Kaempferia parviflora ethanolic extract promoted nitric oxide production in human umbilical vein endothelial cells

Kaempferia parviflora extract and its component polymethoxyflavones suppress adipogenic differentiation of human bone marrow-derived mesenchymal stem cells via the AMPK pathway

BACKGROUND

Kaempferia parviflora Wall. ex. Baker (KP) has been reported to exhibit anti-obesity effects. However, the detailed mechanism of the anti-obesity effect of KP extract (KPE) is yet to be clarified. Here, we investigated the effect of KPE and its component polymethoxyflavones (PMFs) on the adipogenic differentiation of human mesenchymal stem cells (MSCs).

METHODS AND RESULTS

KPE and PMFs fraction (2.5 µg/mL) significantly inhibited lipid and triacylglyceride accumulation in MSCs; lipid accumulation in MSCs was suppressed during the early stages of differentiation (days 0-3) but not during the mid (days 3-7) or late (days 7-14) stages. Treatment with KPE and PMFs fractions significantly suppressed peroxisome proliferator-activated receptor-γ (PPARγ), CCAAT/enhancer binding protein α (C/EBPα), and various adipogenic metabolic factors. Treatment with KPE and PMFs fraction induced the activation of AMP-activated protein kinase (AMPK) signaling, and pretreatment with an AMPK signaling inhibitor significantly attenuated KPE- and PMFs fraction-induced suppression of lipid formation.

CONCLUSIONS

Our findings demonstrate that KPE and PMFs fraction inhibit lipid formation by inhibiting the differentiation of undifferentiated MSCs into adipocyte lineages via AMPK signaling, and this may be the mechanism underlying the anti-obesity effects of KPE and PMFs. Our study lays the foundation for the elucidation of the anti-obesity mechanism of KPE and PMFs.

A systematic review and meta-analysis of animal and human studies demonstrates the beneficial effects of Kaempferia parviflora on metabolic syndrome and erectile dysfunction

Kaempferia parviflora (KP) has traditionally been used for centuries to promote health and well-being. Scant evidence is available to explain the relationship between KP and metabolic syndrome and impotence. We sought to test the hypothesis that administration of KP extract enriched with active ingredients, such as polymethoxyflavone, could improve metabolic syndrome, erectile dysfunction, and related outcomes in in vivo. We performed a systematic review and meta-analysis to evaluate the in vivo effects of KP extract on metabolic syndrome, erectile dysfunction, and related outcomes. Studies from 4 databases (i.e., PubMed, Scopus, Embase, and Cochrane Library) were searched from inception up to December 2022. Animal experiment studies and randomized controlled trials comparing KP extract to a placebo control were retrieved and analyzed using RevMan 5.4.1 software. The effect estimate was presented as the standardized mean difference along with its 95% confidence interval (CI). Of 664 articles, a total of 57 articles met our prespecified criteria. KP extract significantly decreased fasting blood glucose in both animal and human studies with standardized mean difference of -0.88 (95% CI, -1.63 to -0.14) and -0.51 (95% CI, -0.98 to -0.05), respectively. Furthermore, KP extract also markedly improved sexual function and physical performance. In sum, KP extract is shown to have effects beneficial to metabolic syndrome, erectile dysfunction, and physical performance.

The effect of Thai ginger (Kaempferia parviflora) extract orally administration on sperm production, semen preservation, and fertility in Thai native chickens under heat stress

Thai indigenous roosters are exposed to unsuitable temperatures and humidity, resulting in a lower reproductive potential. Kaempferia parviflora (KP) extract containing methoxyflavones was fed to roosters to improve their reproductive performance. Thirty-two Thai native roosters were orally administered KP extract at 300, 450, and 600 mg, calculated according to their average body weight, for at least 14 d before semen collection and continued supplementation until the end of the experiment. The nonsupplemented group served as the control. Fresh semen in terms of semen volume, sperm concentration, mass movement score, and sperm viability were evaluated. Semen preservation at 5°C and fertility test were examined for total motility (MOT), progressive motility (PMOT), sperm viability, and lipid peroxidation up to 48 h of storage. Testosterone concentrations and testicular function were also determined. The results showed that the highest sperm concentration and sperm motility of fresh semen were observed in KP extract at 600 mg (P < 0.001). KP extract at 600 mg resulted in higher sperm viability than the control and KP extract at 300 mg (P < 0.05), but was not different from KP at 450 mg (P > 0.05). The highest MOT, PMOT, and viability were found in the roosters that received 600 mg oral KP extract (P < 0.05), while those of the roosters that received oral KP extract 300 mg and the control were the lowest (P < 0.05) at all storage times. Lipid peroxidation was significantly lower in the KP extract up to 24 h (P < 0.05). The fertility and hatchability of the KP extract at 600 mg at T48 showed a minor decrease compared to the control at T0. These results might be inferred as a result of good spermatogenesis, as revealed by the results of histological examination and testosterone activity. In summary, oral administration of 600 mg KP extract improved sperm production and successfully preserved rooster semen for a long duration of up to 48 h of storage.

