|Scientific names||Common names|
|Adambea glabra Lam.||Agaro (Sbl.)|
|Adambea hirsuta Lam.||Bugarom (S. L. Bis.)|
|Lagerstroemia flos-reginae Retz.||Banaba (Tag.)|
|Lagerstroemia hirsuta (Lam.) Willd.||Duguam (S. KL. Bis.)|
|Lagerstroemia major Retz.||Kauilan (P. Bis.)|
|Lagerstroemia munchausia Willd.||Makablos (Pang.)|
|Lagerstroemia plicifolia Stokes||Mitla (Pamp.)|
|Lagerstroemia reginae Roxb.||Nabulong (Neg.)|
|Lagerstroemia speciosa (L.) Pers.||Pamalauagon (S. L. Bis.)|
|Munchausia speciosa (L.)||Pamarauagon (S. L. Bis.)|
|Murtughas hirsuta (Lam.) Kuntze||Parasabukung (Sub.)|
|Tabangau (Ibn., Neg.)|
|Pride of India (Engl.)|
|Queen's flower (Engl.)|
|Queen of flowers (Engl.)|
|Lagerstroemia speciosa (L.) Pers. is an accepted name. The Plant List|
|Other vernacular names|
|CHINESE: Bai ri hong, Da hua zi wei.|
|HINDU: Jarul, Arjuna, Bondaro, Challa, Ajhar, Varagogu, Moto-bhandaro.|
|INDONESIA: Bungur, Bungur tekuyung, Ketangi.|
|MALAYSIA: Bungor raya, Bongor biru, Tibabah.|
|THAILAND: Chuang-muu, Tabaek dam, Inthanin nam.|
|VIETNAM: B[awf]ng l[aw]ng n[uw][ows]c.|
• Corosolic Acid / Lagerstroemin / Gallotannins: Studies have identified several compounds as responsible for its anti-diabetic activity. (1) corosolic acid (2) Lagerstroemin, an ellagitannin (3) gallotannins, of which PPG – penta-O-galloyl-glucopyranose–was identified as the most potent, with a higher glucose transport stimulatory activity than Lagerstroemin. In addition to stimulating glucose uptake in fat cells, it also has anti-adipogenic properties.
• Inhibition of TNF-induced Activation: Diabetes leads to cardiomyocyte hypertrophy in association with upregulation of vasoactive factors and activation of nuclear factor (NF)-kappaB and activating protein-1. Study results indicate L speciosa can inhibit DNA-binding of NF-kappaB which may explain its possible inhibition of diabetes-induced cardiomyocyte hypertrophy. (8)
• Ellagitannins / Insulin-like Glucose Uptake Stimulatory/ Inhibitory Activities / Adipocyte Differentiation-Inhibitory Activity: Study yielded seven ellagitannins, including lagerstroemin from the leaves of L speciosa. The ellagitannins exhibited strong activities in both stimulating insulin-like glucose uptake and inhibiting adipocyte differentiation . Also, ellagic acid derivatives showed inhibitory effect on glucose transport. (5)
• Glucose Transport Activators: Screening has identified lagerstroemin, flosin, and reginin A as activators of glucose transport in rat fat cells.
• Diabetes: (1) Banaba has been extensively studied for its application in the treatment of diabetes. Early on, Its ability to lower blood sugar was attributed to corosolic acid, a triterpenoid glycoside, believed to facilitate glucose-transport into cells. (2) Studied with abutra, akapulko, makabuhay for antidiabetic activity through activation of glucose transporter activity. One of the active principles from Banaba was the tripertene, corosolic acid.
• Weight loss: Studies in mice suggest an antiobesity effect. It is becoming a common ingredient in weight-loss supplements / products as a metabolic enhancer.
• Hypertension: It is also being studied for its use in the treatment of blood pressure, renal and immune system benefits.
• Lipid-lowering: Studies in mice suggest a lipid lowering effect - decreasing triglyceride and total cholesterol levels. To date, no toxicity has been identified.
