Science of Spices & Culinary Herbs: Latest Laboratory, Pre-clinical, and Clinical Studies: Volume 6 E-Book
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- Herausgeber: Bentham Science Publishers
- Kategorie: Fachliteratur
- Sprache: Englisch
Many herbs and spices, in addition to their culinary use for taste, contain chemical compounds which have medicinal uses. For this reason, herbs and spices have been used for treating various ailments since ancient times. Modern scientific methods have enabled researchers to isolate and analyze bioactive compounds from herbs and spices to develop medicines for different diseases. Science of Spices and Culinary Herbs presents current reviews on studies performed on herbs and spices. This book series is an informative resource for medicinal chemists, herbalists and biomedical researchers interested in the science of natural herbs and spices that are a common part of regional diets and folk medicine. The sixth volume of this series features reviews on medicinal aspects of a selection of herbs and spices, including: Pimpinella anisum L. (Anise, Aniseed) Sinapis alba L. (Mustard Seeds) Cinnamomum verum (Cinnamon) Tamarindus indica L (Tamarind) Curcuma longa (Curcumin) Glycyrrhiza glabra (Licorice) Readership Medicinal chemists, herbalists, and biomedical researchers interested in the science of natural herbs and spices
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Veröffentlichungsjahr: 2024
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PREFACE
Spices and culinary herbs have been among the richest sources of medicines, fragrances, and recreational substances since antiquity. The modern concept of “food and medicine homology” is largely based on the use of spices as food and medicine. We have recently coined the term “phytodietoceuticals” for all those plant parts that are not only rich in nutrition but also prevent and treat diseases. Extensive research studies on spices and culinary herbs have proven their utility as anti-oxidants and anti-infectious, anti-inflammatory and neuroprotective agents. Volume 6 of the ebook series titled “Science of Spices & Culinary Herbs” is an excellent compilation of ethnobotanical, phytochemical, pharmacological and clinical work being conducted on the most commonly consumed spices and herbs globally. The book series is an attempt to demystify the existing information about these fascinating natural products by presenting comprehensive reviews of scientific studies and their results. This makes ebook series a must to have in general libraries, pharmaceutical R&D institutions, and nature-based healthcare facilities.
The review by Ceyda Sibel Kilic provides an excellent account of the ethnomedicinal uses and phytochemistry, as well as pharmacological, dietary, and cosmetic applications of aniseed or anise (Pimpinella anisum L.). Sinapis alba L., commonly called white or yellow mustard, is the focus of the article contributed by Hattab et al. The authors have explained the taxonomy, phytochemical methods, essential oil extraction, and chemical and biological properties of aniseeds. Maithanil et al. updated the literature review on world-famous herb cinnamon bark powder (Cinnamomum verum J. Presl), covering recent work on tremendous health benefits and mechanisms of action, largely due to the presence of its main constituent, cinnamaldehyde. Recent studies on the globally famous spice tamarind (Tamarindus indica L.) were reviewed by Ahmad et al. The authors have explained the phytochemicals of the pulp of tamarind and their pharmacological and clinical properties. Curcumin, a key constituent of Curcuma longa, has been the subject of extensive research in recent years due to its numerous medicinal properties. Badavath et al. reviewed the work conducted on the synthetic analogs of curcumin for improved anticancer and anti-oxidant properties. Glycyrrhiza glabra L. is the source of licorice derived from its dried roots and rhizomes and used as a natural sweetener. Aksoyalp et al. commented on the novel aspect of licorice pharmacology. They reviewed recent studies on the interplay between the use of licorice constituents and human gut microbiota and resulting therapeutic effects on neurodegenerative diseases.
We gratefully acknowledge the scholarly contributions of all authors and the production team of Bentham Science Publishers for a job very well done. Among them, Mrs. Fariya Zulfiqar (Manager Publications) and Mr. Mahmood Alam (Editorial Director) of Bentham Science Publishers deserve special recognition. We sincerely hope that the contributions of the authors and the production team will help readers better understand and appreciate the therapeutic effects and disease-preventive potential of colorful, tasty, and aromatic spices and herbs.
