Biological activity and phytochemistry of Dracaena angolensis Welw. ex Carrière

Dracaena angolensis Welw. ex Carriere also known as Sansevieria cylindrica is a decorative plant due to its unique shape. Beside its ornamental value, it is recognized for its ability to eliminate unpleasant odours and absorb air pollutants. In various African and Asian countries, the plant ’ s leaves and roots have been widely used as traditional medicine to treat an assortment of ailments, including coughs, diarrhoea, hemorrhoids, chickenpox, rheumatism, gynaecological problems, as well as an antiseptic, snake bites, wound healing and refreshing beverage. Previous research showed that leaves and rhizomes of D. angolensis contain bioactive compounds such as alkaloids, saponins, cardenolides, polyphenols, steroids and abamagenin. Therefore, this review aims to provide information on the D. angolensis plant in terms of its distribution, taxonomy, phytochemical content and pharmacological potential. It presents the use of D. angolensis as traditional medicine in various regions as a candidate for natural medicine and identifies the opportunities for its development. Based on pharmacological literature, the plant has the potential as an antioxidant, anticancer, antibacterial and antitoxic agent. However, the literature on its antioxidant and anticancer potential is more extensive than its antibacterial and antitoxic properties. Further research on the pharmacological potential of this plant is necessary and its safety parameters need to be research in greater detail.


Introduction
Most of the species the genus Dracaena originate from the continent of Africa and Asia.Morphologically, the genus has thick leaves with high water content and various of leaf shapes, from cylindrical to rigid sword-like blades (1).Similarly, the colors and patterns also vary, from green, yellow, to white (2,3).
The species of Dracaena that is commonly used and easy to grow is Dracaena angolensis Welw.ex Carrière or commonly known as Sansevieria cylindrica.African spear or Cylindrical snake plant is a succulent indoor decorative plant.Beside its decorative value, this plant is a traditional medicine commonly used to treat influenza, coughs and respiratory tract inflammation (1,(4)(5)(6)(7).In ethnobotanical research, it has been used by communities in several regions such as the Buton tribe in Southeast Sulawesi Province, Central Sulawesi, South Sulawesi, Liwa in Lampung, Lubuk Linggau in South Sumatra, Purwakarta in West Java and Kaliurang Village in Yogyakarta (8)(9)(10)(11).The leaves and rhizomes of the genus are used in traditional medicine to treat various ailments such as cough, asthma, eczema, edema, malaria, anuria in Lampung and Lubuk Linggau.All parts of this plant are used by locals in Purwakarta to treat conditions like viral hepatitis, weak sexual function, high blood pressure, piles, colic, jaundice, palpitations and insect and snake bites.The leaves are medicine for coughs, flu and diarrhoea South Sulawesi and Buton.Meanwhile, the roots treat snake bites in the Bulan Jaya area of Central Sulawesi.People living on the slopes of Mount Merapi in Yogyakarta use D. angolensis as an air freshener, pollution absorber and treat wounds (11)(12)(13)(14).
According to the preceding information, D. angolesis has numerous advantages and contains active compounds that are beneficial to the environment and medicine (1,2,21,(26)(27)(28)(29)(30)(31).However, no ethnopharmacology-related literature studies have ever been conducted.As a result, a systematic review of its traditional use in various countries is required.Furthermore, information from the literature about the pharmacological properties of D. angolensis must be studied and analysed.

Distribution and Habitat
Dracaena angolensis, commonly known as snake plant or mother-in-law's tongue, originates from West Africa.The plant is found in tropical countries from eastern Nigeria to Congo and has been naturalized in Madagascar, India and other tropical regions.The plant can grow up to 4 feet tall in its natural habitat, while indoor plants typically grow to around 2 feet tall (32).Dracaena is a genus of xerophytic perennial plants with 60 species distributed in tropical Africa, Asia and Arabia.There are wide hybrid and horticultural varieties of Dracaena, which makes the classification of plants in this genus difficult (33).Within the genus Dracaena, D. angolensis is the most commercially traded species in the nursery industry.It was reported that at least 20 cultivars of this species are sold in nurseries worldwide, distributed to America, Asia, Australia and the Pacific Islands as ornamental and fiber plants.Furthermore, the plant is widely naturalized in Asia (India, Indonesia, Malaysia, Thailand and Vietnam), Australia, America (United States, Puerto Rico and the Virgin Islands), and in several Pacific islands (Cook Islands, Fiji, Palau, Western Samoa and Hawaii) (34).
The native habitat of this plant was originally in the form of weeds on roadsides, growing in neglected gardens, waste areas, abandoned sites, coastal environments and the edges of wet and dry forests in tropical, subtropical and warm climates.Species within the genus have several adaptations to survive in dry arid areas such as thick and watery leaves to store water and a thick leaf cuticle that reduces moisture loss.The species use crassulacean acid metabolism (CAM) for photosynthesis, reducing water loss through nocturnal transpiration and increasing drought and heat tolerance.Additionally, D. angolensis has high salt tolerance level and low nutrient requirements (33).This species grows in various light conditions ranging from open areas with full sun exposure under forest canopies, in tropical, subtropical and warmer climates (1,31).

