The Genus Allochrusa : A Comprehensive Review of Botany, Traditional Uses, Phytochemistry, and Biological Activities

: The genus Allochrusa (Caryophyllaceae) comprises nine species, which are native to Central Asia, Turkey, Iran, Afghanistan, and the Caucasus. They have been used in folk medicine and in the preparation of various sweets and detergents, especially in Asian countries. A diversity of secondary metabolites has been reported from the genus Allochrusa , including triterpene glycosides, ecdysteroids, ﬂavonoids, volatile compounds, fatty acids, polysaccharides, pectins, hemicelluloses, and other phytochemicals. In vitro and in vivo pharmacological studies on isolated compound fractions and extracts from Allochrusa species showed anti-inﬂammatory, adjuvant, hemolytic, cytotoxic, antifungal, analgesic, antioxidant, and other activities. In this review, the chemical compounds and diverse biological activities of the Allochrusa genus are summarized.


Introduction
The Caryophyllaceae, also referred to as the "pink or carnation family", includes approximately 80 genera with more than 2600 species [1].The family is famous for widely used genera including Silene, Dianthus, Gypsophila, Stellaria, Saponaria, and Allochrusa.Members of the Caryophyllaceae include important medicinal, ornamental, and aromatic plants and have been used as traditional herbal medicines and in various branches of industry [2].Agrostemma githago (Corncockle), Dianthus chinensis (Pink), D. caryophyllus (Clove pink), D. barbatus (Sweet William), Gypsophila paniculata (Baby's Breath), Lychnis coronaria (Rose campion), Saponaria officinalis (Soapwort), S. ocymoides (Rock soapwort), and Silene spp.(Campions) are known as ornamental species.These plants are famous in the cut flower trade for their beautiful flowers.Caryophyllaceae are known to be a rich source of pharmacologically active secondary metabolites.The major chemical constituents of this family are saponins, flavonoids, ecdysteroids, sterols, lignans, polyphenols, essential oils, and N-containing compounds such as vitamins, alkaloids, and cyclic peptides [3].Some saponin-containing species from the Caryophyllaceae, such as Saponaria officinalis (soapwort), Gypsophila paniculata (Baby's breath), and Allochrusa gypsophiloides (Turkestan soap root), have been used as soap since time immemorial.Silene, Acanthophyllum, Gypsophila, Dianthus, Stellaria, and Saponaria are the most studied genera for both ethanomedicinal and biological studies.Their utilizations in traditional medicine include anticancer, antiinflammatory, antifungal, antiviral, antibacterial, and antioxidant properties [4].the same 70-80 cm.In contrast, the leaves are up to 0.5 cm wide and 3 cm long, flat, almost linear or linear-lanceolate, with a pointed tip.The sepals are lanceolate, smooth, and 2-3 times shorter than the petals.The flowers are located in free, forked-branched, wide-grooved inflorescences at the ends of stems and branches.The middle flowers of each branch of the inflorescence are almost sessile; the other two have long filamentous inflorescences.Sepals are five-lobed, cylindrical, smooth, about 2 mm long; they consist of five pinkish-yellow leaves, the node is single-celled, and there are 10 stamens.The fruit is an indehiscent, membranous, one-to-two-seeded calyx with preserved sepals.The seeds are light brown, almost spherical, slightly flattened on the sides, ripen in early August, but do not fall until autumn.The root is an arrowroot, sometimes globose, twisted, up to 2 m long and more, weighing up to 12 kg.Lateral roots branch several times from the tap root.Roots do not have the ability to regenerate after being mined, so the natural dense growth areas of this plant are not regenerated after the raw materials are collected [8]. A. tadshikistanica is a perennial herbaceous plant that grows 30-60 cm high.Stems a few and thin.Leaves 10-25 mm long, linear, flat, without thorns.Flowers pale pink, in terminal lax, spreading panicle.Fruit is a capsule.Flowering in May-August, fruiting in August-September [5,9].
Species of the genus Allochrusa are distributed in Afghanistan, Armenia, Azerbaijan, Iran, Iraq, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Turkey, and Uzbekistan.These plants normally grow in arid regions, deserts, mountain slopes, and temperate zones [10].In the territory of Iran, four species of the section Allochrusa have been found: Allochrusa bungei, A. persica, A. versicolor, and A. lutea.A. lutea is a recently recorded species in the flora of Iran; its natural habitat is limited to northwest Iran [11] (Table 1). A. takhtajanii was listed as a critically endangered species endemic to a region in Armenia in 2014 [12]; A. transhyrcana and A. tadshikistanica are endemic to Turkmenistan and Tajikistan, respectively [10].In the flora of Kazakhstan, A. gypsophiloides is found in four districts of the Turkistan (formerly South Kazakhstan) region [13].In Kyrgyzstan: The Western Tien Shan and Pamir rivers' dry slopes and abandoned arable land at an altitude of 400 to 700 m above sea level are the primary habitats for A. gypsophiloides and A. paniculata species [14].Two species of Allochrusa, A. versicolor and A. bungei, have been found in Turkey [15] (Figure 1).Allochrusa gypsophiloides (syn.Acanthophyllum gypsophiloides) is a perennial plant.The stem is strongly branched and has short hairs or is smooth.Due to the numerous branching of its stems, the plant has a spherical shape and its height and diameter reach almost the same 70-80 cm.In contrast, the leaves are up to 0.5 cm wide and 3 cm long, flat, almost linear or linear-lanceolate, with a pointed tip.The sepals are lanceolate, smooth, and 2-3 times shorter than the petals.The flowers are located in free, forked-branched, widegrooved inflorescences at the ends of stems and branches.The middle flowers of each branch of the inflorescence are almost sessile; the other two have long filamentous inflorescences.Sepals are five-lobed, cylindrical, smooth, about 2 mm long; they consist of five pinkish-yellow leaves, the node is single-celled, and there are 10 stamens.The fruit is an indehiscent, membranous, one-to-two-seeded calyx with preserved sepals.The seeds are light brown, almost spherical, slightly flattened on the sides, ripen in early August, but do not fall until autumn.The root is an arrowroot, sometimes globose, twisted, up to 2 m long and more, weighing up to 12 kg.Lateral roots branch several times from the tap root.Roots do not have the ability to regenerate after being mined, so the natural dense growth areas of this plant are not regenerated after the raw materials are collected [8]. A. tadshikistanica is a perennial herbaceous plant that grows 30-60 cm high.Stems a few and thin.Leaves 10-25 mm long, linear, flat, without thorns.Flowers pale pink, in terminal lax, spreading panicle.Fruit is a capsule.Flowering in May-August, fruiting in August-September [5,9].
Species of the genus Allochrusa are distributed in Afghanistan, Armenia, Azerbaijan, Iran, Iraq, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Turkey, and Uzbekistan.These plants normally grow in arid regions, deserts, mountain slopes, and temperate zones [10].In the territory of Iran, four species of the section Allochrusa have been found: Allochrusa bungei, A. persica, A. versicolor, and A. lutea.A. lutea is a recently recorded species in the flora of Iran; its natural habitat is limited to northwest Iran [11] (Table 1). A. takhtajanii was listed as a critically endangered species endemic to a region in Armenia in 2014 [12]; A. transhyrcana and A. tadshikistanica are endemic to Turkmenistan and Tajikistan, respectively [10].In the flora of Kazakhstan, A. gypsophiloides is found in four districts of the Turkistan (formerly South Kazakhstan) region [13].In Kyrgyzstan: The Western Tien Shan and Pamir rivers' dry slopes and abandoned arable land at an altitude of 400 to 700 m above sea level are the primary habitats for A. gypsophiloides and A. paniculata species [14].Two species of Allochrusa, A. versicolor and A. bungei, have been found in Turkey [15] (Figure 1).In Uzbek flora, Allochrusa is described by three species: Allochrusa gypsophiloides (syn.Acanthophyllum gypsophiloides, local name Etmak), A. paniculata (syn.Acanthophyllum paniculatum), and A. tadshikistanica (syn.Acanthophyllum tadshikistanicum) [16].They are perennial herbaceous saponin-bearing plants.A. gypsophiloides occurs in a relatively limited In Uzbek flora, Allochrusa is described by three species: Allochrusa gypsophiloides (syn.Acanthophyllum gypsophiloides, local name Etmak), A. paniculata (syn.Acanthophyllum paniculatum), and A. tadshikistanica (syn.Acanthophyllum tadshikistanicum) [16].They are perennial herbaceous saponin-bearing plants.A. gypsophiloides occurs in a relatively limited area; it grows only in the western Tien Shan and Pamir-Altay on foothill desert loess steppes, dry slopes of rivers, and on gravelly slopes at 400 to 1500 m above sea level.Eisenman et al. [17] declare that the presence of A. gypsophiloides is more typical at altitudes of 1200-1500 m in Jizzax, Qashqadaryo, Samarqand, Surxondaryo, and Toshkent regions of Uzbekistan on stony slopes with rocky debris of the adyr and tau zones (Figure 2).Small white flowers form openwork clusters on a branched, almost spherical stem.The species is distinguished by a long lifespan (up to 200 years) and a powerful tap root, reaching a weight of 2-12 kg.As a consequence of extensive and unsystematic harvesting, A. gypsophiloides has been added to the list of rare species with a strongly decreasing population in the Red Book of Uzbekistan [18]. A. paniculata (Regel & Herder) Ovcz.& Czukav. is a plant native to Central Asia (Dzungarian Alatau, Tian-Shan, and Alay mountains), where it grows on rocky and graveled slopes of foothills in the lower range of mountains [5,9,19,20].A. tadshikistanica is a herbaceous perennial endemic to the southern Pamir-Alay and recorded in the Red Book of Uzbekistan [5,9,18].