• Hypoglycemic Activity of Irradiated Banaba Leaves: Study showed irradiated banaba leaf extract mixed with insulin was found to have a higher hypoglycemic activity compared with mixtures of BLE and insulin. Results may suggest the potential of reducing the cost of insulin management by lessening the dependence on recombinant insulin. (3)
• Xanthine oxidase inhibitors from the leaves of Lagerstroemia speciosa (L.) Pers: Xanthine oxidase is a key enzyme involved with hyperuricemia, catalyzing the oxidation of hypoxanthine to xanthine to uric acid. Bioassay-guided fractionation isolated two active compounds from the aqueous extracts of L. speciosa leaves viz. valoneic acid dilactone (VAD) and ellagic acid (EA). XOD (xanthine oxidase)-inhibitory activity of VAD was greater than allopurinol, a drug used as XODi. The study supports the dietary use of the aqueous extracts from Banaba leaves for the prevention and treatment of hyperuricemia. (4)
• Antidiabetic Activity: Study showed a significant reduction of blood glucose levels with the soft gel formulation showing better bioavailability than a dry-powder formulation. (•) Study evaluated the effect of leaves on fasting blood glucose in alloxan-induced diabetic rabbits. Results showed significant decrease in blood glucose at doses of 400 and 800 mg/kg. The 800 mg/kg dose was comparable to metformin 62.5 mg/kg. Results suggest favorable effects in protecting alloxan induced hyperglycemia. (34)
• Other studies report potential uses: (1) antibacterial effects from seed extracts (2) significant protection of HIV-infected cells by ellagic acid constituents (3) antioxidative activity of a water extract (4) inhibition of xanthine oxidase by aqueous extract, 31 and anti-inflammatory activity in mice.
• Anti-Inflammatory / Free Radical Scavenging: Study showed antioxidant and anti-inflammatory activities from the ethyl acetate and ethanol extracts of Lagerstroemia speciosa. (9)
• Antioxidant / Leaves: A hydroalcoholic extract of leaves of L. speciosa demonstrated antioxidant activity in the nitric oxide model. (10)
• Hypoglycemic Activity / Mechanism of Action: Study of a hot water extract of leaves of L. speciosa showed hypoglycemic activity on experimental diabetic rats through suppression of gluconeogenesis and stimulation of glucose oxidation using the pentose phosphate pathway. (11)
• Hepatoprotective / Roots: L. speciosa roots showed hepatoprotective activity protecting hepatocytes from CCl4-induced liver damages due to antioxidant effect on hepatocytes. (12)
• Hepatoprotective / CCl4 Toxicity / Flowers: Study of ethanol extracts of petals showed in vitro antioxidant and in vivo hepatoprotective properties against carbon tetrachloride induced liver toxicity in Swiss albino mice. The antioxidant activities of the flower extract were higher than curcumin or ascorbic acid. Results suggest L. speciosa flowers is a reservoir of antioxidant and hepatoprotective components. (41)
• Pharmacognostic Evaluation of Leaves: Study provided important information for the correct identification and herbal standardization of L. speciosa leaves. Phytochemical screening yielded alkaloids, tannins, flavonoids, triterpenoids, sterol, and saponins. Study suggests the season of collection and storage conditions may lead to fluctuations in the corosolic acid content. (13)
• Antimicrobial / Quorum Sensing Modulation: Study showed a fruit extract caused downregulation of the quorum sensing related genes and respective signaling molecules, without affecting P. aeruginosa growth. Results suggest a possible role for quorum sensing mechanisms and the potential source of QS-based antibacterial drugs. (15)
• Review / Antiobesity Therapeutics and Mechanisms: A review of natural products with anti-obesity activity included Lagerstroemia speciosa: (1) a crude aqueous extract promoting lipid metabolism; a 3% decrease in body weight, through PPARs (peroxisome-proliferator activated receptor) agonistic activity (2) Ellagitannins via inhibition of GPDH activity by 20%. (18)
