Black ginger

Black ginger also known as Kaempferia parviflora (Zingiberaceae family), “Thai ginseng”, Thai black ginger or in Thai as “Krachaidum”, is a Thai ginger species with deep purple-colored rhizomes (roots) that has traditionally been used as food and a folk medicine for more than 1000 years in Thailand 1). Kaempferia parviflora is found in tropical areas such as Malaysia, Sumatra, Borneo Island, and Thailand. Among the Hmong hill tribe, Kaempferia parviflora is widely believed to reduce perceived effort, improve physical work capacity, and prolong hill trekking 2). The dried Kaempferia parviflora root is generally pulverized and used as tea bags, while the fresh Kaempferia parviflora root is utilized to brew wine. The wine preparation is increasingly used in Thailand as a tonic and as an aphrodisiac 3). Black ginger supplement has been made into various preparations such as medicinal liquor or liquor plus honey, pills (powdered Kaempferia parviflora root with honey), capsules and tablets. Black ginger or Kaempferia parviflora has been long term used in Thai traditional medicine for treating various ailments including to cure allergy 4), anti-depressant, asthma, fatigue, weakness, impotence, gout, colic disorder, diarrhea, dysentery 5), peptic ulcer 6) and lower blood sugar in diabetes 7). In addition, it is also used as longevity promoting substance and as nerve tonic. A large number of recent studies have demonstrated the biological activities of black ginger extract (Kaempferia parviflora extract) contained numerous flavonoids 8), methoxyflavones 9), phenolic glycosides 10) and terpenoids 11), which was previously reported to possess antioxidant activity 12), cardioprotective 13), aphrodisiac 14), anticholinesterase 15), anti-inflammatory 16), anti-obesity 17) and antimutagenic 18), neuroprotective, and cognitive-enhancing properties 19). Kaempferia parviflora extract has been shown to improve physical fitness performance in clinical studies 20). The anti-oxidative activity of Kaempferia parviflora extract has been reported to exhibit antimalarial, antiviral, antimycobacterial and antibacterial 21) anti-gastric ulcer activities 22). Kaempferia parviflora extract has also exhibited antitumor activity against Hela human cervical and SKOV3 ovarian cancer cells 23).

According to the previous reports by Wongsrikaew et al. 24) and Mekjaruskul et al. 25), typical high-performance liquid chromatography of Kaempferia parviflora root ethanol extract were found to have 5,7-dimethoxyflavone (DMF), 3,5,7,3′,4′-pentamethoxyflavone (PMF), and 5,7,4′-trimethoxyflavone (TMF) as major phytochemicals. These three molecules have a common structure, which comprises two methoxy groups at C-5 and C-7 of the A ring in polymethoxyflavones (Figure 2). In an in vitro study, methoxyflavone was examined for its inhibitory activities against nitric oxide production. Compound 5 (5-hydroxy-3,7,30,40-tetramethoxyflavone) exhibited the highest activity, followed by compounds 4 (5-hydroxy-7,40-dimethoxyflavone) and 3 (5-hydroxy-3,7,40-trimethoxyflavone), whereas other compounds possessed moderate or weak activity 26). In addition, more than 20 chemically identifiable constituents have been reported to have potent pharmacological effects 27). For example, flavonoids contained in Kaempferia parviflora root extract was reported to possess antioxidant activity, neuroprotective effects, and cognition-enhancing effects.21 Methoxyflavone substances in Kaempferia parviflora showed an inhibitory effect of phosphodiesterase types 5 and 6, which enhanced sexual performance 28). For antimicrobial activity, 5,7,4′-trimethoxyflavone (TMF) and 5,7,3′,4′-tetramethoxyflavone exhibited antiplasmodial activity against Plasmodium falciparum, and 3,5,7,4′-tetramethoxyflavone showed antifungal activity against Candida albicans 29). For cholinesterase inhibitory effect, Kaempferia parviflora showed the potential inhibitors toward acetylcholinesterase and butyrylcholinesterase, which may be of great interest to be considered as a treatment agent for Alzheimer’s disease 30).

Figure 1. Kaempferia parviflora bioactive compounds

Footnote: The main structure of methoxyflavone includes benzene A ring with 2 substituent groups at positions 5 and 7, an aromatic B ring with 2 substituent groups at positions 3′ and 4′, and C ring with a substituent group linking on position 3. The substituent groups might be -H, -OH, or -OCH3.