Traditional Uses
The traditional uses of Allochrusa plants date back centuries.The usage of two species of Allochrusa is implemented in official medicine: A. gypsophiloides and A. paniculata. A. gypsophiloides are widely used in conventional medicine and various branches of industry.The roots of Allochrusa (soap root) are used in the food, pharmaceutical, construction, fur, textile, dyeing, and perfume industries.A. gypsophiloides is commonly known as Turkestan soaproot, Beh or Yetmak.A. gypsophiloides is a valuable medicinal and industrial plant that has been widely exported for a long time as the primary source of saponins.A. gypsophiloides (as is the case with most Caryophyllaceae) produces saponins that are utilized in manufacturing sweets or natural washing aids [17].A. gypsophiloides is characterized by high content levels of triterpene saponins (up to 30%) with high surface and hemolytic activities [23].A Central Asian sweet delicacy with a tonic effect called "nisholda" is prepared using large quantities of the roots of A. gypsophiloides as a key ingredient [24].People also use the roots for the preparation of such oriental sweetmeats as parvarda and halva.Additionally, the mining industry (for flotation and the efficient extraction of minerals from waste rocks), the fur cleaning process, and the electrolysis of metals all make extensive use of the roots of saponin-bearing plants [16].The saponins of A. tadshikistanica are also used for the local production of confectionery [5].

