Phytoconstituents and Pharmacological Activities of Indian Camphorweed (Pluchea indica): A Multi-Potential Medicinal Plant of Nutritional and Ethnomedicinal Importance

Pluchea indica (L.) Less. (Asteraceae) commonly known as Indian camphorweed, pluchea, or marsh fleabane has gained great importance in various traditional medicines for its nutritional and medicinal benefits. It is utilized to cure several illnesses such as lumbago, kidney stones, leucorrhea, inflammation, gangrenous and atonic ulcer, hemorrhoids, dysentery, eye diseases, itchy skin, acid stomach, dysuria, abdominal pain, scabies, fever, sore muscles, dysentery, diabetes, rheumatism, etc. The plant or its leaves in the form of tea are commonly used for treating diabetes and rheumatism. The plant is a rich source of calcium, vitamin C, dietary fiber, and β-carotene. Various biomolecules have been isolated from P. indica, including thiophenes, terpenes, quinic acids, sterols, lignans, phenolics, and flavonoids. The current review reports detailed information about the phytoconstituents and pharmacological relevance of P. indica and the link to its traditional uses. The reported studies validated the efficacy and safety of P. indica, as well as supported its traditional uses for treating various ailments and promoting health and well-being. Thus, this could encourage the development of this plant into a healthy food supplement or medicine for the prevention and treatment of various diseases. However, further studies on the drug interactions, mechanism of action, pharmacokinetics, toxicology, and metabolism, as well as clinical trials, should be carried out.


Introduction
Plants play a remarkable role in medicine development because of their capacity to biosynthesize secondary metabolites with significant bioactivities [1][2][3][4]. Traditionally, plants were utilized to treat various ailments [5][6][7]. It was reported that more than 80% of the population still rely on folk and traditional medicine, most of which are based on plant remedies according to the WHO [1]. The global herbal trade of medicinal plants has been growing exponentially at the rate of 15% annual growth and is likely to reach a scale of five trillion USD by 2050 [8]. Medicinal plants are often cheaper, more easily obtainable, and have fewer side effects than synthetic drugs [9][10][11]. Many promising compounds have been discovered from plants that can be utilized in modifying the existing drugs or designing completely new ones [1][2][3][4]. The Asteraceae (Compositae) family is one of the largest plant families, which includes about 24,000-30,000 species and 1600-1700 genera [12]. Its plants are shrubs and herbs, which have been commonly used since ancient times as GC-MS analysis of the essential oil obtained from P. indica leaves collected from Sidoarjo and Surabaya in Indonesia using the hydro-distillation technique revealed the existence of 66 components: aldehydes, alcohols, aliphatic unsaturated hydrocarbons (cyclic, aliphatic, heterocyclic, and aromatic), ketones, esters, sulfoxides, and ethers. (10S,11S)-himachala-3-(12)-4-diene (25) (17.13%) was the major volatile constituent [43]. Ruan et al. investigated the chemical profiling of P. indica aerial parts using OC (orthogonal chromatography)-MS integrated normal-phase SiO 2 column with reverse-phase BEH C18 column, revealing the identification of 114 metabolites: sesquiterpenes, monoterpenes, sulphated flavonoids, flavonoids, lignans, thiophenes, caffeoylquinic acid derivatives, and other phenolics. By comparing with standard references, 67 metabolites were identified, whereas 47 compounds were speculated based on MS/MS fragmentation, 10 of them were new metabolites [44]. On the other hand, the LC-MS of the leaves EtOH extract demonstrated major metabolites, including campesteryl ferulate (33), quercetin (44), 6-hydroxykaempferol 7-glucoside (51), 8-hydroxyluteolin 8-glucoside (57), apigenin 7-(2 ,3 diacetylglucoside) (54), and transtrismethoxy resveratrol-d4 (97) [45] (Table 1). It is noteworthy that P. indica cultivation in coastal saline land would improve its medicinal quality and increase the caffeoylquinic acid derivatives concentration [46].

Biological Activities
The traditional practices and knowledge on P. indica utilization rely exclusively on the observations and practical experience that are passed on verbally from one generation to the next with little documented evidence. Therefore, many studies have been carried out to understand the contemporary relevance of its traditional uses based on biological evaluation ( Table 2).