• Antiobesity and Antiobesity Polyherbal Formulation: A polyherbal formulation for obesity containing G. sylvestre, G. cambogia, and Lagerstroemia speciosa was studied in normal and obese STZ-induced diabetic rats. Results showed an antidiabetic and antiobesity effect similar to that observed with glibenclamide and sibutramine. (19)
• Safety of Banaba and Corosolic Acid: The hypoglycemic effect of banaba has been attributed to corosolic acid and elligatannins. Corosolic acid also exhibited antihyperlipidemic, antioxidant, anti-inflammatory, antifungal, antiviral, antineoplastic, and osteoblastic activities. Its antidiabetic and lipid effects involve multiple mechanisms, including enhanced cellular uptake of glucose, impaired hydrolysis of starches and sucrose, plus other signal transduction factors. No adverse effects were observed in animal studies or controlled human clinical trials. (20)
• Antibacterial / Phytochemicals / Leaves: A methanolic extract of leaves yielded anthraquinones, flavonoids, saponins, and tannins. The extract exhibited high antibacterial activity against three of the test bacteria: E. coli > S. aureus > P. aeruginosa. It showed no activity against Salmonella typhimurium. (21)
• Ellagitanins / Activators of Glucose Transport in Fat Cells: Bioassay fractionation of aqueous acetone extra t yielded three active ellagitannins: lagerstroemin, flosin B and reginin A. The compounds increased glucose uptake of rat adipocytes. Results suggest the insulin like action of ellagitannins or their metabolites is responsible for the hypoglycemic effect of banaba extract in vivo. (22)
• Metals in Leaves: Study confirmed the presence of essential metals i.e., magnesium, zinc, and iron in Lagerstroemia speciosa. Heavy metals like cadmium, chromium, mercury, and lead were below detectable limit. Magnesium and zinc were used in the treatment of type II diabetes. Study supports the anti-diabetic activity of the species. (23)
• Hypoglycemic: Study evaluated the hypoglycemic effect of aqueous extract of L. speciosa in STZ-nicotinamide induced type 2 diabetic male albino Wistar rats. Results showed significant decrease in fasting serum glucose levels, accompanied by decreased glycosylated hemoglobin and lipid profile. (24)
• Effect of Extract on Hyperglycemia and Obesity: Study showed a unique combination of a glucose uptake stimulatory activity and effective inhibition of adipocyte differentiation induced by IS-IBMX-DEX in 3T3-L1 cells suggesting use in prevention and treatment of hyperglycemia and obesity in type II diabetes. (25)
• Antinociceptive / Antidiarrheal / Cytotoxic / Dried Fruits: Study evaluated of extract of dried fruits for antinociceptive, antidiarrheal, and cytotoxic activities in animal models. Results showed significant writhing inhibition in acetic acid-induced writhing in mice, antidiarrheal activity on castor oil induced diarrhea, and prominent cytotoxic activity against brine shrimp Artemia salina. (26)
• Ellagic acid & Gallic Acid / Inhibition of HIV-1 through Inhibition of HIV-1 Protease and Reverse Transcriptase Activity / Leaves and Stems: Gallic acid and ellagic acid from extracts of leaves and stems of banaba showed novel anti-HIV activity through inhibition of reverse transcriptase and HIV-protease, suggesting promising candidates for development of topical anti-HIV1 agents. (27)
• Cytoprotective Effects / Leaves: Study evaluated the cytoprotective effects of hot water extracts from L. speciosa leaves on 3-morpholinosydnonimine (SIN-1)-induced oxidative damage in Syrian hamster pancreatic insulinoma HIT-T15 cells. Results showed a cytoprotective effect through inhibition of lipid peroxidation, a decrease in ROS levels and an increase in antioxidant enzyme activity. (28)
• Acute Toxicity Study / Non-Toxic: Study evaluated the toxicity impact of ethanol concentrates of banaba in 30 make grown-up Sprague Dawley rats. Results showed the crude ethanol extract is non-toxic and well tolerated at tested dose levels (500, 1000, 2000, and 3000 mg/kg). (31)
• Metals Content / Leaves: Study dealt with the detection of metals present in leaves of L. speciosa. Essential metals like sodium, potassium, iron, magnesium and zinc were found to be predominant, while heavy metals like cadmium, mercury, and lead were found below detectable limit. It has been clinically proven that essential metals like magnesium and zinc were used in the treatment of type 2 diabetes. (see constituents above) (32)
