Phytochemical composition and health properties of Sembung plant (Blumea balsamifera): A review

Indonesia’s mindset has been focusing on the use of natural medicines, food, and healing practices widely recognized by the nation’s culture. Traditional medicines and herbs used in traditional medicine can often lead to the discovery of drugs against certain diseases. The aim of this review was to study evidence-based data on the importance of Sembung plant, Blumea balsamifera, as a potential traditional medicine. The distribution, ethnopharmacology, secondary metabolites, and bioactivity against several diseases are focused in this review. Information and research related to Sembung plant were searched using the terms “B. balsamifera,” “phytochemicals,” and “pharmacological activity” on ResearchGate, Google Scholar, Science Direct, PubMed, and scientific information-based databases up to 2020. Several ethnomedical articles recommend B. balsamifera for the treatment of sinusitis, colic pain, cough, kidney stones, flu, or as a diuretic. This knowledge has already been applied in several countries in Southeast Asia. B. balsamifera has been reported to contain several phytochemicals both volatile (terpenoids, fatty acids, phenols, alcohol, aldehydes, ethers, ketones, pyridines, furans, and alkanes) and non-volatile (flavonoids, flavanones, and chalcones). Extracts and phytochemicals of B. balsamifera contain several biological capacities such as antioxidant, antimicrobial, antifungal, anti-inflammatory, hypolipidemic, anti-infertility, hepatoprotective activity, antidiabetic, gastroprotective, antitumor, anticancer, and immunomodulatory agent against Coronavirus disease-19 infection. This review provides essential data for the potential application of B. balsamifera as a nutraceutical or in future medicinal preparations.


Introduction
Indonesia has enormous potential for the development of herbal medicines and traditional medicinal preparations that have been already traditionally used to treat various diseases [1]. Apart from Indonesia, the use of traditional medicines has also been developed in other countries of the Southeast Asian Association (ASEAN) in recent years [2]. The use of these traditional plants has been targeting several diseases, from a common cold to cancer [3]. Contemporary research has validated several parts of plants from roots, stems, and leaves in potential medicinal preparations by screening for active ingredients such as plant metabolites [4][5][6].
Blumea balsamifera (L) DC. (Asteraceae) or known as local Sembung (in Indonesia) has been widely used as a traditional medicinal preparation for thousands of years. Several countries in Southeast Asia, such as China, Malaysia, Thailand, Vietnam, and the Philippines, have also used the Sembung plant as a traditional medicine [7]. Species from the genus Blumea are distributed across tropical Asia, Africa, and Oceania [8], with the highest level of diversity in tropical Asia [9,10], including Indonesia. To date, as many as 49 species of Blumea are distributed worldwide, with 27 found in Southeast Asia [11]. In the last decade, researchers have focused their investigations on species from the genus Blumea that are used in Ayurvedic (Indian) medicinal ingredients and traditional drinks (Loloh) by Balinese people in Indonesia [12,13].
Therefore, this review provides evidence-based information on the potential biological activity of B. balsamifera, not only toward a central role as a nutraceutical in traditional medicine but also as an interesting plant to undergo further phytochemical and pharmacological studies.

Traditional Use in Several Countries
B. balsamifera is a wild terrestrial plant that can grow to an altitude of 2200-3500 m asl in humid to dry areas ( Figure-1) [14]. B. balsamifera has many names in several countries such as Ainaxiang and Dafeng "ai" in China, and it is commonly used Available at www.veterinaryworld.org/Vol.14/May-2021/17.pdf as an incense because of its high content in essential oil [15]. In Thailand, dried leaves of the Sembung (Naat) plant can be used as a cigarette to relieve sinusitis, colic pain, and cough and can be combined with other plants as a bath ingredient for women after giving birth [16]. In addition, Thai population also believes that Sembung "drives away spirits." In the Philippines, people are more familiar with the name Sambong, used as a traditional medicine for patients with kidney stones, common cold or as a diuretic [17]. Other Asian countries such as Malaysia and India also use Sembung as an Ayurvedic medicine [18,19].

Progress on Phytochemical Studies Using B. balsamifera
Studies show that more than 100 phytochemical constituents of B. balsamifera can be both volatile and non-volatile. The volatile constituent compounds consist of terpenoids, fatty acids, phenols, alcohols, aldehydes, ether, ketones, pyridine, furans, and alkanes. Flavonoids, flavanones, and chalcones are non-volatile constituents [7]. The diversity of the constituents found in B. balsamifera has potential medicinal benefits, as shown in Table-1  .

