Sub-chronic oral toxicity of a water-soluble extract of Centella asiatica (Centell-S) in Wistar rats.

BACKGROUND: Centell-S, a water-soluble extract from Centella asiatica, is predominantly composed of madecassoside and asiaticoside, exceeding 80% w/w. Pursuing its development as an herbal medicinal product, Centell-S underwent sub-chronic toxicity assessment adhering to OECD GLP 408 standards. METHODS: In a study involving 100 Wistar rats, varying doses of Centell-S (50, 200, or 800 mg/kg/day) or a vehicle control were administered orally over 90 days. To evaluate Centell-S's safety profile, assessments included clinical observations, health examinations, clinical biochemistry analyses, and detailed anatomical pathology evaluations were conducted. RESULTS: Over the 90 days of treatment, the administration of Centell-S did not lead to any fatalities in the test animals. Clinical observations did not reveal any signs indicative of toxic effects. Notably, an increase in total white blood cell and lymphocyte counts was observed in both sexes, yet these levels returned to normal following a two-week discontinuation period post-treatment. CONCLUSIONS: Under the specific conditions of the OECD GLP 408, Repeated Dose 90-day Oral Toxicity Study in Rodents, the no observed adverse effect level (NOAEL) of Centell-S was 800 mg/kg/day. These findings are promising for the continued development of Centell-S as a phytopharmaceutical for clinical applications.

Enhancing oral bioavailability of andrographolide using solubilizing agents and bioenhancer: comparative pharmacokinetics of Andrographis paniculata formulations in beagle dogs.

CONTEXT: The therapeutic potential of andrographolide is hindered by its poor oral bioavailability and unpredictable pharmacokinetics, primarily due to its limited water solubility. OBJECTIVE: This work aimed to enhance the solubility and pharmacokinetics of andrographolide, a bioactive compound in Andrographis paniculata (Burm. f.) Nees (Acanthaceae), using solubilizing agents and a bioenhancer. MATERIALS AND METHODS: Four groups of beagles were compared: (1) A. paniculata powder alone (control), (2) A. paniculata powder with 50% weight/weight (w/w) ß-cyclodextrin solubilizer, (3) A. paniculata powder with 1% w/w sodium dodecyl sulfate (SDS) solubilizer, and (4) A. paniculata powder co-administered with 1% w/w SDS solubilizer and 10% piperine bioenhancer. All groups received a consistent oral dose of 3 mg/kg of andrographolide, administered both as a single dose and multiple doses over seven consecutive days. RESULTS: Thirteen chemical compounds were identified in A. paniculata powder, including 7 diterpenoids, 5 flavonoids, and 1 phenolic compound. A. paniculata co-administration with either 50% w/w ß-cyclodextrin or 1% w/w SDS, alone or in combination with 10% w/w piperine, significantly increased systemic andrographolide exposure by enhancing bioavailability (131.01% to 196.05%) following single and multiple oral co-administration. Glucuronidation is one possible biotransformation pathway for andrographolide, as evidenced by the excretion of glucuronide conjugates in urine and feces. CONCLUSION: The combination of solubilizing agents and a bioenhancer improved the oral bioavailability and pharmacokinetics of andrographolide, indicating potential implications for A. paniculata formulations and clinical therapeutic benefits. Further investigation in clinical studies is warranted.

Absolute oral bioavailability and possible metabolic pathway of panduratin A from Boesenbergia rotunda extract in beagle dogs.

CONTEXT: Attempts are ongoing to develop medications to fight against the COVID-19 pandemic. Our previous study revealed the in vitro anti-SARS-CoV-2 activity of fingerroot [Boesenbergia rotunda (L.) Mansf. (Zingiberaceae)] and its phytochemical, panduratin A. OBJECTIVE: To investigate the pharmacokinetic profiles of panduratin A as a pure compound and in a fingerroot extract formulation in beagle dogs. MATERIALS AND METHODS: A total of 12 healthy dogs were randomly divided into three groups, a single dose of 1 mg/kg panduratin A by intravenous and multiple doses of 5 and 10 mg/kg panduratin A fingerroot extract formulation by oral administration for seven consecutive days. The plasma concentration of panduratin A was determined by LCMS. RESULTS: The peak concentrations of a single dose of 5 and 10 mg/kg panduratin A fingerroot extract formulation were 12,416 ± 2,326 and 26,319 ± 8,221 µg/L, respectively. Increasing the oral dose of fingerroot extract formulation, equivalent to panduratin A 5-10 mg/kg, showed dose proportionality, with an approximately 2-fold increase in Cmax and AUC. The absolute oral bioavailability of panduratin A in the fingerroot extract formulation was approximately 7-9%. The majority of panduratin A was biotransformed into several products via oxidation and glucuronidation, and predominantly excreted via the faecal route. CONCLUSION: The oral formulation of fingerroot extract was safe in beagle dogs, and increasing dose showed dose proportionality in terms of the systemic exposure of panduratin A. This information will support the phytopharmaceutical product development of fingerroot extract against the COVID-19 pandemic.