• Inhibition of TNF-Induced Activation of NF-kappaB in Cardiomyocyte H9c2 Cells: Diabetes leads to cardiomyocyte hypertrophy in association with an upregulation of vasoactive factors and activation of nuclear factor (NF)-kappaB and activating protein-1. Lagerstroemia speciosa completely blocked the activation of NF-kappaB by TNF in a dose- and time-dependent manner in H9c2 cells. This may explain the possible inhibition of diabetes-induced cardiomyocyte hypertrophy. (33)
• Neuroprotective / STZ-Induced Painful Neuropathy: Study evaluated the neuroprotective of L. speciosa on painful diabetic neuropathy. Results showed neuroprotective property with dose-dependent reduction in pain threshold tested by mechanical, cold and thermal hyperalgesia. (35)
• Anti-Diabetes / Gallotannins and Elligatannins: Study suggests that tannin molecules are responsible for the insulin-like glucose transport stimulatory activity of the banaba extract. Gallotannins such as PGG (penta-O-galloyl-glucopyranose) seems to be more potent and efficacious than ellagitanins such as Lagerstroemin in IR binding, IR activation and glucose transport induction. Also, corosolic acid does not possess insulin-like transport stimulatory activity; its antidiabetic activity, if confirmed, may be through a non-insulin-like indirect mechanism. (7)
• Hypoglycemic Effect / Leaves: Study of spray-dried powder and decoction of leaves significantly reduced blood (p<0.01) and urinary glucose (p<0.05) levels in alloxan induced diabetic mice. (36)
• Analgesic / Antidiarrheal / Roots: Study evaluated a methanolic crude extract of roots for possible analgesic and anti-diarrheal activity in experimental animal models. Extract showed anti-diarrheal activity in a castor oil-induced diarrhea model. Analgesic activity was evaluated using acetic acid induced writhing inhibition in Swiss albino mice. At 200 and 400 mg/kbw dose, extract produced 35.38% and 53.85% (p<0.001) of writhing inhibition. (37)
• Antiviral / Human Rhinoviruses / Ellagic Acid: Study evaluated the cytotoxic and antiviral activities of tannin ellagic acid from leaves of L. speciosa toward HeLa cells and rhinoviruses HRV-3, -3, and -4. Results suggest ellagic acid does not interact with HRV-4 particles and may directly interact with human cells in the early stage of HRV infections to protect the cells from viral destruction. Ellagic acid also strongly inhibited RNA replication of HRV-4 in HeLa cells suggesting inhibition of viral replication via targeting of cellular molecules, rather than viral molecules. (38)
• Anti-Diabetic / Leaves: Study evaluated the cytoprotective effect of L. speciosa on pancreatic ß-cells. Study showed hot water extracts from leaves has a cytoprotective effect against SIN-1-induced oxidative stress in HIT-T15 cells through inhibition of lipid peroxidation, a decrease in ROS levels and an increase in antioxidant enzyme activity, together with an increase in insulin secretion. Results suggest a potential for LWE in the treatment of diabetes. (39)
• Diuretic Effect / Leaves: Study evaluated various extracts of leaves for diuretic activity in rat models. Extracts were administered at doses of 250 mg/kbw. The aqueous extract showed the best diuretic effect with a higher Na/K ratio followed by ethanol, EA and methanol extracts. (40)
• Banaba and Coroslic Acid in the Management of Diabetes and Its Complications: There is a growing body of evidence from animal and human studies as well as in vitro systems that banaba leaf extracts exert antidiabetic and antiobesity effects. Strong evidence indicate both corosolic acid and ellagitanins are responsible for these effects. No adverse effects have been reported in animals or in controlled human clinical trials. However, no animal studies have specifically addressed toxicity or LD50 values for corosolic acid and Banaba extracts standardized to specific concentrations of corosolic acid. Additional human efficacy and safety studies are warranted, as well as additional acute and subchronic animal safety studies. (2012) (42)
