The protective effects of Ninjin'yoeito against liver steatosis/fibrosis in a non-alcoholic steatohepatitis model mouse.

Non-alcoholic steatohepatitis (NASH) is a progressive fibrotic form of non-alcoholic fatty liver disease. Liver fibrosis leads to liver cancer and cirrhosis, and drug therapy for NASH remains lacking. Ninjin'yoeito (NYT) has shown antifibrotic effects in a model of liver fibrosis without steatosis but has not been studied for NASH. Therefore, we evaluated the efficacy of NYT in mice fed a choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) as a NASH model. Compared with the normal diet group, mice fed CDAHFD showed decreased body weight and increased white adipose tissue, liver weight, and triglyceride content in the liver. Furthermore, a substantial increase in the hepatic concentration of hydroxyproline, expression of α-smooth muscle actin (α-SMA), and transforming growth factor-ß was observed in CDAHFD-fed mice. Masson's trichrome and Picro-Sirius red staining revealed a remarkable increase in collagen fiber compared with the normal diet group. Compared with mice that received CDAHFD alone, those supplemented with NYT exhibited reduced hepatic triglyceride and hydroxyproline levels and α-SMA expression. Additionally, compared with the group fed CDAHFD alone, the stained liver tissues of NYT-treated mice exhibited a reduction in Masson's trichrome- and Picro-Sirius red-positive areas. Locomotor activity was significantly reduced in the CDAHFD-fed group compared with the normal diet group. In the NYT-treated group, the CDAHFD-induced decrease in locomotor activity was significantly suppressed. The findings indicate that NYT inhibited fatty and fibrotic changes in the livers of NASH mice and alleviated the decrease in locomotor activity. Therefore, NYT may serve as a novel therapeutic approach for NASH.

Effects of Ninjin'yoeito on Human CYP3A and Mouse CYP3A Activity.

Ninjin'yoeito (NYT) is widely used clinically for the management of patients with frailty and other multiple symptoms. NYT is often administered with other drugs; however, little information is available on its drug interactions. Previous studies using human liver microsomes have reported that constituents of NYT either inhibit (schisandra fruit, cinnamon bark, glycyrrhiza, and poria sclerotium) or induce (schisandra fruit and glycyrrhiza) CYP3A4 expression. Herein, we conducted in vitro and in vivo studies targeting human CYP3A and mouse CYP3A to elucidate the effects of NYT coadministration with other drugs on hepatic drug metabolism. In an inhibition study using human liver microsomes, NYT showed concentration-dependent reversible inhibition and time-dependent inhibition. Furthermore, in an induction study using frozen human hepatocytes, the addition of 0.01-0.1 mg/mL NYT resulted in a concentration-dependent increase in CYP3A gene expression. Contrarily, no significant changes in CYP3A substrate blood concentrations were observed between untreated mice and mice that received either a single dose of NYT or repeated doses for 15 days. These results demonstrate that NYT has inhibitory and inductive effects on hepatic CYP3A in vitro, but orally administered NYT does not affect drug metabolism mediated by hepatic CYP3A in vivo in the mouse model. Although there is a little information about drug interactions of NYT, this study provides new evidence for that.

Impact of Ninjin'yoeito on frailty and short life in klotho-hypomorphic (kl/kl) mice.

With the recent aging of society, the prevention of frailty has become an important issue because people desire both a long and healthy lifespan. Klotho-hypomorphic (kl/kl) mice are known to show phenotypes of premature aging. Ninjin'yoeito (NYT) is a traditional Japanese Kampo medicine used to treat patients with vulnerable constitution, fatigue or physical exhaustion caused by aging and illness. Recent studies have reported the potential efficacy of NYT against frailty. We therefore evaluated the effect of NYT on the gait function, activity, the histopathological status of organs and survival using kl/kl mice as a model of aging-related frailty. Two sets of 28-day-old male kl/kl mice were assigned to the vehicle (non-treated; NT), 3% or 5% NYT dietary groups. One set of groups (NT, n = 18; 3% NYT, n = 11; 5% NYT, n = 11) was subjected to the analysis of free walking, rotarod, and spontaneous activity tests at approximately 58 days old. Thereafter, we measured triceps surae muscles weight and myofiber cross-sectional area (CSA), and quantified its telomere content. In addition, we evaluated bone strength and performed histopathological examinations of organs. Survival was measured in the second set of groups (NT, 3% NYT and 5% NYT group, n = 8 each). In the walking test, several indicators such as gait velocity were improved in the NYT 3% group. Similar results were obtained for the latency to fall in the rotarod test and spontaneous motor activity. Triceps muscle mass, CSA and its telomere content were significantly improved in the NYT 3% group. Bone density, pulmonary alveolus destruction and testicular atrophy were also significantly improved in the NYT 3% group. Survival rate and body weight were both significantly improved in the NYT3% group compared with those in the NT group. Continuous administration of NYT from the early stage of aging improved not only gait performance, but also the survival in the aging-related frailty model. This effect may be associated with the improvements in aging-related organ changes such as muscle atrophy. Intervention with NYT against the progression of frailty may contribute to a longer, healthier life span among the elderly individuals.