Polymethoxyflavone purified from Kaempferia parviflora reduces visceral fat in Japanese overweight individuals: a randomised, double-blind, placebo-controlled study

Visceral fat is a more important factor in obesity-associated disorders in Japanese individuals than in Caucasian individuals. The objective of this randomised, double-blind, placebo-controlled parallel group study, conducted in Japanese overweight adults, was to investigate the effects of polymethoxyflavone purified from Kaempferia parviflora on visceral fat. A total of 80 subjects (aged 20-64 years, 23.0 ≤ body mass index < 30 kg m-2) were randomly assigned in 1 : 1 ratio to either the active (polymethoxyflavone purified from K. parviflora) or placebo group. Over a 12-week period, each subject received two capsules containing polymethoxyflavone purified from K. parviflora (12 mg polymethoxyflavone per day) or placebo. The primary outcome was a reduction in visceral fat area (VFA), while the secondary outcome was a reduction in subcutaneous fat area (SFA) and total fat area (TFA). VFA was measured at 0, 8, and 12 weeks using computed tomography scanning. Results showed that VFA significantly reduced after 12 weeks in the active group and was significantly lower than in the placebo group at 8 and 12 weeks. A significant reduction was observed in SFA and TFA after 8 and 12 weeks in the active group; TFA was significantly lower than that in the placebo group at 8 and 12 weeks. No adverse events associated with the test supplements were observed in either group. Our study shows that administration of polymethoxyflavone purified from K. parviflora reduces visceral fat in Japanese overweight adults.

Evaluation of the Safety of Daily Consumption of Kaempferia parviflora Extract (KPFORCE): A Randomized Double-Blind Placebo-Controlled Trial

This study's aim was to evaluate the safety of daily consumption of Kaempferia parviflora extract (KPE) using a randomized double-blind placebo-controlled study with 52 recruited healthy Japanese subjects. Each subject received five KPE tablets (containing 150 mg of KPFORCE^™/tablet) or placebo daily for 4 weeks. There were no adverse events related to KPE intake or any abnormalities compared with placebo group in anthropometric, cardiovascular, blood, and urine parameters during the course of the study. Thus, daily KPE ingestion was found to be safe in healthy Japanese men and women.

A simple and effective preparation of quercetin pentamethyl ether from quercetin

Among the five hydroxy (OH) groups of quercetin (3,5,7,3',4'-pentahydroxyflavone), the OH group at 5 position is the most resistant to methylation due to its strong intramolecular hydrogen bonding with the carbonyl group at 4 position. Thus, it is generally difficult to synthesize the pentamethyl ether efficiently by conventional methylation. Here, we describe a simple and effective per-O-methylation of quercetin with dimethyl sulfate in potassium (or sodium) hydroxide/dimethyl sulfoxide at room temperature for about 2 hours, affording quercetin pentamethyl ether (QPE) quantitatively as a single product. When methyl iodide was used in place of dimethyl sulfate, the C-methylation product 6-methylquercetin pentamethyl ether was also formed. A computational study provided a rationale for the experimental results.

Kaempferia parviflora and Its Methoxyflavones: Chemistry and Biological Activities

Kaempferia parviflora (KP), a health-promoting herb, has been traditionally used for treating a variety of diseases. Pharmacological studies have claimed the various benefits from KP and its main effective methoxyflavones, including cellular metabolism-regulating activity, anticancer activity, vascular relaxation and cardioprotective activity, sexual enhancing activity, neuroprotective activity, antiallergic, anti-inflammatory, and antioxidative activity, antiosteoarthritis activity, antimicroorganism activity, and transdermal permeable activity. These might be associated with increased mitochondrial functions and activated cGMP-NO signaling pathway. However, the underlying molecular mechanisms of KP and its methoxyflavones are still under investigation. The clinical applications of KP and its methoxyflavones may be limited due to their low bioavailability. But promising strategies are on the way. This review will comprehensively discuss the biological activities of KP and its methoxyflavones.

Kaempferia parviflora ethanol extract improves self-assessed sexual health in men: a pilot study

BACKGROUND

Sexual health positively correlates with overall wellbeing. Existing therapeutics to enhance male sexual health are limited by factors that include responsiveness, adherence and adverse effects. As the population ages, safe and effective interventions that preserve male sexual function are needed. Published research suggests that various preparations of Kaempferia parviflora, a plant in the Zingiberaceae (ginger) family, support cardiovascular health and may ameliorate erectile function.

OBJECTIVE

The aim of this study was to examine the effects of KaempMax™, an ethanol extract of the K. parviflora rhizome, on erectile function in healthy middle-aged and older men.

DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS

We conducted an open-label, one-arm study on 14 generally healthy males aged 50-68 years with self-reported mild erectile dysfunction, who were not using prescription treatments. Participants took 100 mg KaempMax™ daily for 30 days.

MAIN OUTCOME MEASURES

Evaluations were conducted at baseline and on the final study assessment. Primary efficacy analyses included the International Index of Erectile Function (IIEF); secondary efficacy analyses included the Global Assessment Question about erectile function.

RESULTS

Thirteen participants completed the 30-day study. Supplementation with KaempMax™ resulted in statistically significant improvements in erectile function, intercourse satisfaction and total scores on the IIEF questionnaire. KaempMax™ was well tolerated and exhibited an excellent safety profile.

CONCLUSION

Our results suggest that KaempMax™ may improve erectile function in healthy middle-aged and older men. While the effects were not as pronounced as what might be seen with prescription medication, most participants found them satisfactory. Additional, longer and placebo-controlled clinical trials will be needed.

TRIAL REGISTRATION

Clinicaltrials.gov identifier NCT03389867.

Mechanisms of Kaempferia parviflora extract (KPE)- induced vasorelaxation in the rat aorta