Polyphenolic Compounds
The leaf extract of B. balsamifera was reported to contain 18 polyphenol compounds, including 17 flavonoids and one phenyl ethanone, after analysis using high-performance liquid chromatography (HPLC) [55]. In addition, the flavonoid contents of this plant demonstrated antityrosinase and anticancer activities [56,57].

Antioxidant Activity
B. balsamifera extract has demonstrated high antioxidant activity. Fresh and dry leaf extracts from B. balsamifera have been used as a traditional drink by Balinese people in Indonesia called Loloh. It was reported that dried leaves of B. balsamifera, obtained by brewing, had a tannin content of 13.15±0.11 mg GAE/g, while boiled dried leaves showed a high antioxidant capacity of 5.55±0.01 mg GAE/g [13]. Apart from B. balsamifera, other species such as Blumea lanceolaria were also reported to have good health benefits. The antioxidant activity of the methanol extract of B. lanceolaria leaves was assessed through three different methods 2,2-diphenylpicrylhydrazyl, ferric reducing antioxidant power test, and total phenolic content test, showing an antioxidant activity of 302.37±59.78 mg/100 g, 4.60±0.17 mg/100 g, and 1298.93 mg/100 g [81], respectively. Essential oils obtained from B. balsamifera have been widely used in various countries, especially in tropical Asia. Parts of the B. balsamifera plant were also reported to contain different essential oils. The b a highest yield of essential oil, 0.65 mL/100 g, was obtained from young leaves. In addition, shoots and young leaves also showed the strongest antioxidant activity. Dimethoxydurene, β-caryophyllene, and α-caryophyllene, which played an important role in the plant's antioxidant activity, have the potential to be developed as ingredients in the cosmetic and medicinal industries [58].

Antimicrobial Activity
B. balsamifera leaves have been used in the treatment of bacterial infections. The essential oil, and n-hexane, dichloromethane, and methanol extracts of B. balsamifera have been evaluated for their antibacterial activity using agar diffusion and microdilution methods. The essential oil gave the best results with a minimum inhibition concentration (MIC) value of 150 µg/mL against Bacillus cereus and a MIC of 1.2 mg/mL against Staphylococcus aureus. Besides, the n-hexane extract also showed good bactericidal activity [62]. Compounds with high antioxidant activity, such as δ-elements, α-cubenene, caryophyllene, caryophyllene epoxide, γ-eudesmol, xanthoxylin, and α-eudesmol, were identified from the essential oil of B. balsamifera [82].

Antifungal Activity
Antifungal activity had also been reported in B. balsamifera extract. Antifungal activity tests have been carried out on Aspergillus niger, Trichophyton mentagrophytes, and Candida albicans. Compounds with antifungal activity in Sembung leaves include icthyothereol acetate and cryptomeridiol [63]. The antifungal role of B. lacera was studied against Aspergillus flavus, A. niger, Alternaria sp., Penicillium sp., and Fusarium sp. Almost all extracts from both methanol, acetone, and water extracts were reported to have antifungal activity, when compared to standard carbendazim [84].

Anti-inflammatory Activity
Scientific evidence has demonstrated B. balsamifera anti-inflammatory activity. When the wound healing process occurs, it will go through several stages such as inflammatory response, migration, proliferation, and regeneration of new tissue [85]. Total flavonoids isolated from B. balsamifera were used as a skin wound healing agent in Sprague-Dawley rats. The healing activity was determined by measuring CD68 levels, vascular endothelial growth factor, transformation growth factor-β1, and hydroxyproline. The results of that study indicated that flavonoids were key in the successful wound healing process, increasing the expression of growth factors [22].
The study of the anti-inflammatory process was also carried out using Blumea aurita. B. aurita had the highest percentage of inhibition of edema (EI% = 53%) after 4 h of oral administration of the extract at a dose of 400 mg/kg, followed by 6 h (EI% = 67%) at a dose of 800 mg/kg, with albino Wistar mice [86]. The aqueous extract of Blumea mollis was also used in an acute and chronic anti-inflammatory therapy on carrageenan-induced rat leg edema [87].
In addition, B. balsamifera extract was also reported to have anti-inflammatory neuroprotective activity by reducing nitric oxide in lipopolysaccharide-induced rat microglial BV-2 cells. This inhibition may have occurred due to the interaction of the bioactive compounds of B. balsamifera extract with iNOS protein [64].

Hypolipidemic Activity
Hypolipidemic drug agents lower lipoprotein concentrations, transporting excess cholesterol, and triglycerides in the blood [88]. The antihyperlipidemic nature or potential in plants is important in reducing atherosclerosis [89]. The Sembung plant has been used as an antihyperlipidemic agent in vitro in 3-4 months old adult male Wistar rats (Rattus norvegicus) with induced high-fat feed. The Sembung extract had anti-hyperlipidemic activity by increasing spermatocytes [65]. A traditional drink from Southeast Sulawesi, Indonesia, "Lansau," made from 44 traditional ingredients (including Sembung) showed that Lansau's ethanol extract was antihyperlipidemic, reducing fat degeneration and being able to repair cell damage at a dose of 27,628 mg/kg [90].