Anti-Inflammatory Activity
Pulchea indica was assessed for anti-inflammatory activity using various models. The plant showed promising potential, which supported the pharmacological basis of its uses as a traditional herbal medicine for treating inflammation. P. indica roots' MeOH fraction of the defatted chloroform extract was assessed for its anti-inflammatory capacity utilizing several inflammation models. The extract possessed remarkable inhibitory potential towards histamine-, carrageenin-, serotonin-, sodium urate, and hyaluronidase-induced pedal inflammation. It prohibited cotton pellet-and carrageenin-induced granuloma formation, adjuvant-induced polyarthritis, and turpentine-produced joint edema. Further, it prohibited leucocyte migration and protein exudation. This revealed the extract's effectiveness in the chronic, proliferative, and exudative stages of inflammation [36]. Sen et al. reported that the root MeOH fraction showed significant anti-inflammatory capacity towards PAF (platelet activation factor), compound 48/80, and AA (arachidonic acid)-produced paw edema with noticeable suppression of spontaneous, as well as compound 48/80-induced histamine release from mast cells [33]. Additionally, it had prominent protective potential towards alcohol-, indomethacin-, and indomethacin-alcohol-caused ulceration, as evident by the significant decrease in acidity and gastric volume in pylorus ligated rats. Additionally, it exhibited a significant protective effect on the gastric mucosa [32]. It was suggested that its dual antiulcer and anti-inflammatory activity could be due to the 5-lipoxygenase inhibition pathway. Another study by Sen et al. demonstrated that the methanol extract of roots (doses 150 and 300 mg/kg) exhibited significant anti-inflammatory potential toward paw edema induced by glucose oxidase [63].
Sen et al. reported that pretreatment with root MeOH extract remarkably attenuated severe gastric mucosal vaso-congestion, hematological alteration, inflammation, necrosis, and ulceration induced by PAF administration in rats [64]. It significantly suppressed edema and decreased the hydroperoxides formation induced by croton oil in mice. It also significantly reduced lipid peroxidation induced by CC1 4 /NADPH and Fe 3+ /ADP/NADPH systems [64]. The significant anti-inflammatory activity of the EtOH extract was attributed to taraxasterol acetate that was separated from the hexane fraction (Figures 2 and 3) [36].        The root MeOH extract had significant inhibitory potential on carrageenin-caused edema in rats. It remarkably prohibited granuloma formation induced by a cotton pellet in rats. It reduced the paw diameter in formaldehyde-induced arthritic rats. Additionally, it exhibited antipyretic potential on the pyrexia induced by yeast in rats [74].
The EtOAc fraction of ethanol extract of leaves exhibited potent inhibition of NO (nitric oxide) production induced by LPS (lipopolysaccharide) in RAW 264.7 macrophages and prohibited PGE2 release. It decreased iNOS (inducible nitric oxide synthase) mRNA and protein expression through suppressed iNOS promoter activity and nuclear translocation of subunit p65 of nuclear factor-kB. Moreover, it possessed anti-inflammatory potential in the inflammation acute phase, as observed in EPP (ethylphenylpropiolate)-induced ear edema and carrageenan-induced paw edema in rats. Therefore, its anti-inflammatory effectiveness was proposed to be due to iNOS suppression and NO production inhibition, which mediated via the suppression of NF-kB activation [67]. The leaf EtOH extract (dose 300 mg/kg, orally) demonstrated a remarkable inhibition of edema induced by carrageenan similar to indomethacin (dose 10 mg/kg). It noticeably prohibited (doses 10, 30, 100, and 300 mg/kg, ip) the abdominal constriction induced with acetic acid (0.6% v/v) in mice with a maximal effect at a dose of 300 mg/kg (60.7%), which was comparable to that of indomethacin (63.2%). These effects were attributed to the inhibition of PG synthesis [37]. Additionally, the EtOH extract possessed anti-inflammation potential towards TNF-α-boosted vascular inflammation on EAhy926 (human vascular endothelial) cells by reducing ROS production and lessening the ICAM-1 (intercellular adhesion molecule-1) and VCAM-1 (vascular cell adhesion molecule-1), which was partly mediated via the HO-1 up-regulation [68].
Additionally . It was found that the number of caffeoyl groups in the quinic acid moiety and connecting position had a noticeable role in the inhibitory activity [58] (Figures 4 and 5, Table 3).

Anti-Obesity and Anti-Hyperlipidemic Activities
The incidence of dyslipidemia and obesity is currently growing at a dramatic rate throughout the world. Hyperlipidemia and obesity have resulted from energy expenditure/intake energy imbalance that leads to several health complications, including diabetes, stroke, cancer, and ischemic heart diseases [75]. The conventional anti-obesity and antihyperlipidemic therapy, such as orlistat and simvastatin, have severe adverse effects and limited effectiveness, often accompanied by weight gain after drug cessation [75,76]. Hence, the focus has been directed to traditional medicine as an alternative treatment for alleviating these diseases that may possess fewer undesirable influences in comparison with the conventional treatment [77].
The leaf H 2 O extract (concentrations of 750 to 1000 µg/mL) markedly reduced the accumulation of lipids, suppressed adipogenesis, and modified protein, carbohydrate, glycogen, and nucleic acid concentrations in the 3T3-L1 adipocytes. Additionally, it possessed lipase inhibitory potential (concentration 250 to 1000 µg/mL) [69]. In another study, the leaf extract was found to prohibit pancreatic lipase with % inhibition ranging from 11.7% to 18.4% at a concentration ranging from 625 to 1000 ppm compared to orlistat (% inhibition from 26.6 to 36.6%) and epicatechin (% inhibition from 10.7 to 18.6%) at the same concentrations [73]. Therefore, it could be further developed into an herbal supplement for managing obesity or overweight [69]. P. indica tea (herb, 400 and 600 mg/kg, orally) ameliorated hyperglycemia, dyslipidemia, and obesity in high-fat diet-induced (HFD) mice. Moreover, it significantly lowered TG, TC, LDL-C, and perigonadal fat weight in HFD-treated mice; however, it increased HDL-C. This was related to its total phenolic and flavonoid contents (TFC), caffeoylquinic acid derivatives, betacaryophyllene, and gamma-gurjunene (Figures 6-11) [70].

