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Core areas represent small regions within animal home-ranges intensively used during a given period of time. We assessed the quality of core areas relative to the rest of the home-ranges (i.e., non-core areas) of 11 groups of the territorial and highly frugivorous white-handed gibbon (Hylobates lar) over a short-time scale to reflect temporarily available resources. Weekly core areas included consistently higher densities of the gibbons' important foods compared to non-core areas. Gibbon core areas partially overlapped at 46 percent with a model comprising the best hypothetical core areas based on a concentration map of available food sources. In addition, a maximization ratio estimated by dividing the cumulative dbh covered by gibbon core areas and the model reached an intermediate value. Gibbon core areas only partially mirrored food distribution probably because they represent a trade-off between covering regions with important food locations and areas needed for other biologically relevant activities such as territory defense. Results do not support the concept that core areas can represent the minimum area requirement that would allow a gibbon group to survive and reproduce successfully irrespective of the time period considered, which indicates that core areas alone should not be treated as a conservation target.

Tool use has allowed humans to become one of the most successful species. However, tool-assisted foraging has also pushed many of our prey species to extinction or endangerment, a technology-driven process thought to be uniquely human. Here, we demonstrate that tool-assisted foraging on shellfish by long-tailed macaques (Macaca fascicularis) in Khao Sam Roi Yot National Park, Thailand, reduces prey size and prey abundance, with more pronounced effects where the macaque population size is larger. We compared availability, sizes and maturation stages of shellfish between two adjacent islands inhabited by different-sized macaque populations and demonstrate potential effects on the prey reproductive biology. We provide evidence that once technological macaques reach a large enough group size, they enter a feedback loop – driving shellfish prey size down with attendant changes in the tool sizes used by the monkeys. If this pattern continues, prey populations could be reduced to a point where tool-assisted foraging is no longer beneficial to the macaques, which in return may lessen or extinguish the remarkable foraging technology employed by these primates. Published version

Human overpopulation, deforestation, invasion of agricultural areas, and livestock are the primary causes for population fragmentation of wildlife. The distribution range of species of the genus Macaca is constantly decreasing and becoming increasingly fragmented due to forest deterioration. Assamese macaques (M. assamensis) are classified as near threatened in the International Union for Conservation of Nature (IUCN) Red List of Threatened Animals (2008) and have been declared a protected wildlife animal according to Wildlife Preservation and Protection Act, B.E.2535 (1992) of Thailand. As studies of the population history and genetic diversity of Assamese macaques in Thailand are currently lacking, we aimed at a first investigation of their genetic diversity based on mitochondrial DNA [hypervariable regions 1 and 2 (HV1, HV2) and cytochrome B (CYTB) regions], as well as 15 microsatellite markers of five sampling sites distributed across Thailand. Our results indicate that Assamese macaques in Thailand are diverse, with eight maternal haplotypes and a low inbreeding coefficient in the Phu Khieo Wildlife Sanctuary (PKWS) population. Moreover, our phylogenetic and median-joining network analysis based on mitochondrial (mt)DNA suggests a population distribution in accordance with the evolutionary scenario proposed for M. sinica. Today, the population of Assamese macaques is fragmented, and conservation strategies are needed to ensure the maintenance of genetic diversity of this primate species.

Recent research has shown that social relationships may exert positive effects on fitness. Therefore, it is expected that animals make efforts to develop and preserve close social bonds. Reconciliation is a conflict resolution mechanism, which allows buffering the negative effects of aggressive conflict on social relationships. As socioecological theories claim that intrasexual competition and conflict-shaped social interactions among macaque males, postconflict behaviour should reflect the effects of these evolutionary forces. Here, we present the results of a study on a provisioned group of Macaca arctoides in Thailand focusing exclusively on male postconflict behaviour. Through an Information Theory–Model Selection approach, we evaluated the relative support for three predictions about the occurrence of reconciliation and the quality of the opponents' social relationships. The strength of the opponents' affiliative relationship was the only variable predicting reconciliation occurrence. This agrees with the main prediction of the valuable relationship hypothesis for the function and distribution of reconciliation, which states that the opponents sharing high-quality relationships are more likely to reconcile, and this interaction is aimed to repair the disturbing effects of previous aggression on their relationship. The conciliatory tendency found among these wild males is much lower than reported previously for this species from captive conditions, matching more closely the rates reported for species with an intolerant-despotic dominance style. The results offer strong support for the importance of developing and preserving valuable relationships, even among rather intolerant males.

Complex food-processing techniques by gorillas, chimpanzees, and orangutans have allowed comparisons of complex hierarchical cognition between great apes and humans. Here, we analyse preliminary observations of free-ranging long-tailed macaques (Macaca fascicularis) (n = 3) in Thailand processing Opuntia sp. cactus fruits. From our observations, we suggest that there is potential to extend the analyses of hierarchical cognition to Old World monkeys. We found that the macaques used six behavioural sequences to obtain Opuntia fruits, remove irritant hairs from the skin of the fruits, and break open, and consume the fruits, each a unique combination of 17 action elements. Removing irritant hairs involved abrading fruits on a sand or rock substrate, and washing fruit in water. The behavioural sequences that macaques use to process Opuntia potentially show features of hierarchical organisation described in the leaf-processing behaviours of great apes. Our observations highlight the need for closer study of complex food-processing behaviour in monkeys to better understand the organisational capacities involved.

More than 3 million years of excavated archaeological evidence underlies most major insights into the evolution of human behaviour. However, we have seen almost no use of archaeological excavation to similarly broaden our understanding of behaviour in other animal lineages. The few published examples include recovery of a late Holocene assemblage of stones from the Ivory Coast, attributed to the agency of both humans (Homo sapiens) and chimpanzees (Pan troglodytes verus), and exploration of the occupation sites of nontool-using species such as penguins and other birds. The development of viable methods for identifying and interpreting past non-human tool use landscapes is essential if we are to gain a better understanding of technological evolution within other animals, including our close relatives, the primates. Recently, the growth of primate archaeology has built on the close phylogenetic relationship between humans and other primates to begin filling in this lacuna. Here, we present thefirst report on an archaeologically excavated Old World monkey tool use site, which was created by wild Burmese long-tailed macaques (Macaca fascicularis aurea) during shellfish-processing activities in coastal Thailand. These macaques use stone and shell pounding tools to access a wide variety of coastal and inter-tidal resources, including shellfish, crabs and nuts, and previous work has demonstrated that use-wear on the stone tools permits reconstruction of past macaque activities (Haslam et al., 2013). Uncovering the history of this foraging behaviour opens up opportunities to study its evolution within the macaque lineage and, more broadly, to retrieve comparative data for researchers studying human and primate coastal exploitation.