Medicinal Uses
In traditional medicine, the decoction of the roots of A. tadshikistanica is used as an expectorant for bronchitis and other respiratory conditions, similar to other plant drugs with saponins [25][26][27][28].A. tadshikistanica (contains saponins) has an expectorant and wound-healing effect [21].By stimulating the Nervus vagus in the stomach, saponins indirectly induce the secretion of water in the lungs; the secretion of water solubilizes the mucus (typical for an expectorant).An infusion of roots of A. gypsophiloides is used as a choleretic, diuretic, and laxative in traditional medicine (a teaspoon of crushed roots is poured into a glass of cold boiled water, left to stand for 8-10 h, and is drunk during the day).Tea or a drink can be brewed to treat gastrointestinal, spleen, skin, liver, kidney, and venereal diseases as well as metabolic dysfunction.Saponins can increase the immunogenicity of several antigens and have been employed in veterinary medicine as an

Traditional Uses
The traditional uses of Allochrusa plants date back centuries.The usage of two species of Allochrusa is implemented in official medicine: A. gypsophiloides and A. paniculata. A. gypsophiloides are widely used in conventional medicine and various branches of industry.The roots of Allochrusa (soap root) are used in the food, pharmaceutical, construction, fur, textile, dyeing, and perfume industries.A. gypsophiloides is commonly known as Turkestan soaproot, Beh or Yetmak.A. gypsophiloides is a valuable medicinal and industrial plant that has been widely exported for a long time as the primary source of saponins.A. gypsophiloides (as is the case with most Caryophyllaceae) produces saponins that are utilized in manufacturing sweets or natural washing aids [17].A. gypsophiloides is characterized by high content levels of triterpene saponins (up to 30%) with high surface and hemolytic activities [23].A Central Asian sweet delicacy with a tonic effect called "nisholda" is prepared using large quantities of the roots of A. gypsophiloides as a key ingredient [24].People also use the roots for the preparation of such oriental sweetmeats as parvarda and halva.Additionally, the mining industry (for flotation and the efficient extraction of minerals from waste rocks), the fur cleaning process, and the electrolysis of metals all make extensive use of the roots of saponin-bearing plants [16].The saponins of A. tadshikistanica are also used for the local production of confectionery [5].

Medicinal Uses
In traditional medicine, the decoction of the roots of A. tadshikistanica is used as an expectorant for bronchitis and other respiratory conditions, similar to other plant drugs with saponins [25][26][27][28].A. tadshikistanica (contains saponins) has an expectorant and woundhealing effect [21].By stimulating the Nervus vagus in the stomach, saponins indirectly induce the secretion of water in the lungs; the secretion of water solubilizes the mucus (typical for an expectorant).An infusion of roots of A. gypsophiloides is used as a choleretic, diuretic, and laxative in traditional medicine (a teaspoon of crushed roots is poured into a glass of cold boiled water, left to stand for 8-10 h, and is drunk during the day).Tea or a drink can be brewed to treat gastrointestinal, spleen, skin, liver, kidney, and venereal diseases as well as metabolic dysfunction.Saponins can increase the immunogenicity of several antigens and have been employed in veterinary medicine as an adjuvant for vaccines against anthrax and brucellosis [24].Allochrusa gypsophiloides extracts have been found to have high immunostimulatory [29], antiviral [30], and anti-tumor action [31][32][33][34].

Phytochemical Compounds
To our knowledge, the phytochemistry of saponin-containing plants of the Allochrusa is yet to be investigated comprehensively.Only three species have undergone thorough research.Studies on the phytochemical content of various Allochrusa species have shown the presence of several classes of primary and secondary metabolites.A literature search found that the Allochrusa is a rich source of triterpene glycosides including saponins [35][36][37][38][39][40][41][42], polysaccharides [16,[43][44][45][46], ecdysteroids [21,47], flavonoids [21,47,48], volatile compounds [49], lignins [50], and other compounds.More than 70 metabolites have been found in the genus.Among these substances, triterpene glycosides are the principal active constituents of Allochrusa species and a typical characteristic of Caryophyllaceae.In the following section, the isolated compounds from the Allochrusa species based on their chemical structures are classified.The most appropriate citation relating to the isolation and characterization of these metabolites is mentioned and highlighted.
The most characteristic and prominent compounds in Allochrusa are terpene glycosides, the highest amount of which were described in A. gypsophiloides and A. paniculata.In previous research on A. gypsophiloides growing in Uzbekistan, the saponin concentration in the aerial parts was 0.79%, and that of the roots ranged from 14.19 to 22.16% depending on their age [48,54].Few data exist on the amount of saponins in A. gypsophiloides based on plant age and growth stage.Accordingly, the content of saponins in the roots rises with plant age, from 9.5% in annuals to 23% in plants that are five years old [55].After the introduction of A. gypsophiloides to Turkmenistan, phytochemical studies were conducted yielding results revealing that the maximal concentration of saponins in the plant roots (up to 20%) could only be observed after five years of culture [56].From the methanol root, the extract of A. gypsophiloides gypsoside (1) was isolated, which is similar to a triterpene glycoside previously isolated from Gypsophila paniculata and Gypsophila pacifica [35].Later, Belous and Ryabinin [57] found gypsogenic acid (8) in considerably lower yields by the saponification of a methanolic extract of A. gypsophiloides.Allochroside is a mixture of four glycosides of triterpene saponins from A. gypsophiloides.It contains acanthophylloside A (minor component, chemical formula unspecified) [36], acanthophylloside B (2, 40%), acanthophylloside C (3, 25%), and acanthophylloside D (4, 25%).They belong to the group of 3,28-O-bidesmoside saponins, specifically glucuronides of quillaic acid and gypsogenin.Compounds from this group have a (substituted) glucuronic acid moiety at the C-3 hydroxyl of the aglycone and belong to the highest glycosylated bidesmosides.Acanthophyllosides B-D (2-4) were identified in the roots of A. gypsophiloides [36,37,[40][41][42]54].Two triterpenoid saponins, 5 and 6, were isolated by Khatuntseva et al. [58] from the methanolic extract obtained from the roots of A. gypsophiloides.The saponins 5 and 6 have quillaic acid or gypsogenin moieties as an aglycon, as in the case of acanthophyllosides B-D, and both bear similar sets of oligosaccharide chains-a 3 Fucp pentasaccharide connected through an ester linkage to C-28 (Table 2).Another triterpene glycoside, paniculatoside C (7), was found in the roots of A. paniculata [41,59,60].