Anti-infertility Activity
Infertility can be defined as a medical condition that can cause psychological and physical harm. Several factors such as age, tubal factors in women, obesity, significant reduction in semen parameters, cigarette consumption, and excessive alcohol consumption in men could trigger infertility [91]. Ethnopharmacological surveys on uses of traditional medicines against infertility have been widely completed around the world [92].
Local plant extracts from the Dayak tribe, Kalimantan, Indonesia, such as B. balsamifera¸ Croton tiglium, Metroxylon sagu, and Fagraea racemosa Jack, have been used as anti-infertility substances in vitro. All extracts were able to inhibit the estrous and metestrus cycles. A decrease in the corpus luteum and fetus was attributed to the anti-infertility effect of the extract against the inhibition of folliculogenesis. Researchers also reported that B. balsamifera extract had promising anti-infertility activity compared to other plant extracts used in this study [66].

Hepatoprotective Activity
The incidence of liver diseases affects millions of people worldwide. The prevalence of liver cirrhosis from autopsy studies ranges globally from 4.5% to 9.5% of the global population [93,94], with more than 50 million people worldwide (adult population) potentially affected by chronic liver disease [95].
A phytotherapy approach in the development of modern medicines is still very much needed [96]. The benefits of the phytochemical compounds in B. balsamifera have been widely used to improve physiological disorders and other degenerative diseases. Researchers also mentioned that the methanol extract of B. balsamifera (BME) induced growth and developmental inhibition of human hepatocellular carcinoma cells (McA-RH7777 and HepG2, respectively) in mice. These results were confirmed by the antiproliferative effect of BME, which increased slightly but significantly reduced the level of proliferation-related ligand (APRIL) stimulating tumor cells [67].
The hepatoprotective effect was also reported for the ethanol extract of B. lacera, which showed minimal damage to liver structures, decreased aspartate aminotransferase, Alkaline phosphatase, and bilirubin in ethanol-induced rats [97].

Antidiabetic Activity
The use of B. balsamifera as an antidiabetic in traditional medicine has been widely used, especially in Ayurvedic medicine in India. The administration of a hydro-ethanolic extract from B. balsamifera Available at www.veterinaryworld.org/Vol.14/May-2021/17.pdf (HEBB) at doses of 300 and 600 mg/kg, in streptozotocin (STZ)-induced diabetic rats, showed a decrease in blood glucose, lipid profile, serum marker enzymes, and levels of glutathione and catalase, when compared with the diabetes control group [68].
Other species such as B. lacera D.C (Asteraceae) was also reported to have antidiabetes benefits. Methanol extract B. lanceolaria (MEBL) and water extract B. lanceolaria were tested on hyperglycemic rats induced by STZ. Treatment with MEBL at doses of 200 and 400 mg/kg BW was able to lower blood glucose levels, increasing glycated hemoglobin, restoring lipid levels, rejuvenating pancreatic beta cells, and increasing the level of insulin secretion in the blood [98].

Gastroprotective Activity
Digestive disorders such as peptic ulcers are caused by an imbalance of aggressive factors (gastric acid and pepsin) and defense factors (mucosal secretion, bicarbonate secretion, and to mucosal epithelial regeneration) [69]. Some traditional plants, such as Sembung can be used as a medicinal ingredient for gastrointestinal disorders. Experimentally, the gastroprotective effect of herbal ingredients was applied to mice in a model of aspirin-induced gastric ulcers. This study confirmed that the herbal extract formulation using Sembung was able to provide a gastroprotective effect, with the lowest eosinophil and mast cells count [69,99].

Antitumor Activity
The essential oil extract of B. balsamifera was reported to have 42 types of chemical components, which were tested for their antitumor activity using the method of shrimp-larvae mortality determination, which is a simple, convenient, and inexpensive method of determining internal biological activity initiated by Jiang et al. [70]. This method has been widely used in determining the toxic components and contaminants in food, as well as the determination of biological activity [100]. The method was carried out using 25-30 larvae in each group. Treatment was given when shrimp eggs hatched (1% DMSO was added to dissolve the sample). The survival rate was observed for 24 h at room temperature. The treatment at 65 µg mL showed strong cytotoxicity to shrimp larvae. In conclusion, this extract was set as potential for further studies on antitumor activity [70].