[Source 31) ]

Figure 2. Chemical structures of methoxyflavones

Footnote: Chemical structures of polymethoxyflavones. Structures of (A) 5,7-methoxyflavone (DMF), (B) 5,7,4′-trimetholxyflavone (TMF), and (C) 3,5,7,3′,4′-pentamethoxyflavone (PMF).

[Source 32) ]

Kaempferia parviflora benefits

A systematic review on clinical effects of Kaempferia parviflora has shown positive benefits, but it is inconclusive due to small studies included 33). Modern research technologies have demonstrated that Kaempferia parviflora can suppress body weight gain, inhibit lipid accumulation, and prevent from pathological changes resulted by insulin resistance, fatty liver, and hypertension 34). The weight gain may be obtained by the imbalance between energy expenditure and energy intake. brown adipose tissue plays a crucial role in controlling the whole-body energy expenditure and body fatness. The ethanol extract of Kaempferia parviflora at the dose of 100 mg causes a significant increase in whole-body energy expenditure by recruiting brown adipose tissue in male volunteers aged 21-29 in Japan 35).

In Mong hill tribe in Thailand, Kaempferia parviflora is believed to enhance physical work capacity and reduce perceived efforts. Kaempferia parviflora extract at the doses of 25 mg or 90 mg for 8 weeks has been demonstrated to increase physical fitness performance in 30-second chair stand test and 6 minute walk test, increase the scavenger enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px)) expression, and decrease malondialdehyde production 36). In the double-blind, placebo-controlled clinical trial, oral administration of sports nutritional supplement (Fitnox) at the single dose of 250 mg can significantly increase the levels of nitrate (NO3) and nitrite (NO2) in serum and saliva, leading to enhancement of overall performance and physical endurance 37). Consistently, Kaempferia parviflora extract has been found to improve physical fitness, as indicated by enhancement of grip and leg strength, balance, endurance, and locomotor activity. In addition, the daily visual analog scale (VAS) figure score, postphysical fitness test VAS fatigue score, and chronic fatigue syndrome score are found to be enhanced greatly than those in the placebo group 38). However, a randomized, double-blind, and crossover study has been demonstrated that acute administration of Kaempferia parviflora (1.35g) does not enhance exercise performance, compared with the placebo, as confirmed by repeated sprint exercise and submaximal exercise to exhaustion in college males in Thailand 39). In contrast, supplement with Kaempferia parviflora extract at 180 mg per day for 12 weeks, the soccer players are found to increase the right-hand trip strength and left-hand grip strength, compared with those in the placebo group. On the other hand, 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 do not show any significant difference from those in the placebo group 40).

Blood circulation is closely associated with blood fluidity. It has been demonstrated that 70% methanol extract of Kaempferia parviflora significantly improves blood fluidity through activation of fibrinolysis, as indicated by elongation of euglobulin lysis time in disseminated intravascular coagulation (DIC) rat models and the fibrinolysis assays in vitro. Kaempferia parviflora methoxyflavones been involved in activation of fibrinolysis 41). In the ventricular fibrillation (VF) of swine heart model, the saline extract of Kaempferia parviflora at high doses of 100 mg/kg and 50 mg/kg is found to increase the defibrillation threshold and the upper limit of vulnerability. But it does not change ventricular fibrillation threshold. In addition, Kaempferia parviflora administration attenuates diastolic and systolic blood pressures 42). On the other hand, the extract of Kaempferia parviflora (100mg/kg) has been demonstrated to decrease cardiac functions in normal rat hearts through upregulation of cyclic guanosine monophosphate (cGMP) level and nitric oxide (NO) signaling and downregulation of Ca2+ transient 43). This is consistent with 5,7-dimethoxyflavone induced vasorelaxation through increased K+ efflux and attenuated Ca2+ influx 44).