Ninjin'yoeito ameliorated PPE-induced pulmonary emphysema and anxiety/depressive-like behavior in aged C57BL/6J mice.

The prevalence of chronic obstructive pulmonary disease (COPD) is increasing in the elderly. COPD is a chronic respiratory disease characterized by airway remodeling and alveolar emphysema. COPD patients are also at high risk for mental illnesses such as depression and anxiety. Ninjin'yoeito (NYT) is prescribed to patients with conditions such as post-illness and postoperative weakness, fatigue, poor appetite, skin rash, cold hands and feet, and anemia. In addition to traditional uses, NYT is also prescribed as a therapeutic drug for poor functioning of the digestive organs, respiratory organs, and urinary organs. NYT is also known to have an antioxidant effect. The objective of this study was to investigate whether NYT could ameliorate COPD-induced lung injury and anxiety/depression in aged C57BL/6J mice exposed to porcine pancreatic elastase (PPE). While intratracheal administration of PPE induced emphysema in elderly mice, long-term administration of NYT suppressed the pathology. NYT was also found to suppress the apoptosis and oxidative stress caused by PPE. In addition, long-term administration of NYT was found to ameliorate PPE-induced depressive-like behavior in three different behavioral studies. These results suggest that NYT has a therapeutic effect on emphysema and the behavioral abnormalities caused by PPE.

Ninjin'yoeito suppressed the onset of arthritis, pain, and muscle atrophy in rheumatoid arthritis model mice.

Rheumatoid arthritis is one of the most common diseases in orthopedic surgery. The main symptoms are joint pain and systemic symptoms. In recent years, rheumatoid arthritis is known to cause sarcopenia. Ninjin'yoeito (NYT), a traditional Japanese medicine, has been prescribed for patients with post-illness or post-operative weakness, fatigue, loss of appetite, rash, cold limbs, and anemia. In addition to its traditional use, NYT has been prescribed for treating frailty in gastrointestinal, respiratory, and urinary functions. Further, NYT is known to be effective in suppressing muscle atrophy in the prior literature. The present study aimed to investigate whether NYT suppresses various symptoms of the Collagen-induced arthritis (CIA) model. Long-term administration of NYT inhibited the increases in arthritis scores, decreases pain threshold, and muscle atrophy in the CIA model. In addition, NYT inhibited the elevation of the plasma IL-6 level. These results suggest that NYT may have therapeutic effects on symptoms, muscle atrophy and increase in plasma IL-6 level caused by rheumatoid arthritis.

Disuse muscle atrophy-improving effect of ninjin'yoeito in a mouse model.