Antidiabetic Activity
Diabetes mellitus (DM) is a complicated metabolic illness that is characterized by the destruction of insulin-secreting β-cells or by insulin resistance, whereby the insulintarget organs are unresponsive to insulin action [78,79]. One of the effective strategies in diabetes management is to decrease postprandial hyperglycemia through the inhibition of α-glucosidase in the digestive system [80][81][82][83]. The available antidiabetic agents of chemical origin cause harmful side effects. Hence, developing safe and effective alternative natural antidiabetic agents is an important era of research.
Nopparat et al. reported that the pretreatment with the leaf EtOH extract (dose 100 mg/kg for 2 weeks) effectively alleviated β-cell injury produced by cytokine in STZ (streptozotocin) mice as it minimized the levels of inflammatory markers IFN-γ (interferonγ), TNF-α (tumor necrosis factor-α), and IL-1β (interlukin1-β), along with prohibiting caspases; 3, 8, and 9, pSTAT1 phosphorylation (signal transducer and activator of transcription 1), NF-κBp65 (nuclear factor-κBp65), and iNOS. Further, it protected β-cells by boosting cell proliferation and suppressing apoptosis. The blood glucose-lowering potential of the leaf extract was attributed to the antioxidant capacities of the extract's constituents, particularly resveratrol derivative and quercetin [45]. Additionally, it was noted that the P. indica leaf extracts possessed α-glucosidase and maltase inhibitory capacities that could delay the breakdown of starch into glucose and increase the glucose uptake, thereby lowering the blood glucose level [57,84].  Suriyah et al. carried out an in vitro study to assess the potential of P. indica's various leaf extracts: n-hexane, CH 2 Cl 2 , EtOAc, MeOH, and H 2 O in stimulating glucose consumption in a human liver CCL-13 cell line model. It was found that P. indica markedly increased glucose consumption of the cells, which revealed that the antidiabetic potential of the extract was due to the stimulation of glucose uptake in the liver cells [85]. Additionally, Widyawati et al. established that the leaf H 2 O extract had higher blood glucose-reducing capability (56.37%) than glibenclamide (49.59%) and other extracts (EtOAc 19.11% and MeOH 24.27%) in rats [39]. Conversely, the leaf MeOH extract (200 and 400 mg/kg, per os/orally (p.o.)) was found to reduce blood glucose levels in both STZ-mediated diabetic (36.1 and 41.87%) and normal rats (35.12 and 36.1%) [71]. α-Glucosidase inhibitory assay-directed fractionation of the leaves' EtOAc fraction yielded caffeoylquinic acid derivatives, 38 and 40-43, which were isolated using SiO 2 , RP-18 CC, and HPLC and elucidated by MS and NMR analyses. Compound 42 had the highest α-glucosidase inhibitory effectiveness among the separated caffeoylquinic acid derivatives (IC 50 2.0 µM) compared to acarbose (IC 50 0.5 µM), while the other compounds displayed moderate to weak activity compared to the activity of acarbose. It was found that increasing numbers of caffeoyl groups attached to the quinic acid moiety and methyl esterification of the carboxylic group in quinic acid promoted the α-glucosidase inhibitory capacity [57].

Insecticidal and Herbicidal Activity
Weeds and pests that affect the plants are very harmful and represent a problem because they can prohibit the growth of cultivated plants and decrease the yield of various crops [86]. Weeds and pests can be controlled utilizing synthetic pesticides and herbicides. Nevertheless, these synthetic agents cause diverse side effects due to the toxic residual active matter that remains in the soil. Additionally, these synthetic agents can affect nontarget organisms such as plants or animals. Other undesirable effects are pest resurgence and pest resistance, as well as environmental pollution [87]. The traditional methods of pest and weed control using plants or their derived metabolites are commonly used because they are safe and eco-friendly.
Yuliani and Rahayu reported that biopesticides derived from P. indica leaf extract caused optimal mortality (81.90% at concentration 12%) of Spodoptera litura larva with LC 80 9.88% and LC 50 4.00%. It also markedly prohibited the seed germination of the plant weed, Amaranthus spinosus [88]. Therefore, the leaf extract could be a potential bioinsecticide and bioherbicide.