Kaempferia parviflora is believed to benefit men’s sexual activity. However, the ethanol extract of Kaempferia parviflora at dose of 70 mg/kg does not have any effects on weights of reproductive organs but decreases mount latency, ejaculation latency, and postejaculation latency 45). On the other hand, the ethanol extract of Kaempferia parviflora has been found to increase blood flow to the testis dose-dependently 46). Phosphodiesterase type 5 (PDE-5) inhibition has become the strategy for management of erectile dysfunction. However, PDE-5 inhibitors require sexual stimulation to activate cGMP-NO and trigger erection. Thus, targeting for relaxation directly to corpus cavernosum might be a new effective approach for erectile dysfunction management. It has been demonstrated that 3,5,7,3′,4′-pentamethoxyflavone exhibits a relaxant activity on isolated human cavernosum precontrated by phenylephrine. The possible mechanism might be that 3,5,7,3′,4′-pentamethoxyflavone inhibits L-type Ca2+ channel and induces immobilization of Ca2+ from sarcoplasmic reticulum. On the other hand, 3,5,7,3′,4′-pentamethoxyflavone does not act as a calcium-activated potassium channels (KCa channels) opener, a PDE inhibitor, and a Rho-kinase inhibitor but a rather weak stimulator of NO release 47). Kaempferia parviflora extract has been demonstrated to potentially manage age-related erectile dysfunction. At the dose of 90 mg/day, Kaempferia parviflora extract significantly increases all parameters. However, it does not alter the concentration of testosterone, follicle stimulating hormone (FSH), and luteinizing hormone (LH) 48).

