plateau (South Eastern Serbia)

Geranium species are widely used in traditional medicine of Balkan. The aim of this work was to investigate and compare chemical composition of volatile fractions obtained by hydrodistillation from aerial parts of G. macrorrhizum, G. phaeum, G. sanguineum, G. robertianum, G. palustre, G. pyrenaicum, G. columbinum and G. lucidum as well as from underground parts of G. macrorrhizum and G. phaeum, originated from Vlasina plateau in South Eastern Serbia. The volatiles were analyzed using GC/MS and GC-FID. G. palustre volatiles have been studied for the first time with β-selinene (18.6 %) as a characteristic compound. The cluster analysis revealed separation of volatiles into two main groups. Volatile fractions of G. macrorrhizum were separated from all other samples due to high sesquiterpene content (92.3 % in aerial and 94.6 % in underground parts). The volatile fractions of other samples were mainly composed of sesquiterpenes (10.8-61.8 %), diterpenes (12.9-43.0 %) and fatty acids and their derivatives (6.6-21.6 %) with the exception of volatile fraction of G. phaeum underground parts which was dominated only by fatty acids and their derivatives (76.6 %). The results presented in this article contribute to the knowledge on the chemistry of this genus and advances the knowledge on flora of southeast Serbia.

(Geraniaceae)

Rose-scented geranium, Pelargonium graveolens L'Hérit. (Geraniaceae), is an economically important plant. GC-MS analysis of the essential oil, prepared by hydro-distillation from this plant species, showed the presence of iso-menthone (15.71%), epi-α-cadinol (15.49%), iso-menthol (6.46%), geranyl formate (6.22%), geraniol (6.16%) and citronellol (5.53%). The composition of the absolute prepared by solvent extraction was compared to that of the essential oil. Change in citronellol to geraniol ratio in the absolute was monitored during leaf development. Estimation of the ratio of the two compounds was carried out using ¹H NMR spectroscopy. Geraniol content was highest in young leaves and citronellol content increased with increase in leaf age. Meta-analysis of the essential oil constituents reported from different countries was carried out. Menthone and isomenthone as well as citronellol and geraniol were negatively correlated. A significantly positive correlation was found between geraniol and linalool.

species Using Scanning Electron Microscopy

Macro and micromorphology of different parts that is, sepals, petals, flowers, indumentum, and leaf shape of 22 Geranium L. taxa from Iran were studied. These taxa representing the eight sections of the genus as sect. Dissecta, sect. Geranium, and sect. Tuberosa (of subgen. Geranium); sect. Batrachioidea, sect. Divaricata, sect. Lucida, sect. Ruberta and sect. Trilopha (of subgen. Robertium), that were collected from different geographical habitats of Iran. The biometric study involved 27 quantitative and 33 qualitative characters which were studied by use of stereomicroscopy and scanning electron microscopy (SEM). Statistical analyses were done by use of PAST software. Principal Component Analysis defined the most variable characters. Results showed that the diagnostic features were; length, width, apex of sepals, petals, trichomes type in pedicles and sepals along with their density, the shape length and width of leaves. In general, the present study revealed that the species could be differentiated by macro and micro-morphological characters. Taxa of two subgenera were clearly separated based on selected characters. These characters were found useful for the taxonomic identification and species delimitation in almost all taxa studied at the sub generic level, although some species of section Geranium and section Dissecta are mixed and nested in both subgenea.

Organ-specific phytohormone synthesis in two Geranium species with antithetical responses to far-red light enrichment

Plants growing in high densities experience a reduced red (R) to far-red (FR) light ratio and shade-intolerant species respond with accelerated elongation growth to reach the top of the canopy: the shade avoidance syndrome (SAS). FR-enriched light inactivates phytochrome photoreceptors, which results in subsequent action of several plant hormones regulating growth. SAS is adaptive for shade-intolerant plants, but is suppressed in shade-tolerant plant species. Inspired by a previously published transcriptome analysis, we use two species of the genus Geranium here to study the involvement of auxin, brassinosteroids (BRs), and gibberellins (GAs) in supplemental FR-induced elongation growth. G. pyrenaicum, a shade-avoiding species, strongly induces auxin and gibberellin levels, but not BR, in elongating petioles. We show that, in this species, FR light perception, hormone synthesis, and growth are local and restricted to the petiole, and not the leaf lamina. Using chemical hormone inhibitors, we confirm the essential role of auxin and GAs in supplemental FR-induced elongation growth. Shade-tolerant G. robertianum does not display the change in hormone levels upon FR light enrichment, resulting in the lack of a shade avoidance response.