Taxonomic characters
Dracaena angolensis is a succulent plant with a striking morphology.The roots have fibrous or wild roots grown from the base of stem.Another characteristic of D. angolensis has rhizomes that grow on the surface or inside the soil (3,16).The stem is inside the creeping rhizome and has relatively thick soil.The rhizome is bright orange on the outside and whitish on the inside.It has round, rough and stiff leaves with fine greenish-grey lines.One leaf is 1.2-3 cm thick and grows 0.9-2.1 m long with a dense, stiff, cylindrical leaf colony that grows in a fan shape from the basal rosette.Furthermore, it has slow growth supported by underground rhizomes that support 3-4 or more leaves (16).The plant has many flowers that grow in clusters near the top of the plant.They grow in groups of 1-3 along the stem that produces the flowers.The flower stalk stands upright, relatively slender and shorter than the leaves with a 30-75 cm long stalk.The flowers are 2.5 -4 cm long, tube-shaped, smooth and colored greenish-white to pink.The plant can produce white flowers with pink buds up to 90 cm tall when grown in sufficiently bright light.The plant blooms once a year and can flower more frequently at a young age than other species (16).The solitary flowers are arranged in 2 or 3 clusters.These flowers have six flower sepals partly fused into a tube about 6-12 mm long and separated into six 15-20 mm long lobes the end.The lobes are narrow and bend backward when the flower is fully open.Each flower is supported on a stalk that is 6-8 mm long, has 6 stamens about 7-8 mm long and a pistil about 15-18 mm long with a small stigma on top.The fruit of D. angolensis is small and round and the color changes from green to bright orange when ripe.This fleshy fruit has a 7-9 mm diameter and consists of two seeds, which are pale brown and elongated in shape, with a length and width of 6-7 mm and 5 mm (33) (Fig. 1).

Traditional medical Uses
D. angolensis Welw.ex Carrière originates from subtropical regions of Africa and is cultivated in Myanmar as an ornamental plant.This species is also utilized as a traditional medicine, particularly in remote rural areas of the country where herbal remedies are commonly used insteas of less available Western drugs.The entire plant is used to treat cuts, sprains and broken bones, while the roots are used to treat snakebites.It was reported that D. angolensis contains several amino acids and proteins useful for healing certain diseases (24).It is traditional use in several countries includes the treatment of fever, itching, respiratory infections, coughs, hemorrhoids, influenza, cough, diabetes, cancer and respiratory infections (35).As a hair tonic, natural antibiotic and pain reliever, this plant is often used externally for treating bruises, sprains, wounds and boils.It is used by boiling its leaves and roots before consumption.For external treatment such as wounds and snakebites (Table 1).

Antioxidant Activity
The research on D. angolensis indicates the exploration of its potential as an antioxidant and the testing method used was the 2,2-diphenyl-1-picrylhydrazyl (DPPH) (Table 2).Furthermore, 3 research on the antioxidant potential showed IC50 values below 100 µg/mL (21,22,36), indicating high and promising antioxidant activity.High antioxidant activity is influenced by the phytochemical compounds present in D. angolensis, especially phenolic compounds (37,38).Previous studies have reported that D. angolensis leaf extracts contain phenolic compounds, including flavonoids such as homoisoflavone and pyran-isoflavone (3,26,39).In addition, triterpenoid compounds, namely squalene and saponin compounds have also been reported to have antioxidant activity (40,41).

Anticancer activity
Based on Table 3, research on the cytotoxicity of D. angolensis has been conducted on breast cancer cells (MCF-7), colon cancer cells (Caco-2), colon cancer cells (HT116), liver cancer cells (HepG2) and cervical cancer cells (HeLa).Cytotoxicity activity categories based on the US National Cancer Institute ( (42,43), showed that the methanol extract of D. angolensis rhizomes exhibited very strong cytotoxic activity against HeLa cells.The methanol extract of D. angolensis leaves showed weak and moderate cytotoxic activity against MCF-7 cells HepG2 cells.The methanol extract of D. angolensis also showed moderate cytotoxicity activity leaves against MCF-7, HT116 and HepG2 cells, while weak cytotoxic activity was shown against Caco-2 cells.From Table 3, it is evident that the strongest anticancer activity is present in the roots.
Further investigation is still needed on the potential of phytochemical compounds contained in both the roots and leaves of D. angolensis as anticancer agents.Exploration of other solvents and plant parts that can be used, such as flowers, is necessary.Moreover, it is necessary to examine which compounds present in the roots are responsible for the anticancer activity that is not found in the leaves.