Cytotoxicity Activity
Cancer is one of the most prevalent health problems with wide epidemiology and great mortality [89]. Its current remedies include chemotherapy, surgery, and radiation therapy [90]. These treatment strategies can result in a high recurrence rate in the case of surgical treatment, whereas chemo-and radiation therapy are lacking specificity and may harm normal cells, causing countless side effects [91].
It was found that the root EtOH extract markedly prohibited NPC (nasopharyngeal carcinoma)-TW04 and NPC-TW01 cell viability and migrations, whereas the NPC-TW04 cells had more susceptibility [92]. It noticeably increased NPC apoptosis that was triggered by up-regulation of pro-apoptotic protein Bax and suppression of anti-apoptotic protein Bcl-2 expression. Therefore, it induced the NPC cells' apoptosis by activating p53 and regulating apoptosis-related proteins. Hence, it could be further assessed as an alternative chemotherapeutic agent for NPC [66,92]. It also prohibited K562 (human leukemia cells) proliferation, induced cell cycle arrests in the G2/M phase, and caused apoptosis [93].
The leaf and root aqueous extracts demonstrated prominent anti-migratory and antiproliferative potential on HeLa and GBM8401 cells. They induced critical tumor suppressor molecules: phosphorylated-p53 and p21 and down-regulated phosphorylated-AKT. This effect was attributed to tannins, flavonoids, and the total phenolic contents of these extracts [91].
Moreover, the root hexane fraction exhibited a potent suppressive potential versus GBM cell growth, apparently by inducing G0/G1-phase cell cycle arrest. Further, it enhanced autophagy by increasing the formation of AVOs (acidic vesicular organelles), LC3-II expression (microtubule-associated light chain 3-II), and p38 and JNK phosphorylation [94].
Goswami et al. prepared SLN (solid lipid nanoparticle), utilizing compound 102 purified from P. indica, which displayed anticancer potential on EAC (Ehrlich ascites carcinoma) cells in Swiss albino mice. It prolonged the lifespan of cancer-bearing mice and reduced tumor volume compared to PITC-2-treated groups, and it promoted the apoptosis of tumor cells [95] (( Figure 12).
The human liver cytochrome P 450 (CYP)-2A13 and -2A6 enzymes demonstrated a crucial function in the activation of tobacco-specific nitrosamine carcinogens and nicotine metabolism. Their prohibition could represent a strategy for smoking abstinence and decreasing the risk of lung cancer and respiratory complaints. Flavonoids 44, 53, 55, 56, 102, 106, and 107 isolated from the EtOAc fraction of the aerial parts by SiO 2 CC and HPLC were evaluated for their inhibition capacity towards CYP2A6-and CYP2A13-mediated coumarin 7-hydroxylation in enzymatic reconstitution spectrofluorometric assay (Figures 12 and 13). Flavonoids were the most effective metabolites at inhibiting CYP2A6 and CYP2A13 (IC 50 ranging from 0.90 to 2.66 µM for CYP2A6 and from 0.05 to 0.80 µM for CYP2A13), followed by thiophenes (IC 50 values 3.90 to 6.43 for CYP2A6 and 2.40 µM to 6.18 µM for CYP2A13) compared to methoxsalen (IC 50 0.19 and 0.43 µM, respectively). Thiophenes exhibited irreversible inhibition towards both enzymes with inactivation kinetic K I values of 0.11-1.01 and 0.67-0.97 µM, respectively). These metabolites could have application in smoking stoppage and lessened risks of lung cancer and respiratory illnesses [59] (Figure 13).
Further, 102 purified from the EtOAc soluble fraction of the root extract of tissue cultured P. indica induced apoptosis and suppressed sarcoma-180 cancer cell proliferation, alongside G1 cell cycle arrest through cyclin D1, Bcl-2, and Ki-67 down-regulation, revealing its apoptotic and antiproliferative capacities versus sarcoma-180 solid tumor in vivo in mice [61].

Venom Neutralizing Activity
Death and injury due to snakebite are important sociomedical concerns in tropical countries [96,97]. In some hospitals, the antiserum is the only available antidote for a snakebite, which does not show complete protection against venom-induced necrosis, nephrotoxicity, or hemorrhage, and often produces adverse hypersensitivity reactions [98,99]. People in rural areas tend to choose herbal medicine from Traditional Healers because of limited or lacking hospitals [100].
P. indica root methanolic extract was reported to have the potential to neutralize viper venom and counter venom-induced hemorrhagic and lethality influences [97]. Further, 29 and 31 purified from the root extract were able to neutralize cobra and viper venom and antagonize cobra venom-induced cardiotoxicity, lethality, respiratory changes, and neurotoxicity, as well as potentiating the action of equine polyvalent snake venom antiserum in mice [96]. Therefore, these studies give scientific evidence for the folk use of the plant versus snakebite.