Bioenhancing effects of piperine and curcumin on triterpenoid pharmacokinetics and neurodegenerative metabolomes from Centella asiatica extract in beagle dogs.

Centell-S is a water-soluble extract of Centella asiatica containing more than 80% w/w triterpenoid glycosides. Madecassoside and asiaticoside are two major components of the extract and can be converted into active metabolites, triterpenic acids in large mammal species. In this study, the pharmacokinetic profiles and metabolomic changes generated by the bioactive triterpenoids of Centell-S alone, and in combination with the bioenhancers piperine and curcumin, were investigated in beagle dogs. The test substances were orally administered over multiple doses for 7 consecutive days. At day 1 and 7 after receiving the test compounds, the level of major bioactive triterpenoids and related metabolites were measured using triple quadrupole and high-resolution accurate mass orbitrap models of LCMS to determine pharmacokinetic and metabolomic profiles, respectively. Centell-S was well tolerated, alone and in all combination groups. The combination of Centell-S and piperine significantly increased (p < 0.05) the systemic exposure of madecassoside on day 1 and asiatic acid on day 7, by approximately 1.5 to 3.0-fold of Cmax and AUC values as compared to the Centell-S alone, while the addition of curcumin did not provide a significant improvement. Several metabolomic changes were observed from pre-dose to 4 h post-dose, with some biomarkers of neurodegenerative diseases including L-glutamine, lysophosphatidylcholine (17:0), taurochenodeoxycholic acid, uric acid, stearic acid, palmitic acid, and lactic acid showing good correlation with the systemic exposure of the bioactive triterpenoids (asiatic acid). Thus, the combining of piperine to Centell-S exhibits the improvement of bioactive triterpenoids which are related to the biomarkers of neurodegenerative diseases. These promising results might be useful for the development of this standardised extract to become a more effective phytomedicine for neurodegenerative diseases.

Increase water solubility of Centella asiatica extract by indigenous bioenhancers could improve oral bioavailability and disposition kinetics of triterpenoid glycosides in beagle dogs.

A newly standardised extract of Centella asiatica (Centell-S) with better water solubility than the previous standardised extract of C. asiatica (ECa 233) was developed, and pharmacokinetic profiles of bioactive triterpenoids were investigated in beagle dogs. The test substances were administered via intravenous or oral administration with single and multiple doses for 7 days. The concentrations of major bioactive triterpenoids, including madecassoside, asiaticoside, madecassic acid, and asiatic acid, in biological samples were measured by liquid chromatography-tandem mass spectrometry. The dogs in this study showed good tolerability to all test substances, based on the physical appearance and blood chemistry 24 h after dosing. The major bioactive triterpenoids found in systemic blood circulation were madecassoside, asiaticoside, and asiatic acid; the concentration of these components ranged from 1 to 10,000 µg/L after intravenous administration of 1.0 mg/kg Centell-S. Oral administration of 10 and 20 mg/kg Centell-S generated approximately twofold higher plasma levels of both madecassoside and asiaticoside compared with equivalent doses of ECa 233. In addition, there was an accumulation of triterpenoid glycosides after multiple oral administrations of Centell-S for 7 days, while triterpenic acids showed little tendency for accumulation. Beagles had good tolerability to both standardised extracts of C. asiatica, and showed a similar pattern of bioactive triterpenoids to humans. Centell-S increased oral bioavailability of major triterpenoid glycosides and can be further developed into a phytopharmaceutical product.

Immunomodulatory effect of standardized C. asiatica extract on a promotion of regulatory T cells in rats.