Antimicrobial activity
Research on the antibacterial activity of D. angolensis is still very limited.It was reported that the leaves extract have the potential as an antibacterial agent (44).Active compounds functioning as antibacterial agents include saponins, polyphenols and flavonoids (44).Phytochemical tests of D. angolensis root and leaf extracts contain alkaloids, tannins, anthraquinones, terpenoids, saponins, flavonoids, steroids and phenols and have the ability as a natural antiseptic and antibacterial agent to inhibit the growth of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa (15,20,26,45).Further studies are still needed to explore the full potential of D. angolensis as an antibacterial agent.4).The antibacterial activity is stronger than that of other Dracaena species, such as D. trifasciata.Based on research conducted (46), the active fraction of D. trifasciata leaves can inhibit biofilm formation and virulence-related genes of Pseudomonas aeruginosa more effectively than D. angolensis (46).Further research into the potential phytochemical compounds found in D. angolensis as antibacterials is required to validate the plant's potential.Exploration of other solvents and plant parts such as flowers and roots also need to be conducted.Additionally, the mechanism of action of the ethanol extract of the leaves needs to be further research at the cellular and molecular levels.

Toxicity
Toxicity testing of D. angolensis is still limited, and based on Table 5, several species have been used for toxicity testing, including Wistar albino rats and indomethacininduced ulcer in pyloric-ligated rats.The results of toxicity testing using the indomethacin-induced ulcer in pyloricligated rats showed that various extracts of D. angolensis had a toxic effect.Meanwhile, the LC50 values below 1000 μg/mL indicate a toxic treatment.Different results were shown in toxicity testing on Wistar Albino Rats, where the LC50 value was higher than the LC50 value in indomethacininduced ulcer in pyloric-ligated rats.Acute toxicity with the brine shrimp lethality test is classified as toxic when the LC50 value is below 1000 μg/mL (47).However, research on the safety of D. angolensis still needs to be conducted, considering its effects on various organs such as the kidney, liver, and reproductive organs.In addition, toxicity testing using the brine shrimp test needs to be carried out.
Effective antioxidants, antitoxins and antibacterial can be extracted from the leaves of D. angolensis using ethanol and methanol.According to one report (48), compounds present in the ethanol leaves extract can work synergistically, indicating the potential of the extract as a candidate for antibacterial and antioxidant agents.Meanwhile, methanol extract, on the other hand, is commonly used for anticancer activity of both leaves and roots.
Dracaena plant is reported to be rich in sapogenins and steroid saponins.D. angolensis contains phytochemical compounds believed to be involved in its pharmacological activity.Several research showed that the roots, rhizomes and leaves of D. angolensis contain various groups of compounds including alkaloids, tannins, terpenoids, saponins, steroids, phenols, cardenolides, polyphenols, methyl glucuronate acid, glycosides, carbohydrates and abamagenin.Additionally, the plant is rich in bioactive phenolic compounds, including rare homoisoflavonoids that form a characteristic subclass.Meanwhile, previous phytochemical investigations of D. angolensis leaves have shown inhibition of capillary permeability.A new steroid saponin has been isolated from the leaves of D. angolensis that exhibits capillary permeability inhibition.The structure of this saponin was (3beta,12beta,15alpha,25S)-26-(beta-Dglucopyranosyloxy)-22-hydroxyfurost-5-en-3-yl 12-O-(6 -deoxy-alpha-L-mannopyranosyl)-15-O-(6-deoxy-alpha-L-mannopyranosyl)-beta-D lucopyranoside (Table 6).Moreover, (+)-Trifasciatine B and dihydrochalcone (+)trifasciatine C from D. angolensis are known to exhibit moderate cytotoxicity against MCF7 cells (19,28,50).Specifically, the chemical compounds identified in the leaves and rhizomes of D. angolensis include tannin, gluco-galin, gallic acid, corilagin, ellagic acid, terchebin, chebulagic acid, chebulinic acid, mucic acid, phyllembic acid and emblicol (Table 6).The content of steroid saponin in the methanol extract of D. angolensis leaves was 0.058 mg of DE/g and the rhizomes was 0.065 mg of DE/g.Some of the chemical compounds studied in the leaves and rhizomes of D. angolensis include (25R  (19,28,50).These compounds were capable of inhibiting biofilm growth and reducing the expression of genes in P. aeruginosa that cause its pathogenicity (17).Furthermore, Squalene, campesterol, neophytadiene, palmitic acid and linoleic acid have been reported to have anticancer properties (40,48,51,52).D. angolesis contains bioactive compounds that could be used in the development of natural medicine.The presence of these phytochemical compounds strengthens the potential of D. angolensis to be used as a medicinal plant in the community, including its potential as an antioxidant, anticancer, antimicrobial, antitoxicity agent.The plant can be a valuable source of natural products with the potential to be recommended for applications in

Table 1 .
The use of D. angolensis as traditional medicine in various countries

Table 2 .
Antioxidant activity of D. angolensis

Table 4 .
Antimicrobial activity of D. angolensis

Table 5 .
Toxicity of D. angolensishuman and veterinary medicine in the future.