Hepatoprotective and Neurological Activities
Some reported findings validated the ethnomedicinal uses of P. indica for managing diabetic liver injury. P. indica leaf EtOH extract (doses 50 and 100 mg/kg for 2 weeks) ameliorated hyperglycemia-induced liver damage in STZ mice through the modulation of inflammatory responses and oxidative stress by inhibiting IL-6, TNF-α, TGF-β1, NF-κB p65, and PKC (protein kinase C), resulting in a reduction in hepatic apoptosis and improvement of hepatic architecture [101]. Further, the roots MeOH fraction displayed remarkable protective potential toward CCl 4 -induced hepatotoxicity in rats and mice. It reduced the elevated serum enzyme levels and bilirubin content. It also demonstrated a significant reduction in the prolonged pentobarbitone-produced sleeping time and plasma prothrombin time as well as a reduction in the increased bromo-sulphthalein retention produced by CCl 4 treatment [32].
Another study reported that the root extract (doses 50-100 mg/kg, p.o.) remarkably prolonged pentobarbital sleep and reduced locomotor activity in isolated mice but not in group-housed mice. However, at high doses (dose 400 mg/kg, p.o.), it reduced locomotor activity and prolonged pentobarbital sleep in group-housed mice in comparison to diazepam (doses 0.1 and 0.5 mg/kg), which noticeably prolonged pentobarbital sleep in both isolated and group-housed mice. The effect of root extract and diazepam on pentobarbital sleep was significantly attenuated by flumazenil (1 mg/kg, i.v.). It suppressed the isolated mice's aggressive behavior induced by social isolation. It was suggested that the GABAergic system was partly implicated in pentobarbital-caused sleep [34]. In another study, P. indica root extract reduced spontaneous motility, altered behavior patterns, prolonged pentobarbitone-induced sleep, and suppressed aggressive behavior patterns. Therefore, it possessed a potent CNS depressing potential [102].

Antifertility Activity
The population growth has raised remarkable economic and social concerns. The current strategies for controlling fertility have been debated for a long time [103]. Recently, male fertility regulation has been widely studied, aiming at developing a new male contraceptive for further inclusion of men in family planning [104]. Based on traditional methods of birth rates control, natural products represent a promising source for developing a male contraceptive. Many plants and their constituents have been investigated for their antifertility potential [105]. Interestingly, P. indica has been used orally in men as an antifertility alternative medicine [20,21,106].
Spermiogenesis is the last phase of spermatogenesis in which spermatids are converted to spermatozoa, which play a substantial function in the fertilization process [107]. It was reported that the leaf extract (doses 1.4, 2.8, and 5.6 mg/kg for 10 days) caused a decrease in the number of spermatid cells in male mice when the dose increased [106]. It was found that the treatment of white male adult rats with leaf tannin reduced the number of spermatozoa and spermatids [20,21]. Further, tannin remarkably reduced glutamic acid levels with an average decrease ranging from 494.43 to 341.40 mg/100 g in the semen of male white rats in comparison to the control group (547.48 mg/100 g glutamic acid level) [21,108]. Glutamic acid is needed for spermatozoa metabolism, and decreasing its level leads to the reduction in spermatozoa motility [109].

Wound-Healing Activity
Wound healing is a complex process that involves a variety of molecular, cellular, and biochemical reactions, which play a role in hemostasis, proliferation, inflammation, re-epithelialization, growth, and remodeling phases [110]. The healing ability is greatly influenced by systemic and local factors such as adequate nutrition, depth and location of the wound, infection, oxygenation, stress, age, obesity, diabetes, medications, and smoking [111].
In Thai traditional medicines, P. indica leaf was used as stringent to heal wounds and ulcers [112]. Fibroblasts represent the major type of connective tissue cells that produce an extracellular matrix accountable for maintaining tissue structural integrity [113,114]. They have a substantial function in the wound-healing proliferative phase, causing deposition of extracellular matrix [115]. Over proliferation of fibroblast during wound healing leads to the production of abnormally large amounts of collagens and extracellular matrix, resulting in scar formation and functional impairment that may further trigger permanent fibrosis [116]. The EtOH extract of leaves that was rich in flavonoids (19.44 mg/gram) exhibited remarkable antioxidant potential (IC 50 21.53 µg/mL) and had no effect on fibroblast 3T3 BALB C viability (IC 50 311.776 µg/mL) in the prestoblue cytotoxicity test. This supported the use of leaf extract as a nutrient to accelerate wound healing in the oral cavity injury [112]. Buranasukhon et al. assessed the influence of P. indica leaf ethanol extract and nanoparticles prepared from the leaf extract on enhancing oral wound healing using a human oral squamous carcinoma cell line. It was found that the NPs possessed wound-healing potential (concentration 62.5 µg/mL), as evident by increased cell survival and migration, as well as increased the extract's colloidal stability in the oral spray formulation. Therefore, P. indica leaf extract NPs could relieve oral mucositis [113].
It was reported that the leaf extract (concentration 80 µmol/L) prevented the fibroblasts' hyperproliferation by its major flavonoid quercetin, which prohibited collagen synthesis by interfering with the biosynthesis of procollagen (collagen precursor molecule) [5].
Increasing the synthesis of collagen is a crucial problem, particularly in the fibrotic tissue repair response due to chronic inflammation/cellular damage [117].