Disuse syndrome indicates psychosomatic hypofunction caused by excess rest and motionless and muscle atrophy is termed disuse muscle atrophy. Disuse muscle atrophy-induced muscle weakness and hypoactivity further induces muscle atrophy, leading to a vicious cycle, and this is considered a factor causing secondary sarcopenia and subsequently frailty. Since frailty finally leads to a bedridden state requiring nursing, in facing a super-aging society, intervention for a risk factor of frailty, disuse muscle atrophy, is important. However, the main treatment of disuse muscle atrophy is physical therapy and there are fewer effective preventive and therapeutic drugs. The objective of this study was to search for Kampo medicine with a disuse muscle atrophy-improving effect. Ninjin'yoeito is classified as a qi-blood sohozai (dual supplement) in Chinese herbal medicine, and it has an action supplementing the spleen related to muscle. In addition, improvement of muscle mass and muscle weakness by ninjin'yoeito in a clinical study has been reported. In this study, the effect of ninjin'yoeito on disuse muscle atrophy was investigated. A disuse muscle atrophy model was prepared using male ICR mice. After surgery applying a ring for tail suspension, a 1-week recovery period was set. Ninjin'yoeito was administered by mixing it in the diet for 1 week after the recovery period, followed by tail suspension for 14 days. Ninjin'yoeito administration was continued until autopsy including the hindlimb suspension period. The mice were euthanized and autopsied immediately after completion of tail suspension, and the hindlimb muscles were collected. The food and water intakes during the hindlimb unloaded period, wet weight of the collected muscle, and muscle synthesis and muscle degradation-related factors in blood and muscle were evaluated. Ingestion of ninjin'yoeito inhibited tail suspension-induced reduction of the soleus muscle wet weight. In addition, an increase in the blood level of a muscle synthesis-related factor, IGF-1, and promotion of phosphorylation of mTOR and 4E-BP1 in the soleus muscle were observed. It was suggested that ninjin'yoeito has a disuse muscle atrophy-improving action. Promotion of the muscle synthesis pathway was considered the action mechanism of this.

[Effects of Yokukansankachimpihange on Memantine-induced Dizziness in Mice with Memory Impairment].

Memantine (Mem) is a non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist used in the treatment of Alzheimer's disease. However, side effects, including dizziness, headache and confusion, have been reported. Therefore, although it reduces the symptoms of dementia, such as memory loss, its use is limited by side effects for patients at risk of injury. In the present study, we investigated the effects of the Japanese Kampo medicine yokukansankachimpihange (YKSCH) on Mem-induced dizziness in a mouse model of memory impairment. Mem (20 mg/kg B.W., p.o.) reduced the performance score during the beam balance test and walking time on a rotarod, confirming the disrupted sense of balance and motor coordination. In contrast, YKSCH (750 mg/kg B.W., p.o.) significantly suppressed this disruption of balance and motor coordination in mice. Moreover, YKSCH did not attenuate the ameliorative effects of Mem on learning and memory impairment in the Y-maze test or step-through passive avoidance task. Spatial learning and memory significantly recovered in the Mem-treated group and Mem plus YKSCH-treated group, suggesting no pharmacological interaction between Mem and YKSCH in mice. Therefore, YKSCH may be effective at alleviating the Mem-induced equilibrium disturbance in mice with memory impairment without reducing its memory disorder improvement effects. Our study may be useful for future studies on the combined use of Mem and YKSCH in the treatment of Alzheimer's disease.

Ninjin'yoeito Alleviates Neuropathic Pain Induced by Chronic Constriction Injury in Rats.

Kampo medicines are frequently used empirically to treat pain in clinical practice. Ninjin'yoeito (NYT), which is associated with few adverse effects, is often used to treat the elderly, but has not yet been examined in detail. We herein investigated the effects of NYT, at 500 and 1,000 mg/kg p.o. (NYT500/NYT1000 group) in single and repeated administrations for 14 days, on pain in rats with peripheral neuropathy induced by loose ligation of the sciatic nerve (chronic constriction injury: CCI). Untreated CCI rats given distilled water were used as a control group. To assess induced pain, the pain threshold was measured using the von Frey test. To evaluate spontaneous pain, the ground-contact area of the paw with neuropathic pain was measured using the Dynamic Weight Bearing test. Serum samples were collected after the test to elucidate the mechanism of action of NYT, and brain-derived neurotrophic factor (BDNF) and corticosterone protein levels, which have been reported to change due to chronic pain, were analyzed. After single administration of NYT, the pain threshold rose in the NYT500 and NYT1000 groups. The pain threshold tended to rise on day 14 of repeated administration in the NYT500 group (p = 0.08) and it significantly rose at NYT1000 group (p < 0.05) compared to Control group. In addition, the foot contact area increased (p = 0.09). Therefore, CCI-induced pain was significantly remitted and spontaneous pain was remitted after repeated administration of NYT. Serum BDNF levels were higher in untreated CCI rats than in normal rats (p = 0.05), but decreased after the repeated administration of NYT (NYT1000, p = 0.15), while serum corticosterone levels were lower (p = 0.12) than those in normal rats and increased after the repeated administration of NYT (NYT1000, p = 0.07). The blood BDNF level has been suggested to influence pain intensity. The findings demonstrated NYT effectively treats neuropathic pain, suggesting that a NYT-induced decrease in blood BDNF contributed to the mechanism of pain relief. In addition, the variation of corticosterone was observed, suggesting that normalization of responsiveness to stress by NYT contributed to the pain relief.