Background: The rhizomes of Kaempferia parviflora (KP) have been widely used in Thai traditional medicine to treat several diseases such as hypertension. Recent studies have shown that the ethanolic extract of KP (KPE) exerts vasorelaxant effects in the rat aorta. However, the underlying mechanisms of these vascular responses remain unclear. Objectives: Investigate the mechanisms of KPE-induced vasorelaxation in the rat aorta. Methods: Aortic rings from male Wistar rats were precontracted with methoxamine. Changes in tension were measured using an isometric force transducer and recorded on the MacLab recording system. Vasorelaxation to KPE was examined in the presence of 10 μM indomethacin, 300 μM NG-nitro L-arginine methyl ester (L-NAME), 60 mM KCl, 5 mM tetraethylammonium chloride (TEA), 10 μM glibenclamide, 1 mM 4-aminopyridine (4-AP) or 30 μM barium chloride (BaCl2). The effects of KPE on vascular responses to carbachol, sodium nitroprusside, and CaCl2 were evaluated. Results: KPE (0.1-100 μg/mL) caused vasorelaxations, which were reduced with removal of the endothelium. In addition, indomethacin, L-NAME, and indomethacin plus L-NAME reduced KPE-induced vasorelaxation. Raising the extracellular KCl concentration to 60 mM, or pre-treatment with BaCl2, TEA, or glibenclamide reduced relaxant responses to KPE. Contractions to CaCl2 were inhibited after pre-incubation with KPE. Pre-treatment with KPE enhanced endothelium-dependent relaxations to carbachol, but not to sodium nitroprusside. Conclusion: KPE had a vasodilator effect in the rat isolated aortic rings. These effects involved endotheliumderived NO and prostanoids via a COX pathway. In addition, KPE-induced vasorelaxation was due to increasing K+ efflux probably through KCa, KIR and KATP channels. These provide pharmacological evidence for mechanism of KPE-induced vasorelaxation and support the traditional use of KPE as an antihypertensive agent.

Effect of the active ingredient of Kaempferia parviflora, 5,7-dimethoxyflavone, on the pharmacokinetics of midazolam

5,7-Dimethoxyflavone (5,7-DMF), one of the major components of Kaempferia parviflora, has anti-obesity, anti-inflammatory, and antineoplastic effects. On the other hand, in vitro studies have reported that it directly inhibits the drug metabolizing enzyme family cytochrome P450 (CYP) 3As. In this study, its safety was evaluated from a pharmacokinetic point of view, based on daily ingestion of 5,7-DMF. Midazolam, a substrate of CYP3As, was orally administered to mice treated with 5,7-DMF for 10 days, and its pharmacokinetic properties were investigated. In the group administered 5,7-DMF, the area under the curve (AUC) of midazolam increased by 130% and its biological half-life was extended by approximately 100 min compared to the control group. Compared to the control group, 5,7-DMF markedly decreased the expression of CYP3A11 and CYP3A25 in the liver. These results suggest that continued ingestion of 5,7-DMF decreases the expression of CYP3As in the liver, consequently increasing the blood concentrations of drugs metabolized by CYP3As.

Daily intake of Kaempferia parviflora extract decreases abdominal fat in overweight and preobese subjects: a randomized, double-blind, placebo-controlled clinical study

PURPOSE

Obesity is a serious problem, which is now a worldwide health problem. Kaempferia parviflora extract (KPE) exhibits anti-obesity effects in animals. However, as no clinical trials have evaluated the anti-obesity effects of KPE in humans, we examined the effects of KPE in reducing abdominal fat in overweight and preobese Japanese subjects.

MATERIALS AND METHODS

A 12-week, single-center, randomized, double-blind, placebo-controlled clinical trial was conducted. Seventy-six subjects (males and females aged 20 to <65 years) with a body mass index ≥24 and <30 kg/m² were randomly assigned into two groups. The subjects in each group ingested one capsule of placebo or active KPE (containing 150 mg of KPE) once daily for 12 weeks. The primary outcome was reduction in visceral fat area as determined by computed tomography scanning. The key secondary outcomes were reductions in subcutaneous fat area and total fat area. Subgroup analysis was also performed in healthy subjects without dyslipidemia, hypertension, or hyperglycemia. The safety of KPE ingestion was also evaluated.

RESULTS

Compared with the placebo group, the active KPE group exhibited significant reduction in abdominal fat area (visceral, subcutaneous, and total fat) and triglyceride levels after 12 weeks. Subgroup analyses demonstrated a significant reduction in abdominal fat area and triglyceride levels in healthy subjects compared with the placebo group after 12 weeks. Neither group exhibited adverse events related to the test foods or clinically relevant abnormal changes in physical, biochemical, or hematologic parameters, or in urinalysis results and medical interview.

CONCLUSION

Daily ingestion of KPE safely reduces body fat, particularly abdominal fat, in Japanese overweight and preobese subjects.

A Randomized Single Dose Parallel Study on Enhancement of Nitric Oxide in Serum and Saliva with the Use of Natural Sports Supplement in Healthy Adults

Sports supplements that stimulate the production of nitric oxide (NO) are widely promoted agents in the sports nutrition domain, and nitric oxide plays an important role to enhance the cardiovascular and physical fitness of the sports participants. The purpose of the study is to investigate whether oral intake of a sports nutritional supplement (Fitnox) is able to increase nitrate (NO₃^-) and nitrite (NO₂^-) levels in blood serum and saliva of healthy adults. Fitnox is a unique blend of Kaempferia parviflora methoxy flavones, pomegranate peel polyphenols, and Moringa oleifera leaf saponins. Twenty-four healthy male adults were equally divided and underwent the double-blind, placebo-controlled clinical trial with a single oral dose of sports nutrition formulation (250 mg capsules); blood and saliva samples were analyzed at different time intervals by high-performance liquid chromatography (HPLC). After administration of Fitnox (250 mg capsule as single dose), NO₃^- and NO₂^- levels in serum and saliva were found to be significantly higher (p <.05) than in the placebo group in 24 hours. Pharmacokinetic parameters such as the area under the plasma concentration-time curve extrapolated to infinity (AUC_0-inf), AUC calculated to the last measured concentration (AUC_0-t), maximum drug serum concentrations (C_max), time of maximum concentration in serum observed (T_max), and time required for the concentration of the drug to reach half of its original value (T_half) were also statistically significant (p <.05) compared with the placebo. The results indicate that a single oral dose of Fitnox is able to increase the NO₃^- and NO₂^- levels considerably in the body relative to placebo for at least 12 hours. Therefore, Fitnox can improve the overall performance of sport participants and enhance physical endurance.