Anti-Hemorrhoidal Activity
Hemorrhoids are the major reason for rectum bleeding. They can be treated with nonsurgical or surgical treatments. Generally, initial hemorrhoid therapy is a nonsurgical treatment, which includes dietary modifications, medical management, and behavioral therapies [118].
The leaves of P. indica are traditionally utilized for treating hemorrhoids. This was supported by a study performed by Senvorasinh et al. They reported that the oral administration of hot P. indica tea H 2 O extract remarkably attenuated (dose 50 mg/kg/day) the rectal damage and hemorrhoids induced by croton oil in rats, as evident by no noticeable reduction in rectum and spleen weights. Conversely, it had no effect on gastrointestinal movement in mice, indicating it did not reduce constipation [119].

Antimicrobial Activity and Pharmaceutical Preparations
The leaf extract prohibited the growth of Streptococcus mutans, the causative organism of dental caries (MIC 10%), in the disk diffusion assay [120,121]. Further, the leaf extract toothpaste prevented dental caries in rats based on Rontgen examination results. Additionally, it reduced the virulence of mouth bacteria that initiated dental caries. Therefore, P. indica herbal toothpaste could treat caries in rat teeth [122]. P. indica leaf EtOH extract had inhibitory effects on C. albicans (MIC 100 mg/mL) [123]. Further, Alvionida et al. prepared different gel formulae using HPMC (hydroxypropyl methylcellulose) and carbopol 940. It was found that the gel formula with 1% carbopol 940 and 1.5% HPMC possessed antibacterial potential toward P. aeruginosa and S. aureus in the cup-plate diffusion assay [124]. Komala et al. stated that the deodorant rolls with 3 to 5% P. indica leaf extracts exhibited antibacterial potential towards S. epidermidis without causing skin irritation in both women and men. The 3% extract deodorant roll was most effective against S. epidermidis than the other formulae for removing the bad body odor [125], which proved its traditional use to eliminate bad odor. The leaf extract was evaluated for antibacterial potential (concentration 2.5 to 6.5%) towards E. faecalis, P. gingivalis, F. nucleatum, and S. mutans, which are accountable for root canal infections, periodontal disease, and caries. It showed significant growth inhibition towards E. faecalis (inhibition zone diameter (IZD) 12.6 mm), followed by S. mutans (IZD 12.2 mm) and P. gingivalis (IZD 12.2 mm) at a concentration of 6.5%, compared to chlorhexidine (IZDs 10.9, 11.4, and 10.6 mm, conc 2%) [126]. It also prohibited biofilm formation and decreased adhesion of E. faecalis and F. nucleatum in the micro-titter plate and auto-aggregation assays, respectively [127]. Hence, it could be utilized as an alternative to root canal sterilization dressing [127]. It had activity versus S. epidermidis (IZD 21.73 mm) and P. aeruginosa (IZD 21.44 mm) at 1 mg/mL [128]. Sittiwet suggested the possible urinary tract infection treatment potential of the aerial parts aqueous extract through its inhibitory effect on E. coli and Klebsiella pneumoniae [129]. Further, the root MeOH extract of P. indica (doses 0.5 and 1.0 mg/kg body weight) remarkably alleviated S. typhimurium caused typhoid fever in mice in vivo [130]. Fresh stems, roots, and twigs prohibited the growth of S. aureus, P. fluorescens, B. cereus, S. typhimurium, and E. coli, whereas fresh samples had more potent inhibitory potential than dried samples [131]. Farhamzah et al. prepared foot spray from the leaf EtOH extract that possessed antibacterial activity versus B. subtilis, which causes foot odor [132].

Antioxidant Activity
Oxygen radicals and other oxygen-related species are considered a cause of diverse diseases and health disorders such as degenerative and cardiovascular diseases, cancer, and immune-system and brain dysfunction [133]. The endogenous antioxidant defenses are not effective enough to alleviate or prohibit oxygen-radical-related diseases [134]. Thus, free radicals' scavengers or exogenous antioxidants are required. The protection against free radicals or oxidizing agents can be enhanced with adequate dietary antioxidants intake.
P. indica fresh leaves are used in many kinds of foods, including soups, salads, and side dishes. Additionally, leaf extracts and dried leaves are commonly consumed as food supplements and tea in Thailand. Several studies confirmed the significant antioxidant potential of various extracts of P. indica that is highly correlated to its high total phenols and flavonoids contents. This current work summarizes these studies.
In 2002, Sen et al. reported that the MeOH fraction of P. indica root extract prohibited superoxide and HO . radical generation, H 2 O 2 -produced lysis of erythrocytes, and CCl 4caused lipid peroxidation, in addition to lipoxygenase's dioxygenase activity in the absence and presence of H 2 O 2 [63]. Additionally, the EtOH extract of the leaves prohibited oxidation of linoleic acid and displayed ferric cyanide, ABTS, and DPPH antioxidant potential [28]. Noridayu et al. mentioned that the leaf MeOH extract had remarkable antioxidant potential (IC 50 24.45 µg/mL) in the DPPH assay, compared to quercetin (IC 50 6.70 µg/mL); however, the MeOH extract of the stem and hexane extracts of stems and leaves exhibited moderate to weak DPPH radical-scavenging capacity with IC 50 ranging from 83.74 to 401.68 µg/mL [41]. Abdul Rahman et al. further reported the DPPH and β-carotene-linoleic scavenging potential of the P. indica leaf EtOH extract (IC 50 42.24 and 59.8 µg/mL, respectively) [73].
Interestingly, the hot water leaf extract possessed marked DPPH scavenging potential (EC 50 23.8 µg/mL) greater than BHT (EC 50 44.4 µg/mL) [135]. In 2018, Widyawati et al. evaluated the antioxidant capacity of black tea-Pluchea leaves drink using different proportions (0:100, 25:75, 50:50, 75:25, and 100:0% w/w). It was found that increased black tea proportion remarkably reduced iron ion-reducing power and DPPH free radical scavenging activity, except for 100% black tea proportion [136]. The leaf MeOH extracts potentially scavenged superoxide radical, reduced iron ion, and inhibited linoleic acid-β-carotene bleaching. Conversely, the EtOAc fraction exhibited a remarkable potency to scavenge superoxide radicals, reduce iron ions and TBARS, and chelate iron ions and hemoglobin. Additionally, the EtOAc fraction had an anti-warmed-over flavor (WOF) effect on duck meat, where it prevented the oxidation of linoleic acid to hexanal. Hexanal can result in a warmed-over flavor (WOF) of meat and its products [137]. Further, the antioxidant capacity of leaf extracts from mature leaves in the flowering and pre-flowering stage, as well as juvenile leaf shoots for P. indica samples obtained from various locations in Thailand, was estimated. Regardless of origin, the juvenile leaf shoots displayed potent antioxidant potential [84].