• Interaction with Antidiabetic Medications: Banaba interacts with antidiabetic medications. It can lower blood sugar and may cause blood sugar to go too low when taken together with antidiabetic medications. These medications include glimepiride (Amaryl), glyburide (Micronase), insulin, glipizide (glucotrol) among others. (43)
• Antibacterial / Cytotoxicity / Bark: Study evaluated a bark extract of L. speciosa for antibacterial activity by time-kill curves assay and cytotoxicity by brine shrimp lethality assay on eukaryotic cells. Extract showed concentration dependent killing for both B. spizizenii and A. anitratus. Extract was nontoxic during short term (acute) exposure but was toxic during prolonged (chronic) exposure with LC50 of 3422.68 and 35.30 µg/ml, respectively. (44)
• Essential Oil / Cytotoxic Effect / Flowers: GC-MS hydrodistillation analysis of essential oils from L. speciosa flowers yielded 0.085% with 45 compounds. Major volatiles in the flowers were α-terpineol (12.76), α-pinene (10.38), ß-pinene (8.45), myrcene (6.76), αß-bisabolene (5.97), α-bisabolol (3.14), among others. Cytoxicity assay of essential oil by Dalton's Lymphoma Ascites cells (DLA) and Ehrlich Ascites Carcinoma cells (EAC) at 50 µL/mL concentration produced 13.33% and 31% cytotoxicity, respectively. (45)
• Corosolic Acid / Glucose Uptake-Stimulatory Potential: Review focused on discussing the mechanisms associated with the anti-diabetic potential of corosolic acid. Studies have shown corosolic acid is beneficial for obesity and in maintaining blood sugar levels. Corosolic acid works as "insulin sensitizer" that may activate the IRS and other adapter proteins intracellularly for transmitting signals to P13K/AKT and MAPK/ERK pathways. (46)
• DPP-IV Inhibitory Activity / Antioxidant: The Krom Luang Chomphon folk recipe is used as alternative anti-diabetes recipe. Study evaluated 14 selected medicinal herb extracts from this recipe for their DPP-IV inhibitory activity, antioxidant property, and phytochemical compositions. While all extracts exhibited DPP-IV inhibitory activity, the highest inhibitory activity at 50 µg/mL, were detected in L. speciosa (71.07 ±0.07) and Terminalia catappa (69-89 ±0.43%), while standard diprotin A gave 90.07 ±0.39 inhibition. All extracts exhibited antioxidant activity at varying levels. (47)
• Insulin Sensitizers in Pre-Diabetes / DLBS3233 / Cinnamomum burmanii and Lagerstroemia speciosa: Study evaluated the efficacy and safety of DLBS3233, a novel bioactive fraction derived from Cinnamomum burmanii and Lagerstroemia speciosa, in improving insulin resistance and preserving ß-cell performance in patients with impaired glucose tolerance (IGT). Study showed DLBS3233 at 50-100 mg once daily was well tolerated and showed promising efficaciousness in improving insulin sensitivity and preserving ß-cell function in patients with IGT. (48)
• Antioxidant / Phenolic Content / Seeds: Study evaluated a methanolic extract of dried seeds of L. speciosa for total phenol content and antioxidant activity. Results showed an appreciable quantity of phenolic content (325±0.01 µg GAE/mg extract). Antioxidant oxidant activity by radical scavenging in DPPH assay was dose dependent with IC50 value of 9.63±0.20 mL. There was dose-dependent reducing activity. Activity was attributed to the presence of phenolic compounds. (49)
• Quercetin-7-Glucoside / Anti-Human Rhinovirus 2 Activity: HRVs are a major cause of the common cold, with no registered clinically effective antiviral for its treatment. Study evaluated the antiviral activity of Q7G (quercetin 7-glucoside) from L. speciosa against HRV2 (human rhinovirus 2 using a cytopathic effect (CPE) reduction method. Results suggest Q7G exerted an anti-HRV2 effect via the inhibition of virus replication in the early stage. (50)
- Cultivated for flowers.
- Tablets, leaf extracts, capsules, powder and tea in local commerce and the cybermarket.
© Godofredo U. Stuart Jr., M.D.
Updated July 2017 / March 2017 / April 2016
|Photos / Content © Godofredo Stuart / StuartXchange|
Sources and Suggested Readings
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