Chemical constituents and pharmacological activities of Mirabilis jalapa- A review

Mirabilis jalapa was used traditionally in the treatment of kidney infections, as diuretic, tonic, cathartic, purgative and emetic. The phytochemical screening of the extracts of the leaves and stems of the Mirabilis jalaparevealed the presence of tannins, alkaloids, flavonoids, phenolic compounds, carbohydrates, terpenes, glycosides, saponins, protein, cardiac glycosides, steroids and emodin. The previous pharmacological studies revealed that Mirabilis jalapa possessed wide range of pharmacological and therapeutic effects included antimicrobial, antiparasitic, dermatological, anticancer, antiinflammatory, analgesic, antidiabetic, antihistaminic, immune-modulatory, antispasmodic and many other pharmacological effects. The chemical constituents, nutritional, pharmacological and therapeutic effects ofMirabilis jalapawere discussed in the current review.


Introduction
Medicinal plant research received much attention as it brings to light the numerous unknown medicinal virtues especially of plant origin which needs evaluation on modern scientific lines such as chemical analysis, pharmacological investigation, pharmacokinetic and pharmacodynamic studies and clinical trials. Mirabilis jalapa was used traditionally in the treatment of kidney infections, as diuretic, tonic, cathartic, purgative and emetic. The phytochemical screening of the extracts of the leaves and stems of the Mirabilis jalaparevealed the presence of tannins, alkaloids, flavonoids, phenolic compounds, carbohydrates, terpenes, glycosides, saponins, protein, cardiac glycosides, steroids and emodin. The previous pharmacological studies revealed that Mirabilis jalapa possessed wide range of pharmacological and therapeutic effects included antimicrobial, antiparasitic, dermatological, anticancer, anti-inflammatory, analgesic, antidiabetic, antihistaminic, immune-modulatory, antispasmodic and many other pharmacological effects. The current review will highlight the chemical constituents, nutritional, pharmacological and therapeutic effects of Mirabilis jalapa.
The seeds showed high protein content (11.0 ± 0.75 g/100 seed). Amino acid analyses of the total protein isolates showed that it consisted of 17 amino acids of which 9 were essential [25].
Quantitative analysis showed that Mirabilis Jalapa leaves contained 0.034mg/kg alkaloids [16]. The flavonoid content was 4.41 ± 0.02 mg /gram of the methanolic extract of Mirabilisjalapaaerial parts [34]. The total phenolic contents of the extracts of Mirabilis jalapa tubers was varied from 21.45 to 364.6mg gallic acid equivalent (GAE)/g dried extract and the total flavonoid from 5.2 to 71.6 mg quercetin/g dried extract, respectively [28]. The total phenolic content and total flavonoid content of the ethyl acetate extract of the seed epicarp were 4.24 mg GAE/g and 0.39 mg RE/g of dry powder weight respectively [35].