Other Activities
The leaf extract (dose 750 mg/kg, orally) increased growth hormone serum levels, milk production, and body weight in lactating rats [72]. The hexane extracts of stems and leaves exhibited AChE inhibitory potential that was correlated to its terpenoids content [41]. Compound 102 was purified and characterized from the EtOAc fraction of the root MeOH extract by SiO 2 CC and spectroscopic analyses. This metabolite possessed marked anti-proliferative potential (MIC 50 µg/mL) and lytic activity on trophozoites within 4 h administration compared with metronidazole that produced complete lysis (concentration 5 µg/mL) within 2 h towards Entamoeba histolytica HM1 in the cell count assay [60].

Toxicity and Safety of P. indica
Many studies have been conducted to evaluate the safety of P. indica. The acute toxicity assessment was carried out using different doses.
Pramanik et al. proved that the MeOH extract of the leaves did not display any sign of toxicity in rats at a dose of 3200 mg/kg orally [71]. Further, the toxicity assessment of P. indica tea in randomized clinical trials on prediabetic humans revealed no toxicity to the liver, kidney, and blood, as evident by the lack of any remarkable variation in ALT, BUN, creatinine, CBC, and ALP of the P. indica-received group compared to the placebo [70]. In another study, Sirichaiwetchakoon et al. stated that P. indica tea (dose 600 mg/kg/day) was non-toxic to the kidney, liver, and blood in mice [139]. Nopparat et al. carried out a study to validate the toxicity of P. indica administration on experimental animals. The results revealed no toxic effect on kidney and liver functions, as evident by the lack of any significant variation in serum TC, TG, AST, BUN, creatinine, ALP, albumin, and ALT among all experimental groups, indicating its safety [45]. P. indica leaf H 2 O extract (concentration 25 to 400 µg/mL) exhibited no cytotoxic effectiveness on RAW 264.7 macrophage cells [135]. Conversely, the leaf EtOH extract did not have a cytotoxic influence (concentration 12.5-50 µg/mL) on EA.hy926 cells, while it reduced cell viability at concentrations ≥ 100 µg/mL in the MTT assay [68]. It was found that P. indica fresh herb H 2 O extract was safe at a concentration ≤ 1000 µg/mL on 3T3-L1 cells [69]. A sub-chronic toxicity study revealed that the oral administration of water extract was safe for mice (dose 2.6 mg/20 g b.w.); however, EtOAc and MeOH extracts (doses 1.3 and 2.6 mg/20 g b.w.) caused mortality in mice [39]. Thongpraditchote et al. reported that the root extract did not cause any mortality at a dose of up to 5 g/kg orally [34]. Additionally, it did not produce mortality in mice at a dose up to 1100 mg/kg [102].

Clinical Traits
Werdani and Widyawati stated that the regular administration of P. indica twice daily (2 g of tea of P. indica with 100 mL hot H 2 O without sugar for two months) reduced random blood glucose levels and eliminated subjective patient complaints, such as tingling in the extremities, and improved physical fatigue [140]. A randomized clinical trial in 45 prediabetic patients who received P. indica tea (1.5 g, daily for 12 weeks) revealed that the tea alleviated dyslipidemia and hyperglycemia, where it noticeably lowered TG and LDL-C and raised HDL-C. This supports its utilization as herbal medicine for dyslipidemia and hyperglycemia prevention [70].