List of Contributors
Pimpinella anisum L. (Anise, Aniseed)
Ceyda Sibel Kılıç1,*Abstract
Pimpinella anisum L. is an aromatic species of the Apiaceae (Parsley) family, commonly known as anise or aniseed. Fruits of the plant, which are also known as seeds, have widespread usage throughout the world for culinary and medicinal purposes, in cosmetics industry, and also is used in the flavoring of some alcoholic beverages, candies etc. Usage of the plant for medicinal purposes dates back to ancient Egypt and the plant is currently being used mainly for its digestive properties and hormonal activities such as increasing milk production in breast feeding mothers. The plant is sometimes confused with star anise, another species called Illicium verum Hook. f. from Schisandraceae family due to the fact that they both have trans-anethole within the composition of their volatile oils, though anise is an annual herbaceous plant and star anise is an evergreen tree. In this chapter composition, traditional usages, biological activities and some issues related to the utilization of this world-renowned plant are focused on.
INTRODUCTION
Pimpinella anisum L. is an annual plant of the Apiaceae family, formerly known as Umbelliferae. The plant is known to be cultivated since ancient Egypt (for at least ~4000 years) for its beneficial usages. While texts of ancient Egyptians stated the usage of the plant for digestive problems, as diuretic and against toothache, Greeks and Romans also mentioned the cultivation and uses of the plant for different purposes; furthermore, it has been used in China as a traditional remedy since the 5th century [1, 2]. It is reported to be used in embalming of Scythian kings [3]. The plant is reported to be used in Serbia during medieval times as carminative, digestive, against splenomegaly, stomachache, female genitalia disorders, bruising, to increase spermatogenesis, lactation [4]. The plant
is still being used traditionally in many countries as an anticonvulsant and for the treatment of gastrointestinal, inflammatory, dermatological diseases, against nightmares, melancholy, seizures, epilepsy [5-7]. Not only the seeds, but volatile oil of the fruits/seeds are also being used for their medicinal activities [8].
In addition to the plant’s utilization for medicinal and culinary purposes, volatile oil obtained from the seeds is used in the cosmetic industry in the making of toothpastes, lotions, soaps, skin care products; used in the production of different alcoholic beverages in different countries (e.g. rakı in Türkiye, ouzo in Greece, Anisette or Pastis in France, anesone in Spain, Sambuca in Italy and arak mainly in Armenia and Syria) [1, 9]. A Cuban refreshment called Pru was also prepared with the species once, however basic Pru recipes do not include the plant currently [10]. Furthermore, volatile oil is also used in the aromatization of candies and tobacco [1, 7, 11]. The plant is considered to be a functional food and nutraceutical preparations are also being prepared with the volatile oil of the plant [12, 13]. With all these different usages, it is no surprise that anise seed is listed in various pharmacopoeia such as British, German and European Pharmacopoeia [14, 15], and is also approved by Herbal Medicinal Products Committee (HMPC) of European Medicines Agency (EMA) as a traditional herbal medicinal product [16].
The plant can be up to 30-50 cm in height, peak height is reported to be 50-60 cm; leaves are heterophyllous, petiolate basal leaves are simple, 2-5 cm long, reniform/ovate shaped with dentate margins; lower cauline leaves are pinnate having ovate/obovate segments and upper cauline leaves are 2-3 pinnate with linear-lanceolate lobes and sheathing petioles. The plant has white flowers, umbels 7-15 rayed, has 1 bract or none, and bracteoles also none or few, very narrow if present. Approximately 10 white flowers are present per umbellule and has greenish-grey to brown colored schizocarp fruits of 2-5 mm with a conical stylopodium. The flowering period of the plant is June and fruits are harvested in August [17-19]. The general appearances of the plant and the fruits are given in Fig. (1).
The plant is known by different names in various countries, some examples are listed in Table 1.
Fig. (1)) (a) Pimpinella anisum field; (b) General appearance of P. anisum (Photos by A.M. Gençler Özkan); (c) P. anisum fruits (Photo by C.S. Kılıç).Distribution and status of the species
According to the World Flora Online, the genus Pimpinella L. consists of 197 taxa, however some of them are unchecked names awaiting taxonomic scrutiny [44]. The genus is distributed through Europe, Asia and Africa [45]. The plant is reported to be native to Southwest Asia, Middle East and the Mediterranean region, and is being cultivated in many countries, such as Brazil, Bulgaria, China, Egypt, Greece, France, India, Iran, Italy, Mexico, Spain, Syria, Russia, Tunisia, Türkiye and United States due to its aromatic fruits, which are also called seeds, commercially [7, 27, 46-48]. However, it is now considered to as no longer exist in the wild and is only being cultivated [49].