Clinical Effects of Krachaidum ( Kaempferia parviflora): A Systematic Review

Kaempferia parviflora (Krachaidum) is a medicinal plant in the family Zingiberaceae. Its rhizome has been used as folk medicine for many centuries. A number of pharmacological studies of Krachaidum had claimed benefits for various ailments. Therefore, this study aimed to systematically search and summarize the clinical evidences of Krachaidum in all identified indications. Of 683 records identified, 7 studies were included. From current clinical trials, Krachaidum showed positive benefits but remained inconclusive since small studies were included. Even though results found that Krachaidum significantly increased hand grip strength and enhanced sexual erotic stimuli, these were based on only 2 studies and 1 study, respectively. With regard to harmful effects, we found no adverse events reported even when Krachaidum 1.35 g/day was used. Therefore, future studies of Krachaidum are needed with regards to both safety and efficacy outcomes.

Inhibition of Angiotensin Converting Enzyme, Angiotensin II Receptor Blocking, and Blood Pressure Lowering Bioactivity across Plant Families

Hypertension is a major risk factor for coronary heart disease, kidney disease, and stroke. Interest in medicinal or nutraceutical plant bioactives to reduce hypertension has increased dramatically. The main biological regulation of mammalian blood pressure is via the renin-angiotensin-aldosterone system. The key enzyme is angiotensin converting enzyme (ACE) that converts angiotensin I into the powerful vasoconstrictor, angiotensin II. Angiotensin II binds to its receptors (AT1) on smooth muscle cells of the arteriole vasculature causing vasoconstriction and elevation of blood pressure. This review focuses on the in vitro and in vivo reports of plant-derived extracts that inhibit ACE activity, block angiotensin II receptor binding and demonstrate hypotensive activity in animal or human studies. We describe 74 families of plants that exhibited significant ACE inhibitory activity and 16 plant families with potential AT1 receptor blocking activity, according to in vitro studies. From 43 plant families including some of those with in vitro bioactivity, the extracts from 73 plant species lowered blood pressure in various normotensive or hypertensive in vivo models by the oral route. Of these, 19 species from 15 families lowered human BP when administered orally. Some of the active plant extracts, isolated bioactives and BP-lowering mechanisms are discussed.

Anti-Hypertensive Herbs and Their Mechanisms of Action: Part II

Traditional medicine has a history extending back to thousands of years, and during the intervening time, man has identified the healing properties of a very broad range of plants. Globally, the use of herbal therapies to treat and manage cardiovascular disease (CVD) is on the rise. This is the second part of our comprehensive review where we discuss the mechanisms of plants and herbs used for the treatment and management of high blood pressure. Similar to the first part, PubMed and ScienceDirect databases were utilized, and the following keywords and phrases were used as inclusion criteria: hypertension, high blood pressure, herbal medicine, complementary and alternative medicine, endothelial cells, nitric oxide (NO), vascular smooth muscle cell (VSMC) proliferation, hydrogen sulfide, nuclear factor kappa-B (NF-κB), oxidative stress, and epigenetics/epigenomics. Each of the aforementioned keywords was co-joined with plant or herb in question, and where possible with its constituent molecule(s). This part deals in particular with plants that are used, albeit less frequently, for the treatment and management of hypertension. We then discuss the interplay between herbs/prescription drugs and herbs/epigenetics in the context of this disease. The review then concludes with a recommendation for more rigorous, well-developed clinical trials to concretely determine the beneficial impact of herbs and plants on hypertension and a disease-free living.

Effect of Kaempferia parviflora Extract on Physical Fitness of Soccer Players: A Randomized Double-Blind Placebo-Controlled Trial

Background

Physical fitness is a fundamental prerequisite for soccer players. Kaempferia parviflora is an herbal plant that has been used in some Asian athletes with the belief that it might prevent fatigue and improve physical fitness. This study aimed to determine the effects of Kaempferia parviflora on the physical fitness of soccer players.

Material/Methods

Sixty soccer players who routinely trained at a sports school participated in a double-blind placebo-controlled trial and were randomly allocated to the treatment group or the placebo group. The participants in both groups were given either 180 mg of Kaempferia parviflora extract in capsules or a placebo once daily for 12 weeks. Baseline data were collected using the following 6 tests of physical performance: a sit-and-reach test, a hand grip strength test, a back-and-leg strength test, a 40-yard technical test, a 50-metre sprint test, and a cardiorespiratory fitness test. All of the tests were performed every 4 weeks throughout the 12-week study period.

Results

The study showed that after treatment with Kaempferia parviflora, the right-hand grip strength was significantly increased at weeks 4, 8, and 12. The left-hand grip strength was significantly increased at week 8. However, the back-and-leg strength, the 40-yard technical test, the sit-and-reach test, the 50-metre sprint test, and the cardiorespiratory fitness test results of the treatment group were not significantly different from those of the placebo group.

Conclusions

Taking Kaempferia parviflora supplements for 12 weeks may significantly enhance some physical fitness components in soccer players.

Potent SIRT1 Enzyme-stimulating and Anti-glycation Activities of Polymethoxyflavonoids from Kaempferia parviflora

The SIRT1 enzyme-stimulating and anti-glycation activities of Kaempferia parviflora extract and its main polymethoxyflavonoids were evaluated in vitro. K. parviflora extract elevated SIRT1 catalytic activity by eight- and 17-fold at 20 μg/mL and 100 μg/mL, respectively, compared with vehicle only. Two major polymethoxyflavonoids, 3,5,7,3′,4′-pentamethoxyflavone (4) and 5,7,4′-trimethoxyflavone (5), were isolated from this extract and are four- and fivefold more potent than resveratrol, hitherto the strongest known natural SIRT1 activator. In addition, the anti-glycation activity of K. parviflora extract was observed to be seven times more effective than aminoguanidine, a clinical anti-diabetes drug. 3,5,7,3′,4′-Pentamethoxyflavone (4) and 5,7,4′-trimethoxyflavone (5) showed the strongest anti-glycation activity among the tested polymethoxyflavonoids. Further comparison of the activity of these structurally related polymethoxyflavonoids revealed a possible structure-activity relationship, in particular, for the contribution of methoxy moieties.