Conclusion and Recommendations
Medicinal plants and their phytoconstituents have been proven to have a significant contribution to the prevention and therapy of several diseases and to have diverse pharmacological properties. Encouragingly, the current work reviewed several promising bioactivities that are induced by a variety of phytoconstituents of P. indica. This plant is widely used by various traditional medicines for treating various diseases, especially diabetes and its related complications. Many studies have been carried out to prove these traditional uses. The plant studied from various regions has terpenoids and caffeoylquinic acid derivatives, as well as high phenolics and flavonoid contents (TFC), which confer most of the characteristic bioactivities of this plant (Figures 14 and 15). The majority has been purified from aerial parts ( Figure 16).
It is noteworthy that the reported studies in this work validate the efficacy and safety of P. indica and support its traditional uses for treating various ailments and promoting health and well-being, particularly for people for whom modern health care is not easily accessible. Therefore, reported results could encourage the food supplement manufacturers to develop this plant into a healthy food supplement or medicine for the prevention and treatment of various diseases. isting drugs or designing completely new ones [1][2][3][4]. The Asteraceae (Compositae) family is one of the largest plant families, which includes about 24,000-30,000 species and 1600-1700 genera [12]. Its plants are shrubs and herbs, which have been commonly used since ancient times as herbal medicines and diets all over the world [13]. It contains wellknown species, such as sunflower, chicory, coreopsis, lettuce, daisy, and dahlias, as well as several significant medicinal plants, such as chamomile, wormwood, and dandelion [14].
Pluchea is a flowering plants genus of the Asteraceae family, comprising about 80 species [15]. Its members are known as plucheas, camphorweeds, or fleabanes, and some are called sour bushes [16]. Pluchea indica (L.) Less. is an evergreen shrub found abundantly in salt marshes and mangrove swamps with a 1 to 2 m height that has an important role in maintaining the ecological balance in the coastal areas [17]. It is known as Indian camphorweed, pluchea, or marsh fleabane, Khlu (Thai), Kukrakonda, Kakronda, or Munjhu rukha (Bengali), Kuo bao ju (Chinese), luntas (Javanese), Beluntas (Malaysia, Indonesia, Bahasa), and kalapini (Philippines) [18]. This plant is mainly found in the subtropical and tropical zones of Asia, Africa, Australia, and America and in warm temperature regions of countries such as Indonesia, Malaysia, Taiwan, Australia, Mexico, and India [5,17,18]. A chemical investigation of this plant revealed the existence of various phytoconstituents: thiophenes, sesquiterpenes, quinic acids, sterols, lignans, and flavonoids. Additionally, this plant has wide folk uses and diverse bioactivities: antiinflammatory, anti-cancer, antioxidant, anti-microbial, and insecticidal activities. The current review summarizes the reported literature on the traditional uses, phytoconstituents, and bioactivities of this plant and isolated metabolites to highlight its positive influences on human health. P. indica root and leaf extracts revealed anti-inflammatory potential towards different types of induced inflammations using various models. The suppression of NF-κB, attenuation of antioxidant enzymes, up-regulation of HO-1, and inhibition of PGE2 and 5-LOX are the reported molecular mechanisms for the anti-inflammatory potential of P. indica. P. indica leaves/tea could have the potential to prevent and treat metabolic syndrome because they possess blood glucose and lipid-lowering effects. The antihyperlipidemic effect was due to the suppression of adipogenesis and lipase inhibition, whereas the antidiabetic effect was due to the protection of β-cell towards inflammatory responses and apoptosis, α-glucosidase and maltase inhibition, and stimulation of glucose uptake. Further, caffeoylquinic acid derivatives of the leaves were proven to have α-glucosidase inhibitory potential that was promoted by increased numbers of caffeoyl groups linked to quinic acid moiety and methyl esterification of quinic acid's carboxylic group. The discovery of natural anticancer agents is a major concern of scientists. The reviewed plant was established to have cytotoxic potential, which is most often linked to chemoprevention. The plant was found to promote apoptosis and inhibit the migration and proliferation of diverse cancer cell lines. Further studies are warranted to specify the bioactive compound(s) accountable for the induction of these effects and to elucidate the mechanisms of P. indica on in vivo models. Additionally, the venom-neutralizing potential of P. indica root was attributed to its phytoconstituents: stigmasterol and beta-sitosterol. The plant showed liver injury, hemorrhoids, and wound-healing capacity.

Methodology
Several studies confirmed the significant antioxidant potential of various extracts of P. indica that is highly correlated to its high total phenols and flavonoids contents. Therefore, the plant may positively contribute to dietary antioxidant intake. Moreover, P. indica could be further developed into functional food and nutraceutical products.
P. indica extracts and their pharmaceutical preparations possessed antibacterial capacity towards the causative organisms of dental caries, bad body odor, and urinary tract infections.
Despite the diverse studies carried out on P. indica, a limited number of studies focus on the isolation of their chemical constituents and evaluation of their activities. Further, the clinical and toxicity studies suggested the safety of this plant for human use. Based on these facts, the authors hope that this review highlights the role of P. indica in various treatments and recommend that further phytochemical and clinical research should be conducted on this traditional medicinal plant for the discovery of safer drugs.