Background White-handed gibbons (Hylobates lar) are small Asian apes known for living in stable territories and producing loud, elaborate vocalizations (songs), often in well-coordinated male/female duets. The female great call, the most conspicuous phrase of the repertoire, has been hypothesized to function in intra-sexual territorial defense. We therefore predicted that characteristics of the great call would correlate with a caller’s physical condition, and thus might honestly reflect resource holding potential (RHP). Because measurement of RHP is virtually impossible for wild animals, we used age as a proxy, hypothesizing that great call climaxes are difficult to produce and maintain over time, and that older adults will therefore perform lower quality great calls than young adults. To test this we analyzed the great call climaxes of 15 wild lar gibbon females at Khao Yai National Park, Thailand and 2 captive females at Leo Conservation Center, Greenwich, CT. Results Findings show that call climaxes correlate with female age, as young animals (n = 8, mean age: 12.9 years) produced climaxes with a higher frequency range (delta F0), maximum F0 frequency and duty cycle than old animals (n = 9, mean age: 29.6 years). A permuted discriminant function analysis also correctly classified calls by age group. During long song bouts the maximum F0 frequency of great call climaxes’ also decreased. Additional data support the hypothesis that short high notes, associated with rapid inhalation as an individual catches its breath, reflect increased caller effort. Older females produced more high notes than younger females, but the difference only approached statistical significance, suggesting that calling effort may be similar across different ages. Finally, for the first time in this species, we measured peak intensity of calls in captive females. They were capable of producing climaxes in excess of 100 dB at close range (2.7 m). Conclusions Age and within-bout differences in the lar gibbon great call climax suggest that call features correlate with physical condition and thus the call may have evolved as an honest signal in the context of intra-sexual territorial defense and possibly also in male mate choice via sexual selection, although further testing of these hypotheses is necessary.

Environmental variables used in the species distribution models and construction of the forest cover layers. Details of the covariate data used are provided together with their source details. The construction and validation of the intact and disturbed forest layers is described in detail. (DOCX 27Â kb)

The 0.025 and 0.975 quantile model predictions, and the top predictors, for each mosquito model. For each mosquito species, complex or group, the 0.025 and 0.975 quantile model outputs, masked out on islands outside each species or complex range, are provided with the mean AUC (Âą standard error) and the relative influence of the top predictors for that model. (DOCX 1331Â kb)

The 0.025 and 0.975 quantile model predictions, and the top predictors, for each macaque species. For each macaque species the 0.025 and 0.975 quantile model outputs, masked out on islands outside each species range, are provided with the mean AUC (Âą standard error) and the relative influence of the top predictors for that species. (DOCX 1183Â kb)

Proportional land cover in areas with high predicted probability of species occurrence. Plots showing the relative density of pixels at each percentage land class coverage for all pixels where the probability of species occurrence was greater than 0.75, for each species. (DOCX 795Â kb)

Distributions of the model input data in space and time. The spatial distributions of the species occurrence data and background data are shown on a series of maps and their temporal distributions are shown by a series of histograms. (DOCX 1584Â kb)

Investigating the impact of using annual land cover data. The model was run using identical datasets and either 1) year-matched land cover data or 2) 2012 land cover data. The resulting distributions are shown with the AUCâ Âąâ standard error, and the top predictors with their relative influences. A map showing the difference between the two resulting distributions is also provided. (DOCX 2977Â kb)

Inter-specific hybrid zones for Hylobates gibbons are known in Southeast Asia. Among these, one hybrid zone between Hylobates lar and H. pileatus is located in Khao Yai National Park, Thailand. To find molecular evidence for the natural hybridization of the gibbons in this region, we studied mitochondrial DNA (mtDNA) of 68 gibbons of the H. lar phenotype living adjacent to the hybrid zone. Nucleotide sequencing of a fragment of mtDNA spanning hyper variable segment I showed that nine gibbons had an mtDNA haplotype of H. pileatus, and that seven of these nine gibbons belonged to a single maternal lineage over three generations. It is thus confirmed that introgression between H. lar and H. pileatus exists and the initial hybridization took place ages ago.

We determined the neurotherapeutic effects of Pueraria mirifica extract (PME) and pure puerarin (PU) in comparison with 17β-estradiol (E2 ) in early- and late-stage cognitive impaired rats. Rats were ovariectomized (OVX), kept for 2 and 4 months to induce early- and late-stage cognitive impairment, respectively, and divided into four groups that were treated daily with (i) distilled water, (ii) 100 mg/kg of PME, (iii) 7 mg/kg of PU, and (iv) 80 µg/kg of E2 for 4 months. The estrogen deficiency symptoms of OVX rats were abrogated by treatment with E2 or PME, but not by treatment with PU. The mRNA level of genes associated with amyloid production (App and Bace1) and hyperphosphorylated Tau (Tau4) were upregulated together with the level of impaired cognition in the 2- and 4-month OVX rats. Treatment with E2 reduced the level of cognitive impairment more than that with PME and PU, and 2-month OVX rats were more responsive than 4-month OVX rats. All treatments down-regulated the Bace1 mRNA level in 2-month OVX rats, while PU and PME also decreased the App mRNA level in 2- and 4-month OVX rats, respectively. Only PU suppressed Tau4 expression in 2-month OVX rats. Thus, PME and PU elicit neurotherapeutic effects in different pathways, and earlier treatment is optimal. Copyright © 2016 John WileySons, Ltd.

In the past decade, many researchers have published papers about hybridization between long-tailed and rhesus macaques. These previous works have proposed unidirectional gene flow with the Isthmus of Kra as the zoogeographical barrier of hybridization. However, these reports analyzed specimens of unknown origin and/or did not include specimens from Thailand, the center of the proposed area of hybridization. Collected specimens of long-tailed and rhesus macaques representing all suspected hybridization areas were examined. Blood samples from four populations each of long-tailed and rhesus macaques inhabiting Thailand, Myanmar, and Laos were collected and analyzed with conspecific references from China (for rhesus macaques) and multiple countries from Sundaic regions (for long-tailed macaques). Ninety-six single nucleotide polymorphism (SNP) markers specifically designed to interrogate admixture and ancestry were used in genotyping. We found genetic admixture maximized at the hybrid zone (15-20°N), as well as admixture signals of varying strength in both directions outside of the hybrid zone. These findings show that the Isthmus of Kra is not a barrier to gene flow from rhesus to long-tailed populations. However, to precisely identify a southernmost barrier, if in fact a boundary rather than simple isolation by distance exists, the samples from peninsular Malaysia must be included in the analysis. Additionally, a long-tailed to rhesus gene flow boundary was found between northern Thailand and Myanmar. Our results suggest that selection of long-tailed and rhesus macaques, the two most commonly used non-human primates for biomedical research, should take into account not only the species identification but also the origin of and genetic admixture within and between the species.

