Norstaminane- and isopimarane-type diterpenes of Orthosiphon stamineus from Okinawa

Asymmetric synthesis of the fully functionalized six-membered A-ring of siphonol A

A synthetic study toward the construction of the fully functionalized six-membered A-ring of siphonol A is described. The salient features include the introduction of a six-membered ring system through a HWE reaction, the construction of a stereocenter at C5 via a hetero-Diels-Alder reaction, and the installation of the fully functionalized six-membered A-ring of siphonol A through photolytic decarboxylation.

A Study of the Medicinal Plants of Genus Orthosiphon sp.: Aiming to Expand Valuable Medicinal Resources for Medical Treatment

<b>Background and Objective:</b> <i>Orthosiphon</i> sp., contains many active ingredients that are beneficial to health. In addition to prevention, they are also used in treatment. This study aims to evaluate the agronomic characteristics of 9 <i>Orthosiphon</i> sp., based on morphology and combine molecular biology methods to determine the genetic relationship based on the "ITS1-4" gene region. <b>Materials and Methods:</b> Nine seed samples/species <i>Orthosiphon</i> sp., grown in 9 provinces in South Vietnam were collected and planted for survey at the Can Tho experimental farm. The method of observing and describing the external morphology and microdissection of the eye cage is carried out. The DNA extraction was performed at the Molecular Biology Laboratory, Institute of Food and Biotechnology, Can Tho University. <b>Results:</b> There are differences in some parameters except leaf width and flower diameter. A simple pedigree chart can classify nine cat breeds into 3 groups: Group I includes An Giang (Râ1), Ca Mau (Râ2) and Can Tho (Râ3) breeds that are genetically close to each other and have only the same quantity, group II includes 2 varieties of Vinh Long (Râ8) and Dong Thap (Râ6), group III includes 4 identical samples in Kien Giang (Râ7), Hau Giang (Râ4), Soc Trang (Râ5) and Tien Giang (Râ9). <b>Conclusion:</b> With molecular biology techniques, 9 cat breeds have been identified, all belonging to the species <i>Orthosiphon aristatus</i>. However, to have more accurate and complete conclusions, it is necessary to study some specific gene sequences related to the morphology and substances contained in the plant.

An integrative analysis to predict the active compounds and explore polypharmacological mechanisms of Orthosiphon stamineus Benth

BACKGROUND

Orthosiphon stamineus Benth is a dietary supplement and traditional Chinese herb with widespread clinical applications, but a comprehensive understanding of its active compounds and polypharmacological mechanisms is lacking. This study aimed to systematically investigate the natural compounds and molecular mechanisms of O. stamineus via network pharmacology.

METHODS

Information on compounds from O. stamineus was collected via literature retrieval, while physicochemical properties and drug-likeness were evaluated using SwissADME. Protein targets were screened using SwissTargetPrediction, while the compound-target networks were constructed and analyzed via Cytoscape with CytoHubba for seed compounds and core targets. Enrichment analysis and disease ontology analysis were then carried out, generating target-function and compound-target-disease networks to intuitively explore potential pharmacological mechanisms. Lastly, the relationship between active compounds and targets was confirmed via molecular docking and dynamics simulation.

RESULTS

A total of 22 key active compounds and 65 targets were identified and the main polypharmacological mechanisms of O. stamineus were addressed. The molecular docking results suggested that nearly all core compounds and their targets possess good binding affinity. In addition, the separation of receptor and ligands was not observed in all dynamics simulation processes, whereas complexes of orthosiphol Z-AR and Y-AR performed best in simulations of molecular dynamics.

CONCLUSION

This study successfully identified the polypharmacological mechanisms of the main compounds in O. stamineus, and predicted five seed compounds along with 10 core targets. Moreover, orthosiphol Z, orthosiphol Y, and their derivatives can be utilized as lead compounds for further research and development. The findings here provide improved guidance for subsequent experiments, and we identified potential active compounds for drug discovery or health promotion.