Evaluation of four commercial natural products for repellency and toxicity against the lone star tick, Amblyomma americanum (Acari: Ixodidae)

Lone star ticks are aggressive ectoparasites of domestic and wild animals, as well as humans. These ticks can transmit many pathogens that cause disease including Erhlichia and tularemia. Common compounds used for personal protection and area sprays are N-diethyl-3-methyl benzamide (DEET) and permethrin, but public concern over personal and environmental safety require the development of new, safer products. In the current study, four commercially available products (Wondercide, Essentria IC³, Vet's Best, and Mosquito Barrier) were tested for both repellent and toxic effects against lone star tick nymphs and adults. Overall, all four products were more effective against nymphs than against adults. Wondercide and Essentria IC³ were as toxic to nymphs as permethrin at concentrations of 3.13% and higher, and as repellent as DEET at all concentrations. Nymphs were also repelled by Mosquito Barrier and Vet's Best, but these products had about half or less of the repellent effects of Wondercide and Essentria IC³ at most of the concentrations. Adult ticks were repelled similarly by all products at all tested concentrations, but at lower levels than nymphs. Toxicity of the four tested products on adults was similar at concentrations of 12.5% and below, less than half of what was observed with permethrin with declining effectiveness as concentrations decreased. Overall, these four products may offer a natural way to repel lone star ticks, but further field testing is needed to determine rates of application and residual activity.

The relationship between nectaries and floral architecture: a case study in Geraniaceae and Hypseocharitaceae

BACKGROUND AND AIMS

Flowers of Geraniaceae and Hypseocharitaceae are generally considered as morphologically simple. However, previous studies indicated complex diversity in floral architecture including tendencies towards synorganization. Most of the species have nectar-rewarding flowers which makes the nectaries a key component of floral organization and architecture. Here, the development of the floral nectaries is studied and placed into the context of floral architecture.

METHODS

Seven species from Geraniaceae and one from Hypseocharitaceae were investigated using scanning electron microscopy and light microscopy. Samples were prepared and processed using standard protocols.

KEY RESULTS

The development of the nectary glands follows the same trajectory in all species studied. Minor differences occur in the onset of nectarostomata development. The most striking finding is the discovery that a short anthophore develops via intercalary growth at the level of the nectary glands. This anthophore lifts up the entire flower apart from the nectary gland itself and thus plays an important role in floral architecture, especially in the flowers of Pelargonium. Here, the zygomorphic flowers show a particularly extensive receptacular growth, resulting in the formation of a spur-like receptacular cavity ('inner spur'). The nectary gland is hidden at the base of the cavity. Various forms of compartmentalization, culminating in the 'revolver flower' of Geranium maderense, are described.

CONCLUSIONS

Despite the superficial similarity of the flowers in Geraniaceae and Hypseocharitaceae, there is broad diversity in floral organization and floral architecture. While the receptacular origin of the spur-like cavity in Pelargonium had already been described, anthophore formation via intercalary growth of the receptacle in the other genera had not been previously documented. In the context of the most recent phylogenies of the families, an evolutionary series for the floral architecture is proposed, underscoring the importance of synorganization in these seemingly simple flowers.

Performance of rose scented geranium (Pelargonium graveolens) in heavy metal polluted soil vis-à-vis phytoaccumulation of metals

An investigation was carried out to evaluate the effect of heavy metal toxicity on growth, herb, oil yield and quality and metal accumulation in rose scented geranium (Pelargonium graveolens) grown in heavy metal enriched soils. Four heavy metals (Cd, Ni, Cr, and Pb) each at two levels (10 and 20 mg kg-1 soil) were tested on geranium. Results indicated that Cr concentration in soil at 20 mg kg-1 reduced leaves, stem and root yield by 70, 83, and 45%, respectively, over control. Root growth was significantly affected in Cr stressed soil. Nickel, Cr, and Cd concentration and accumulation in plant increased with higher application of these metals. Chromium, nickel and cadmium uptake was observed to be higher in leaves than in stem and roots. Essential oil constituents were generally not significantly affected by heavy metals except Pb at 10 and 20 ppm, which significantly increased the content of citronellol and Ni at 20 ppm increased the content of geraniol. Looking in to the higher accumulation of toxic metals by geranium and the minimal impact of heavy metals on quality of essential oil, geranium can be commercially cultivated in heavy metal polluted soil for production of high value essential oil.