BACKGROUND: ECa 233 is a standardized extract of C. asiatica containing the triterpenoid glycosides, madecassoside to asiaticoside in the ratio of (1.5 ± 0.5):1. Anti-inflammatory activities of ECa 233 have been reported; however the immunomodulatory effects of ECa 233 on regulatory T cells, which have a pivotal role in immune regulation, has not been elucidated. Therefore, we investigated the effects of ECa 233 on regulatory T cells that may provide benefits in autoimmune and chronic inflammatory diseases. METHODS: ECa 233 was prepared as oral suspension in 0.5% carboxymethylcellulose and administered to male Wistar rats via oral gavage. The pharmacokinetics and toxicity of ECa 233 were evaluated. Splenic lymphocytes were isolated and analyzed by flow cytometry and qPCR to determine the immunomodulatory effects of ECa 233 on regulatory T cells. RESULTS: All rats had good tolerability to ECa 233 and other test preparations. The pharmacokinetic study showed low oral bioavailability for both triterpenoids, with the maximum plasma concentration reached at 4 h for asiaticoside and at 0.5 h for madecassoside. Multiple oral administration of ECa 233 reduced the frequency of T cells, particularly CD8 T cells in rats. ECa 233 enhanced the percentage of regulatory T cells, characterized by high expression of CD25+ and upregulation of FoxP3 gene. CONCLUSIONS: The present study demonstrated that ECa 233 possesses immunosuppressive properties by enhancing regulatory T cells. These results provide in vivo evidence for the anti-inflammatory action of ECa 233, in line with previously reports, and the potential uses of ECa 233 in the treatment of chronic inflammatory and autoimmune diseases.

Anti-SARS-CoV-2 Activity of Andrographis paniculata Extract and Its Major Component Andrographolide in Human Lung Epithelial Cells and Cytotoxicity Evaluation in Major Organ Cell Representatives.

The coronaviruses disease 2019 (COVID-19) caused by a novel coronavirus (SARS-CoV-2) has become a major health problem, affecting more than 50 million people with over one million deaths globally. Effective antivirals are still lacking. Here, we optimized a high-content imaging platform and the plaque assay for viral output study using the legitimate model of human lung epithelial cells, Calu-3, to determine the anti-SARS-CoV-2 activity of Andrographis paniculata extract and its major component, andrographolide. SARS-CoV-2 at 25TCID50 was able to reach the maximal infectivity of 95% in Calu-3 cells. Postinfection treatment of A. paniculata and andrographolide in SARS-CoV-2-infected Calu-3 cells significantly inhibited the production of infectious virions with an IC50 of 0.036 µg/mL and 0.034 µM, respectively, as determined by the plaque assay. The cytotoxicity profile developed over the cell line representatives of major organs, including liver (HepG2 and imHC), kidney (HK-2), intestine (Caco-2), lung (Calu-3), and brain (SH-SY5Y), showed a CC50 of >100 µg/mL for A. paniculata extract and 13.2-81.5 µM for andrographolide, respectively, corresponding to a selectivity index of over 380. In conclusion, this study provided experimental evidence in favor of A. paniculata and andrographolide for further development as a monotherapy or in combination with other effective drugs against SARS-CoV-2 infection.

Pharmacokinetics and metabolomics investigation of an orally modified formula of standardized Centella asiatica extract in healthy volunteers.

The formula of a standardized extract of Centella asiatica (ECa 233) was modified to improve its dissolution, with implications for pharmacokinetics and metabolomic profile. This study aimed to understand the resultant changes in disposition kinetics of ECa 233 and alterations to human metabolome after oral administration. This study was a two-sequence of dosages (250 and 500 mg), with an open-label phase I clinical trial. The modified formula was administered in single and multiple doses to twelve healthy Thai volunteers. The major parent compounds, madecassoside and asiaticoside, were rarely absorbed, instead undergoing biotransformation into active metabolites, madecassic acid and asiatic acid with possibility to be eliminated via fecal route. Increasing the dose of ECa 233 resulted in significantly greater plasma levels of those active metabolites, with accumulation of asiatic acid after multiple oral administration for seven days. Examining the impacts of accumulation behavior on metabolomics, the study traced changes in levels pre- and post-dose of five relevant human metabolites. Administration of ECa 233 was found to be significantly associated with an increase of choline, an endogenous metabolite with documented benefits for learning and memory. Therefore, ECa 233 may be useful in mitigating cognitive impairment, through its role in modulating human metabolites.

Comparative Pharmacokinetics of Puerarin Alone and in Pueraria mirifica Extract in Female Cynomolgus Monkeys.