Long-tailed macaques (Macaca fascicularis fascicularis) are widely distributed in Southeast Asia and are morphologically and genetically (Tosi et al. in International Journal of Primatology 23:161–178, 2002) distinguishable on either side of the Isthmus of Kra (ca. 10.5°N). We compared the somatometry and body color of 15 local populations of long-tailed macaques in Thailand distributed over areas from 6.5°N to 16.3°N and also a Thai rhesus macaque population at 17.2°N. Limb proportions and body color variation follow the geographical trend. However, contrary to a previous report, body size does not decrease with latitude in the northern group and also in the southern (southerly distributed) rhesus macaque. Relative tail length (RTL) and color contrast in yellow between the back and thigh are the sole traits that distinctively separate the 2 groups: the southern group has a long relative tail length (RTL >125%) and small color contrast, whereas the northern group has a short RTL (

There is evidence that people discount food more steeply than money, suggest-ing that primary or consumable reinforcers lose value quickly, whereas con-ditioned or nonconsumable reinforcers lose value slowly. In the present study, discounting rates of baht (unstable currency) and rice (preservable food) were compared during a period of unstable economic conditions in Thailand. Delay discounting of 2 amounts of hypothetical money and 2 matched amounts of hypothetical rice were examined. For smaller amounts of rewards, there was no difference in rates of discounting between money and a matched amount of rice. For larger amounts of rewards, however, money was discounted more steeply than a matched amount of rice. It was suggested that the unstable cur-rency might be discounted more severely than a durable good of comparable monetary value in some circumstances.

Stump-tailed macaques (Macaca arctoides) exhibit significant intraspecific variation in pelage color. Based on their pelage color and geographical distribution, they are classified into 2 subspecies: northern bright brown Macaca arctoides arctoides and southern black Macaca arctoides melanota. However, studies on the natural population are extremely scarce, and researchers have occasionally questioned the subspecific classification. We quantitatively examined pelage color variation of Macaca arctoides in 3 free-ranging populations in Thailand. Pelage color difference between populations is significant. The population distributed south of the Isthmus of Kra showed wide intrapopulational variation, including bright brown, dark brown, and completely black, whereas the northern populations primarily had dark brown hairs. Thus, we conclude that one cannot classify the color variants into subspecies. Further, we hypothesize that the distinctive polymorphism in southern Thailand resulted from geographical isolation caused by the Pleistocene eustatic fluctuations and subsequent recovery of land connection and subsequent gene flow.

Objective Effects of Pueraria mirifica on bone loss in fully mature ovariectomized rats are examined. Methods Two series of experiments were performed. In the first series, rats were kept with their ovaries intact and divided into two groups; initial control (IC) and sham control (SH). The IC rats were sacrificed on day 1 and their data were kept as baseline control. The SH rats were subjected to sham operation on day 0 and gavaged daily with distilled water for 90 days. In the second series, rats were subjected to ovariectomy, divided into five groups and gavaged daily with 0.1 mg/kg B.W./day of 17-alpha-ethinylestradiol (EE), 0, 10, 100 and 1000 mg/kg B.W./day of P. mirifica (P0, P10, P100 and P1000, respectively) for 90 days. Changes of bone mineral density and bone mineral content were measured using peripheral Quantitative Computerized Tomography. Results Bone loss was significantly induced by ovariectomy and it was dose-dependently prevented by P. mirifica treatment for 90 days. The preventive effects of P. mirifica on bone loss depended on bone types (axial or long bone), bone sites (metaphysis or diaphysis), and bone compartments (trabecular and cortical). At P100 and P1000, bone loss was completely prevented both in trabecular bone mineral density and content. The effects of P. mirifica were, as expected, comparable to that in the EE group. Conclusion These results suggest that P. mirifica may be applicable to treat the osteoporosis in menopausal women; however, an undesirable side effect on stimulating reproductive organs should be concerned.

We investigated a non-invasive method of specimen collection for determining the changes of reproductive hormones in aged menopausal monkeys after a long-term feeding of the Thai herb Pueraria mirifica (PM) containing phytoestrogens. Three groups of aged menopausal monkeys (n = three in each group) were fed daily with 10, 100, or 1000 mg of PM for a 90 day treatment period, and fed with distilled water for 30 and 60 days of the pre- and post-treatment periods, respectively. Urine samples were collected for 14 h daily every 5 days and assayed for follicle stimulating hormone (FSH), luteinizing hormone (LH) and estradiol levels. The result showed that monkeys fed with PM 10, PM 100, and PM 1000 had a decrease in urinary FSH levels during the treatment period, followed by a rebound increase during the post-treatment period. Urinary estradiol levels tended to decrease and fluctuated between 4.28 and 266.71, 2.85–42.27, and 6.24–203.50% of the pre-treatment levels in those three groups, respectively. Decreases in urinary LH levels could not be observed in all the three groups. These results suggest that FSH could be a candidate marker to detect the estrogenic effects of phytoestrogens in aged menopausal monkeys when changes of urinary hormones need to be used as an indicator.

Objective: Estrogens and estrogen-like substances have been reported to play an important role in male bone homeostasis and to prevent bone loss. Pueraria mirifica (Leguminosae), a Thai herbal plant, containing a high amount of phytoestrogens was a choice of interest for this study. We examined the effects of crude P. mirifica on bone loss and influences on reproductive organs in male rats. Methods: Using fully mature and orchidectomized (ORX) rats, the effects of 0, 10, 100 and 1000 mg/kg B.W./day of P. mirifica and 0.1 mg/kg B.W./day of 17 alpha-ethinylestradiol (a positive control) were evaluated on bone mineral density (BMD) and bone mineral content (BMC) measured with a peripheral Quantitative Computerized Tomography (pQCT) densitometry. Results: Bone loss in trabecular and cortical bones of the various sites of axial bone (fourth lumbar vertebral body) and long bones (tibia and femur) after ORX was dose-dependently prevented by P. mirifica. The effects were specific on bone types and sites. The weights of the accessory sex organs, seminal vesicle and ventral prostrate gland, which significantly decreased after 3-month of ORX, were not altered by P. mirifica. Conclusion: The results suggest that P. mirifica treatment may be useful to prevent an osteoporosis in elderly hypogonadism subjects without influences on reproductive organs. © 2006 Elsevier Ireland Ltd. All rights reserved.