"Kidney Tea" and Its Bioactive Secondary Metabolites for Treatment of Gout

Clerodendranthus spicatus, popularly known as "kidney tea" in China, is consumed traditionally as a functional food for treatment of renal inflammation, dysuria, and gout. We evaluated the effects of C. spicatus on gout by assessing activities of antihyperuricemia, anti-gouty arthritis, and analgesia in vivo, and the results indicated that the ethyl acetate fraction shows potential activities. Subsequent phytochemical investigation of this fraction led to the isolation of 32 compounds, consisting of 20 diterpenoids (including the new orthosiphonones E and F), 2 triterpenoids, 6 flavonoids, 2 lignanoids, and 2 phenolic acid derivatives. Pharmacological investigation of the pure compounds in the cellular model of hyperuricemia indicated that 12 compounds could promote the excretion of uric acid at 10 μg/mL, and compounds 3, 4, 5, and 21 had better effects than that of benzbromarone, a famous uricosuric drug. Furthermore, compounds 4, 6, 7, 9, 14, 15, 23, 26, and 31 showed significant anti-gouty arthritis activity in monosodium urate (MSU)-induced joint swelling at the dose of 50 mg/kg, while compounds 4, 5, 7, 9, and 26 exhibited significant inhibition of pain induced by acetic acid. Our findings provided scientific justification to support the traditional application of "kidney tea" for treating gout and suggested its good application prospects in the future.

In vitro antioxidant, antimicrobial and antiproliferative studies of four different extracts of Orthosiphon stamineus, Gynura procumbens and Ficus deltoidea

Background

Medicinal plants are important source of drugs with pharmacological activities. Therefore, there is always rising demands to discover more therapeutic agents from various species. Orthosiphon stamineus, Gynura procumbens and Ficus deltoidea are high valued medicinal plants of Malaysia contain rich source of phenolic and flavonoid compounds. The aims of the present study were to evaluate anti-oxidant, antimicrobial and anti-proliferative effects on A549, HeGP2 and MCF7 cell lines of four different extracts of Orthosiphon stamineus, Gynura procumbens and Ficus deltoidea.

Methodology

The leaves of all selected plants were extracted with methanol, chloroform, ethyl acetate and butanol separately with simple cold maceration. Antioxidant activity of all crude extracts were quantitatively measured against DPPH and Ferric Reducing Assay. Antimicrobial evaluation was done by Microdilution and MTT assay and antipoliferative activity of all extracts of selected plant were evaluated against A549, HePG2 and MCF7 cell lines.

Results

Results showed that methanol extract exhibited highest percentage free radical scavenging activity of almost all extracts of selected plants. Antimicrobials results showed chloroform and methanol extracts of O. stamineus extract were the two most active extracts against resistant MRSA but not S. aureus. Only methanol extract of G. procumbens showed antimicrobial activity against the tested pathogens. Chloroform and methanol extracts of F. deltoidea elicited antimicrobial activity against S. aureus but not MRSA. Antiproliferative activity against three tested cell lines results showed that ethyl acetate extract of O. stamineus showed good effect whereas methanol extract of F. deltoidea and G. procumbens exhibited good antiproliferative activity.

Conclusions

The results of the present investigation demonstrated significant variations in the antioxidant, antimicrobial and antiproliferative effects of different solvent extracts. These data could be helpful in isolation of pure potent compounds with good biological activities from the extracts of plants.

Phytochemical profile of Orthosiphon aristatus extracts after storage: Rosmarinic acid and other caffeic acid derivatives

BACKGROUND

Orthosiphon aristatus (Blume) Miq. is a medicinal herb which is traditionally used for the treatment of diabetes and kidney diseases in South East Asia. Previous studies reported higher concentration of antioxidative phytochemicals, especially rosmarinic acid (ester of caffeic acid) and other caffeic acid derivatives in this plant extract than the other herbs such as rosemary and sage which are usually used as raw materials to produce rosmarinic acid supplement in the market.

PURPOSE

The phytochemical profile of O. aristatus was investigated at different storage durations for quality comparison.