Ecdysteroids
Ecdysteroids are steroid hormones present in insects, aquatic animals, fungi, and higher plants.Plant ecdysteroids are important antifeedant defense compounds, as they interfere with the molting hormone ecdysone of insects.Currently, there are more than 500 known structural analogues of ecdysteroids.They are produced biochemically from C27-, C28-, or C29-sterols.20-Hydroxyecdysone (2β,3β,14α,20R,22R,25-hexahydroxycholest-7-en-6-one) is the most commonly encountered analogue, which is found in plants and arthropods [61,62].Ecdysteroids are primarily produced in the tribe Lychnideae of the subfamily Caryophylloideae of Caryophyllaceae, in which Silene, Lychnis, Petrocoptis, Sagina, and Saponaria are the main ecdysteroid-synthesizing genera of the Caryophyllaceae [63,64].Allochrusa species have been found to contain some ecdysteroids.An investigation of the qualitative and quantitative composition of 20-hydroxyecdysone (ecdysterone) (9) and polypodine B (10) in the aerial parts of the species A. tadshikistanica was carried out by Darmogray et al. [21].The content of these ecdysteroids in this plant was determined by HPLC.Later, another representative of the ecdysteroids, 3-epi-2-deoxyecdysone (syn.3α,14α,22R,25-tetrahydroxy-5β(H)-cholest-7-en-6-one) (11), having analgesic and anti-inflammatory activities, was obtained from a water-ethanol extract of the aerial part of A. gypsophiloides [47,65].This plant was discovered to be a prospective source of the main ecdysteroid 9 whose content in the water-ethanol extract was 0.19%.

Flavonoids
Flavonoids are a group of polyphenolic compounds that belong to one of the most widely studied constituents of the Caryophyllaceae [3].Although some species of Allochrusa were investigated chemically, the characterization of flavonoids in this genus is incomplete.Grudzinskaya et al. [48] reported that A. gypsophiloides and A. paniculata contain the flavonoid quercetin (12).In an HPLC analysis, the flavonoid vicenin (13) was first detected in A. tadshikistanica [21].It should be noted that the C-glycosides of flavones are less common than other flavonoids.[49]

Essential Oils
Essential oils contain aromatic, partially water-soluble, inflammable, and volatile secondary metabolites that are soluble in organic solvents.Steam distillation is used to extract essential compounds from plant material.Essential oils include monoterpenes, sesquiterpenes, phenols, oxides, esters, aldehydes, and ketones.There are three main biosynthetic pathways that produce the most essential oils: mono-and diterpenes are created in the methyl-erithrytol pathway; sesquiterpenes are produced via the mevalonate pathway; phenylpropenes are formed via the shikimic acid pathway [66][67][68].Essential oils were isolated from the aerial parts (leaves, stems, flowers) of A. gypsophiloides [49].The chemical composition of the essential oil was qualitatively and quantitatively analyzed by GLC-MS and the yield of oil was 0.008% (v/w).Fifty-nine compounds were identified in total, accounting for 89.8% of the oil.Pulegone ( 14), trans-p-menthan-3-one (15), transverbenol ( 16), phytol (17), 2-isopropyl-5-methylcyclohexanone (18), and isopiperitenon (19) were the main constituents of A. gypsophiloides essential oil.The results presented that oxygen-containing monoterpenes made up the main fraction in the essential oil of A. gypsophiloides.

Fatty Acids
Fatty acids are lipid biomolecules that are present in all organisms and perform a variety of functions (component of biomembranes and lipid stores).They are used not only in the production of numerous food products, but also in soaps, detergents, and cosmetics [69].No reports are available on the presence of fatty acids in Allochrusa species.For the first time, from the aerial parts of A. gypsophiloides using GLC-MS, several fatty acids were identified [49].According to GLC-MS analysis, hexadecanoic acid (3.6%), tetradecanoic acid (1.1%), octadecanoic acid (0.5%), and linoleic acid (0.2%) were the main fatty acids in A. gypsophiloides.