In January and March of 2005, we conducted surveys of long-tailed macaques at Piak Nam Yai Island, Laem Son National Park (9° N 34–35′, 98° E 28′), Ranong Province, situated in southern Thailand. Two of the three troops of long-tailed macaques found on the island were observed using axe-shaped stones to crack rock oysters, detached gastropods (Thais tissoti, Petit, 1852), bivalves (Gafrarium divaricatum, Gmelin, 1791), and swimming crabs (Thalamita danae, Stimpson, 1858). They smashed the shells with stones that were held in either the left or right hand, while using the opposite hand to gather the oyster meat. Some monkeys used both hands to handle the stones. According to Matsuzawa's 1996 hierarchical classification of tool usage (levels 0–3), the tool usage by Thai long-tailed macaques could be characterized as either level 1 (cracking rock oysters with stones) or level 2 (cracking drifting mollusks and crabs with stones by placing them on a rock). Our discovery of stone-tool usage by Thai long-tailed macaques provides a new point of reference for discussions regarding the evolution of tool usage and the material culture of primates. Am. J. Primatol. 69:1–7, 2007. © 2006 Wiley-Liss, Inc.

This study investigated the changes in the urinary hormone levels of female monkeys (Macaca fascicularis) after single-dose and long-term treatments with Pueraria mirifica (PM). The monkeys were separated into 3 groups (n=3) and orally treated with 10, 100, or 1,000 mg of PM in each group. Two series of experiments were performed. In the first series of experiments, the monkeys were orally treated with a single dose of PM. The experimental schedule was divided into a one menstrual cycle pretreatment period and a two menstrual cycle post-treatment period. In the second series of experiments, the monkeys were orally treated daily with PM for 90 days. The experiment schedule was divided into a one menstrual cycle pretreatment period, a three menstrual cycle treatment period, and a two menstrual cycle post-treatment period. Urinary samples were collected daily and assayed for the FSH, LH, estradiol, and progesterone levels. The results showed that there were no changes in the FSH, LH, estradiol, and progesterone levels after treatment with a single dose of 10, 100, or 1,000 mg of PM or after daily treatment with 10 mg of PM for 90 days compared with the levels observed during the pretreatment period. Daily treatment with 100 mg and 1,000 mg of PM for 90 days only produced a clear reduction in the urinary FSH levels. This suggests that changes of urinary FSH levels can be considered an indicator for study of estrogenic effects on hormonal levels in female monkeys.

Long-tailed macaques in Lopburi, Thailand, use human hair as if it were dental floss. This eccentric behavior is seen mainly in a large group of macaques that live at the old Buddhist shrine of Prang Sam Yot. Many monkeys of this group take hair and sort a few pieces to make a string and then brush their teeth by pulling it tightly with right and left hands alternatively between their teeth. This habit is not seen in the other localities near Lopburi and is rare even in the surrounding groups. Monkeys in the Prang Sam Yot shrine are worshipped as servants of God and people respect them, even when they ride on their heads. This behavior could be considered a newly occurring cultural behavior, which has become established under very specialized circumstances.

Macaca fascicularis aurea (Mfa) is the only macaque which has been recorded to use stone tools to access encased foods. They live in close contact with M. fascicularis fascicularis (Mff) in southwestern Thailand and the hybrids were reported [Fooden, 1995]. Although Mff and Mfa can be seen in the same habitat types, tool-use behavior has never been reported in Mff. Thus, comparing the morphological characteristics and genetics between Mfa and Mff should help elucidate not only the morphological differences and genetic divergence between these subspecies but also potentially the relationship between genetics and their tool use behavior. We surveyed Mfa and Mff in Myanmar and Thailand, ranging from 16° 58' to 7° 12' N. Fecal or blood samples were collected from eight, five, and four populations of Mfa, Mff, and Mff × Mfa morphological hybrids along with three individuals of captive Chinese M. mulatta (Mm), respectively, for mtDNA and Y-chromosome (TSPY and SRY genes) DNA sequence analyses. In addition, eight populations were captured and measured for 38 somatometric dimensions. Comparison of the somatic measurements revealed that Mfa had a statistically significantly shorter tail than Mff (P 0.05). Based on the mtDNA sequences, Mfa was separated from the Mm/Mff clade. Within the Mfa clade, the mainland Myanmar population was separate from the Mergui Archipelago and Thailand Andaman seacoast populations. All the morphological hybrids had the Mff mtDNA haplotype. Based on the Y-chromosome sequences, the three major clades of Mm/Indochinese Mff, Sundaic Mff, and Mfa were constructed. The hybrid populations grouped either with the Mm/Indochinese Mff or with the Mfa. Regarding the genetic analysis, one subspecies hybrid population in Thailand (KRI) elicited tool use behavior, thus the potential role of genetics in tool use behavior is raised in addition to the environmental force, morphological suitability, and cognitive capability. Am. J. Primatol. 78:441-455, 2016. © 2015 Wiley Periodicals, Inc.

Rhesus (Macaca mulatta) and long-tailed (M. fascicularis) macaques belong to the same species, and are parapatric within a zone that lies between 15° and 20° N on the Indochinese peninsula. Researchers have reported probable hybrids between the 2 species from that zone, but have not studied the extent of introgression. To test for phenotypic evidence of hybridization, we collected body mass, morphometrics (body size and proportions), and pelage color readings from free-ranging rhesus living close to the zonal boundary at Wat Tham Pa Mak Ho (WTPMH), Wang Saphun district, Loei province, northeastern Thailand (17°14′N, 101°47′E). Female WTPMH rhesus macaques (n =12) were 10–20% smaller, but with a greater relative tail length than the captive Chinese or Indian female rhesus. Female WTPMH were larger than the free-ranging long-tailed macaques, but with similar limb proportions and a shorter relative tail length. The WTPMH rhesus macaques also displayed the bipartite pelage color pattern typical of Macaca mulatta . The evidence suggests slight contribution of long-tailed macaques to the gene pool of the WTPMH population. Further sampling of other macaque populations within the zone and genetic analysis are essential to address better the question of hybridization. Determination of the distribution and range of biobehavioral variation of macaques within the zone is urgently needed, because their habitat is being rapidly destroyed by deforestation, and their demography and social structure are threatened by artificial disturbance.