Pueraria mirifica is an endemic Thai plant that has been used for rejuvenation and in the relief of various aging diseases. Puerarin is one of the major isoflavones found in this plant and shows several pharmacological activities in relation to the Thai traditional use of P. mirifica. Therefore, comparative pharmacokinetics of pure puerarin alone and that in a P. mirifica extract in cynomolgus monkeys were conducted in order to investigate the pharmacokinetic profiles of the 2 preparations. To this end, puerarin and P. mirifica extract, at an equivalent dose of 10 mg/kg of puerarin, were orally dosed to adult female monkeys for 7 consecutive days. A single intravenous injection of puerarin at a dose of 1 mg/kg was also peformed. Serial blood samples and excreta were collected from 0 - 24 h and 0 - 48 h after dosing. Determination of the puerarin levels and its metabolites in biological samples was conducted by liquid chromatography tandem mass spectrometry. Plasma levels of aspartate aminotransferase, alanine aminotransferase, and creatinine fluctuated in the normal range, with no abnormal physical signs in the animal. The absolute oral bioavailability of puerarin was approximately 1% in both preparations. Accumulation of puerarin was found after oral dosing for 7 consecutive days in both groups. Major metabolites of puerarin found in monkeys were hydroxylation and deglycosylation products. A negligible amount of unchanged puerarin was detected in urine and feces. Pharmacokinetic profiles obtained from this study could help to design the prescribed remedy of puerarin and P. mirifica extract phytopharmaceutical products for human use.

High-content screening of Thai medicinal plants reveals Boesenbergia rotunda extract and its component Panduratin A as anti-SARS-CoV-2 agents.

Since December 2019, the emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused severe pneumonia, a disease named COVID-19, that became pandemic and created an acute threat to public health. The effective therapeutics are in urgent need. Here, we developed a high-content screening for the antiviral candidates using fluorescence-based SARS-CoV-2 nucleoprotein detection in Vero E6 cells coupled with plaque reduction assay. Among 122 Thai natural products, we found that Boesenbergia rotunda extract and its phytochemical compound, panduratin A, exhibited the potent anti-SARS-CoV-2 activity. Treatment with B. rotunda extract and panduratin A after viral infection drastically suppressed SARS-CoV-2 infectivity in Vero E6 cells with IC50 of 3.62 µg/mL (CC50 = 28.06 µg/mL) and 0.81 µΜ (CC50 = 14.71 µM), respectively. Also, the treatment of panduratin A at the pre-entry phase inhibited SARS-CoV-2 infection with IC50 of 5.30 µM (CC50 = 43.47 µM). Our study demonstrated, for the first time, that panduratin A exerts the inhibitory effect against SARS-CoV-2 infection at both pre-entry and post-infection phases. Apart from Vero E6 cells, treatment with this compound was able to suppress viral infectivity in human airway epithelial cells. This result confirmed the potential of panduratin A as the anti-SARS-CoV-2 agent in the major target cells in human. Since B. rotunda is a culinary herb generally grown in China and Southeast Asia, its extract and the purified panduratin A may serve as the promising candidates for therapeutic purposes with economic advantage during COVID-19 situation.

The Effects of a Standardized Extract of Centella asiatica on Postlaser Resurfacing Wound Healing on the Face: A Split-Face, Double-Blind, Randomized, Placebo-Controlled Trial.

Background: Centella asiatica, a medicinal plant, has been used traditionally to promote wound healing. Its efficacy on promoting postlaser resurfacing wound healing is lacking. Methods: Thirty individuals with facial acne scars underwent a treatment with 2940 nm Er:YAG laser. Half side of the face was randomized to receive 0.05% w/w ECa 233 gel, a standardized extract of C. asiatica, and the other half a placebo gel. The gels were applied four times daily for 7 days then twice daily for 3 months. Erythema, melanin, and texture index (TI) from Antera3D,® and skin biophysics were obtained at baseline, days 2, 4, and 7, then every 2 weeks for the first month, and every month for 3 months. Three blinded dermatologists assessed the photographs and provided a grading scale of wound appearances. Results: The ECa 233 treated side exhibited significantly less erythema index over total follow-up by 0.03 U (coefficient = -0.03 [95% CI -0.06 to -0.0006]; p = 0.046). In keeping with the physicians' assessment that showed significantly higher improvements in skin erythema at days 2, 4, and 7 (p = 0.009, 0.0061, 0.012), crusting at days 2 (p = 0.02), and general wound appearance at days 2, 4, and 7 (p = 0.008, 0.001, 0.044), TI showed a trend toward better outcome in the ECa 233 group. Skin biophysics did not differ between the two groups. Conclusion: ECa 233 might be an option for postlaser treatment to improve wound appearance.