[Mechanism of Inhibitory Effects of Cherry Bark-containing Jumihaidokuto on Benzoyl Peroxide Induced Erythema in Hairless Mice].

Benzoyl peroxide (BPO) has been widely used to treat acne vulgaris. Skin flaking, erythema and skin irritation have been observed as side effects of BPO in the treatment of this disorder. In a clinical study, cherry bark-containing jumihaidokuto significantly reduced the erythema induced by BPO application. However, its mechanism of action has not been clarified. In the present study, an application of 10% BPO caused erythema and an increase in interleukin (IL)-1α in the skin of hairless mice, and these changes were significantly suppressed by cherry bark-containing jumihaidokuto at 600 mg/kg. In addition, using a three-dimensional cultured human epidermis model (LabCyte EPI-MODEL), cherry bark-containing jumihaidokuto extract at 250 or 500 µg/mL significantly suppressed IL-1α mRNA expression induced by the application of 0.2 mM BPO. Therefore, cherry bark-containing jumihaidokuto may have suppressed BPO-induced erythema by inhibiting the increase in the IL-1α level in the skin.

[Pharmacological Effects of Yokukansankachimpihange on Urinary Catecholamine in Restraint-stressed Mice].

Herbal medicines, acupuncture and moxibustion are often used for unidentified complaints. It is well known that catecholamine secreted by the sympatho-adrenal medullary system primarily functions to increase cardiac output and raise glucose levels in the blood during acute stress. In the present study, the effects of yokukansankachimpihange (YKSKCH, a Kampo medicine) on urinary catecholamine in mice that were repeatedly stressed by restraining were examined. Restraint stress (240 min/d×3 d×3 cycles, daytime: 12:00-16:00) induced a marked increase in noradrenaline (NA) and adrenaline (A) levels in the urine. Oral administration of YKSKCH (750 mg/kg of body weight) significantly inhibited the increase in urinary NA and A levels in mice after repeated restraint stress. In addition, the NA/dopamine (physical stress) and A/dopamine (mental stress) ratios were lower in the 750 mg/kg YKSKCH-treated group than in the control group. The tail suspension test was also performed and locomotor activity was investigated. Oral administration of YKSKCH at 750 mg/kg significantly reduced the immobility time, which was longer in mice after repeated restraint stress. Furthermore, oral administration of YKSKCH at 750 mg/kg increased locomotor activity, which was lower in mice after repeated restraint stress. These results suggest that YKSKCH has positive effects on mental and physical stress after repeated restraint stress, without reducing locomotor activity.

Anti-inflammatory and Antinociceptive Constituents of Atractylodes japonica Koidzumi.

The rhizomes of many Atractylodes species, including Atractylodes chinensis Koidzumi, Atractylodes macrocephala Koidzumi, and Atractylodes japonica Koidzumi, are collectively termed Atractylodis Rhizoma. We prepared n-hexane extracts of the three species and evaluated their anti-inflammatory effects on lipopolysaccharide (LPS)-induced RAW 264.7 cells. Among all n-hexane extracts, those of A. japonica most strongly inhibited nitric oxide (NO) production in LPS-induced RAW 264.7 cells; five sesquiterpenes, atractylon, atractylenolide I, atractylenolide II, atractylenolide III, and 8-epiasterolid, were isolated from A. japonica. The phytochemical content of A. japonica was similar to those of A. chinensis and A. macrocephala. Moreover, the atractylon concentration was higher in A. japonica than in A. chinensis and A. macrocephala. Atractylon significantly inhibited NO and prostaglandin E2 production as well as inducible NO synthase and cyclooxygenase-2 expression in LPS-induced RAW 264.7 cells. Atractylon (40 mg/kg) also significantly reduced the acetic-acid-induced writhing response, carrageenan-induced paw edema, and hot-plate latent pain response in mice. According to the results, A. japonica has anti-inflammatory and antinociceptive effects and atractylon is the major active component of A. japonica. Therefore, atractylon can be used as a bioactivity marker in A. japonica.