Polysaccharides, Pectins, and Hemicelluloses
Allochrusa species are plants rich in polysaccharides.From the aerial organs (stems and leaves) and roots of A. gypsophiloides water-soluble polysaccharides, pectin substances, and hemicellulose were isolated.Arifkhodzhaev et al. [46] reported that the neutral polysaccharide of the roots of A. gypsophiloides was polydisperse (molecular weights from 1000 to 2000); the polysaccharide included galactose and glucose residues (5:1) traces of mannose, arabinose, and rhamnose residues.Later, the same researchers [43] investigated the polysaccharides of the stems and leaves, which did not contain polysaccharides of the glucogalactan type that are characteristic for the roots of the plant.
The water-soluble polysaccharides of A. gypsophiloides are described as a mixture of low-molecular-weight glucogalactans.The results of the structural analysis of a glucogalactan from the underground part of A. gypsophiloides showed that the glucogalactan is a branched polysaccharide whose main chain is composed of α-1→6-bound galactopyranose residues.C-2 atoms of the galactopyranose residues function as the branching points, and the reducing ends of the glucogalactan are both galactopyranose and glucopyranose residues [44].The glucogalactan obtained from the A. gypsophiloides was partially acid hydrolyzed and produced four oligosaccharides.Two of them, branched tetra-and pentasaccharides, were obtained for the first time [45].
The polysaccharides obtained from the roots of A. paniculata have been studied by Arifkhodzhaev [16] and pectin substances, water-soluble polysaccharides, and hemicelluloses have been yielded and described.The principal neutral polysaccharide of A. paniculata was a glucoarabinogalactan.The quantity, structure, and monosaccharide composition of the neutral polysaccharide of A. paniculata were significantly different from those of the neutral polysaccharide of A. gypsophiloides.The water-soluble polysaccharides consisted of glucose, galactose, mannose, xylose, arabinose, and rhamnose residues in the following ratios: 5.0:11.0:1.0:3.5:4.4:4.0,respectively.The pectin substances within the neutral polysaccharide of A. paniculata contained galactose, glucose, mannose, arabinose, and rhamnose residues (1.1:1.0:1.0:8.5:2.8 ratio, respectively).The results also showed that the hemicelluloses of the neutral polysaccharide were composed of galactose, glucose, mannose, xylose, arabinose, and rhamnose residues (1.0:2.1:1.6:3.6:3.2:tr.).In addition to the neutral saccharides mentioned above, all the polysaccharides of A. paniculata also had uronic acid units bonded within their structures [16].

Other Compounds
The species of Allochrusa have tested positive for alkaloids, lignins, and carbohydrates [48].Lignins are polymeric compounds with complex structures.The natural lignin of paniculata has been studied by catalytic hydrogenolysis and the results showed that there are three forms of lignin structural units: syringyl, guaiacyl, and p-coumaryl, which is typical for plants [50].

Biological Activities
Allochrusa species are used for a variety of purposes in conventional medicine around the world; therefore, they have been studied for their different biological activities.Mostly, Allochrusa species have been used in Central Asian ethnomedicine for treating bronchitis, gastrointestinal, skin and genital conditions, as well as spleen, liver, and kidney disorders [24].The biological activities, including adjuvant, cytotoxic, anti-inflammatory, hemolytic, antifungal, analgesic, antioxidant, and other effects, have been revealed in some studies.Most investigations of triterpene glycosides have been conducted without studying the nature of the active compounds.The findings of these investigations, including both positive and negative results, are given below.

Anti-Inflammatory Activity
Any damage of cells or tissues results in inflammation, often accompanied by pain [27,28,70,71].Chronic diseases can develop as a result of the persistent exposure to these different stresses, which can include viruses, toxins, UV radiation, and pollution, among others.The components isolated from the Allochrusa species have never been studied for their anti-inflammatory effects.However, there is evidence that saponins have antiinflammatory properties.In many studies, the mice paw model with histamine-induced acute inflammation was employed to determine edema development [57].There were two methods to administer saponins: orally and intraperitoneally.In the first experiment, compound 5 (20 mg/kg and 50 mg/kg body weight), compound 6 (20 mg/kg and 50 mg/kg BW), indomethacin (20 mg/kg BW), and water were given orally to six groups of eight mice each (control).An hour after receiving the medications, each mouse received a subcutaneous injection of 0.05 mL 0.1% histamine in the right hind paw.Edema production was evaluated after the injection of histamine.The anti-inflammatory effect of compounds 5 and 6 was measured by the decrease in the index of edema compared to the control group, which is calculated as the percentage difference between the mass of the healthy and the inflamed paw, relative to the mass of the healthy paw.In contrast to the experiment with oral administration, saponins 5 and 6 had an anti-inflammatory effect that was generally dose dependent.Compound 6 failed to demonstrate any consistent anti-inflammatory activity in the trial based on oral dosing.The results of the experiments showed that compound 5 had stronger anti-inflammatory effects than compound 6 in the trial based on intraperitoneal dosing [58].The ecdysteroid 11 isolated from A. gypsophiloides was studied for its anti-inflammatory activity by Tuleuov et al. [47].In this screening, the anti-inflammatory effect of compound 11 was performed on male rats.Peritonitis (acute exudative response) was induced by injecting 1% acetic acid intraperitoneally (1 mL per 100 g of the rat body weight).Compound 2 decreased the exudation volume in rats by 24% at a dosage of 50 mg/kg body weight when compared to the control group.Saponins may exert corticomimetic properties or can inhibit phospholipase A2α (PLA2α); these properties could explain the anti-inflammatory activities [72].