Effects of Kaempferia parviflora Wall. Ex. Baker and sildenafil citrate on cGMP level, cardiac function, and intracellular Ca2+ regulation in rat hearts

Although Kaempferia parviflora extract (KPE) and its flavonoids have positive effects on the nitric oxide (NO) signaling pathway, its mechanisms on the heart are still unclear. Because our previous studies demonstrated that KPE decreased defibrillation efficacy in swine similar to that of sildenafil citrate, the phosphodiesterase-5 inhibitor, it is possible that KPE may affect the cardiac NO signaling pathway. In the present study, the effects of KPE and sildenafil citrate on cyclic guanosine monophosphate (cGMP) level, modulation of cardiac function, and Ca transients in ventricular myocytes were investigated. In a rat model, cardiac cGMP level, cardiac function, and Ca transients were measured before and after treatment with KPE and sildenafil citrate. KPE significantly increased the cGMP level and decreased cardiac function and Ca transient. These effects were similar to those found in the sildenafil citrate-treated group. Furthermore, the nonspecific NOS inhibitor could abolish the effects of KPE and sildenafil citrate on Ca transient. KPE has positive effect on NO signaling in the heart, resulting in an increased cGMP level, similar to that of sildenafil citrate. This effect was found to influence the physiology of normal heart via the attenuation of cardiac function and the reduction of Ca transient in ventricular myocytes.

Phyllanthus emblica L. Enhances Human Umbilical Vein Endothelial Wound Healing and Sprouting

Endothelial dysfunction is the hallmark of impaired wound healing and increased risk of cardiovascular disease. Antioxidants from natural sources decrease oxidative stress and protect against cellular damage caused by reactive oxygen species (ROS). In this study, we examined the antioxidant constituents and capacity of Phyllanthus emblica L. (PE) fruit in freeze-dried power form. The pharmacological properties of PE were investigated using human umbilical vein endothelial cells (HUVECs) in the aspects of endothelial cell proliferation, nitric oxide (NO) production, wound healing, cell migration, in vitro angiogenesis, and VEGF gene expression. The ASC content of PE was 1.574% + 0.046% (w/w) as determined by HPLC and the total phenolic content was 36.1% ± 0.7% gallic acid equivalent when measured by Folin-Ciocalteu assay. The FRAP assay revealed a relatively high antioxidant capacity at 3,643 + 192.5 µmole/mg. PE at 0.1 to 10 µg/mL did not significantly influence endothelial cell proliferation, but at higher concentrations PE decreased cell survival to 62%. PE significantly promoted NO production, endothelial wound closure, endothelial sprouting, and VEGF mRNA expression. Therefore, PE is a candidate for antioxidant supplement that promotes endothelial function and restores wound healing competency.

Protection effect of endomorphins on advanced glycation end products induced injury in endothelial cells

Endomorphins (EMs) have a very important bridge-function in cardiovascular, endocrinological, and neurological systems. This study is to investigate the effects of EMs on the synthesis and secretion of vasoactive substances induced by advanced glycation end products in primary cultured human umbilical vein endothelial cells (HUVECs). Firstly, HUVECs were stimulated with AGEs-bovine serum albumin (AGEs-BSA), bovine serum albumin (BSA), or both AGEs-BSA and EMs together, respectively. Then, HUVEC survival rate was calculated by MTT assay, the levels of NO, endothelial nitric oxide synthase (eNOS), and inducible nitric oxide synthase (iNOS) were detected by colorimetric analysis, and the contents of endothelin-1 (ET-1) were detected by ELISA. The mRNA levels of eNOS and ET-1 were measured by RT-PCR. The expression of p38 mitogen-activated protein kinase (p38 MAPK) was detected by immunofluorescence assay. The results showed that the mRNA expression and secretion of eNOS were significantly enhanced after incubation with EMs compared to those with AGEs-BSA, while the secretion of NO and iNOS, mRNA expression, and secretion of ET-1 had opposite changes. The fluorescence intensity of p38MAPK in nuclear was decreased after pretreatment with EMs compared to incubation with AGEs-BSA. Conclusion. The present study suggests that EMs have certain protection effect on AGEs-BSA-induced injury in HUVEC.

Positive Modulation Effect of 8-Week Consumption of Kaempferia parviflora on Health-Related Physical Fitness and Oxidative Status in Healthy Elderly Volunteers

Health-related physical fitness declines as the age advances. Oxidative stress is reported to contribute the crucial role on this phenomenon. This condition is also enhanced by antioxidant. Therefore, we aimed to determine the effect of Kaempferia parviflora, a plant reputed for antifatigue, longevity promotion, and antioxidant effects, on health-related quality physical fitness and oxidative status of the healthy elderly volunteers. Total 45 subjects had been randomized to receive placebo or K. parviflora extract at doses of 25 or 90 mg once daily for 8 weeks. They were determined baseline data of physical performance using 30 sec chair stand test, hand grip test, 6 min walk test, and tandem test. Serum oxidative stress markers including malondialdehde (MDA) level and the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were also assayed. All assessments were performed every 4 weeks throughout the 8-week study period. The results showed that K. parviflora increased performance in 30-second chair stand test and 6 min walk test together with the increased all scavenger enzymes activities and the decreased MDA level. Therefore, K. parviflora can enhance physical fitness partly via the decreased oxidative stress. In conclusion, K. parviflora is the potential health supplement for elderly. However, further study is required.