Comparative pharmacokinetics of oxyresveratrol alone and in combination with piperine as a bioenhancer in rats.

BACKGROUND: Oxyresveratrol is a major bioactive component derived from the heartwood of Artocarpus lacucha. This compound exerts several biological activities, including neuroprotective effects in vitro and in vivo. However, there is limited pharmacokinetic information on this compound, especially its distribution in neuronal tissue and its route of excretion. The aim of this study was to investigate the pharmacokinetic profiles of oxyresveratrol alone and in combination with piperine as a bioenhancer in rats. METHODS: Male Wistar rats were administered with oxyresveratrol 10 mg/kg, oxyresveratrol 10 mg/kg plus piperine 1 mg/kg via intravenous or oxyresveratrol 100 mg/kg, oxyresveratrol 100 mg/kg plus piperine 10 mg/kg via oral gavage. Plasma, internal organs, urine, and feces were collected. Determination of the oxyresveratrol concentration in biological samples was performed by liquid chromatography tandem mass spectrometry. RESULTS: The combination with piperine had shown a significantly higher maximum concentration in plasma approximately 1500 µg/L within 1-2 h after oral dosing, and could increase oral bioavailability of oxyresveratrol approximately 2-fold. Oxyresveratrol could widely distributed most of the internal organs with a tissue to plasma ratio of 10-100 fold within 5 min after dosing. Urinary excretion of oxyresveratrol glucuronide was the major route of excretion after administration of oxyresveratrol alone and in combination with piperine. CONCLUSION: The addition of piperine could enhance some of the pharmacokinetic properties of oxyresveratrol via both intravenous and oral administration. This pharmacokinetic information will be useful for appropriate strategies to develop oxyresveratrol as a phytopharmaceutical product.

Pharmacokinetics of cucurbitacin B from Trichosanthes cucumerina L. in rats.

BACKGROUND: Cucurbitacin B is the major bioactive constituent in Trichosanthes cucumerina L. fruits, which the pharmacological properties have been studied for decades particularly an anti-tumor activity. The pharmacokinetic profile of this compound is still limited and investigation is needed for further phytopharmaceutical product development. This study aimed to investigate the pharmacokinetic profile of cucurbitacin B after administering the compound at different doses and routes to rats. METHODS: Male Wistar rats (n = 6) were treated by cucurbitacin B extracted from Trichosanthes cucumerina L. The cucurbitacin B was administered at 0.1 mg/kg intravenously or by oral gavage at 2-4 mg/kg. Blood samples and internal organs were collected serially within 24 h after administration. Urine and feces were collected from time 0 to 48 h. The level of cucurbitacin B in biological samples was determined by liquid chromatography-tandem mass spectrometry. RESULTS: The absolute oral bioavailability of cucurbitacin B was approximately 10%. The maximum concentration in plasma after normalization by dose ranged from 4.85-7.81 µg/L and the time to reach maximum value was approximately within 30 min after oral dosing. The level of cucurbitacin B in plasma increased proportionally to the given dose. After intravenous administration, cucurbitacin B had a large volume of distribution of about 51.65 L/kg and exhibited a high tissue to plasma concentration ratio, approximately 60 to 280-fold in several organs. Negligible amount of unchanged cucurbitacin B could be detected in urine and feces and accounted less than 1% of administered dose. CONCLUSION: Cucurbitacin B had low oral bioavailability, but could be distributed extensively into internal organs with a high volume of distribution and tissue to plasma ratio. Only negligible amounts of unchanged cucurbitacin B were excreted via urine and feces suggesting that the compound might be biotransformed before undergoing an excretion. Further studies of the metabolic pathway and tissue uptake mechanism are required to strategize the future development of cucurbitacin B into clinical studies.

Safety and Pharmacokinetics of Standardized Extract of Centella asiatica (ECa 233) Capsules in Healthy Thai Volunteers: A Phase 1 Clinical Study.