We investigated the effect of Pueraria mirifica (PM) on gonadotrophin and estradiol levels in aged animals; nine menopausal cynomolgus monkeys were divided into three groups. Each group (n = 3) was fed with 10, 100, and 1000 mg/d of PM for 90 d. PM-10 induced the decrease of follicle stimulating hormone (FSH) levels on d 15-90 in one out of three monkeys. PM-100 and PM-1000 decreased FSH levels of all monkeys throughout the treatment period. After the treatment period, FSH levels continued to decrease for 5 and 10-20 d in PM-100 and PM-1000, respectively, and the levels rebounded in all groups thereafter. PM-10 decreased luteinizing hormone (LH) levels throughout the treatment period in one out of three monkeys and returned to the pretreatment levels immediately after stopping treatment. PM-100 and PM-1000 prominently decreased LH levels between d 10 and 90 during treatment and persisted until d 15-25 and d 20-30 for PM-100 and PM-1000, respectively, during the post-treatment period. Serum LH levels rebounded after returning to pre-treatment levels in a dose-dependent manner. Estradiol levels tended to decrease during the treatment period in all groups. The daily feeding of PM suppressed gonadotrophin levels in aged menopausal monkeys based on dose. Moreover, they can be recovered, and there is a direct correlation between dosage and recovery time. PM may be effective as an alternative medicine in menopausal women because the effects are not permanent.

To investigate the estrogenic effect of Pueraria mirifica (PM), a Thai herbal plant that contains many phytoestrogens, sexual skin coloration was studied in cynomolgus monkeys. Aged menopausal monkeys were divided into three groups. Each group (n=3) was fed 10, 100, or 1,000 mg of PM daily. The treatment schedule was divided into three periods, a 30-day pre-treatment period, 90-day treatment period, and 60-day post-treatment period. The results show that the sexual skin exhibited reddish coloration within 24 h after PM-treatment and remained this way for the first half of the PM-feeding period. The changes in sexual skin coloration were not dose-dependent. The present results indicate that PM had estrogenic action by increasing reddish sexual skin coloration in aged menopausal monkeys.

The effects of Pueraria mirifica (PM) on reproductive organs and fertility of adult male mice were investigated. Male mice were divided into four groups (10 mice/group). Groups 1-3 were orally treated with PM at doses of 0 (PM-0), 10 (PM-10), and 100 (PM-100) mg/kg BW/d in 0.2 mL distilled water, and group 4 was subcutaneously injected with 200 microg/kg BW/d of synthetic estrogen diesthylstilbestol (DES). The treatment schedule was separated into two periods: treatment and posttreatment (8 wk for each period). The PM-10 and PM-100 treatments had no effect on testicular weight, sperm number, and serum LH, FSH, and testosterone levels. Only the PM-100 treatment reduced weights of epididymes and seminal vesicle and the sperm motility and viability. Histopathological examination demonstrated that testis, epididymis, and seminal vesicle were normal in all doses of PM treatment. PM-treated males showed no alterations in mating efficiency and on causing pregnancy of their female partners. DES injection impaired all those parameters. Offspring fathered by the PM- and DES-treated males exhibited neither malformations nor change of body weight gains, and the reproductive organ weights of 50-d old pups were in the normal range. The present data clearly demonstrate that a long-term treatment of PM at doses 10 and 100 mg/kg BW/d, via oral route, does not alter a male fertility and a hypothalamus- pituitary-testis axis. Although PM-100 can cause some moderate impairment, no persistent effects were observed. Most of PM-treated mice increased the mating efficiency after stop treatment.

Pueraria mirifica (PM), a Thai herb containing phytoestrogens, may act as estrogen and disturb reproduction. To investigate the effect of PM on the menstrual cycle length and related hormones, nine adult female monkeys (Macaca fascicularis) were separated into three groups. Each group (n=3) was fed with 10, 100, and 1000 mg/d of PM for three menstrual cycles. The menstrual cycle length increased significantly in monkeys treated with PM-10 and PM-100 and disappeared completely in monkeys treated with PM-1000. Serum follicle stimulating hormone, luteinizing hormone, estradiol, progesterone, and ir-inhibin were lower during the treatment period in a dose-dependent manner. Changes in menstrual cycle length and the hormonal levels recovered during the post-treatment period only in monkeys treated with PM-10 and PM-100. PM greatly influences menstrual cycles and may suppress ovulation by lowering serum levels of gonadotropins.

To determine the effect of Pueraria mirifica (PM) on serum parathyroid hormone (PTH) and calcium levels on aged menopausal monkeys (Macaca fascicularis), subjects were treated with 10, 100, or 1,000 mg/day of PM. Blood samples were collected every 5 days for 30, 90, and 60 days during pre-treatment, treatment, and post-treatment periods, respectively. Sera were assayed for PTH, estradiol, and calcium levels. PM-1,000 had the strongest effect on the decrease in PTH (0.001

This study investigated the estrogenic effect of Pueraria mirifica (P. mirifica) on menstrual cycle length and hormone-related ovarian function. Nine normal cyclic monkeys (Macaca fascicularis) were separated into 3 groups; each group was force fed with a single dose of 10, 100, and 1,000 mg of P. mirifica. The experimental schedule was separated into the pre-treatment and post-treatment periods. Blood samples were collected on days 3, 9 – 14, 19, 24, 29, and every 10 days until the next menstruation for one and two menstrual cycles during two consecutive periods and assayed for serum levels of gonadotropins and ovarian hormones. The result showed a significant increase in lengths of the follicular phase and total menstrual cycle in monkeys treated with 1,000 mg of P. mirifica, but no change in menstrual cycle length in monkeys treated with 10 and 100 mg of P. mirifica. Serum levels of follicle stimulating hormone, luteinizing hormone, estradiol, progesterone, or immunoreactive-inhibin did not change during the first and second menstrual cycles of the post-treatment period for all monkey groups. Our findings demonstrate that although changes in hormonal levels could not be observed in this study, a single dose of 1,000 mg of P. mirifica can disturb ovarian function and menstrual cycle in monkeys. Keywords:: Pueraria mirifica, phytoestrogen, monkey, reproductive hormone, menstrual cycle

We report here the preliminary results of studies on the distribution and status of five macaque species in Thailand. The latter lies in the center of the Indochinese Peninsula and is an important biogeographical region in SE Asia. We are conducting surveys through out Thailand in the order of questionnaire, census, and capture-and-release fieldwork where feasible. We have determined seven localities of stump-tailed macaques (M. arctoides); 36 localities of long-tailed macaques (M. fascicularis); eight localities of rhesus macaques (M. mulatta); six localities of assamese macaques (M. assamensis); and two localities of pig-tailed macaques (M. nemestrina leonina). Long-tailed and rhesus macaques belong to the same species-group, and are generally distributed allopatrically. The boundary between the two species in NE Thailand appears to lie close to latitude of 16oN. The phenotypic (pelage color and relative tail-length) and genetic characters (mtDNA and TSPY locus) of rhesus macaques resident in the area supposed close to the boundary have been analyzed; the results support the "Hybridization hypothesis" by Fooden ([2000], Fieldiana Zoology 96: 1-180). Troops of long-tailed macaques in Thailand, although their numbers sometimes exceed 1,000 animals, are isolated from other conspecifics. In addition, the genetic disturbance (pollution) introduced by artificial means, e.g., the breeding of released pets and human transfer of macaque troops threatens the innate biodiversity of the Thai macaque species.