Antimicrobial effects
The antimicrobial effect of ethanolic extract of Mirabilis Jalapa leaves was studied against Gram positive and Gram negative bacteria and against two fungi. The zones of growth inhibition of the ethanolic leaves extract were: Staphylococcus aureus 11.1mm, Salmonella typhi 13.5mm, Escheichia coli 15.0mm, Pseudomonas aeruginosa 15.5mm, Penicilliumnotatum 35.0mm and Rhizopusstolonifer 30mm [16].
Two antimicrobial peptides, designated as Mj-AMP1 and Mj-AMP2, were isolated fromMirabilis jalapa seeds, they exhibited a broad spectrum antifungal activity, they were active against 13 plant pathogenic fungi. Concentrations required for 50% inhibition of fungal growth vary from 6 to 300 micrograms/ml for the first peptide, and from 0.5 to 20 micrograms/ml for the second peptide. Both peptides were also active against two Gram-positive bacteria but showed no effect against Gram-negative bacteria [37].
The aqueous and methanolic seeds powder extracts and their combination (1:2 mixture of the aqueous and methanol extracts) at dilutions of 40, 4, 0.4 and 0.04 mg/ml, were tested for antibacterial effect against Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Enterobactersp., Vibrio cholerae, Shigellaflexneriand Salmonella typhi. The aqueous extract possessed good growth inhibition against all the bacteria except Enterobacter sp., while the methanol extract showed good inhibition against all except Staphylococcus aureus. The combination of extracts showed good inhibition of all the bacteria to a dilution of 4 mg/ml, and inhibition of Staphylococcus aureus at 0.4 mg/ml [12].
The antibacterial activity of the aqueous, ethanol, methanol, chloroform and petroleum ether, leaves extracts were tested for their antibacterial activity against Escherichia coli, Staphylococcus aureus, Streptococcus pneumoniae, Bacillus cereus, Enterococcus faecalis, Pseudomonas aeroginosa, Klebsiellapneumoniae, Lactobacillus acidophilus, Salmonella typhiandShigelladysenteriae. Aqueous, chloroform and petroleum ether extracts displayed the minimal inhibition while all the ethanolic and methanolic extracts showed good antibacterial activity against the selected pathogens (zone of growth inhibition 11-15mm against all the tested bacteria, except against Streptococcus pneumoniae 8mm) [38].
The antimicrobial effects of acetone, chloroform, ethanol and methanol extracts of the leaves of Mirabilis jalapa were investigated against Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Streptococci pneumonia, Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger and Aspergillus terreus. The methanol extract at 500μg/disc extract exerted the largest zone of growth inhibition (21mm) against Staphylococcus aureus and the highest inhibition of fungal radial mycelial growth (97.5% at 500μg/ml medium) against Aspergillusflavus. The methanol extract showed the lowest MIC against Staphylococcus aureus (39μg/ml) and Aspergillus flavus(45μg/ml) [19].
The investigation of the antibacterial effects of aqueous and alcoholic Mirabilis jalapa leaves extracts showed that 0.5 mg/ml concentration was effective inhibitor of growth of Staphylocoous aureus, Escherichia coli and Proteus mirabilis [18].
The antibacterial potential of the methanolic extract of Mirabilisjalapaaerial parts was examined against Gram positive and Gram negative organisms.The extract displayed significant activity against all the tested microorganisms with MIC of 1mg/ml [34,39].
The methanol, acetone, diethyl ether and chloroform extracts of different Mirabilis jalapavarieties were tested for antibacterial activities against Gram negative bacteria (Pseudomonas aeruginosa and Escherichia coli) and Gram positive bacteria (Staphylococcus aureus and Bacillus subtilis). The methanol extracts followed by acetone extracts of all variety showed more potent inhibitory activity than the diethyl ether and chloroform extracts. However the leaf methanolic extract from the white flowered variety showed highest antibacterial activity at 500 mg/ml followed by the methanolic leaf extracts from pink flowered variety, yellow and orange flowered variety, respectively [40].
The antimicrobial activities of various extracts of Mirabilis jalapa tubers were investigated against Gram-positive (Bacillus cereus, Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus and Enterococcusfaecalis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa and Klebsiellapneumoniae) bacteria. Water extract was the most effective with minimum inhibitory concentration of <200µg/ml against Staphylococcus aureus, Micrococcus luteus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Bacillus cereus and Enterococcus faecalis. Only water extract showed antifungal activity against Aspergillus niger, Fusarium solani, Fusarium oxysporium and Fusarium granularium [28].
The petroleum ether, benzene, chloroform, ethyl alcohol and methanol extracts of the leaves of Mirabilis jalapa were examined for antibacterial effect against Gram positive (Staphylococcus aureus, Staphylococcus epidermidisand Bacillus subtilis), Gram negative (Escherichia coli, Pseudomonas aeruginosa andKlebsiella pneumonia) and antifungal potential against Candida albicans. All extracts except petroleum ether extract possessed potent antibacterial and antifungal effects. Methanol extract showed stronger and broader spectrum of microbial activity as compared to other extracts with zones of growth inhibition of 25, 22, 21, 21, 20, 22, 23mm against Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Pseudomonas aeruginosa, Klebsiella pneumonia, Escherichia coli and Candida albicans respectively [42].
The antibacterial effect of the ethanolic leaf extract of Mirabilis jalapawas examined against Salmonella typhiand Bacillus cereus. Zones of growth inhibition for the extract at a concentration of 20 ug/l were 34.33±1.70mm and 51.33±1.88mm against Salmonella typhiand Bacillus cereus, respectively while the zones of growth inhibition of separated bioactive fraction at 3mg/ml were 40.33±1.33mm and 40.67±1.70mm, against the same microorganisms, respectively [44].
Aqueous, acetone and ethanol extracts of leaves of Mirabilis jalapawere tested for antimicrobial activity in vitro against biofilm and extended spectrum of beta lactamase (ESBL) producing uropathogenicEscherichia coli (UPEC). Ethanol extract of Mirabilisjalapaleaves exhibited the most potent antibacterial activity against all tested biofilm producing UPEC strains, whereas it inhibited only the ESBL producing 2 of 4 UPEC strains [45]. Two fractions of the crude extract of from Mirabilis jalapa radix (triterpenoid and flavone) showed antimicrobial activity when tested against Staphylococcus aureus and Candida albicans [46].
A protein isolated from the root and leaf of Mirabilis jalapashowed anti-plant viral activity (potato virus X, potato virus Y, potato leaf roll virus, and potato spindle tuber viroid) comparable to that of the roots and leaves of the original plant [47][48][49][50][51].
The isoflavone and dehydrorotenoid identified in the plant cell culture of Mirabilis jalapa possessed antifungal activity with IC50 of 25 and 48 microg/ml, respectively, against Candida albicans DSY1024 [53].