The aim of this study was to investigate the safety and pharmacokinetic profiles of a newly developed, standardized extract of Centella asiatica (ECa 233) capsule in healthy Thai volunteers. This study was designed as an open-labeled, 2-sequence dosage, single- and repeated-dose study investigated under fasting conditions. Plasma concentrations of the parent compounds and their relative acid metabolites were measured and pharmacokinetic parameters were calculated using noncompartmental analysis. Tolerability was assessed based on physical examinations, monitoring of vital signs, clinical laboratory tests, and any observed adverse events. A key finding of this study was that the pharmacokinetics of ECa 233 in healthy volunteers did not correspond with its pharmacokinetics in animal studies. As indicated in human pharmacokinetic parameters, maximum plasma concentration and area under the curve of the parent compounds (madecassoside and asiaticoside) were very low, while their respective metabolites (madecassic acid and asiatic acid) demonstrated higher values. Based on the pharmacokinetic results observed in the dose comparison, accumulation of active metabolites after repeated dose is highly suggestive. In addition, the asiatic acid profile showed 2-fold increase in Cmax and AUC(0-t) after increasing dose from 250 to 500 mg of ECa 233. Lastly, the safety and tolerability evaluation illustrated that single and multiple doses in both 250 and 500 mg oral administration of ECa 233 were well tolerated, and none of the volunteers discontinued their participation due to adverse effects during the study.

Absolute oral bioavailability and disposition kinetics of puerarin in female rats.

BACKGROUND: Pueraria candollei var. mirifica is a medicinal plant that is promoted as a "Champion Product" by the Government of Thailand. This plant has been reported to relieve postmenopausal symptoms, prevent and reverse bone loss, inhibit the growth of breast cancer, and alleviate cardiovascular diseases in preclinical and clinical studies. However, there is little information on the oral bioavailability and tissue distribution of puerarin with respect to its pharmacodynamic activities. Therefore, the aim of this study was to determine the pharmacokinetics of puerarin, including absorption, distribution, metabolism, and elimination, in rats. Moreover, this is the first study to examine the tissue distribution of puerarin in the hippocampus, femur, tibia, and mammary gland. METHODS: Adult female rats were administered puerarin at 1 mg/kg intravenously or 5 and 10 mg/kg orally. Blood, tissue, urine, and feces were collected and analyzed by liquid chromatography-tandem mass spectrometry. RESULTS: Puerarin reached a maximum concentration in the blood of 140-230 µg/L within 1 h of oral dosing, and had an absolute oral bioavailability of approximately 7%. Following intravenous administration, puerarin was widely distributed in several tissues, including the hippocampus, heart, lung, stomach, liver, mammary gland, kidney, spleen, femur, and tibia. Approximately 50% of the intravenous dose was excreted as glucuronide metabolites via the urinary route. CONCLUSIONS: The absolute oral bioavailability of puerarin was approximately 7% at doses of 5 and 10 mg/kg. Puerarin was widely distributed to several organs related to the diseases of aging, including the hippocampus, femur, tibia, and mammary gland. Glucuronides were the major metabolites of puerarin and were mainly excreted in the urine. These results are useful for the development of puerarin and Pueraria candollei var. mirifica as phytopharmaceutical products.

Comparative pharmacokinetics between madecassoside and asiaticoside presented in a standardised extract of Centella asiatica, ECa 233 and their respective pure compound given separately in rats.

1. ECa 233, the standardised extract of Centella asiatica, contains not less than 80% triterpenoid glycosides, in a madecassoside:asiaticoside ratio of 1.5 (±0.5):1. 2. The pharmacokinetic comparison of madecassoside and asiaticoside was performed in rats following intravenous and oral administration of ECa 233, or an equivalent dose of the individual compounds. Blood, tissues, urine and faeces were collected after dosing to determine drug and metabolite levels using liquid chromatography-tandem mass spectrometry. 3. Our study demonstrated that plasma levels of madecassoside, and to a lesser extent asiaticoside, were higher after administration of ECa 233 than the corresponding values for the pure compounds. There was a bidirectional interconversion between asiaticoside and madecassoside consistent with the increased exposure of madecassoside and asiaticoside in ECa 233. 4. Both madecassoside and asiaticoside appeared to be widely distributed in several organs and metabolized extensively; following intravenous administration of either compound, approximately 80-90% of the dose was recovered as madecassic acid and asiatic acid in the faeces.

Pharmacokinetics of a Standardized Extract of Centella asiatica ECa 233 in Rats.