Table 1. Clinical effects of Kaempferia parviflora classified by outcomes

Outcomes, Study Sample Subgroup Interventions Time or Methods of Measurement Kaempferia parviflora Control Summary
Mean SD Mean SD
Physical or exercise performance
Maximum power output (watt)
Deema, 2007 Endurance training groups Kaempferia parviflora 1.35 g/day vs placebo Baseline 203.5 3.3 214.2 2.4 Significantly increased at weeks 4 and 8 in the Kaempferia parviflora group and week 8 in the placebo group (difference from baseline)
4 weeks 233.7 2.9 232.1 1.6
8 weeks 245 3.2 247 2.9
No endurance training groups Baseline 184.1 2.8 200.8 4.9 No significant effects
4 weeks 190.5 2.1 197.4 5.3
8 weeks 192 2 198.2 5.3
Wasuntarawat, 2010 Anaerobic exercise (exhaustive sprint) Kaempferia parviflora 1.35 g/day vs placebo Wingate 1 545 95 554 114 Maximum power output declined (P < .05) across Wingate tests 1, 2, and 3 but there were no differences (P > .05) between Kaempferia parviflora and placebo
Wingate 2 499 99 495 109
Wingate 3 454 116 473 96
Mean power output (watt)
Wasuntarawat, 2010 Anaerobic exercise (exhaustive sprint) Kaempferia parviflora 1.35 g/day vs placebo Wingate 1 417 65 416 65 Mean power output declined (P < .05) across Wingate tests 1, 2, and 3 but there were no differences (P > .05) between Kaempferia parviflora and placebo
Wingate 2 369 59 369 58
Wingate 3 323 61 334 57
Time to finish work max test (minutes)
Deema, 2007 Endurance training groups Kaempferia parviflora 1.35 g/day vs placebo Baseline 8.2 0.1 8.5 0.1 Significantly increased at weeks 4 and 8 in the Kaempferia parviflora group and week 8 in the placebo group (difference from baseline)
4 weeks 9.2 0.1 9.4 0.1
8 weeks 9.7 0.1 9.9 0.1 0
No endurance training groups Baseline 7.2 0.1 7.9 0.2 No significant effects
4 weeks 7.5 0.1 7.8 0.2
8 weeks 7.5 0.1 7.8 0.1
Time to exhaustion (minutes)
Wasuntarawat, 2010 Anaerobic exercise (exhaustive sprint) Kaempferia parviflora 1.35 g/day vs placebo 28.3 12.5 27.6 11.5 Acute ingestion of Kaempferia parviflora did not improve time to exhaustion
Rating of perceived exertion
Wasuntarawat, 2010 Anaerobic exercise (exhaustive sprint) Kaempferia parviflora 1.35 g/day vs placebo 10 min 14 2 14 2 Ratings of perceived exertion at 10 and 20 minutes and immediately after exhaustion were also not different between placebo and Kaempferia parviflora. Time to exhaustion was rated between 17 (“very hard”) and 19 (“extremely hard”)
20 min 17 2 17 2
Post a 19 1 18 1
Percentage fatigue (%)
Wasuntarawat, 2010 Anaerobic exercise (exhaustive sprint) Kaempferia parviflora 1.35 g/day vs placebo Wingate 1 43 13 40 15 No differences in percent fatigue during each 30-second sprint were observed between placebo and Kaempferia parviflora. Percent fatigue during the third Wingate test was significantly (P < .05) greater than during the first Wingate test in both placebo and Kaempferia parviflora trials
Wingate 2 48 12 44 15
Wingate 3 51 13 53 10
Heart rate (BPM)
Deema, 2007 Maximum heart rate
Endurance training groups Kaempferia parviflora 1.35 g/day vs placebo Baseline 181 0.8 179.6 0.5 Significantly increased at week 8 in the placebo group (difference from baseline)
4 weeks 184.7 0.7 181.3 0.6
8 weeks 184.6 0.8 186.6 0.8
No endurance training groups Baseline 185 2 180 2.4 No significant effects
4 weeks 199.6 0.6 176.2 2.6
8 weeks 186.4 1.6 181.2 1.8
Wasuntarawat, 2010 Aerobic exercise (endurance) Kaempferia parviflora 1.35 g/day vs placebo 10 min 165 13 164 11 Heart rate at 10 and 20 minutes and immediately after exhaustion were also not different between placebo and Kaempferia parviflora
20 min 174 10 172 9
Posta 177 8 174 10
Lactate threshold (watt)
Deema, 2007 Endurance training groups Kaempferia parviflora 1.35 g/day vs placebo Baseline 129.6 1.7 142.5 1.7 Significantly increased lactate threshold at weeks 4 and 8 in the Kaempferia parviflora group (difference from baseline)
4 weeks 156.8 2.7 155 2.3
8 weeks 165.9 3.3 0 160 1.8
No endurance training groups Baseline 120 4.2 120 4.2 No significant effects from baseline
4 weeks 118.80 5.4 118.80 6
8 weeks 118.80 2.8 106.3 3.1
Hand grip strength test
Wattanathorn, 2012 Right hand (kg) Kaempferia parviflora 25 mg/day vs placebo Baseline 25.06 3.01 24.53 2.55 No significant effects
4 weeks 25 2.97 24.33 2.28
8 weeks 24.86 3.18 24.33 2.46
Kaempferia parviflora 90 mg/day vs placebo Baseline 23.93 3.3 No significant effects
4 weeks 24.6 3.13
8 weeks 24.8 3.14
Left hand (kg) Kaempferia parviflora 25 mg/day vs placebo Baseline 22.06 1.86 21.06 1.83 No significant effects
4 weeks 21.66 1.5 21.33 1.58
8 weeks 21.26 1.48 21.2 1.56
Kaempferia parviflora 90 mg/day vs placebo Baseline 20.86 2.72 No significant effects