METHODS

The phytochemicals were extracted from the leaves and stems of O. aristatus using a reflux reactor. The extracts were examined for total phenolic and flavonoid contents, as well as their antioxidant capacities, in terms of radical scavenging, metal chelating and reducing power. The phytochemical profiles were also analyzed by unsupervised principal component analysis and hierarchical cluster analysis, in relation to the factor of storage at 4 °C for 5 weeks.

RESULTS

The leaf extract was likely to have more phytochemicals than stem extract, particularly caffeic acid derivatives including glycosylated and alkylated caffeic acids. This explains higher ratio of total phenolic content to total flavonoid content with higher antioxidant capacities for the leaf extracts. Rosmarinic acid dimer and salvianolic acid B appeared to be the major constituents, possibly contributing to the previously reported pharmacological properties. However, the phytochemical profiles were found changing, even though the extracts were stored in the refrigerator (4 °C). The change was significantly observed at the fifth week based on the statistical pattern recognition technique.

CONCLUSION

O. aristatus could be a promising source of rosmarinic acid and its dimer, as well as salvianolic acid B with remarkably antioxidant properties. The phytochemical profile was at least stable for a month stored at 4 °C. It is likely to be a good choice of herbal tea with comparable radical scavenging activity, but lower caffeine content than other tea samples.

Genotoxicity, acute and subchronic toxicity studies of nano liposomes of Orthosiphon stamineus ethanolic extract in Sprague Dawley rats

Background

Orthosiphon stamineus (OS) Benth is a medicinal plant and native in Southeast Asia. Pharmacological effects of OS are attributed to the presence of lipophilic flavones. However; lipophilic compounds suffer from poor aqueous solubility which limits the OS oral bioavailability and therapeutic applications. Therefore, OS was prepared in nano formulation form using liposomes from soybean phospholipids. The aim of the present study is to evaluate the in vitro genotoxicity and in vivo oral toxicity of nano liposomes of OS ethanolic extract (OS-EL).

Methods

In the acute toxicity study Sprague Dawley female rats were given a single dose of the OS-EL at 5000 mg/kg/day orally and screened for two weeks after administration. In the subchronic study, three different doses of OS-EL were administered for 28 days. Mortality, clinical signs, body weight changes, hematological and biochemical parameters, gross findings, organ weights, and histological parameters were monitored during the study. Genotoxicity was assessed using the Ames test with the TA98 and TA100 Salmonella typhimurium strains. High-performance liquid chromatography was performed for identification and quantification of the major marker compounds in OS-EL. Heavy metal detection was performed using an atomic absorption spectrometer.

Results

The acute toxicity study showed that the LD₅₀ of the extract was greater than 5000 mg/kg. In the repeated dose 28-day oral toxicity study, the administration of 250 mg/kg, 500 mg/kg, and 1000 mg/kg/day of OS-EL per body weight revealed no significant difference in food and water consumptions, bodyweight change, haematological and biochemical parameters, relative organ weights, gross findings or histopathology compared to the control group. The Ames test revealed that the OS-EL did not have any potential to induce gene mutations in S. Typhimurium.

Conclusions

Analyses of these results with the information of signs, behaviour, and health monitoring could lead to the conclusion that the long-term oral administration of OS-EL for 28 days does not cause sub-chronic toxicity.

Laxiflorol A, the first example of 7,8:15,16-di-seco-15-nor-21-homo-ent-kauranoid from Isodon eriocalyx var. laxiflora

Laxiflorol A (1), an unprecedented 7,8:15,16-di-seco-15-nor-21-homo-ent-kauranoid, and its precursor analogue, laxiflorol B (2), were isolated from the leaves of Isodon eriocalyx var. laxiflora.

Preparation and characterization of nano liposomes of Orthosiphon stamineus ethanolic extract in soybean phospholipids

BACKGROUND

O. stamineus is a medicinal herb with remarkable pharmacological properties. However, poor solubility of the active principles limits its medicinal value. This study sought to prepare nano liposomes of OS ethanolic extract in unpurified soybean phospholipids in order to improve its solubility and permeability. OS liposomes were prepared by the conventional film method, and were characterized for solubility, entrapment efficiency, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), particle size and zeta potential, release, absorption in everted rat intestinal sacs, and DPPH scavenging effect.