Traditional/Ethnomedicinal Uses
Since the plant has been known for thousands of years by mankind, it has been used in the treatment of certain diseases for centuries. In addition, different parts of the plants, like leaves and especially the aromatic seeds are edible and used for culinary purposes [50, 51]. Some examples for ethnobotanical/traditional uses of the species are given in Table 2:
Composition
When we search the literature, we can see that several studies have been performed on the chemical composition of the plant. However, most of them are related to the volatile oil of fruits/seeds of the plant. In general, all of these studies state that trans-anethole, a phenylpropene derivative is the major compound of the volatile oil [43, 46, 86-105]. However, some studies suggest that other compounds are also found in high quantities, for example 4-allylanisole is the major component [106] and estragole was also found to be in high quantities, though much lower [107]; and these differentiations were attributed to geographical differences or harvesting time.
In addition, new compounds are increasingly being isolated from the volatile oil, and their structures are being elucidated. Besides anethole, anise oil is also found to include phenylpropanoids such as umbelliprenine [108, 109].
Phytochemical composition of anise other than the volatile components is given in Table 3.
Biological Activities
The plant has a long history of traditional utilization in countries where it grows naturally and also where it is being cultivated. These utilizations are confirmed with some scientific studies and some of them are focused on in this section.
Anticancer Activity
Cancer is an important health problem having high ratio of mortality. Although we have come a long way in the treatment of different types of cancers, it still is a major cause of mortality and researchers are seeking for treatment alternatives with less or no side effects. Since natural sources are mainly explored in this respect, it is no surprise that anise seed was also tested for its anticancer activity. In a study by Kadan et al. [133], ethanol extract from the seeds was tested for its antiproliferative and apoptotic efficacy against PC-3 (human prostate cancer) cell line and L6 (rat skeletal muscle) cell line used as normal cell line, and it was understood that the seeds had significant anticancer activity against PC-3 cells while it did not harm L6 cells.
Ethanolic extract and volatile oil of the seeds were tested for their cytotoxic activities in gastric cell line (AGS) and it was shown that AGS cell growth was inhibited, and furthermore angiogenesis in HUVEC cells was also inhibited; thus it had the potential to be used in gastric cancer as a plant based cure alternative [134]. However, different cancer cell lines do not always yield the same response. For example, while anise had moderate chemopreventive effect against E2 (17β-estrogen)-induced mammary tumorigenesis in August-Copenhagen-Irish (ACI) rat model in a study by Aqil et al. [135] in which seeds were powdered, lyophilized then added to the animal feed, it had significant cytotoxic activity against KB (human epithelial carcinoma cells) cell line. In this study, powdered seeds were first extracted with ethyl acetate, and then diluted with DMEM to yield solutions of five different concentrations [136].
Trans-anethole found within the composition of the volatile oil is considered to have anticancer activity. In a study by Garzoli et al. [137], this compound was reported to have cytotoxic and antiproliferative activities against He-La cell line with an IC50 of 0.25 mg/mL.
Anticariogenic and Dental Activities
Due to antibacterial activities of anise extracts and volatile oil, anticariogenic activity was also examined with the help of some caries causing bacteria. For example, Streptococcus mutans, Lactobacillus rhamnosus and Actinomyces millefolium were found to be sensitive to the growth inhibitory activity of the hydroalcoholic extract of the seeds [138]. In another study, dental plaque samples obtained from 3-5 years old children were used in a study in which anticariogenic activity of hydroalcoholic anise extract was examined. As a result, it was demonstrated that plant extract had antimicrobial activity against bacteria that lead to dental caries (S. mutans, S. sanguinis and S. salivarius) [139]. Methanol extract of the seeds was also found to have antimicrobial activity against S. sanguinis [140]. In addition to these bacteria, volatile oil of the seeds was also found to be effective against other periodontal pathogens such as Enterococcus faecalis, Aggregatibacter actinomy-cetemcomitans, Lactobacillus casei and Actinomyces naeslundii leading to different dental disorders [141].