4 weeks 21.6 2.02
8 weeks 21.6 1.84
Promthep, 2015 Right hand (kg/wt) Kaempferia parviflora 180 mg/day vs placebo Baseline 0.65 0.09 0.63 0.07 Significantly enhanced at weeks 4, 8, and 12 (difference from the placebo group in the same week) and significant difference compared with the baseline score at week 4
4 weeks 0.7 0.09 0.66 0.07
8 weeks 0.68 0.1 0.63 0.07
12 weeks 0.65 0.08 0.62 0.07
Left hand (kg/wt) Kaempferia parviflora 180 mg/day vs placebo Baseline 0.62 0.08 0.6 0.08 Significantly enhanced at week 8 (difference from the placebo group in the same week)
4 weeks 0.65 0.1 0.62 0.07
8 weeks 0.64 0.08 0.59 0.08
12 weeks 0.61 0.08 0.57 0.07
30-Second chair stand test (seconds)
Wattanathorn, 2012 Kaempferia parviflora 25 mg/day vs placebo Baseline 18.33 2.58 19.13 2.79 No significant effects
4 weeks 19 2.77 19.26 1.43
8 weeks 20 3.11 18.93 1.7
Kaempferia parviflora 90 mg/day vs placebo Baseline 18.6 2.52 Significantly increased at week 8 compared with baseline
4 weeks 19.6 2.13
8 weeks 20.66 2.28
6-Minute Walk Test (m)
Wattanathorn, 2012 Kaempferia parviflora 25 mg/day vs placebo Baseline 571.26 33.68 567.33 33.52 No significant effects
4 weeks 570.33 38.32 598.73 31.57
8 weeks 575.53 36.04 571.26 32.05
Kaempferia parviflora 90 mg/day vs placebo Baseline 572.8 32.65 Significantly increased at week 8 compared with either baseline or placebo
4 weeks 575.46 34.29
8 weeks 601.26 33.7
Tandem stance test (seconds)
Wattanathorn, 2012 Opened eye
Right leg is in front Kaempferia parviflora 25 mg/day vs Placebo Baseline 161.8 11.16 164.8 12.34 No significant effects
4 weeks 164.06 9.63 163.06 10.35
8 weeks 162.26 8.93 165.06 9.8
Kaempferia parviflora 90 mg/day vs placebo Baseline 164 10.5 No significant effects
4 weeks 166.6 6.81
8 weeks 168.46 6.9
Left leg is in front Kaempferia parviflora 25 mg/day vs placebo Baseline 111.93 7.77 112.33 11 No significant effects
4 weeks 112.33 11.39 110.66 10.01
8 weeks 111.8 10.16 109 10.2
Kaempferia parviflora 90 mg/day vs placebo Baseline 108.2 11.32 No significant effects
4 weeks 109.33 13.62
8 weeks 111.8 13.31
Closed eye
Right leg is in front Kaempferia parviflora 25 mg/day vs placebo Baseline 31.86 10.12 33.8 9.22 No significant effects
4 weeks 32.6 7.44 30.8 10.74
8 weeks 32.73 7.67 31.66 10.41
Kaempferia parviflora 90 mg/day vs placebo Baseline 31.26 11.09 No significant effects
4 weeks 31.86 9.33
8 weeks 33.4 8.94
Left leg is in front Kaempferia parviflora 25 mg/day vs placebo Baseline 20.93 3.41 18.8 3.6 No significant effects
4 weeks 21.33 3.79 19.86 5.01
8 weeks 21.26 3.19 21.2 4.57
Kaempferia parviflora 90 mg/day vs placebo Baseline 20.46 4.24 No significant effects
4 weeks 21.26 4.58
8 weeks 22.06 3.93
A sit-and-reach test (cm)
Promthep, 2015 Kaempferia parviflora 180 mg/day vs placebo Baseline 17.98 4.6 16.14 4.93 Significant difference compared with the baseline score at week 4 (both the treatment and placebo groups)
4 weeks 16.43 5.15 14.64 4.92
8 weeks 16.88 5.19 14.61 5.24
12 weeks 18.28 5.1 17.01 4.55
A back-and-leg strength test (kg/wt)
Promthep, 2015 Kaempferia parviflora 180 mg/day vs placebo Baseline 2.77 0.54 2.45 0.39 No significant effects
4 weeks 2.68 0.55 2.45 0.51
8 weeks 2.77 0.55 2.44 0.4
12 weeks 2.79 0.59 2.53 0.52
A 40-yard technical test (seconds)
Promthep, 2015 Kaempferia parviflora 180 mg/day vs placebo Baseline 11.61 0.07 11.99 0.86 Significantly decreased at week 12 compared with the baseline
4 weeks 12.06 1.16 12.34 1.33
8 weeks 11.5 0.74 11.46 0.75
12 weeks 10.08 0.47 10.47 0.9
A 50-metre sprint test (seconds)
Promthep, 2015 Kaempferia parviflora 180 mg/day vs placebo Baseline 6.24 0.31 6.29 0.37 No significant effects in both groups. No significant differences between the groups
4 weeks 6.26 0.31 6.33 0.49
8 weeks 6.37 0.26 6.5 0.5
12 weeks 6.33 0.24 6.47 0.52
A cardiorespiratory fitness test VO2 max (mL/kg/min)
Promthep, 2015 Kaempferia parviflora 180 mg/day vs placebo Baseline 45.09 9.88 45.09 9.96 Significantly increased cardiorespiratory fitness, as indicated by VO2 max values at week 12. No significant difference between the groups
4 weeks 46.95 7.61 47.85 10.08
8 weeks 49.4 8.4 48.34 7.17
12 weeks 51.05 8.4 47.1 8.45
Pain indicators
Chalee, 2010 Pain severity Kaempferia parviflora 7% w/w vs analgesic cream Baseline 8.11 0.99 8.15 1.09 Significantly decreased at week 4 compared with the baseline (both the treatment and placebo groups). No significant difference between the groups
4 weeks 6.8 0.76 6.87 0.65
Circumference of knee joint (cm) Baseline 37.91 2.75 37.15 3
4 weeks 37.03 2.56 36.3 2.64
Range of motion of knee joint (range of motion) Baseline 110.57 9.45 109.39 10.66