Modulatory effects of Kaempferia parviflora extract on mouse hepatic cytochrome P450 enzymes

ETHNOPHARMACOLOGICAL RELEVANCE

Kaempferia parviflora is a herbal plant, the extracts of which are commonly used as alternative medicines. It widely uses as aphrodisiac, anti-inflammation, anti-microbacterial, and anti-peptic ulcer.

AIM OF THE STUDY

In order to obtain an effective utilization and safety of the herb, the influence of Kaempferia parviflora on hepatic CYP450 metabolizing enzymes including CYP1A1, CYP1A2, CYP2B, CYP2E1, and CYP3A was investigated.

MATERIALS AND METHODS

The impact of Kaempferia parviflora on CYP450 both in vitro and in vivo was examined by using ethoxyresorufin O-dealkylation, methoxyresorufin O-dealkylation, pentoxyresorufin O-dealkylation, p-nitrophenol hydroxylation, and erythromycin N-demethylation assays, respectively.

RESULTS

In vitro studies using non-induced mouse hepatic microsomes in the presence or absence of Kaempferia parviflora extract showed that Kaempferia parviflora extract altered CYP1A1, CYP1A2, CYP2B, and CYP2E1 activities by non-competitive, mixed-competitive, competitive, and uncompetitive mechanisms, respectively. Among these enzymes, CYP1A2 was affected by Kaempferia parviflora based on the highest value of V(max) (15.276±0.206 nmol/min) and lowest of K(i) value (0.008±0.002 μg/ml). In addition, the plant extract also modulated CYP2B activity based on the low K(m) value (1.599±0.147 pmol). For in vivo studies, mice were orally treated with 250 mg/kg of Kaempferia parviflora extract for 7, 14, and 21 days. The results demonstrated that Kaempferia parviflora extract significantly induced CYP1A1, CYP1A2 enzyme activities following short-term treatment. CYP2B enzyme activities were markedly increased all Kaempferia parviflora extract treatment timepoints, whereas Kaempferia parviflora extract significantly enhanced CYP2E1 activity only after long-term treatment. However, Kaempferia parviflora extract did not affect the CYP3A enzyme activity.

CONCLUSIONS

Kaempferia parviflora extract modulated several CYP450 enzyme activities, thus, its utilization with drugs or other herbs should raise concern for potential drug-herb interactions.

Kaempferia parviflora, a plant used in traditional medicine to enhance sexual performance contains large amounts of low affinity PDE5 inhibitors

AIM OF THE STUDY

A number of medicinal plants are used in traditional medicine to treat erectile dysfunction. Since cyclic nucleotide PDEs inhibitors underlie several current treatments for this condition, we sought to show whether these plants might contain substantial amounts of PDE5 inhibitors.

MATERIALS AND METHODS

Forty one plant extracts and eight 7-methoxyflavones from Kaempferia parviflora Wall. ex Baker were screened for PDE5 and PDE6 inhibitory activities using the two-step radioactive assay. The PDE5 and PDE6 were prepared from mice lung and chicken retinas, respectively. All plant extracts were tested at 50 μg/ml whereas the pure compounds were tested at 10 μM.

RESULTS

From forty one plant extracts tested, four showed the PDE5 inhibitory effect. The chemical constituents isolated from rhizomes of Kaempferia parviflora were further investigated on inhibitory activity against PDE5 and PDE6. The results showed that 7-methoxyflavones from this plant showed inhibition toward both enzymes. The most potent PDE5 inhibitor was 5,7-dimethoxyflavone (IC(50) = 10.64 ± 2.09 μM, selectivity on PDE5 over PDE6 = 3.71). Structure activity relationship showed that the methoxyl group at C-5 position of 7-methoxyflavones was necessary for PDE5 inhibition.

CONCLUSIONS

Kaempferia parviflora rhizome extract and its 7-methoxyflavone constituents had moderate inhibitory activity against PDE5. This finding provides an explanation for enhancing sexual performance in the traditional use of Kaempferia parviflora. Moreover, 5,7-dimethoxyflavones should make a useful lead compound to further develop clinically efficacious PDE5 inhibitors.

The ethanolic extract of Kaempferia parviflora reduces ischaemic injury in rat isolated hearts

AIMS OF THE STUDY

The ethanolic extract of Kaempferia parviflora (KPE) has been reported to contain a range of flavonoids and to enhance endothelial synthesis of NO. We investigated the vascular relaxant, antioxidant and cardioprotective activities of KPE.

MATERIALS AND METHODS

Vascular function was assessed in rat aortic rings and superoxide generation determined using lucigenin enhanced chemiluminescence. Ischaemia and reperfusion were induced in rat isolated, perfused hearts.

RESULTS

KPE caused vasorelaxation (R(max) 102 ± 2%), which was partly inhibited by removal of the endothelium (R(max) 91 ± 1%) or by N(G)-nitro-l-arginine (L-NNA, R(max) 83 ± 3%) or 1H-[1,2,4] oxadiazolo[4,3-a]quinoxaline-1-one (ODQ, R(max) 80 ± 2%). In addition KPE caused concentration-dependent inhibition of the contractile response to exogenous Ca(2+). KPE (10(-3)M) also significantly inhibited superoxide radical generation induced by of xanthine/xanthine oxidase (2.3 ± 0.4% of control) to a similar extent to the xanthine oxidase inhibitor allopurinol (10(-4)M, 1.6 ± 0.5%) or by rat isolated aorta in the presence of NADPH (30.0 ± 6.3% of control) similarly to the NADPH oxidase inhibitor diphenyliodonium (5 × 10(-6)M, 23.1 ± 5.6%). In the presence of oxidant stress generated by pyrogallol endothelium-dependent relaxation of rat aortic rings was impaired (ACh R(max) control 99 ± 1%; pyrogallol 44 ± 5%), an effect that was significantly reduced by KPE (10(-4)M, ACh R(max) 82 ± 4%). In addition, KPE was found to attenuate the ventricular dysfunction caused by 20 min global ischaemia and 30 min reperfusion (I/R) in rat isolated hearts (dP/dt IR 1016 ± 242, IR+KPE 2238±233 mm Hg/s).