RESULTS

OS liposomes showed substantial enhancement of extract's solubility from 956 ± 34 to 3979 ± 139 μg/ml, with entrapment efficiency of 66.2 ± 0.9%. FTIR study indicates interaction between soybean phospholipids and OS extract. TEM and dynamic light scattering showed presence of round anionic nano liposomes with particle size and zeta potential of 152.5 ± 1.1 nm and -49.8 ± 1.0 mV, respectively. A study using the fluorescent probe pyrene showed the critical micellar concentration is 9.2 ± 2.9 μg/ml. Release studies showed 94 ± 0.1% release in non-formulated extract and 62.4 ± 0.1% in OS liposomes. Released extract from OS liposomes showed improvement in DPPH scavenging effect, IC50 = 23.5 ± 1.1 μg/ml compared to 32.4 ± 0.5 μg/ml in non-formulated extract. OS liposomes were stable at pH 5.5 and 7.4, but showed reversible agglomeration at pH 1.6. Absorption in everted rat intestinal sacs showed substantial improvement in permeability of 3'-hydroxy-5, 6, 7, 4″-tetramethoxyflavone, sinensetin, eupatorin, and 3 other unknown compounds.

CONCLUSIONS

Enhanced solubility, absorption and antioxidant effect may improve the overall pharmacological effects and medicinal value of OS ethanolic extract.

Vascular Reactivity Concerning Orthosiphon stamineus Benth-Mediated Antihypertensive in Aortic Rings of Spontaneously Hypertensive Rats

Orthosiphon stamineus Benth has been traditionally used to treat hypertension. The study aimed to investigate the vascular reactivity of water extract (WOS) and water : methanolic (1 : 1) extract (WMOS) of Orthosiphon stamineus Benth and AT₁ receptors blocker in the mechanisms of antihypertensive mediated by α₁-adrenergic receptor and EDNO and PGI₂ releases in the SHR aortic rings. SHR (230–280 g) were divided into four groups: control, WOS, WMOS, and losartan. After being fed orally for 14 days, the aorta was harvested and subjected to PE (10⁻⁹ to 10⁻⁵ M) and ACh (10⁻⁹ to 10⁻⁵ M) with and without L-NAME (100 µM) and indomethacin (10 µM), respectively. WOS, WMOS, and losartan significantly reduced the contractile responses to PE intact suggesting the importance of endothelium in vasorelaxation. Losartan significantly enhanced the ACh-induced vasorelaxation. L-NAME significantly inhibited the ACh-induced relaxation in all groups. Indomethacin enhanced ACh-induced vasorelaxation in WMOS. Collectively, Orthosiphon stamineus leaves extract reduced vasoconstriction responses by the alteration of α₁-adrenergic and AT₁ receptors activities. The involvement of EDNO releases was clearly observed in this plant. In WOS, PGI₂ releases might not participate in the ACh-induced vasorelaxation. However, in WMOS, enhancement of vasorelaxation possibly due to continuous release of PGI₂.

Toxicity evaluation of a standardised 50% ethanol extract of Orthosiphon stamineus

AIM OF THE STUDY

The present investigation was carried out to evaluate the safety of standardised 50% ethanol extract of Orthosiphon stamineus plant by determining its potential toxicity after acute and subchronic administration in rats.

MATERIALS AND METHODS

For acute toxicity study, up and down method (limit dose) was adapted. A single dose of 5000 mg/kg of the standardised 50% ethanol extract of O. stamineus was given orally to 5 healthy Sprague-Dawley (SD) female adult rats. The rats were observed for mortality and clinical signs for 3 h and then periodically for 14 days. While in the subchronic toxicity study, the extract was administered orally at doses of 1250, 2500 and 5000 mg/kg per day for 28 days to female and male SD rats, respectively. The animals were sacrificed, followed by examination of their organs and blood serum.