Antidepressant / Anxiolytic Activities
Depression and anxiety due to stress are among important mental disorders that are seen in every society with a high prevalence. Since the disorder is triggered by stress and is quite common due to various factors such as daily tasks, diseases, disasters, latest COVID-19 pandemic etc., antidepressants are among the most used medications to relieve these two disorders throughout the world. However, having many side effects on their own, scientists are searching for safer alternatives. In this respect, plants/plant-based remedies are sought for and P. anisum is also tested for this biological activity. Aqueous and 70% ethanolic extracts of the fruits were tested for their antidepressant activities in a study by Shahamat et al. [142] and it was found that anise plant had significant antidepressant activity that was comparable to the synthetic agent fluoxetine. The anxiolytic activity was also examined in a previous study and intraperitoneal injection of the hydro-alcoholic seed extract was found to have anxiolytic activity in male Wistar rats as shown in elevated plus maze model by increased number of entries to the open arm and decreased time spent in close arms [143]. In another study by Es-safi et al. [120], hydro-ethanolic extract prepared after defattening of the seeds with hexane extraction was found to have potent antidepressant and anxiolytic activities possibly due to monoaminergic involvement.
Antidiabetic Activity
Diabetes is a chronic disease leading to secondary complications, and in the search of finding natural antidiabetic sources, anise plant is also being examined among the plants tested for their antidiabetic activities. As a result of various studies, methanolic extracts of the seeds were shown to have inhibitory effects on α-amylase and α-glucosidase enzymes, pointing out to the antidiabetic potential of the plant [111]. Similarly, in another study, aerial parts of the plant were ground and then aqueous infusions were prepared and tested for their α-amylase inhibitory activities, and it was concluded that the plant might be useful against diabetes [116]. Volatile oil was also tested and yielded hypoglycemic activity, which might be beneficial for diabetic patients [88].
Anti-inflammatory Activity
Anise plant is examined for anti-inflammatory activity, as well. In a study by Taş et al. [144], it was shown that the fixed oil of the seeds had anti-inflammatory activity that is comparable to indomethacin’s. In another study that was carried out to confirm the traditional usage of anise in respiratory diseases, volatile oil of the seeds was found to have significant anti-inflammatory activity against HBEpC (primary airway bronchial epithelial cells) and HTEpC (primary airway tracheal epithelial cells) cells and mucus hypersecretion with neutralization of pro-inflammatory cytokines [145]. Another study examined the anti-inflammatory activity of lyophilized seed extract and it was observed that the extract prevented ovalbumin induced asthmatic complications, probably by inhibiting eosinophil trafficking and blockade of Th2 cytokines responses. As a result, anise reduces inflammation of the airways and could be an alternative for the treatment of allergic asthma [146].
Anti-lipase Activity
Obesity has become an important health issue throughout the world. Anti-obesity agents without serious side effects are being sought for by researchers in order to reduce obesity related complications and/or mortality rates.
In a study by Ado et al. [35] in which 98 plant materials were tested for their activities on porcine pancreatic lipase activities, methanolic extract of the anise seeds was reported to stimulate porcine pancreatic lipase by 186.5%, and thus resulted in anti-obesity activity.
Antimicrobial Activity
Volatile oils are known to have antimicrobial activities, and anise oil is no exception. Thus, anise oil has been used in different applications for its antimicrobial activities. Studies related to these activities are given summarized as follows:
Antibacterial Activity
Alcoholic extract of the fruits was tested for its antibacterial activity on some Gram (-) and (+) bacteria, and it was found to be effective against Bacillus cereus, Bacillus subtilis, Cirobacter koseri, Enterobacter aerogenes, Escherichia coli, Helicobacter pylori, Klebsiella pneumonia, Micrococcus luteus, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella typhimurium, Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus pneumoniae, Streptococcus pyogenes [19, 38, 103, 147-152].
The volatile oil of the seeds was tested for its antibacterial activity by different researchers, as well. For example, different researchers showed that, the oil had antibacterial activity against B. subtilis, Clostridium butyricum, C. perfringens, E. coli, P. aeruginosa, S. aureus, S. pyogenes, S. pneumoniae [101, 105, 153-159]. In another study by AlBalawi et al. [128], methanol extract of the seeds was found to inhibit multidrug resistant bacteria growth and thus has the potential to constitute a potential anti-virulence option.
In addition to the volatile oil and the extracts, anethole isolated from the oil is also active against some bacteria, such as Vibrio cholera, the causative agent of cholera [160]. 5% suspension of the seeds was found to be effective against another Vibrio sp. (V. parahaemolyticus) resulting in mild food-borne gastroenteritis [161]. Other researchers have also found that anethole was effective against Bacillus cereus, E. coli, K. pneumonia, P. mirabilis, S. aureus [162].