CONCLUSION

KPE is an effective vasodilator and antioxidant that is able to prevent myocardial ischaemia-reperfusion injury. We suggest that KPE may be useful as an adjunct to thrombolytic therapy in the management of reperfusion injury.

Suppressive effects of methoxyflavonoids isolated from Kaempferia parviflora on inducible nitric oxide synthase (iNOS) expression in RAW 264.7 cells

ETHNOPHARMACOLOGICAL RELEVANCE

The rhizomes of Kaempferia parviflora Wall. ex Baker have been traditionally used in Thailand to treat abscesses, gout, and peptic ulcers.

AIM

Previously, we reported that the chloroform fraction of a Kaempferia parviflora extract had an inhibitory effect on rat paw-edema. In the present study, we isolated the constituents of this fraction and investigated the anti-inflammatory mechanism against nitric oxide (NO) production, tumor necrosis factor-α (TNF-α) and the expression of inducible nitric oxide synthase (iNOS) as well as phosphorylated extracellular signal-regulated kinase (p-ERK), and phosphorylated c-Jun N-terminal kinase (p-JNK). In addition, effects of trimethylapigenin (4) on the enzyme activities of protein kinases possibly leading to iNOS expression were examined to clarify the targets.

MATERIALS AND METHODS

The chloroform fraction was isolated using silica gel column chromatography and HPLC. Isolated compounds were tested against NO and TNF-α using RAW264.7 cells. Cytotoxicity and iNOS, p-ERK and p-JNK expression were also examined.

RESULTS

Three active components, 5,7-dimethoxyflavone (2), trimethylapigenin (4), and tetramethylluteolin (5), markedly inhibited the production of NO in lipopolysaccharide (LPS)-activated RAW264.7 cells. Compounds 2, 4, and 5 moderately inhibited production of TNF-α. Compounds 2, 4, and 5 strongly inhibited expression of iNOS mRNA and iNOS protein in a dose-dependent manner, but did not inhibit p-ERK or p-JNK protein expression. The most active compound, 4, did not inhibit the enzyme activity of inhibitor of κB kinases or mitogen-activated protein kinases, but inhibited that of spleen tyrosine kinase (SYK).

CONCLUSION

The mechanism responsible for the anti-inflammatory activity of methoxyflavonoids from the chloroform fraction of the rhizomes of Kaempferia parviflora is mainly the inhibition of iNOS expression, and the inhibition of SYK by 4 may be involved in the suppression of LPS-induced signaling in macrophages.

Protective effects of methoxyflavone derivatives from black galingale against glutamate induced neurotoxicity in primary cultured rat cortical cells

To examine the neuroprotective effects of black galingale, its protection was tested against glutamate-induced neurotoxicity in primary cortical cultured neurons. It was found that an aqueous extract of this medicinal plant exhibited significant protection against glutamate-induced toxicity in primary cultured rat cortical cells. In order to clarify the neuroprotective mechanism(s) of this observed effect, isolation was performed to seek and identify active fractions and components. By such fractionation, bioactive methoxyflavone derivatives were isolated from the methanol extracts from the air-dried rhizomes of black galingale. 5-Hydroxy-3,7,3',4'-tetramethoxyflavone exhibited significant neuroprotective activities against glutamate-induced toxicity, exhibiting cell viability of about 60-70%, at concentrations ranging from 0.1 μm to 10 μm. Therefore, the neuroprotective effect of black galingale might be due to the inhibition of glutamate-induced toxicity by the methoxyflavone derivatives it contains.

No effect of acute ingestion of Thai ginseng (Kaempferia parviflora) on sprint and endurance exercise performance in humans

Thai ginseng, Kaempferia parviflora, is widely believed among the Mong hill tribe to reduce perceived effort and improve physical work capacity. Kaempferia parviflora is consumed before their daily work. Therefore, we conducted an acute study on the effects of K. parviflora on repeated bouts of sprint exercise and on endurance exercise time to exhaustion. Two studies were conducted in college males using a randomized, double-blind, crossover design. Ninety minutes after consumption of K. parviflora or a starch placebo, participants in study 1 (n = 19) completed three consecutive maximum 30-s sprint cycling Wingate tests, separated by 3 min recovery, while participants in study 2 (n = 16) performed submaximal cycling exercise to exhaustion. Peak and mean power output decreased with successive Wingate tests, while percent fatigue and blood lactate concentration increased after the third Wingate test (P < 0.05). There were no detectable differences in any measures with or without K. parviflora. There was also no effect of K. parviflora on time to exhaustion, rating of perceived exertion or heart rate during submaximal exercise. Our results indicate that acute ingestion of K. parviflora failed to improve exercise performance during repeated sprint exercise or submaximal exercise to exhaustion. However, chronic effects or actions in other populations cannot be excluded.

Effects of Kaempferia parviflora Wall. Ex Baker on endothelial dysfunction in streptozotocin-induced diabetic rats

AIM OF THE STUDY

The aim of the present study was to investigate an ethanolic extract of Kaempferia parviflora (KPE) reduces oxidative stress and preserves endothelial function in aortae from diabetic rats.

MATERIALS AND METHODS

Diabetes was induced in Sprague-Dawley rats by streptozotocin (STZ) treatment (55 mg/kg i.v.). Vascular reactivity and superoxide generation were assessed in aortic rings using standard organ bath techniques and lucigenin-enhanced chemiluminescence, respectively.