Nucleotide sequences of the parathyroid (PTH) gene of 12 species of primates belonging to suborder Anthropoidea were examined. The PTH gene contains one intron that separates two exons that code the sequence of prepro and PTH, respectively. The intron of the PTH gene in Cebus apella, Callithrix jacchus, and Saguinus oedipus was 102 bp long, whereas a 103-bp intron was observed in the remaining species. Phylogenetic analysis using the nucleotide sequences of PTH revealed that these 12 species of primates of suborder Anthropoidea could be divided into two groups of the infraorder Platyrrhini (C. apella, C. jacchus, and S. oedipus) and the infraorder Catarrhini (Macaca fascicularis, Macaca fuscata, Cercopithecus aethiops, Papio hamadryas, Presbytes obscura, Hylobates lar, Pongo pygmaeus, Pan troglodytes, and Pan paniscus). The latter infraorder could be further subdivided into two subgroups belonging to the superfamily Cercopithecoidea (M. fascicularis, M. fuscata, C. aethiops, P. hamadryas, and P. obscura) and the superfamily Hominoidea (H. lar, P. pygmaeus, P. troglodytes, and P. paniscus). The deduced amino acid sequences of PTH gene between 12 species of nonhuman primates and human revealed no amino acid substitution in mature PTH among orangutans, chimpanzees, and humans. The results indicated that the PTH gene is very conserved among primates, especially between great apes and humans. The apes are the most suitable animals to be used for studying the bone metabolism and applying the knowledge to clinical use in humans.

Nut-cracking is shared by all non-human primate taxa that are known to habitually use percussive stone tools in the wild: robust capuchins (Sapajus spp.), western chimpanzees (Pan troglodytes verus), and Burmese long-tailed macaques (Macaca fascicularis aurea). Despite opportunistically processing nuts, Burmese long-tailed macaques predominantly use stone tools to process mollusks in coastal environments. Here, we present the first comprehensive survey of sea almond (Terminalia catappa) nut-cracking sites created by macaques. We mapped T. catappa trees and nut-cracking sites that we encountered along the intertidal zone and forest border on the coasts of Piak Nam Yai Island, Thailand. For each nut-cracking site, we measured the physical properties (i.e., size, weight, use-wear) of hammer stones and anvils. We found that T. catappa trees and nut-cracking sites primarily occurred on the western coast facing the open sea, and cracking sites clusters around the trees. We confirmed previous results that nut cracking tools are among the heaviest tools used by long-tailed macaques; however, we found our sample of T. catappa stone tools lighter than a previously collected sea almond sample that, unlike our sample, was collected immediately after use within the intertidal zone. The difference was likely the result of tidal influences on tool-use sites. We also found that tool accumulations above the intertidal region do not resemble those within them, possibly leading to incomplete assessments of macaque stone tools through archaeological techniques that would use these durable sites.

The estrogenic efficacy of topical vaginal application of Pueraria mirifica extract (PM) on the restoration of vaginal atrophy, and the presence of any systemic side effects, were investigated in postmenopausal cynomolgus macaques. Twelve postmenopausal cynomolgus macaques, with complete cessation of menstruation for at least 5 years before start of this experiment, were divided into three groups. They received a topical vaginal application daily of 0.1 or 1% (w/w) PM cream or a conjugated equine estrogen (CEE) cream (a mixture of estrone, equilin, 17β-dihydroequilin, 17α-estradiol and 17α-dihydroequilin at 0.625 mg total estrogen/g cream) for 28 days. Estrogenic efficacy was assessed weekly by vaginal cytology assay and vaginal pH measurement, whilst the plasma luteinizing hormone (LH) and sex skin coloration levels were determined at the end of each treatment period to evaluate the systemic side effects. PM significantly increased the proportion of superficial cells in a dose-dependent manner, with a similar efficacy between 1% (w/w) PM and CEE. Together with increased vaginal maturation, PM decreased the vaginal pH to acidic levels, as observed in the CEE group. PM induced no detected systemic side effects, whilst CEE decreased the plasma LH level and increased the reddish color of the sex skin during the posttreatment period. Topical vaginal treatment with PM stimulated the maturation of the vaginal epithelium without causing systemic side effects in postmenopausal monkeys. The implication is that PM could be a safer alternative to treat vaginal atrophy in postmenopausal women.

We evaluated the effect of a daily injection of morphine hydrochloride on galactorrhea in male cynomolgus monkeys. Three groups of three monkeys (nine total) were used. The treatment schedule was separated into three periods: pre-treatment, treatment, and post-treatment. Each group of monkeys was subcutaneously injected daily with 1.5, 3.0, or 6.0 mg/kg (monkey weight) of morphine for 74-130 days, respectively, during the treatment period, and with saline during the pre-treatment and post-treatment periods. We then measured the prolactin (PRL) and testosterone (T) levels from weekly blood samples that were taken 20 hours after injection. No statistically significant differences in either the PRL or T level were detected throughout the treatment period. However, monkeys treated with 3.0 and 6.0 mg/kg/day showed a decrease in T level and an increase in PRL level during the early post-treatment period. Seven of the nine monkeys produced a milk-like secretion from their mammary gland (a symptom of galactorrhea) during the treatment and post-treatment periods. For several months of post-treatment period (average 6.75 months), we monitored the time-course changes in PRL and T levels in all monkeys for 10 hours after a single injection of morphine at the same dose given during the treatment period. Morphine induced a sudden increase in the PRL level (peaked within 30 minutes) and a gradual decrease in the T level (leveled off within 6.5-10 hours), and then returned to basal levels. These results indicate that morphine does not cause a long-term effect on hormonal changes and that a morphine-induced transient rise in PRL levels accompanied by a decrease in T levels can induce spontaneous galactorrhea in male cynomolgus monkeys.