Immunomodulatory Activity
Saponins from A. gypsophiloides (Algiox) can form immunostimulatory complexes (ISCOMs) that stimulate cellular immunity in mice as documented by Turmagambetova et al. [32].As control preparations, ISCOMs were used containing the saponin Quil-A and micelles of H7N1 influenza virus glycoprotein antigens.The results demonstrated that a single-dose subcutaneous immunization with ISCOMs containing Algiox saponins was able to stimulate different phases of immunity (similar to ISCOMs containing the saponin Quil-A).A water-extractable fraction of saponins, Quil A, is derived from the plant Quillaja saponaria.When compared to immunization with micelles of H7N1 influenza virus glycoprotein antigens, the studied ISCOMs significantly increased the levels of IFN-, IL-2, IL-4, and IL-10 cytokines.The findings demonstrated that Algiox saponins could form immunostimulatory nanocomplexes with a similar immunostimulatory efficacy and structure to ISCOMs containing the saponin Quil-A.It has been proposed by the authors [32] that Algiox saponins obtained from A. gypsophiloides can be used to stimulate cellular and humoral immunity.

Adjuvant Activity
Saponins are known as effective adjuvant molecules.Extracts from A. gypsophiloides exhibited nonspecific activity compared to various antigenic ргерarations such as bovine serum albumin, the parainfluenza virus, and РG-3 [73].Acanthophylloside (allochroside or a mixture of acanthophyllosides A-D) mediated the most potent adjuvant efficiency, which was similar or even superior to the other saponin preparations obtained from the "Меrck", "Spofa", and "DVN" companies.The agent (allochroside) was also an effective adjuvant when used as an ingredient in the inactivated adsorbed vaccine for foot and mouth disease.It substantially enhanced its immunogenicity in cattle experiments.The data obtained in the course of the experiments showed that the administration of acanthophylloside to guinea pigs significantly activated the process of their antibody formation against immune bovine serum albumin.Based on the data they obtained, the authors concluded that saponins, the aglycones of which are represented by gypsogenin and quillaic acid, have a pronounced adjuvant activity [73].Khatuntseva et al. [58] recently evaluated the adjuvant potential of triterpene glycosides 5 and 6 isolated from A. gypsophiloides.Test immunizations were carried out by using the keyhole limpet hemocyanin (KLH) protein carrier and synthetic vaccine neoglycoconjugate 3 SL-KLH (α-NeuAc-(2→3)-β-Galp-(1→4)-β-Glcp-KLH) on the basis of 3 SL (3 -sialyllactoside) ligands.The specific anti-3 SL IgM and IgG responses were measured after immunizing four groups of mice with the saponin of Quillaja bark, 40 µg of 3 SL-KLH along with 50 µg of compounds 5 and 6, or without an adjuvant.Comparing the test vaccine formulation with the antigen alone in terms of the control vaccine formulation, a substantial specific response was seen for saponins 5 and 6.The results demonstrated that high blood titers of IgM and IgG antibodies were recorded in the vaccination using compound 6 as an adjuvant, while the IgG level was less with the saponin from Quillaja bark.The levels of such antibodies in the saponin 5 experiment were rather modest.The authors concluded that antigen compound 6 demonstrated strong adjuvant qualities when combined with 3 SL-KLH and can thus be viewed as a potential component of vaccination formulations.The investigations of Turmagambetova et al. (2017) demonstrated that Algiox was capable of forming immunostimulatory nanocomplexes that were similar to ISCOMs containing the saponin Quil-A in terms of structure and immunostimulatory effectiveness.The adjuvant effect of the Algiox was studied in mice by subcutaneous injection with lipids and glycoproteins of the H7N1 influenza virus and ISCOMs containing saponins.The findings showed that H7N1 viral glycoprotein antigens, ISCOMs containing lipids, and saponins induced a high level of IgG and IgG2a serum antibodies.The level of the immune response and protective efficacy was greater than that induced by micelles containing glycoproteins combined with an aluminum hydroxide adjuvant, viral glycoproteins, or whole virions; the response was also similar to that elicited by ISCOMs containing Quil-A.
As a result of the investigations, Algiox was recommended as an additional source of effective adjuvants for both human and veterinary vaccines [32].