Evolutionary histories determine DNA barcoding success in vascular plants: seven case studies using intraspecific broad sampling of closely related species

Background

Four plastid regions, rpoB, rpoC1, matK, and trnH-psbA, have been recommended as DNA barcodes for plants. Their success in delimiting species boundaries depends on the existence of a clear-cut difference between inter- and intraspecific variability. We tested the ability of these regions to discriminate among closely related species in seven genera of flowering plants with different generation times (trees, perennials, and annuals). To ensure a maximum coverage of intraspecific diversity, and therefore to better evaluate the resolution power of each barcode, we applied a population genetics approach by sampling three to 45 individuals per species over a wide geographical range.

Results

All possible combinations between loci were analysed, which showed that using more than one locus does not always improve the resolution power. The trnH-psbA locus was most effective at discriminating among closely related species (Acer, Lonicera, Geranium, and Veronica), singly or in combination. For Salix, Adenostyles, and Gentiana, the best results were obtained with the combination of matK, rpoB, and trnH-psbA. No barcoding gap was found within six genera analysed, excepting Lonicera. This is due to shared polymorphisms among species, combined with very divergent sequences within species. These genetic patterns reflect incomplete lineage sorting and hybridization events followed by chloroplast capture.

Conclusions

Our results strongly suggest that adding trnH-psbA to the two obligate DNA barcodes proposed by the CBOL plant-working group (matK and rbcL) should be mandatory for closely related species. In our sampling, generation time had no influence on DNA barcoding success, as the best and worst identification successes were found for the two tree genera (Acer, 64 % success and Salix, 86 % failure). Evolutionary histories are the main factor influencing DNA barcoding success in the studied genera.

Electronic supplementary material

The online version of this article (doi:10.1186/s12862-016-0678-0) contains supplementary material, which is available to authorized users.

Effect of Inhalation of Aroma of Geranium Essence on Anxiety and Physiological Parameters during First Stage of Labor in Nulliparous Women: a Randomized Clinical Trial

INTRODUCTION

Anxiety increases significantly during labor, especially among nulliparous women. Such anxiety may affect the progress of labor and physiological parameters. The use of essential oils of aromatic plants, or aromatherapy, is a non-invasive procedure that can decrease childbirth anxiety. This study examined the effect of inhalation of the aroma of geranium essential oil on the level of anxiety and physiological parameters of nulliparous women in the first stage of labor.

METHODS

In study, was carried out on 100 nulliparous women admitted to Bent al-Hoda Hospital in the city of Bojnord in North Khorasan province of Iran during 2012-2013. The women were randomly assigned to two groups of equal size, one experimental group (geranium essential oil) and one control (placebo) group. Anxiety levels were measured using Spielberger' questionnaire before and after intervention. Physiological parameters (systolic and diastolic blood pressure, respiratory rate, pulse rate) were also measured before and after intervention in both groups. Data analysis was conducted using the x2 test, paired t-test, Mann-Whitney U test, and Wilcox on test on SPSS 11.5.

RESULTS

The mean anxiety score decreased significantly after inhalation of the aroma of geranium essential oil. There was also a significant decrease in diastolic blood pressure.

CONCLUSION

Aroma of essential oil of geraniums can effectively reduce anxiety during labor and can be recommended as a non-invasive anti-anxiety aid during childbirth.

Inhibitory effect of GA3 on the development of thidiazuron-induced somatic embryogenesis in geranium (Pelargonium xhortorum Bailey) hypocotyl cultures

Somatic embryogenesis in geranium (Pelargonium xhortorum Bailey cv 'Scarlet Orbit Improved') can be achieved by incubating hypocotyl explants on MS medium supplemented with thidiazuron (TDZ; 10 μM for 3 days followed by subculture on medium devoid of any plant growth regulators. The presence of gibberellins (GAs) during both the induction and expression phases of embryogenesis was significantly detrimental to somatic embryo formation on the hypocotyl explants. The addition of the GA-synthesis inhibitors paclobutrazol, uniconazole or ancymidol during the period of growth and differentiation of somatic embryos increased the number of somatic embryos formed on each explant. However, paclobutrazol added during the period of induction had no significant influence on somatic embryo formation. Results suggest that both exogenously supplied as well as endogenous GAs play a role, albeit a negative one, on somatic embryogenesis of geranium.