Effects of Hachimijiogan, a Kampo powder, on epididymidis sperm characteristics in healthy male rats.

Purpose: Hachimijiogan (HJG, Rehmannia Eight Formula), a kidney-replenishing Kampo formula, is clinically known to be effective in the treatment of male infertility with oligozoospermia. The purpose of this study was to evaluate the effect of HJG on the epididymal sperm characteristics and related serum hormone changes in rats in an attempt to determine its mechanism. Methods: Male Wistar-Imamichi rats (233.4 ± 5.2 g, nine weeks old) were assigned randomly to four groups (n = 6 for each group). Apart from one control group treated with distilled water, the other groups were administered HJG consecutively for 9-11 days with doses of 250, 500 and 1,000 mg/kg. After the last administration the caude epididymides were quickly removed under anesthesia for assessing sperm characteristics. Additionally, the testes, seminal vesicles, prostate and adrenal glands were removed surgically and their wet weights measured. Results: Results showed that HJG increased sperm numbers and motility as well as the weights of seminal vesicles and adrenal glands at lower doses. Moreover, HJG decreased serum levels of testosterone and luteinizing hormone while increasing follicle-stimulating hormone levels. Conclusions: Our findings may support the conclusion that a lower dosage of HJG has an effect on improving local spermatogenous environments by activating adrenal functions and/or promoting local androgen activity.

Pharmacological effects of "jutsu" (Atractylodis rhizome and Atractylodis lanceae rhizome) on 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI)-induced head twitch response in mice (I).

Hallucinations are a common non-motor symptom of Parkinson's disease and various forms of dementias. Yokukansan and Yokukansankachimpihange have attracted attention due to their effectiveness in the treatment of hallucinations of dementia. To clarify which component in these formulas contribute to the effects, at first, we focused on their differences in compositions to examine the pharmacological effects on the selective 5-HT2A/2C agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI)-induced head-twitch response (HTR) in mice that has been used as animal hallucination model. Results indicated that water extract of Byaku-jutsu (Atractylodes japonica) showed a stronger inhibitory effect on DOI-induced HTR than that of So-jutsu (A. lancea) corresponding to their major constituents of atractylenolide III and ß-eudesmol, and suggested that the major constituents should be active constituents contributing to the antihallucination effects of Byaku- and So-jutsu. Besides, the part B-C ring (butenolide) in atractylenolide III was found to be similar to the structure of serotonin and suggested that the B-C ring may partially play role in antagonistic activity against serotonin receptors. Thus, a novel, rational design of butenolide-related compounds may as potential lead compounds for new drug development. Analysis of the chemical components of Byaku- and So-jutsu and further study on their structure-activity relationships are currently in progress.

A Kampo formula, saikokaryukotsuboreito, improves serum testosterone levels of castrated mice and its possible mechanism.

The term "late-onset hypogonadism (LOH)" is recommended to express the symptoms in middle-aged males with decreased testosterone. Although androgen replacement therapy (ART) might be an effective way to manage LOH, the risk of testosterone supplementation in elderly men is still concerned. On the other hand, to avoid adverse effects of ART, Kampo medicine (traditional Chinese-Japanese medicine) is often a first choice to treat LOH in Japan. However, their pharmacological studies are few. In this study, castrated mice was used as an LOH animal model for examining the pharmacological effects of a Kampo formula, saikokaryukotsuboreito (shortly SKRBT) on serum testosterone levels and seminal vesicles weights. Furthermore, an attempt to elucidate its pharmacological mechanism, inhibition of SKRBT and its components against aromatase were also examined with the enzyme-based assay. As a result, SKRBT improved significantly both the decline of serum testosterone levels and decrease of seminal vesicles weight of castrated mice at a dose of 125 mg/kg with a non dose-dependent manner. SKRBT and two components Scutellariae radix and Rhei rhizoma exhibited inhibitory activities with the IC(50) values of 145, 29.2 and 29.7 µg/ml, respectively. These results suggested that the aromatase inhibitory activity of SKRBT may contribute, to a different extent, to the improvement of serum testosterone levels.

Puerarin exerted anti-osteoporotic action independent of estrogen receptor-mediated pathway.