RESULTS

In the acute toxicity study, standardised 50% ethanol extract of O. stamineus at a dose of 5000 mg/kg caused neither visible signs of toxicity nor mortality. All five rats survived until the end of observation period. While in subchronic toxicity, administration of the standardised 50% ethanol extract of O. stamineus at 1250, 2500, and 5000 mg/kg for 28 days did not produce any mortality and there were no significant differences in the general condition, growth, organ weights, hematological parameters, clinical chemistry values, or gross and microscopic appearance of the organs from the treatment groups as compared to the control group.

CONCLUSIONS

Standardised 50% ethanol extract of O. stamineus did not cause any death nor did it cause abnormalities in necropsy and histopathology findings. There were no acute or subchronic toxicity observed and this extract could be devoid of any toxic risk. The NOAEL for the standardised 50% ethanol extract of O. stamineus is 5000 mg/kg per day for 28 days.

HPLC and anti-inflammatory studies of the flavonoid rich chloroform extract fraction of Orthosiphon stamineus leaves

The aim of the present study was to verify the anti-inflammatory activity of Orthosiphon stamineus leaf extracts and to identify the active compound(s) contributing to its anti-inflammatory activity using a developed HPLC method. Active chloroform extract of O. stamineus was fractionated into three fractions using a dry flash column chromatography method. These three fractions were investigated for anti-peritoneal capillary permeability, in vitro nitric oxide scavenging activity, anti-inflammatory and nitric oxide (NO) inhibition using carrageenan-induced hind paw edema method. The flavonoid rich chloroform extract fraction (CF2) [containing sinensetin (2.86% w/w), eupatorin (5.05% w/w) and 3’-hydroxy-5,6,7,4’-tetramethoxyflavone (1.101% w/w)], significantly reduced rat hind paw edema, NO and decreased dye leakage to peritoneal cavity at p < 0.05. IC₅₀ of in vitro NO scavenging of CF2 was 0.3 mg/mL. These results suggest that the anti-inflammatory properties of these CF2 may possibly be due to the presence of flavonoid compounds capable of affecting the NO pathway.

Studies on diuretic and hypouricemic effects of Orthosiphon stamineus methanol extracts in rats

AIM OF THE STUDY

Orthosiphon stamineus (Labiatae) is a traditional folk medicine widely used in Southeast Asia for the treatment of several kidney disorders, gout and as a diuretic. This study was conducted to examine the diuretic and hypouricemic effects of Orthosiphon stamineus leaf extracts.

MATERIALS AND METHODS

The diuretic effect of different methanol extracts was examined by treating different groups of Sprague-Dawley rats with single (2g/kg) oral doses of methanol and methanol:water (1:1) extracts. Hydrochlorothiazide (10mg/kg) was used as positive control in acute study. Methanol and methanol water (1:1) extracts at 0.5 g/kg were administered for a period of 7 consecutive days. Cumulative urine volume and electrolytes (Na+ and K+) concentrations at different time intervals were measured. On the other hand, hypouricemic activity of methanol:water extract (1:1) was experimented using different oral single doses (0.25, 0.5, 1 and 2g/kg). Allopurinol was used as positive control. Uric acid concentration in serum was analyzed by using RP-HPLC at 280 nm.

RESULTS

Sodium and potassium excretion increased significantly (p<0.05 and <0.01) in the first 8h of treatment with a single dose (2g/kg) of the extracts in a pattern comparable to that of the known diuretic hydrochlorothiazide. Meanwhile, repeated administration of 0.5 g/kg methanol:water (1:1) extract showed a significant increase in urine volume (from day 3 to day 7) (p<0.01) and electrolytes excretion (Na+ and K+) from day 2 to day 7 (p<0.05 and <0.01). On the other hand, 0.5, 1 and 2g/kg of methanol:water (1:1) extract and the standard allopurinol reduced the serum urate level in hyperuricemic rats at hour 6.

CONCLUSION

These results provided an evidence of the high tendency of methanol:water (1:1) extract of Orthosiphon stamineus towards diuretic and hypouricemic effects in rats.