4 weeks 117.43 5.86 116.21 6.62
Modified WOMAC score Baseline 40.31 6.63 39.97 6.02
4 weeks 39.29 5.84 39 5.5
Energy expenditure
Matsushita, 2015 Energy expenditure change (kJ/day)
All Kaempferia parviflora 100 mg/day vs placebo Baseline 6213 143 6196 150 No significant in the placebo group but significant difference between the groups at 30 and 60 minutes, difference from baseline and maximal rise at 60 minutes
60 minutes 6442 212 NR NR
High-brown adipose tissue Kaempferia parviflora 180 mg/day vs placebo Baseline 6076 184 6103 184 No significant in the placebo group but significant difference between the groups at 30 and 60 minutes, difference from baseline at 30, 60, 90 minutes and maximal rise at 60 minutes
60 minutes 6427 234 NR NR
Low-brown adipose tissue Kaempferia parviflora 180 mg/day vs placebo Baseline 6418 223 6334 261 No significant effects
60 minutes NR NR NR NR
Erectile response
Wannanon, 2012 Penile circumference (cm)
Resting state Kaempferia parviflora 25 mg/day vs placebo Baseline 9.4 0.79 9 0.73 No significant effects
1 month 9 0.79 8.7 0.59
2 months 9.4 0.79 8.8 0.59
Delayb 9.15 3.1 9.15 3.1
Kaempferia parviflora 90 mg/day vs placebo Baseline 9.2 0.69 9 0.73 After 1 and 2 months of treatment, significant increase in the length and width of penis when compared with the placebo treated group
1 month 10.2 0.79 8.7 0.59
2 months 10.15 0.79 8.8 0.59
Delay b 9.65 2.71 9.15 3.1
Erection state Kaempferia parviflora 25 mg/day vs placebo Baseline 10.9 3.87 11.5 3.87 No significant effects
1 month 10.5 3.68 10.6 3.1
2 months 11.5 4.26 11.8 2.71
Delay b 11.7 3.1 11.7 2.71
Kaempferia parviflora 90 mg/day vs placebo Baseline 10.8 4.26 11.5 3.87 After 1 and 2 months of treatment, significant increase in the width when compared with the placebo treated group
1 month 12.1 4.26 10.6 3.1
2 months 11.9 4.26 11.8 2.71
Delay b 11.7 0.39 11.7 2.71
Penile length (cm)
Resting state Kaempferia parviflora 25 mg/day vs placebo Baseline 9.7 4.26 9.95 7.55 No significant effects
1 month 9.65 3.87 9.9 3.49
2 months 10.9 3.87 10 3.1
Delay b 10.6 3.49 10.25 0.07
Kaempferia parviflora 90 mg/day vs placebo Baseline 9.4 4.07 9.95 7.55 After 1 and 2 months of treatment, significant increase in the length when compared with the placebo treated group
1 month 11.25 3.49 9.9 3.49
2 months 11.1 2.71 10 3.1
Delay b 10.65 3.49 10.25 0.07
Erection state Kaempferia parviflora 25 mg/day vs placebo Baseline 12.5 5.27 13.1 4.96 No significant effects
1 month 12.95 4.03 12.2 3.87
2 months 13.1 4.34 12.4 4.18
Delay b 13.55 3.87 13.2 2.79
Kaempferia parviflora 90 mg/day vs placebo Baseline 12.9 4.34 13.1 4.96 After 1 and 2 months of treatment, significant increase in the length when compared with the placebo treated group
1 month 13.75 4.34 12.2 3.87
2 months 13.9 4.03 12.4 4.18
Delay b 13.5 4.65 13.2 2.79
Latency time (mins)
Erection state Kaempferia parviflora 25 mg/day vs placebo Baseline 10.9 13.94 11.6 12.39 No significant effects
1 month 8.6 12.39 11.7 11.81
2 months 8 12.39 10 10.65
Delay b 7.8 0.59 10.9 12.78
Kaempferia parviflora 90 mg/day vs placebo Baseline 10.4 9.3 11.6 12.39 Significantly decreased the response latency to sexual erotic stimuli and still showed the significant changes during the delay period
1 month 5.5 7.17 11.7 11.81
2 months 5.5 6.58 10 10.65
Delay b 7.4 6.2 10.9 12.78
Serum hormones concentrations
Testosterone (ng/mL) Kaempferia parviflora 25 mg/day vs placebo Baseline 4.11 1.56 4.14 0.92 No significant effects
Single dose 4.79 4.63 5.28 2.76
1 month 5.11 3.13 5.92 5.49
2 months 4.64 1.22 5.65 1.23
Delay b 5.71 2.38 5.14 0.92
Kaempferia parviflora 90 mg/day vs placebo Baseline 4.11 1.3 4.14 0.92 No significant effects
Single dose 4.89 2.63 5.28 2.76
1 month 4.26 0.83 5.92 5.49
2 months 5.74 2.6 5.65 1.23
Delay b 6.06 3.19 5.14 0.92
FSH (IU/L) Kaempferia parviflora 25 mg/day vs placebo Baseline 8.8 4.29 7.88 4.34 No significant effects
Single dose 7.35 4.23 6.73 2.54
1 month 7.23 5.37 6.52 5.51
2 months 7.96 3.32 5.95 2.34
Delay b 8.81 5.12 5.88 3.34
Kaempferia parviflora 90 mg/day vs placebo Baseline 7.53 2.92 7.88 4.34 No significant effects
Single dose 6.14 2.26 6.73 2.54
1 month 6.29 2.25 6.52 5.51
2 months 6.01 2.79 5.95 2.34
Delay b 7.03 2.35 5.88 3.34
LH (IU/L) Kaempferia parviflora 25 mg/day vs placebo Baseline 7.25 5.9 7.14 5.62 No significant effects
Single dose 8.12 2.72 7.59 3.21
1 month 7.04 5.34 7.3 4.24
2 months 8.48 4.64 7.82 2.34
Delay b 8.72 4.67 8.14 3.23
Kaempferia parviflora 90 mg/day vs placebo Baseline 6.99 4.37 7.14 5.62 No significant effects
Single dose 7.65 1.88 7.59 3.21
1 month 8.55 3.64 7.3 4.24
2 months 7.41 4.67 7.82 2.34
Delay b 8.82 4.44 8.14 3.23