Hemolytic Activity
Triterpene saponins are amphiphilic substances that can interfere with biological membranes.Saponins with lipophilic moiety can complex cholesterol and related lipids inside biomembranes; the hydrophilic side chains bind to proteins on the cell surface.This tension leads to a cell lysis.It can be best demonstrated with red blood cells, which disrupt when exposed to saponins [27,28,70].The hemolytic activity of a bacterium or molecule is its ability to destroy red blood cells, leading to the release of hemoglobin.
The researchers Bazhenova and Aliev [74] investigated the hemolytic index of the saponin (a mixture of seven paniculatosides) isolated from A. paniculata.The hemolytic activity of paniculoside was determined and paniculatoside has a pronounced activity equal to 1 in 5000.For the purified saponin Algiox, the investigation of in vitro hemolysis was performed by Turmagambetova et al. [32].The Quil-A concentration that caused 50% hemolysis (HD 50 ) was 225 µg/mL, whereas the HD 50 for Algiox was 700 µg/mL.The Algiox preparation that was tested contained derivatives of quillaic acid [75].An in vitro hemolysis investigation was conducted by Khatuntseva et al. [58] using compounds 5, 6, and Quillaja bark saponin (as a control).According to the results, the saponin from Quillaja bark induced 100% of the hemolysis at the dose of 5.5 µg/mL.The hemolytic activity of saponins 5 and 6 was substantially lower; 50% hemolysis was seen at doses of 11 to 18 µg/mL, respectively.Compounds 5 and 6 caused hemolysis of 85-95% at a concentration of 62.5 µg/mL.Reference saponins QS-17, 18, and 21 obtained from Quillaja bark induced hemolysis at doses of 7-25 µg/mL.The findings are in good agreement with expectations that bidesmosidic saponins (as in the case of compounds 5 and 6) and the existence of glucuronic acid moiety at C-3 position of the aglycone have limited hemolytic activity [58].

Cytotoxic Activity
Saponins exhibit cytotoxic activities that are promoted by their membrane-disrupting activities described for hemolysis.The in vitro and in vivo toxicity of the Algiox saponin from A. gypsophiloides was experimentally evaluated [32].In comparison to the saponin Quil-A, which was employed as a reference, the saponins isolated from A. gypsophiloides displayed lower cytotoxicity in tests performed with model cell cultures.The cytotoxic concentrations (IC 50 ) of Quil-A were 21 µg/mL and 28 µg/mL in macrophages and MDCK (Madin-Darby canine kidney) cells, respectively.The IC 50 values of Algiox in macrophages and MDCK cells were 103.5 µg/mL and 93.75 µg/mL, respectively.The cytotoxicity of the essential oil isolated from the aerial parts (leaves, stems, flowers) of A. gypsophiloides was determined in human colon adenocarcinoma (HT-29) and prostate cancer (PC-3) cells by MTT assay [49].The results showed a moderate cytotoxicity against PC-3 (IC 50 = 89.9± 2.01 µg/mL) and HT-29 cells (IC 50 = 43.6 ± 2.38 µg/mL).In a different study, biologically active compounds were extracted from the aerial parts of A. gypsophiloides using methanol, chloroform, and water as solvents [76].The water extract had mild cytotoxic effects on leukaemia cell lines (CEM/ADR-5000: IC50 = 31.9g/mL), leukemic lymphoblasts (CCRF-CEM), and breast cancer cells (MCF-7: IC50 = 145.9g/mL).

Analgesic Activity
Tuleuov et al. [47] studied the analgesic activities of 3-epi-2-deoxyecdysone (11) isolated from A. gypsophiloides.The peritoneal chemical irritation test (also known as the acetic acid writhing test) in white outbred mice was used to examine the analgesic effects of the compound 11.The mice were injected with 0.1 mL/10 g BW intraperitoneally with an acetic acid (0.75%) solution.The samples were administered intragastrically at a dose of 50 mg/kg BW before the acetic acid injection.The "writhes" were measured immediately following administration and for a period of 30 min.Tests were conducted using a concentration of 50 mg/kg BW of the reference painkiller diclofenac.The results of the test showed that compound 11 exerted an analgesic effect.

Antifungal Activity
Triterpene glycosides also interfere with biomembranes of fungi and thus have often shown antifungal properties [27,28,70].Compounds 5 and 6 were tested against four fungal cultures: basidiomycetous (Cryptococcus terreus, Filobasidiella neoformans) and ascomycetous (Saccharomyces cerevisiae, Candida albicans) yeasts [58].The results demonstrated that compounds 5 and 6 exhibited an antifungal effect against all the tested yeasts, especially the therapeutically significant C. albicans and F. neoformans.Growth-inhibiting tests revealed that saponins 5 and 6 had stronger antifungal effects at a pH of 4.0 than at a higher pH.At pH 7.0, the tested substances had no effect against C. albicans and F. neoformans.However, against these two strains both saponins were antifungal at pH 4.0.Notably, S. cerevisiae was resistant to compound 5 at either pH level.

Acute Toxicity
The toxicity of the mixture of paniculatosides (paniculatoside) was investigated on white mice that had been treated with saponins (intravenously, subcutaneously, and orally) [74].With an intravenous administration of paniculatoside in doses of 5-20 mg/kg BW, mice showed an increase in motor activity, followed by depression, and the mice huddled together.At high doses, mice died on the first day, and at low doses some mice died on the second and third days after treatment.Therefore, observations were carried out for 8 days.The following LD 50 values were obtained: the LD 50 value for the intravenous administration was 11.1 mg/kg, in the case of subcutaneous administration it was 77.5 mg/kg, and for oral administration 2550 mg/kg.Thus, paniculoside is a relatively toxic drug.Its toxic effect is reduced by subcutaneous and oral administration, which is typical for saponins [74].The acute toxicity study of two triterpene glycosides (5 and 6) isolated from the roots of A. gysophiloides was carried out in vivo with male mice [58].After a single oral or intraperitoneal dose, the corresponding LD 50 values were calculated: The LD 50 for oral administration ranged between 252 ± 57 mg/kg for compound 5 and 304 ± 55 mg/kg for compound 6.The LD 50 for the intraperitoneal administration of compounds 5 and 6 was 5.4 ± 2.8 mg/kg BW and 15.1± 5.6 mg/kg BW, respectively.The strong differences in LD 50 values between oral and intraperitoneal experiments indicated that the saponins were not being absorbed in the intestines.In in vivo tests, the toxicity of Algiox was evaluated [32].Within the study, the toxicity was evaluated based on lethality, weight, and hair loss.For chickens and chicken embryos, the Quil-A LD 50 was 225 µg/animal, while for mice, it was 187.5 µg/animal.Algiox's LD 50 in mice was found to be 650.4µg/animal, whereas it was 850 µg/animal in chickens and chicken embryos.Lethality experiments performed on mice, chicken embryos, and chickens revealed that the assessed Algiox saponins were not toxic in the range of concentrations used.The standard threshold dose for vaccines is 15.0 µg per animal, which is at least 40 times less than the LD 50 calculated for the Algiox saponins.