RESULTS

Eight weeks after STZ treatment blood glucose was elevated compared to citrate treated control rats and there was an increased aortic generation of superoxide anion. In aortic rings acetylcholine-induced relaxation was impaired whereas endothelium-independent relaxation to sodium nitroprusside was unaffected. When aortic rings were acutely exposed to KPE (1, 10 and 100 μg/ml) there was a significant reduction in the detection of superoxide anion and enhanced relaxation to acetylcholine. Two separate groups of rats (control and diabetic) were orally administered daily with KPE (100 mg/kg body weight) for 4 weeks. KPE treatment reduced superoxide generation and increased the nitrite levels in diabetic aortae, and enhanced acetylcholine-induced relaxation. In the presence of N(G)-nitro-L-arginine (L-NNA), the relaxation to acetylcholine in aortic rings of diabetic rats was only partially inhibited, but was totally abolished in aortic rings from the KPE-treated diabetic rats. Indomethacin did not affect relaxation to acetylcholine in aortic rings of any group.

CONCLUSIONS

These results suggest that KPE, acutely in vitro or after 4 weeks administration in vivo, reduces oxidant stress, increases NO bioavailability and preserves endothelium-dependent relaxation in aortae from diabetic rats.

Possible mechanisms of vasorelaxation for 5,7-dimethoxyflavone from Kaempferia parviflora in the rat aorta

The present study investigated the vascular effects of 5,7-dimethoxyflavone (DMF), isolated from the rhizomes of Kaempferia parviflora (KP), on rat isolated aortic rings and its possible mechanisms. DMF (1-100 μM) caused concentration-dependent relaxations in aortic rings precontracted with methoxamine. This effect was significantly reduced by removal of the endothelium, and after pretreatment with N(G)-nitro-L-arginine methyl ester (L-NAME, 300 μM), indomethacin (10 μM) and 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ, 10 μM), but not 9-(tetrahydro-2-furanyl)-9H-purine-6-amine (SQ22536, 100 μM). Relaxant responses to DMF were significantly inhibited by high KCl (60 mM) in both endothelium-intact and -denuded rings. In addition, the relaxations to DMF were significantly reduced by pretreatment with tetraethylammonium (TEA, 5 mM), glibenclamide (10 μM), 4-aminopyridine (1 mM) or barium chloride (10 μM). Preincubation with DMF (10 and 100 μM) for 30 min significantly inhibited the contractile responses to CaCl(2) in a Ca(2+)-free, high K(+) buffer. The present study demonstrated that DMF causes endothelium-dependent relaxation that is partly mediated by NO-cGMP and cyclooxygenase pathways. Interestingly, DMF-induced responses are mainly due to increasing K(+) efflux, and inhibition of Ca(2+) influx from the extracellular space. The vasodilator effects of DMF provide experimental support for the potential use of KP as a medical plant in the treatment of cardiovascular diseases.

Polyphenol-induced endothelium-dependent relaxations role of NO and EDHF

The Mediterranean diet has been associated with greater longevity and quality of life in epidemiological studies. Indeed, because of the abundance of fruits and vegetables and a moderate consumption of wine, the Mediterranean diet provides high amounts of polyphenols thought to be essential bioactive compounds that might provide health benefits in terms of cardiovascular diseases and mortality. Several polyphenol-rich sources, such as grape-derived products, cocoa, and tea, have been shown to decrease mean blood pressure in patients with hypertension. The improvement of the endothelial function is likely to be one of the mechanisms by which polyphenols may confer cardiovascular protection. Indeed, polyphenols are able to induce nitric oxide (NO)-mediated endothelium-dependent relaxations in a large number of arteries including the coronary artery; they can also induce endothelium-derived hyperpolarizing factor (EDHF)-mediated relaxations in some of these arteries. Altogether, these mechanisms might contribute to explain the antihypertensive and cardio-protective effects of polyphenols in vivo. The aim of this review was to provide a nonexhaustive analysis of the effect of several polyphenol-rich sources and isolated compounds on the endothelium in in vitro, ex vivo, and in vivo models as well as in humans.

Anti-inflammatory mechanism of Kaempferia parviflora in murine macrophage cells (RAW 264.7) and in experimental animals

ETHNOPHARMACOLOGICAL RELEVANCE

The rhizomes of Kaempferia parviflora Wall. ex Baker have been used in Thailand for treatment of gout, apthous ulcer, peptic ulcer and abscesses.

AIM OF THE STUDY

In our previous study, the crude ethanol extract of Kaempferia parviflora and its compound (5, 5-hydroxy-3,7,3',4'-tetramethoxyflavone), was reported to show nitric oxide (NO) inhibition in RAW 264.7 cells. The present study is thus investigated the anti-inflammatory mechanism of Kaempferia parviflora extract and compound 5 against inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) mRNA expressions.

MATERIALS AND METHODS

The extract of Kaempferia parviflora and its compound were tested against NO and prostaglandin E(2) (PGE(2)) releases using RAW264.7 cells as well as studied on anti-inflammatory activity in carrageenan-induced rat paw edema and acute toxicity in mice.

RESULTS

The results revealed that the ethanol extract of Kaempferia parviflora markedly inhibited PGE(2) release with an IC(50) value of 9.2 microg/ml. This plant extract and compound 5 also suppressed mRNA expression of iNOS in dose-dependent manners, whereas COX-2 mRNA expression was partly affected. According to the in vivo study, chloroform and hexane fractions greater decreased rat paw edema than ethanol, ethyl acetate and water fractions.

CONCLUSION

The mechanisms for anti-inflammatory activity of Kaempferia parviflora and compound 5 are mainly due to the inhibition of iNOS mRNA expression but partly through that of COX-2 mRNA.