Footnote: a Post: immediately after exercise; b Delay: 1 month after the cessation of Kaempferia parviflora administration.

Abbreviations: VO2 = oxygen consumption; ROM = range of motion; high-BAT = high brown adipose tissue; low-BAT = low brown adipose tissue; FSH = follicle-stimulating hormone; LH = luteinizing hormone.

Kaempferia parviflora on physical or exercise performance

To determine the effects of Kaempferia parviflora on physical or exercise performance, many tests were used, including maximum power output, mean power output, time to exhaustion, rating of perceived exertion, percentage fatigue, heart rate, lactate threshold, hand grip strength, 6-minute walk test, and so on (see Table 1). The main findings from 2 studies 49), 50) indicated that Kaempferia parviflora showed no acute improvement in either repeated sprint performance or endurance exercise. However, other 2 studies 51), 52) provided data of hand grip strength test, which determined the upper-body muscle strength by using a digital dynamometer. It was found that the Kaempferia parviflora 90 to 180 mg/day group significantly increased hand grip strengths of both right-hand and left-hand sides at 2 months compared with the placebo group 53). This might be explained by the increased blood flow effect of Kaempferia parviflora 54). A previous study demonstrated that Kaempferia parviflora supplementation could increase blood flow to the organs due to vasorelaxation induction 55). This partly was mediated through cyclooxygenase and nitric oxide–dependent pathways 56) and Kaempferia parviflora also showed anti-inflammatory effects 57). Therefore, the combination effect of increased blood flow and anti-inflammatory effects may facilitate muscle strength 58).

Kaempferia parviflora effect on erectile dysfunction

Only one randomized controlled trial compared Kaempferia parviflora with placebo in human subjects on erectile response 59). Subjects receiving Kaempferia parviflora 25 mg/day (n = 15), or 90 mg/day (n = 15), were compared with those receiving placebo (n = 15) for 8 weeks of study period. The study found that Kaempferia parviflora at a dose of 90 mg/day exhibited a significant enhancement in all parameters (ie, response latency time to visual erotic stimuli, size and length of penis both in flaccid and erectile states) after 1 and 2 months of treatment compared with placebo 60). In addition, after 1 month and 2 months, the Kaempferia parviflora group at a dose of 90 mg/day experienced a statistically significant increase in length and width of penis both in resting state and erection state compared with the placebo group. Kaempferia parviflora showed no effects on serum hormones (ie, follicle-stimulating hormone, luteinizing hormone) see Table 1. The authors explained that the effects involved nitric oxide (NO). The experimental studies reported that Kaempferia parviflora extract could induce an increase of endothelial nitric oxide synthase and protein expression in human umbilical vein endothelial cell 61). Thus, abundance of endothelial nitric oxide synthase in endothelium of penile vasculature and sinusoidal endothelium within the corpora carvernosa might increase penile erection 62).