Other Activities
Bazhenova and Aliev [74] investigated several pharmacological parameters (the effect on the central nervous system, blood pressure, heart arrhythmia, smooth muscle, diuresis) of the saponins isolated from A. paniculate (a mixture of seven paniculatosides) in rats.
In doses of 1-10 mg/kg body weight, paniculoside briefly decreases blood pressure by 40-50%, followed by its restoration.There are no significant changes in respiration.In experiments with the in situ rat heart, paniculatoside at a concentration of 3 mg/kg body weight increased the amplitude (by 14%) and slightly slowed down the heart rate.With ECG research, the R-R interval increased by 31%.In doses of 3-5-10 mg/kg BW, the drug did not relieve or prevent the development of calcium chloride arrhythmia caused by the intravenous administration of calcium chloride (270 mg/kg).The drug at a concentration of 5 mg/kg body weight significantly, and at a concentration of 20 mg/kg almost completely, suppressed the components of the orientation reaction in white mice.At a concentration of 50 mg/kg, paniculatoside does not affect the sleep of white mice induced by chloral hydrate (300 mg/kg), hexanal (75 mg/kg), and nеmbutal (60 mg/kg).At the same time, at the concentration 50 mg/kg, it remarkably lengthened the latent period of corazole seizure onset.Paniculotoside did not have a ganglioblocking effect and did not change the blood pressure response caused by the intravenous administration of acetylcholine (0.5 µg/kg BW) and adrenaline (10 µg/kg BW).Paniculotoside enhanced the action of histamine (0.5-1 µg/kg BW) both in the acute experiment and in an isolated segment of the intestine of rats, which occurs 30-60 min after the administration of the drug and lasts 1.5-2 h.In experiments on rats, the drug in doses of 10-20 mg does not have a diuretic effect.It briefly lowers blood pressure and enhances the effect of histamine when administered exogenously [74].Saponin isolated from the roots of A. gypsophiloides decreased the convulsive and toxic effects of corazole, potentiated the convulsive effect of strychnine, antagonized the narcotic effect of chloral hydrate, and increased diuresis in mice [77].We studied the anthelmintic effect of the methanol, chloroform, and water extracts of A. gypsophiloides on Caenorhabditis elegans.Antihelmintic tests revealed that samples at the tested concentration of 500 µg/mL did not kill C. elegans [78].

Conclusions and Future Perspectives
This review revealed that Allochrusa species possess diverse chemical compounds and biological activities and people from Central Asia use these plants to treat a wide spectrum of human diseases.Allochrusa species as food and medicinal plants have always been used by people and the impact of plant-based foods and their bioactive secondary metabolites on human health and wellbeing is undoubted.It is necessary to collect this ancient knowledge through official documentation and keep it for future research.The genus Allochrusa is native to the mountains and deserts of Central and South-Central Asia.Apparently, Allochrusa is a good source of bioactive molecules.Therefore, in the next stage of research, the components of Allochrusa species should be subjected to wider phytochemical and pharmacological analyses.The phytochemistry of Allochrusa has not been exhaustively studied, not even in the well-studied species of Allochrusa.Phytochemical studies on A. gypsophiloides are scarce and were mostly conducted in the 1960s-1980s of the last century.Certainly, it would be worth investigating all species for new bioactive molecules.It was established that triterpene glycosides serve as chemotaxonomic markers for the characterization of Allochrusa species.In recent years, natural saponins of this genus have been found to have significant adjuvant, cytotoxic, anti-inflammatory, hemolytic, antifungal, analgesic, antioxidant, and other effects.Therefore, in the next stage of research, the components of Allochrusa species should be subjected to wider phytochemical and pharmacological analyses.Additional chemical analyses of other metabolites using modern analytical methods and pharmacological studies will complete the knowledge of this genus.In addition to their possible use as detergents, saponins have a wide range of other potential applications, including those in the food, cosmetics, and pharmaceutical industries.The saponins from A. gypsophiloides were recommended as an additional source of highly effective adjuvants for vaccines.Some Allochrusa species are rare and endangered in nature.The thickets of Allochrusa have been significantly depleted in recent years, which was the reason for including selected species in the Red Data Books.To meet the needs of the pharmaceutical and food industries for raw materials, it is necessary to cultivate these Figure 1.Photos of some Allochrusa species (https://www.plantarium.ru/lang/en/page/view/item/43196.html/,accessed on 23 December 2022).

Table 1 .
Diversity and distribution of different Allochrusa species in Asia.

Table 2 .
Structures and distribution of secondary metabolites in the genus Allochrusa.

Table 2 .
Structures and distribution of secondary metabolites in the genus Allochrusa.