Staminane- and isopimarane-type diterpenes from Orthosiphon stamineus of Taiwan and their nitric oxide inhibitory activity

From the MeOH extract of Taiwanese Orthosiphon stamineus, two new staminane-type diterpenes, staminols C (1) and D (2), and three new isopimarane-type diterpenes, orthosiphonone C (3) and D (4) and 14-deoxo-14-O-acetylorthosiphol Y (5), have been isolated together with 16 known diterpenes, orthosiphols A, B, D, K, M, N, O, X, and Y, nororthosiphonolide A, neoorthosiphol B, orthosiphonone A, secoorthosiphols B and C, 3-O-deacetylorthosiphol I, and 2-O-deacetylorthosiphol J. Their structures were determined on the basis of the spectroscopic data. All the newly isolated diterpenes exhibited dose-dependent inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-activated macrophage-like J774.1 cells, and 2-O-deacetylorthosiphonone A showed the most potent activity, with an IC(50) value of 35.0 microM, comparable to that of the positive control N(G)-monomethyl-L-arginine (L-NMMA; IC(50), 35.7 microM).

Inhibition of NO production by highly-oxygenated diterpenes of Orthosiphon stamineus and their structure-activity relationship

Nitric oxide (NO) has been implemented in various pathological processes. In the present study, 47 highly-oxygenated isopimarane-type and novel carbon framework staminane-type diterpenes isolated from Orthosiphon stamineus of Indonesia, Okinawa, Myanmar and Vietnam were evaluated for their inhibitory activity in NO production by lipopolysaccharide (LPS)-activated macrophage-like J774.1 cells. All the isolated diterpenes showed concentration-dependent inhibition of NO production in LPS-activated macrophage-like J774.1 cells, and based on the results, their structure-activity relationship were established.

Highly-oxygenated isopimarane-type diterpenes from Orthosiphon stamineus of Indonesia and their nitric oxide inhibitory activity

From the methanolic extract of Indonesian Orthosiphon stamineus, nine new highly-oxygenated isopimarane-type diterpenes [7-O-deacetylorthosiphol B (1), 6-hydroxyorthosiphol B (2), 3-O-deacetylorthosiphol I (3), 2-O-deacetylorthosiphol J (4), siphonols A-E (5-9)] have been isolated together with nine known diterpenes [orthosiphols H (10), K (11), M (12) and N (13); staminols A (14) and B (15); neoorthosiphols A (16) and B (17); norstaminol A (18)]. Their structures were determined based on the spectroscopic data. The isolated diterpenes inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-activated macrophage-like J774.1 cells. Compounds 4-7, 9, 10, 14, and 17 showed inhibitory activities more potent (IC(50), 10.8-25.5 microM) than a positive control N(G)-monomethyl-L-arginine (L-NMMA; IC(50), 26.0 microM).

Nitric oxide inhibitory isopimarane-type diterpenes from Orthosiphon stamineus of Indonesia

A methanolic extract of Orthosiphon stamineus yielded six new highly oxygenated isopimarane-type diterpenes, orthosiphols U-Z (1-6), and 15 previously reported diterpenes. The isolated diterpenes all showed significant dose-dependent inhibitory effects on the nitric oxide (NO) production in lipopolysaccharide (LPS)-activated macrophage-like J774.1 cells. Orthosiphols A (7), B (8), D (9), and X (4) showed more potent inhibitory activities than a positive control, N(G)-monomethyl-l-arginine (l-NMMA), and 1 displayed the strongest activity with an IC(50) value of 6.4 microM.

Siphonols A-E: novel nitric oxide inhibitors from Orthosiphon stamineus of Indonesia

From the methanolic extract of Orthosiphon stamineus, four novel highly oxygenated isopimarane-type diterpenes named siphonols A-D (1-4) and a novel biogenetically interesting norisopimarane-type diterpene named siphonol E (5) were isolated. The new compounds 1-3 and 5 showed more potent inhibitory effects on the nitric oxide (NO) production in lipopolysaccharide (LPS)-activated macrophage-like J774.1 cells than a positive control N(G)-monomethyl-L-arginine (L-NMMA). Siphonols A-E (1-5) represent the first examples of isopimaranes oxygenated at C-20.