Antiparasitic effect
The anthelmintic activity of aerial parts extracts (20%, 40%, 60%, 80%) of Mirabilis jalapa was studied using Pheretima posthuma as a test worms. The methanolic extract of Mirabilis jalapa caused paralysis in 12.6 min and death in 13.5 min. Albendazole showed the same effect (at 2.3 min and 3.24 min), respectively [54].

Antioxidant effect
The total antioxidant capacity of the acetone, ethyl acetate, petroleum ether and ethanol extracts of leaves of Mirabilis jalapa was measured by the ferric reducing antioxidant power (FRAP) assay. Ethanolic extract showed more antioxidant potential compared to other extracts [13]. DPPH test was used to determine the antioxidant activity of petroleum ether, chloroform and methanol extracts of both the leaves and bark of Mirabilis jalapa. The methanol extract of the plant bark showed antioxidant activity with IC50 value of 598.02 μg/ml compared to ascorbic acid (IC50 70.985µg/ml) [56]. Two fractions of the crude extract of Mirabilis jalapa radix (triterpenoid and flavone) showed free-radical scavenging activity by using 2,2-diphenyl-1-picrylhydrazyl solution [46].
The antioxidant effect of the methanolic extract of Mirabilis jalapaaerial parts was evaluated using hydrogen peroxide scavenging method and reducing power assay method. The methanolic extract of Mirabilis jalapawas found to show significant reductive property. Mirabilis jalapaextract also caused a moderate dose-dependent inhibition of hyrogenperoxide [57].
The antioxidant activities of various solvent extracts of Mirabilis jalapa tubers were investigated using DPPH and lipid peroxidation assay. The water extract was the most potent antioxidant in all models, followed by methanol extract [58].
The ethyl acetate extract of the seed epicarp exhibited high free radical scavenging rate as IC50 (DPPH and OH assays) were 6.62 and 3.49 mg dry powder weight /ml [35].