Knowledge of the genetic mating system of animal species is essential for our understanding of the evolution of social systems and individual reproductive strategies. In recent years, genetic methods have uncovered an unexpected diversity of paternal genetic contributions across diverse animal social mating systems, but particularly in pair-living species. In most pair-living birds, for example, genetic and behavioral observations have confirmed a previously unknown significance of extra-pair copulations (EPCs) and extra-pair paternity. Among mammals, white-handed gibbons (Hylobates lar) are also known to live in pairs and are traditionally believed to be single-male single-female breeders. However, at Khao Yai National Park, Thailand, behavioral observations have confirmed the occurrence of both EPCs and functional multi-male grouping, but knowledge about the genetic mating system is still unavailable. In this study, we genotyped 89 white-handed gibbons of the Khao Yai population based on fecal samplings and were able to determine paternity for 41 offspring through short tandem repeat analysis. We found that females' stable social partners sired the majority (90.5%) of offspring (N = 38), while only a few (7.1%) offspring (n = 2 confirmed cases; n = 1 inferred case) were conceived with extra-pair partners. The paternity of one offspring remained inconclusive (2.4%), because the offspring's genotype did not mismatch with the genotypes of two potential sires. Like other predominantly pair-living species, gibbons appear to follow a mixed-reproductive strategy. The genetic mating system of wild white-handed gibbons is best described as flexible, primarily monogamous and opportunistically promiscuous. Inc.

Knowledge of the genetic mating system of animal species is essential for our understanding of the evolution of social systems and individual reproductive strategies. In recent years, genetic methods have uncovered an unexpected diversity of paternal genetic contributions across diverse animal social mating systems, but particularly in pair-living species. In most pair-living birds, for example, genetic and behavioral observations have confirmed a previously unknown significance of extra-pair copulations (EPCs) and extra-pair paternity. Among mammals, white-handed gibbons (Hylobates lar) are also known to live in pairs and are traditionally believed to be single-male single-female breeders. However, at Khao Yai National Park, Thailand, behavioral observations have confirmed the occurrence of both EPCs and functional multi-male grouping, but knowledge about the genetic mating system is still unavailable. In this study, we genotyped 89 white-handed gibbons of the Khao Yai population based on fecal samplings and were able to determine paternity for 41 offspring through short tandem repeat analysis. We found that females' stable social partners sired the majority (90.5%) of offspring (N = 38), while only a few (7.1%) offspring (n = 2 confirmed cases; n = 1 inferred case) were conceived with extra-pair partners. The paternity of one offspring remained inconclusive (2.4%), because the offspring's genotype did not mismatch with the genotypes of two potential sires. Like other predominantly pair-living species, gibbons appear to follow a mixed-reproductive strategy. The genetic mating system of wild white-handed gibbons is best described as flexible, primarily monogamous and opportunistically promiscuous. Inc.

We compared three in vivo assays, determining changes of body weight, and uterotropic and vaginal cytology assays, for the evaluation of estrogenic activity of an estrogen disrupting compound, Pueraria mirifica (PM), in comparison with 17β-estradiol (E). Female rats were ovariectomized and gavaged with distilled water, 0.01, 0.1, 1, 10 and 20 mg/kg BW/day of E and 100 and 1,000 mg/kg BW/day of PM for 14 days. Body weights were measured weekly, and vaginal epithelium cells were monitored daily. The uterus was dissected at the end of the treatment period, weighed and examined for histomorphometry. There were a decrease in body weight and an increase in uterine weight, uterine, endometrium and myometrium areas, uterine gland numbers, and percent of cornified cell which were dependent on doses of E and PM treatments. Of the three assays proposed, although all are reliable and had critical read-out, measurements of body and uterine weights is likely convenient and simple, but the uterotropic assay needs to kill the animals. Vaginal cytology assay appears most promising for sensitivity and shortening the duration of the assay. Compared to those of E, the estrogenic activity of PM at concentrations of 100 and 1,000 mg/kg BW was in the range of 14 to >20 mg/kg BW.

Animal traditions can affect survival by improving how individuals use their environment. They are inherited through social learning and are restricted to small subpopulations. As a result, traditions are rare and their preservation needs to be considered in biodiversity conservation. We studied Burmese long-tailed macaquesMacaca fascicularis aurealiving on Piak Nam Yai Island in Laem Son National Park, Thailand, which maintain a rare stone tool-using tradition for processing hard-shelled invertebrate prey along the island's shores. We found the population had 192 individuals in nine groups and most individuals used stone tools. This population is under pressure from the local human community through the development of farms and release of domestic dogsCanis familiarisonto the island. The level of anthropogenic impact varied in each macaque groups' range and juvenile–infant composition varied with impact. The proportion of young was smaller in groups overlapping farms and was negatively correlated with the amount of dog activity in their range. We also found that coastal use by macaques was negatively related to living near plantations and that the dogs displaced macaques from the shores in 93% of their encounters. We conclude that human impact is negatively affecting Piak Nam Yai's macaques and are concerned this could disrupt the persistence of their stone-use tradition. we discuss the impact and the potential consequences, and we recommend better protection of coastal areas within Laem Son National Park.

Macaca fascicularis fascicularis is distributed over a wide area of Southeast Asia. Thailand is located at the center of their distribution range and is the bridge connecting the two biogeographic regions of Indochina and Sunda. However, only a few genetic studies have explored the macaques in this region. To shed some light on the evolutionary history of M. f. fascicularis, including hybridization with M. mulatta, M. f. fascicularis and M. mulatta samples of known origins throughout Thailand and the vicinity were analyzed by molecular phylogenetics using mitochondrial DNA (mtDNA), including the hypervariable region 1, and Y-chromosomal DNA, including SRY and TSPY genes. The mtDNA phylogenetic analysis divided M. f. fascicularis into five subclades (Insular Indonesia, Sundaic Thai Gulf, Vietnam, Sundaic Andaman sea coast, and Indochina) and revealed genetic differentiation between the two sides of the Thai peninsula, which had previously been reported as a single group of Malay peninsular macaques. From the estimated divergence time of the Sundaic Andaman sea coast subclade, it is proposed that after M. f. fascicularis dispersed throughout Southeast Asia, some populations on the south-easternmost Indochina (eastern Thailand, southern Cambodia and southern Vietnam at the present time) migrated south-westwards across the land bridge, which was exposed during the glacial period of the late Pleistocene epoch, to the southernmost Thailand/northern peninsular Malaysia. Then, some of them migrated north and south to colonize the Thai Andaman sea coast and northern Sumatra, respectively. The SRY-TSPY phylogenetic analysis suggested that male-mediated gene flow from M. mulatta southward to M. f. fascicularis was restricted south of, but close to, the Isthmus of Kra. There was a strong impact of the geographical factors in Thailand, such as the Isthmus of Kra, Nakhon Si Thammarat, and Phuket ranges and Sundaland, on M. f. fascicularis biogeography and their hybridization with M. mulatta.