Moreover, different formulations were also prepared with anise and tested against various bacteria. For example, silver nanoparticles containing aqueous seed extract solution were found to be effective against Staphylococcus pyogenes, Acinetobacter baumannii, K. pneumoniae, Salmonella typhi, P. aeruginosa and were reported to be an eco-friendly alternative with excellent antimicrobial activity [163]. Zayed et al. [164] synthesized metal nanoparticles with optimized anise seed extract prepared by different solvents (hexane, methylene chloride, 70% aqueous methanol, water) and methanol extract and silver nanoparticles prepared by this extract were found to have the highest antibacterial activity against E. coli, S. aureus. Similarly, copper oxide particles containing anise volatile oil had antibacterial activity against E. coli, P. aeruginosa and are considered to be beneficial in future therapeutic applications [165]. In another study [166] an emulgel was prepared with the volatile oil and it was found that the emulgel had significant activity against E. coli.
Antifungal Activity
Fluid extract and volatile oil prepared from the seeds were reported to have potent antifungal activity against yeasts isolated from clinical specimens of blood, wounds, and urine, i.e. Candida albicans, C. parapsilosis, C. tropicalis, C. pseudotropicalis, and C. krusei [167]. Volatile oil was also tested for its antifungal effects and Candida albicans and Saccharomyces cerevisiae yeasts were found to be sensitive to the volatile oil and the compounds found within the composition [101]. Methanolic extract of the seeds was also found to have high fungicide activity against C. albicans, Microsporum canis and Trichophyton mentagrophyes [168]. However, in a previous study, volatile oil was shown to have mild activity against C. albicans [169]. The volatile oil again was tested for its antifungal activity against some fungal isolates and was found to be active against the mycelial growth of Chaetomium oblatum, Drechslera erythrospila, D. euphorbiae, Fusarium sulphureum, Gibberella tricincta, Scopulariopsis brevicaulis, and Setosphaeria rostrata, when the volatile oil was added to the solid medium [170]. A homogenous peptide isolated from the seeds was also tested for its antimicrobial activity and found to be effective against C. albicans, as well [171]. The volatile oil of the seeds was tested for their activity against fungi isolated from chronic einiatrophic oral candidiasis cases (C. albicans, C. parapsilossis, C. glabrata, C. krusei) and concluded to be a promising agent in the prevention and/or treatment of fungal infections of the oral tissue [97]. In another study, volatile oil of the seeds was examined for its antifungal activity against some Penicillium species (P. brevicompactum, P. citrinum, P. crustosum, P. expansum, P. funiculosum, P. glabrum, P. chrysogenum, P. oxalicum, P. polonicum) and found to have antifungal activity at varying extents [172]. In the aforementioned study by Zayed et al. [164] related to antibacterial activity, silver nanoparticles synthesized with methanol extract from the seeds were found to have high antifungal activity against Aspergillus flavus and C. albicans and could be a safe alternative for biomedical applications. Aspergillus fumigatus and A. niger were also found to be sensitive to the methanol extract of the seeds, whereas aqueous extract has lower activity [173].
Methanolic extract of the seeds was tested for its activity against some fungi that cause infection on finger and/or toenails (onychomycosis) and found to be active against Tricophyton rubrum, T. mentagrophytes, Microsporum canis, M. gypseum, C. albicans) due to the phenolic compounds that is possesses [174].
In addition to these aforementioned antimicrobial activities, seeds of the plant are also known to have antiamoebic activity, and methanolic extract of the seeds was demonstrated to be effective against Entamoeba histolytica [175].