Dermatological effect
The effects of hydromethanolic extract of tuberous root of Mirabilis jalapa and its terpenoid and flavonoid fractions on skin wound healing were studied using excision wound model on rat. The results indicated that flavonoid caused significant decrease (P<0.05) in antioxidant enzyme level as compared to control in wound healing process, whereas terpenoid fraction caused significant increase (P<0.05) in expression of growth factor levels but regeneration and remodeling stages were delayed due to formation of thicker ulcus layer and also there were no hair follicle-like blood capillaries formation which ultimately may lead to formation of hypertrophic scar of wound. The authors concluded that terpenoid fraction prolonged proliferation phase and have tendency to convert the wound into hypertrophic wound [60].
The wound healing activity of the ethanolic extract of the leaves of Mirabilis jalapa (1000mg/kg bw) was investigatedusing excision wound model, incision wound model and dead space wound models in experimentally induced diabetic rats. Mirabilis jalapa extract showed significant wound contraction from 9 th to 18 th day, significantly increase in wound breaking strength, significantly increase in dry tissue weight, and increased hydroxyproline content compared to normal control and diabetic control animals [61].

Anticancer effect
Brine shrimp lethality bioassay technique was applied to determine the cytotoxic property of petroleum ether, chloroform and methanol extracts of both the leaves and bark of Mirabilis jalapa. The petroleum ether extract of the bark showed significant cytotoxic activity with LC50 value of 8.12 µg/ml compared to vincristine sulphate (LC50 value: 0.33 µg/ml) [56].
Mirabilis jalapa protein was tested for anticancer effect against different cell lines. It showed cytotoxicity against T47D and SiHa cell lines while it was relatively less cytotoxic to mononuclear cell. It showed more specific cytotoxic activity against cancer cell line such as MACF-7, A549, HCT 116, than the normal cell line (Vero). Furthermore it possessed strong apoptotic effects [62][63][64][65].
A protein fraction with properties like ribosome-inactivating protein (RIP) isolated from the leaves of Mirabilis jalapa possessed cytotoxic effect against T47D and SiHa cell line. The LC50 against T47D cell line and SiHa cell line were 0.36μg/ml and 5.6μg/ml, respectively. While, it was non toxic against normal cells (LC50 of 21.04μg/ml). It produced more cytotoxic activity toward breast and cervical cancer cells (58-fold and 4-fold, respectively) as compared to normal mononuclear cells [67].

Antiinflammatory effect
The total alcoholic extract (300 mg/kg) and petroleum ether fractions (200 mg/kg) of leaves of Mirabilis jalapa were screened for its anti-inflammatory activity using carageenan induced rat paw edema and cotton pellet induced granuloma models. The total alcoholic extract and petroleum ether fraction possessed significant anti-inflammatory activity (P<0.01). They also inhibited granuloma formation significantly (P<0.05) in cotton pellet granuloma model, they inhibited the increase in number of fibroblasts and synthesis of collagen and mucopolysaccharides during granuloma tissue formation [68].
The anti-inflammatory activity of aqueous leaves extract of Mirabilis jalapa was evaluated using carrageenan and formalin-induced paw edema models in rats. The extract possessed dose dependent anti-inflammatory activity in carrageenan-induced paw edema model, it showed significant (P<0.05) inhibition of paw oedema, 37.5% and 54.0% on 4 th hour at the doses of 200 and 400 mg/kg, respectively. In formalin-induced paw edema model, the maximum percentage inhibition in paw edema was 32.9% and 43.0% on 4 th day at the doses of 200 and 400 mg/kg, respectively [69].
The anti-inflammatory effect of Mirabilis jalapahydro ethanolic flowers extract was investigated in formaldehyde and Complete Freund's adjuvant (CFA) induced arthritis in rats. The extract significantly suppressed the paw edema in both formaldehyde and CFA models (P<0.001). Body weight, haematological and antioxidant changes in the CFA rats were restored to normal [70].