Puerarin, a daidzein-8-C glucoside, is the major isoflavonoid in Kudzu (Pueraria lobata), and is unique in that it contains C-C conjugated glucose at position 8 of the isoflavonoid structure. A puerarin diet at a dose of 5 mg/kg b.w./d to fed ovariectomized mice for 2 mo diminished the urinary deoxypyridinoline, a typical bone-degradation product. Since the bone absorption marker, serum tartarate-resistant acid phosphatase (TRAP) activity of puerarin-fed mice decreased but the bone formation marker, osteocalcin level, did not alter, the puerarin diet was proved to specifically depress the bone absorption, but not the overall bone metabolism. In accordance with that results, the femur structure of puerarin-fed mice was restored compared with that of puerarin-free diet mice. The atrophied uterine due to low estrogen (E2) level after ovariectomy was not restored by the puerarin diet, suggesting that puerarin exerted the anti-osteoporotic action through a non estrogen receptor (ER) mediated-pathway, in vivo. The growth of an ER-positive human breast cancer cell, MCF-70, was not enhanced by puerarin, suggesting that puerarin did not show estrogen-like action on MCF-7 cells, even at a ten thousand times higher concentration than that of E2. Furthermore, ICI182,780 (ICI), an estrogen antagonist, suppressed the enhanced growth of MCF-7 cells by E2, but not that by puerarin. In an ER-binding assay, puerarin was proved not to bind to ERα or ß, or if all, extremely weakly, although daidzein, an aglycon of puerarin, showed a little stronger binding compared with puerarin. All these results strongly indicate that puerarin exerts its anti-osteoprotic action independently of the ER-mediated pathway.

Kudzu (Pueraria lobata) vine ethanol extracts improve ovariectomy-induced bone loss in female mice.

Bone-loss-improving action of kudzu vine ethanol extracts (PVEE) was clarified. PVEE was composed roughly of 80% fiber, 10% puerarin, 3.6% daidzin, 2.5% 6″-O-malonyldaidzin, and the other minor isoflavones. Ten-week-old ovariectomized (OVX) mice were fed diets containing PVEE (20 mg/kg body weight/day) for 8 weeks. The bone resorption markers (urinary deoxypyridinoline and tartrate-resistant acid phosphatase activity) was elevated in OVX mice and was significantly decreased in OVX mice that consumed PVEE for 8 weeks. Consistent with the decrease in the markers, the number of matured osteoclasts in the distal femur was diminished in OVX mice fed PVEE diets. PVEE diets also suppressed the decrease in femoral bone mineral density (BMD) by OVX. PVEE showed the affinity for estrogen receptor α and ß nearly 1/10000 weaker than 17ß-estradiol. No hypertrophy in the uterus by the PVEE diet was observed. These results suggest that PVEE could be a promising resource for a functional food that improves osteoporosis.

Effects of keishibukuryoganryokayokuinin (gui-zhi-fu-ling-wanliao-jia-yiyiren) on the epidermal pigment cells from DBA/2 mice exposed to ultraviolet B (UVB) and/or progesterone.

The production of melanin is not only activated by external factors such as sunlight or UV-exposure, but is also considered to be triggered by hormonal factors, particularly sex hormones such as ovarian hormones. Previously, keishibukuryoganryokayokuinin (KBY) was reported to increase the pigmentation and moisture content of dermis in women during the luteal phase of the menstrual cycle, thus suggesting that progesterone could play a critical role in the development of skin pigmentation. In the present study, female DBA/2 mice, a dilute brown strain, were used to examine the effects of KBY on the increase in epidermal pigment cells in mice exposed to ultraviolet B (UVB) radiation or progesterone in an attempt to elucidate its mechanism. An increase in epidermal pigment cells was observed in mice exposed to progesterone. To the best of our knowledge, this is the first study to demonstrate that progesterone causes pigmentation in vivo. Furthermore, administration of KBY to progesterone-exposed mice significantly reduced the number of epidermal pigment cells. However, KBY had no such effects on UVB-induced pigmentation. Another important finding was the gain in body weight in progesterone-exposed mice, while body weight gain was reduced by KBY. The body weight gain was believed to be due to sodium and fluid retention, a kind of adverse effect of progesterone, which may further affect the intracellular pH of melanosomes, which synthesize melanin, in turn, leading to melanin production because tyrosinase activity is linked to the intracellular pH environment. This may help explain the mechanism of the role of KBY in pigmentation.