Antiviral Activity
Seeds of the plant were also tested for their antiviral activities and lignin-carbohydrate complexes isolated from the seeds were found to be effective against Herpes simplex virus types, HSV-1, HSV-2, human cytomegalovirus (HCMV) and measles virus [176]. Influenza is an important viral disease with respiratory complications and high morbidity rates. Anise volatile oil was examined for its antiviral effect against A7WS733 influenza virus at a concentration of 100 µg/ml, and it was found that the oil was quite effective in the reduction of visible cytopathic effects of the virus [177]. With the COVID-19 pandemic that resulted from SARS-CoV-2 infection, thousands of people were affected and yet thousands of lives were lost. Natural sources and/or compounds with known antiviral activities started to be examined in respect to their anti-COVID-19 effects and El Alami et al. [178] reported that anise seeds were used during the pandemic by Moroccan people, Iqbal et al. [179] stated that anise was used during the COVID-19 pandemic, and Abdulrahman et al. [180] reported the usage of anise seeds against the virus in the form of tea, or as directly chewed. Khabour and Hassanein also stated that [181] fruits of the plant were used in the form of an immune-boosting beverage in Egypt. Volatile oil of the seeds was also used for its bioactivity against COVID-19. For example, anise seed oil was found in an oral spray including a mixture of some volatile oils that is considered to have potent antiviral activity and determined to reduce virus load [182]. A study performed on Saudi patients also revealed that anise plant was used commonly in the form of an herbal solution that contained various herbs during the pandemic [183]. In addition to these literature studies, many studies found with the “anise” keyword search were determined to include star anise plant which was also used against and/or in the treatment of COVID-19 infection, as well.
Antioxidant Activity
Oxidative processes underlie many diseases that have important adverse effects, thus natural sources with antioxidant activities are important in the struggle with oxidative processes. All green plants are known to have antioxidant activities with varying extents, some with significant activities. In a study by Gülçın et al. [147], water and ethanol extracts of the seeds were shown to have potent antioxidant activity as demonstrated by reducing power, hydrogen peroxide, DPPH radical and superoxide anion scavenging, metal chelating activities. Hydromethanolic extract of the seeds was found to have high free radical scavenging activity due to its high phenolic content [115]. Amer et al. [19] also showed that water and alcoholic extracts of the seeds had the potential to fight free radicals due to its free radical scavenging activity. Moreover, hot distilled water extract of the aerial parts was reported to have antioxidant activity as demonstrated with total antioxidant activity, ferric reducing antioxidant power and reducing power by Farzaneh et al. [116].
In another study, acetone extract from anise leaves was demonstrated to have antioxidant activity shown by DPPH radical scavenging method, probably due to phenolic compounds that the plant possesses [130]. In another study [132], oxadiazole compounds found in the seeds were considered to have antioxidant activity since they scavenge free radicals, and furthermore were found to inhibit acetylcholinesterase that contributes to the development of Alzheimer’s Disease. Related to this activity, methanolic extract of the seeds was shown to have antioxidant activity that contributes to its antiamnesic action in a previous study [184]. In another study, Mushtaq et al. [185] reported that this antiamnesic activity (of the methanol extract of the seeds) is due to the prevention of neuronal damage caused by oxidative stress.
The volatile oil of the seeds was tested for their antioxidant activities in different studies, as well. For example, in a study by Singh et al. [89], both the oil and the oleoresin isolated from the seeds were examined in respect to their antioxidant activities (via inhibition of linoleic acid peroxidation, DPPH radical scavenging, and ferric reducing power and different lipid peroxidation methods) and it was found that both of them had significant antioxidant and radical scavenging activities.
With the knowledge that anise has significant antioxidant activity, as reported by AlBalawi et al. [128] as stronger than antioxidant effect of vitamin C through conducting DPPH, ABTS and iron-reducing power assays with the methanol extract of the seeds, various researchers tried to optimize the extraction of phenolic compounds and thus, antioxidant abilities of the extract as demonstrated by DPPH assay [186]. In a previous study by Rebey et al. [117], extraction of the seeds by 2-methyltetrahydrofuran, which is a bio-based and bio-degradable solvent, was found to yield stronger antioxidant activity as shown by DPPH assay that is comparable to conventional extraction methods with petroleum-based solvent extraction.
Central Nervous System (CNS)-related Activities
Anise plant has various central nervous system (CNS) related activities as demonstrated by different researchers. Some are related to beneficial activities of anise in some disorders, and some are related to the prevention and/or treatment of neurotoxicity caused by different toxic agents.
In a study by Sahraei et al. [187], volatile oil of the fruits was examined for its effect on the expression and acquisition of CPP (conditioned place preference) in mice induced by morphine, which is an important issue in drug dependence. Volatile oil injected intraperitoneally was shown to induce conditioned place aversion and reduce morphine’s effect probably via GABAergic mechanism.