ECa 233, a standardized extract of Centella asiatica, has been found to exhibit various positive neurological effects and to have a good safety profile. The present study aimed to explore the disposition kinetics of ECa 233, containing madecassoside (53.1 %) and asiaticoside (32.3 %), in rats. The extract was intravenously or orally administered at doses from 50 to 200 mg/kg. Plasma, tissues, urine, and feces were collected at time points from 0 to 48 h after dosing. The levels of madecassoside and asiaticoside, as well as their postulated triterpenic metabolites, madecassic acid and asiatic acid, in biological samples, were simultaneously measured by liquid chromatography-tandem mass spectrometry. The results showed that all animals had a good tolerability for ECa 233, whereas madecassic and asiatic acids were found in negligible amounts after pharmacokinetic assessment. Madecassoside and asiaticoside demonstrated rather similar absorption and tissue distribution profiles. They were rapidly absorbed, reaching maximum levels within 5-15 min after oral administration, but they had poor oral bioavailability, less than 1 %. Both triterpenoids were extensively distributed in the brain, stomach, and skin within 1 h and remained there for at least 4 h after dosing. Madecassoside and asiaticoside in ECa 233 were mainly excreted as an unchanged form after being injected, and exclusively as triterpenic acid metabolites in feces after oral administration. The pharmacokinetic results obtained could provide some guidance for an appropriate dosing regimen of ECa 233 in future studies. This study also provided the first evidence demonstrating the presence of madecassoside and asiaticoside in their target tissues.

Pueraria mirifica alleviates cortical bone loss in naturally menopausal monkeys.

Since the in vitro and in vivo anti-osteoporotic effects of Pueraria mirifica (PM) in rodents have been verified, its activity in menopausal monkeys was evaluated as required before it can be applicable for human use. In this study, postmenopausal osteoporotic monkeys were divided into two groups (five per group), and fed daily with standard diet alone (PMP0 group) or diet mixed with 1000 mg/kg body weight (BW) of PM powder (PMP1000 group) for 16 months. Every 2 months, the bone mineral density (BMD), bone mineral content (BMC) and bone geometry parameters (cortical area and thickness and periosteal and endosteal circumference) at the distal radius and proximal tibia were determined using peripheral quantitative computed tomography together with plasma and urinary bone markers. Compared with the baseline (month 0) values, the cortical, but not trabecular, BMDs and BMCs and the cortical area and thickness at the metaphysis and diaphysis of the radius and tibia of the PMP0 group continuously decreased during the 16-month study period. In contrast, PMP1000 treatment ameliorated the bone loss mainly at the cortical diaphysis by decreasing bone turnover, as indicated by the lowered plasma bone-specific alkaline phosphatase and osteocalcin levels. Generally, changes in the cortical bone geometry were in the opposite direction to the cortical bone mass after PMP1000 treatment. This study indicated that postmenopausal monkeys continuously lose their cortical bone compartment, and they have a higher possibility for long bone fractures. Oral PMP treatment could improve both the bone quantity (BMC and BMD) and quality (bone geometry).

Pharmacokinetics of Compound D, the Major Bioactive Component of Zingiber cassumunar, in Rats.

Rhizomes of Zingiber cassumunar have been used for many years in traditional Thai medicine as an anti-inflammatory agent. The major bioactive component of this plant is Compound D [E-4-(3', 4'-dimethoxyphenyl)but-3-en-1-ol], which is a strong smooth muscle relaxant, and has antihistamine and anti-inflammatory actions. There is, however, incomplete information available for the pharmacokinetics of Compound D in mammals. In this study, we examined the pharmacokinetic profiles of Compound D in male Wistar rats. A standardized extract of Z. cassumunar containing 4 % w/w Compound D was administered intravenously at 25 mg/kg or by oral gavage at 25, 75, or 250 mg/kg to Wistar rats. Blood, tissues, urine, and feces were collected from 0 to 48 h after dosing and the level of Compound D was determined by liquid chromatography-tandem mass spectrometry. The concentration of Compound D ranged from 10-100 µg/L, reached a maximum approximately 0.15 h after oral dosing. Compound D exhibited an excellent tissue to plasma ratio, ranging from 1- to 1000 in several organs at 1-4 h after oral dosing. Less than 1 % of unchanged Compound D was excreted in the urine and feces. Further studies on tissue uptake and metabolite identification are required to obtain complete pharmacokinetic information and to develop appropriate dosing strategies of Compound D and the standardized extract of Z. cassumunar.