Anticancer Activity
Cancer is a potentially life-threatening disease with more than 100 different types already occurring due to molecular changes in cells [101]. Cancer is also reported to be the third leading cause of death worldwide after cardiovascular and infectious diseases [102]. Medicinal plants have been reported as potential cancer treatment agents, as about 50% of compounds derived from medicinal plants demonstrate anticancer activity [103].
A study reported the anticancer activity of the BME on mice induced by human hepatocellular carcinoma cells (McA-RH7777 and HepG2, respectively). BME was able to reduce the level of APRIL, which is able to stimulate tumor cells. APRIL is a new member of the tumor necrosis factor, which is reported to stimulate tumor cell growth, modulate tumor cell apoptosis, and regulate humoral immunity [104,105].
The anticancer potential of other species such as Blumea eriantha was also tested in vitro using the microtetrazolium assay (MTT) test on cervical cancer cell (HeLa) and B16F10 cell gallus. The expressions of the p53 and Bcl-2 genes associated with apoptosis were also determined. The results showed that the methanol extract of B. eriantha induced strong antioxidant and anticancer properties. In addition, this extract was also to prevent cancer cell metastasis [106].

Immunomodulator Activity for Severe Acute Respiratory Syndrome-Coronavirus (SARS-CoV-2) in CoV Disease (COVID)-19
Novel COVID-2019, related with SARS, has been declared as a global pandemic causing deaths in 216 countries worldwide [107]. Until now, no vaccine or special treatment for SARS-CoV-2 has been available despite the extraordinary recent research efforts [108]. The use of drugs such as remdesivir, lopinavir/ritonavir, and hydroxychloroquine has been widely claimed to reduce the symptoms of COVID-19. To date, 200 clinical trials have been registered on the clinicaltrials.gov site. However, the expediency of drugs being studied is still unclear [109].
Therefore, the use of traditional medicinal plants is recommended by some for management or increasing the immune status of patients with COVID-19. A report showed that 90% of traditional medicines resulted in 90% recovery in 214 patients treated for COVID-19 [110]. The use of traditional medicine also claimed to be able to prevent COVID-19 infection in healthy people and to increase the immunity of patients with mild or severe COVID-19 symptoms [110]. In Indonesia, the use of "Empon-empon" (In Java) or Loloh (Balinese) made from traditional medicinal plants is also believed to have a role in modulating the immune system in COVID-19 patients [71].
Therapeutic agents against COVID-19 can be divided into several categories based on specific pathways: (1) Preventing the synthesis and replication of viral RNA, (2) blocking the virus in order not to bind to human cell receptors or by inhibiting the assembly process of viral genetic material, (3) restoring the innate immunity of the host, and (4) acting on specific receptors or enzymes so that the virus does not enter the host cell. Until now, there is still no specific scientific data mentioning B. balsamifera as an antiviral agent for COVID-19. Therefore, we suggest that the antiviral potential of its phytocomponents could be tested through computational studies (in silico studies), in vitro, and in vivo. Figure-2 summarizes the Available at www.veterinaryworld.org/Vol.14/May-2021/17.pdf potency of B. balsamifera as a medicinal agent and possible anti-SARS-CoV-2.

Future Prospective
More exploration and research have been carried out to verify the benefits of B. balsamifera, which is widely used against various diseases by people in several countries. The diversity of its constituents, molecular structure, bioactivity, and pharmacological studies has been extensively described in this review. Researchers have also demonstrated the efficacy of this plant in treating diseases (Table-2). However, further and more detailed studies should be carried out to assess the use of this plant in a number of other experimental animals such as Ferret (Mustela putorius) [111], or Zebrafish (Danio rerio) as well as on human subjects (can be considered) [112]. It has been reported that the leaves of B. balsamifera are the most widely used part in extracts (water, methanol, and ethanol) in studies against cancer, diabetes, hyperlipidemia, infertility, and infectious diseases. Its biological activity is still not fully proven, so other clinical studies would be needed [3].
Some other species of this family have been the focus of some research. B. lacera was reported to be antidiabetic, antifungal, and hepatoprotective; B. eriantha was able to demonstrate its anticancer activity. Therefore, research should focus in the identification and isolation of bioactive compounds according to the known pharmacological activity of B. balsamifera. Especially during the COVID-19 pandemic, authentic Indonesian herbal ingredients are needed to assess their benefits in modulating the immune system.

Conclusion
The Sembung plant (B. balsamifera) has proven to possess important biological activities with additional potential to be developed as a candidate for future essay-based isolation and identification of its bioactive.

Authors' Contributions
IGW designed and prepared the manuscript. IMJ made a critical comment in this manuscript. Both authors read and approved the final manuscript.