Volatile oil of the seeds was also examined for its effects related to epilepsy, which is among the most common neurological disorders. The plant is reported to have antiepileptic action and is being used accordingly in traditional medicine. Volatile oil of the seeds was reported to suppress tonic convulsions induced by pentylenetetrazole or maximal electroshock in mice, however the mechanism of this action could not be elucidated at the time when the study was carried out [188]. In subsequent studies, it was stated that the volatile oil induced neuronal hyperexcitability via attenuation of after-hyperpolarization in an experiment performed with snails. Enhancement of Ca2+ channel activity or inhibition of voltage and/or K+ channels dependent on Ca2+, as a result of hyperpolarization potential was also reduced. The authors also reported that the plant should be used with caution in the treatment of epilepsy patients [189].
Anticonvulsant effects of the volatile oil was examined in a study performed on rats and it was understood that anise oil had significant anticonvulsant activity against pentylenetetrazol induced seizures, probably via inhibition of synaptic plasticity. Production of dark neurons was also prevented when seizure was inhibited, thus the oil might also be considered as a neuroprotective agent [190].
Neuroprotective activity of the plant is also worth examining and anise is known to have protective effect against toxic agents. For example, lead is known to have toxic effects in different organs and it also has neurotoxic actions like apoptosis, excitotoxicity, etc. Developmental lead exposure is known to induce depression and anxiety and volatile oil obtained from the seeds was demonstrated to correct depression and anxiety due to chronic lead intoxication [191]. Another study demonstrated that aqueous extract of the seeds was able to have protective effect against lead neurotoxicity and this activity was attributed to antioxidant potential of the plant that contains flavonoids and phenolic substances [192].
Aspartame is another agent leading to significant side effects, however it is also the most commonly used artificial sweetener despite its adverse effects. It is known to penetrate blood-brain barrier and result in excitotoxicity in the brain i.e. damaging of the brain and the nervous system. Volatile oil of the seeds was tested for its protective activity against aspartame induced changes in the cerebellar cortex and it was found that histopathological, ultrastructural and immunohistochemical changes were less observed with the usage of the oil; thus the volatile oil has neuroprotective activity [193]. In another study, the volatile oil was reported to provide protection against aspartame induced cerebellar damage as observed by structural and ultrastructural changes in the cerebellar cortex, as well [194].
Mercury is another toxic element that results in neurological disorders and changes in tissues. It is found in many sources such as water, seafood, soil, air, dental amalgams and vaccines, so we are exposed to this element one way or another. Lyophilized extract of the seeds was shown to have protective effect against depression and it was able to improve locomotor capabilities and spatial learning in Wistar rats exposed to mercury chloride during gestation and then lactation periods [195].
In a study by Mushtaq et al. [132], aqueous extract of the seeds was fractioned with different solvents and found to contain oxadiazole compounds that are responsible for the memory enhancing activity of the plant due to the inhibition of acetylcholinesterase enzyme, which is known to be involved in the development of Alzheimer’s Disease.
Gastro-Intestinal System (GIS)-related Activities
In accordance with the traditional usage of the anise plant as digestive, carminative etc. some herbal formulations directed to gastrointestinal disorders have been developed and GIS-related activities of the plant were examined in some studies. For example, an herbal formulation named Thatbunjob is being used in Thailand for this purpose and is included in National List of Essential Medicines [196]. In a study by Al Mofleh et al. [197], aqueous suspension of the seeds was shown to inhibit gastric mucosal damage induced by necrotizing agents such as ethanol, NaOH and NaCl and indomethacin. This protective activity was attributed to its anti-secretory and antioxidant properties and might be prostaglandin mediated.
Chronic constipation is an important health problem and many remedies, both traditional and conventional, have been proposed against it. A phytotherapic mixture containing anise, fennel, elder and senna is being used in Brazil as a remedy against chronic constipation, however laxative efficacy and safety of the mixture were not elucidated. Thus, in an attempt to evaluate the efficacy and safety of the mixture, a randomized controlled trial was performed and it was concluded that the mixture was an effective and safer alternative [198].
Functional dyspepsia is among the most frequent gastrointestinal disorders having symptoms such as epigastric pain and/or burning sensation, early satiety and postprandial fullness lasting for more than 12 weeks. Anise seed powder was administered as 3 g after meals and it was reported that this usage increased the quality of life in patients having functional dyspepsia [199].
Irritable bowel syndrome (IBS) is another disorder related to gastro-intestinal system and some of the major psychiatric disorders like depression and anxiety are also frequently seen in patients with IBS. Aqueous extract of anise seeds was reported to have beneficial effect on IBS, probably due to the antioxidant compounds that are found within the plant [200].