Analgesic effect
The antinociceptive effect of leaf ethyl acetate fraction from Mirabilis jalapa (10mg/kg, orally) was investigated in mice. The extract fraction caused marked reduction in the pain caused by complete Freund's Adjuvant-CFA, surgical incision and partial sciatic nerve ligation. However, the fraction did not alter the paw edema or the increase in the IL-1β levels produced by CFA. The antinociceptive effect of the fraction was reversed by the pre-treatment of animals with the muscarinic receptor antagonists (atropine, 5mg/kg, sc) or nicotinic receptor antagonists (mecamylamine, 0.001mg/kg, sc.). The fraction did not alter in vitroacetylcholinesterase activity in blood or spinal cord samples, but it reversed the increase in the acetylcholinesterase activity observed in the spinal cord samples from mice injected with CFA. Furthermore, the fraction did not alter the indicators of liver or kidney lesion [71].
The antinociceptive effect of Mirabilis jalapa crude hydroethanolic leaves and stems extracts was investigated in pain models in mice. The crude hydroethanolic extract of leaves was more potent than the crude extract of stems to inhibit abdominal constrictions induced by acetic acid (ID50 values of 5.5 (2.3-13.1) and 18.0 (11.3-28.5) mg/kg, respectively]. Crude hydroethanolic leaves extract also possessed antinociceptive effect in the tail-flick test. Pre-treatment with naloxone did not modify the antinociceptive effect, but co-administration with atropine completely prevented it, which indicated that the antinociceptive effect might depend on the cholinergic system [72].

Antidiabetic effect
The hypoglycemic and hypolipidemic activities of ethanolic extract of Mirabilis jalapa root were studied in normal and streptozotocin induced diabetic mice (2, 4, 8 g/kg, for 14 before and 28 days after induction). Both after and before induction of diabetes, the repeated administration of 4, 8 g/kg of the extract lowered blood glucose level, improved insulin sensitivity index, lowered serum total cholesterol, triglyceride levels, and decreased triglyceride and increased glycogen content in liver and skeletal muscle. Single administration of the extract (4 and 8 g/kg) possessed hypoglycemic effect in oral glucose tolerance test in normal and diabetic mice, but showed no hypoglycemic and hypolipidemic effects on normal and diabetic mice [73].
The anti-hyperglycemic effect of hydroethanolic leaf extract of Mirabilis jalapa was investigated in streptozotocin induced diabetic rats. The hydroethanolic leaf extract at the concentration of 200 and 400 mg/kg showed significant decrease in the levels of glucose, urea, creatinine, aspartate transaminase, alanine transaminase and alkaline Phosphatase in streptozotocin induced diabetic rats [74].

Antihistaminic and immune-modulatory effects
The antihistaminic activity of an ethanol: acetone (1:1) extract of the roots of Mirabilis jalapa was studied using Guinea pig tracheal chain preparation and clonidine-induced mast cell granulation in mice. The extract (0.5 ml of 100 mg/ml) inhibited histamine-induced Guinea pig tracheal chain contractions non-competitively. The extract (100 or 200 mg/kg, ip) also inhibited milk-induced eosinophilia, albumin-induced paw oedema and protected mast cells against clonidineinduced granulation [75].
The immunomodulatory activity of the methanolic extract (100, 200 and 400 mg/kg) of Mirabilis jalapatuber was investigated in mice by using heamagglutination antibody titer, delayed type hypersensitivity, neutrophil adhesion test and carbon clearance test. Oral administration of 200 and 400mg/kg of the methanolic extract of Mirabilis jalapasignificantly increased antibody titer, phagocytic index, adhesion of neutrophils and positive hypersensitivity response in mice compared to control group [20].

Other effects
The aqueous and alcoholic Mirabilis jalapa leaves extracts were examined for their inhibitory effects on hyaluronidase. The percentage of inhibition for aqueous extract was7.5% , and for alcoholic extract was 6.25% with respect to control assays [18].

Conclusion
Mirabilis jalapa contained many bioactive metabolites. It possessed wide range of pharmacological and therapeutic effects included antimicrobial, antiparasitic, dermatological, anticancer, anti-inflammatory, analgesic, antidiabetic, antihistaminic, immune-modulatory, antispasmodic and many other pharmacological effects. The current review highlighted the chemical constituents, traditional uses and pharmacological effects of Mirabilis jalapa.