Kaempferia parviflora effects on pain

A study by Chalee 63) compared Kaempferia parviflora cream with analgesic cream on pain reduction in knee osteoarthritis. Pain severity, circumference of knee joint, range of motion of knee joint, and modified Western Ontario and McMaster Universities Arthritis Index score were assessed and compared within the group from baseline, or between the groups with analgesic cream. Comparing with baseline, the results in both groups showed significantly reduce pain in all indicators at 4 weeks. On the contrary, comparing with analgesic cream, Kaempferia parviflora cream showed no significant difference (Table 1). Since anti-inflammatory effect was studied only using oral administration of Kaempferia parviflora 64), the mechanism of Kaempferia parviflora cream on pain reduction was still unclear.

Kaempferia parviflora effects on energy expenditure

The effect of Kaempferia parviflora on energy expenditure has been linked to the activity of brown adipose tissue, a site of nonshivering thermogenesis 65). A previous study found that the components of Kaempferia parviflora extract activate hormone-sensitive lipase in adipocyte 66). Furthermore, 5,7-dimenthoxyflavone, the major flavonoid in Kaempferia parviflora extract, was demonstrated to have a the potent inhibitory effect on phosphodiesterase 5 (PDE5) enzyme 67). Since cGMP is a signal of hormone-sensitive lipase in adipocyte, it activates brown adipose tissue thermogenesis. Thus, it is possible that the brown adipose tissue–mediated thermogenic effect of Kaempferia parviflora extract exist via the inhibition of phosphodiesterase in brown adipose tissue. A study showed that Kaempferia parviflora extract could potentially increase whole-body energy expenditure probably through the activation of brown adipose tissue, which might benefit as an antiobesity treatment 68). A study by Matsushita et al 69) evaluated the effect of 2 doses of Kaempferia parviflora 100 mg/day or 180 mg/day on energy expenditure change compared with placebo. They found that when comparing with baseline, Kaempferia parviflora showed significant increase in energy expenditure at 30 minutes and 60 minutes in both groups. However, compared with placebo, no significant additional benefit of Kaempferia parviflora on energy expenditure was found (Table 1).

Kaempferia parviflora dosage

Till now, there is not enough scientific evidence to elucidate the optimal Kaempferia parviflora dose. Recommendation from Thai traditional medicine institute suggests the daily dose of Kaempferia parviflora is 1.2g. In addition, the powder of Kaempferia parviflora extract has been developed as a food ingredient on the market, which is standardized for containing not less than 2.5% of 5,7-dimethoxyflavone (Compound-6) and 10% of total methoxyflavones 70).

Fitnox, a sports nutritional supplement, is a unique blend of Kaempferia parviflora methoxyflavones, pomegranate peel polyphenols, and Moringa oleifera leaf saponins 71). Subchronic toxicological study shows that administration of Fitnox (at the dose of 1000 mg/kg/day for 90 days) to rats exhibits no any drug-related toxicity or mortality in either sex and no significant changes between the control and Fitnox treated groups in all parameters at the hematological, biochemistry, and histological levels 72). Another study for evaluating the toxicology of the ethanol Kaempferia parviflora extract (5, 50, and 500 mg/kg/day for 6 months) demonstrates no notable histological changes in all groups. The hematological parameters are also within the normal range in both sexes. But the body weight and the triglyceride levels at the 500 mg/kg dose rats group are lower, and the glucose and cholesterol levels are higher 73).

Kaempferia parviflora side effects

Administration with 1.35g of Kaempferia parviflora daily does not produce any adverse effects 74). Acute and chronic toxicity study has been proven that oral administration of Kaempferia parviflora does not induce any abnormal changes in body weight and histology in various visceral organs 75), 76). Toxicological study exhibits that the ethanol Kaempferia parviflora extract (at the doses of 60, 120, and 240 mg/kg for 60 days) does not induce significant changes in hemoglobin, white blood cells, or differential cell count. No any negative effects on renal and hepatic functions have been found at the tested doses 77).

An animal study of Kaempferia parviflora extract on chronic toxicity was conducted 78). They randomly divided 120 Wistar rats into 5 groups, 24 rats each (12 males and 12 females). Then, 3 treatment groups were orally administered with Kaempferia parviflora extract at doses of 5, 50, and 500 mg/kg/day for 6 months, respectively, which were equivalent to 1, 10, and 100 times that of human use, while 2 control groups were orally given distilled water and 1.0% tragacanth, respectively 79). The results showed that the histopathological study of visceral organs revealed no remarkable lesions related to the toxicity of Kaempferia parviflora extract 80). There has only been one reported case of anaphylaxis caused by black ginger in a dietary supplement 81).

References   [ + ]

Black Ginger Extract