This study aims to delineate the relationship among estrogen deficiency, neurodegeneration, and cognitive impairment of ovariectomized rats. Female Sprague-Dawley rats were ovariectomized and euthanized after 1-4 month periods (M(0)-M(4) groups). Blood samples were collected for the determination of serum levels of 17β-estradiol (E(2)), luteinizing hormone (LH), and follicle stimulating hormone (FSH). Five consecutive days before the euthanization, cognitive performance of the rats was examined by Morris water maze test. After euthanization, the hippocampus was collected, and expression of the genes associated with amyloid plaques (App, Adam10 and Bace1) and neurofibrillary tangles (Tau4 and Tau3) were examined by real-time PCR. Serum E(2) levels were declined following 2 weeks of ovariectomy. Conversely, serum FSH and LH levels were profoundly increased by 2 weeks of ovariectomy for approximately 4 and 22 times, respectively. Cognitive impairments, indicated by the longer latency and distance, were observed only in the M(3) and M(4) groups. The Tau4 mRNA levels were significantly increased as early as 1 month after ovariectomy (in the M(1) group; P0.05), and tended to be increased further with the advancing time. Similarly, the Tau3 mRNA levels were increased by ovariectomy, but with the highest level in the M(1) group, and decreased thereafter. The mRNA levels of App, Adam10 and Bace1 were increased by ovariectomy, but significant differences were observed only in the M(4) group. These results indicate that estrogen deficiency can induce a sequence of events that results in the production of neurofibrillary tangles, amyloid deposition, and spatial memory deficit in rats.

Long-tailed macaques (Macaca fascicularis) feed opportunistically in many habitats. The Burmese subspecies (M. f. aurea) inhabits coastal areas in southwestern Thailand and Myanmar, and some of their populations have adapted lithic customs for processing encased foods in intertidal habitats. We investigated the diet of such macaques in Laemson National Park, Thailand, and identified the variety of foods they processed with stones. We conducted 36 shore surveys to study tool sites following feeding activity, during which we counted the minimum number of individual (MNI) food items found at each site. We identified 47 food species (43 animals and four plants), from 37 genera. We counted 1,991 food items during surveys. Nearly all were mollusks (n = 1,924), with the small remainder primarily consisting of crustaceans and nuts. The two most common foods, rock oysters (Saccostrea cucullata; n = 1,062) and nerite snails (Nerita spp.; n = 538), composed 80.2% of our sample. Four prey species comprised 83.2% of the sample (MNI = 1,656), S. cucullata (n = 1,062), Nerita chamaeleon (n = 419), Thais bitubercularis (n = 95), and Monodonta labio (n = 80). Macaques selected a wide variety of foods. However, they heavily concentrated on those that were abundant, easy to access, and sufficiently sized. The Burmese long-tailed macaque stone-processed diet, which focuses on intertidal marine prey, differs from Sapajus and Pan, who use stones primarily for encased nuts and fruits. In terms of diversity of foods exploited, coastal stone-based predation by macaques resembles the diet of coastal-foraging humans (Homo sapiens sapiens). Am J Phys Anthropol, 2012.

Phytoestrogens have attracted attention for their potential in the prevention of postmenopausal osteoporosis. Recently, phytoestrogen-rich herb Pueraria mirifica has been demonstrated to possess an osteogenic effect on bone in ovariectomized rats, but its underlying cellular mechanism was not known. Here, we investigated the effects of P. mirifica extract and its major isoflavone compound, puerarin, on cell viability, cell proliferation and the expression of differentiation markers in rat osteoblast-like UMR106 cells. After exposure to 17β-estradiol (E2), genistein, P. mirifica extract and puerarin, proliferation but not viability of UMR106 cells was markedly decreased. Quantitative real-time PCR revealed that P. mirifica extract and puerarin significantly increased the mRNA expression of alkaline phosphatase (ALP) and osteoprotegerin, but not Runx2, osterix or osteocalcin. Puerarin also decreased the mRNA expression of receptor activator of nuclear factor-κB ligand, an osteoclastogenic factor, suggesting that it could induce bone gain by enhancing osteoblast differentiation and suppressing osteoclast function. Furthermore, after an exposure to high affinity estrogen receptor (ER) antagonist (ICI182780), the E2-, genistein-, P. mirifica extract- and puerarin-induced upregulation of ALP expressions were completely abolished. It could be concluded that P. mirifica extract and puerarin induced osteoblast differentiation rather than osteoblast proliferation in an ER-dependent manner. The present findings, therefore, corroborated the potential benefit of P. mirifica extract and puerarin in the prevention and treatment of postmenopausal osteoporosis.

Stephania venosa Spreng is a traditional herb which has been used for cancer treatment as well as an aphrodisiac. The scientific literature strongly supports its in vitro antiproliferative effects on cancer cell lines and has suggested developing this plant as a potential anticancer drug. However, the in vivo steroidogenic activity and toxicity of this plant have never been tested. We analyzed the levels of five key isoflavones in the plant extract by quantitative HPLC and then evaluated the in vivo estrogenic activity and toxicity in ovariectomized rats, in comparison with the phytoestrogen-rich plant, Pueraria mirifica. Twenty rats were first ovariectomized, and then seven days later divided into four groups and gavaged daily with 0, 10 and 100 mg/kg body weight/day of S. venosa, or 100 mg/kg body weight/day of P. mirifica for 28 days. A trace amount of puerarin, daidzin and daidzein with a subtle amount of genistein and genistin were isolated from the S. venosa tuber extract. S. venosa tuber powder, at both doses, did not exhibit any detectable estrogenic activity in ovariectomized rats, as assessed by the vaginal cytology and uterotropic assays, whilst P. mirifica induced a remarkable vaginal and uterine proliferation. S. venosa induced a toxicological effect on the hematological values and histopathological appearance of metabolic organs. Taken together, these results suggest that S. venosa has no discernable estrogenic activity but that it is toxic, at least to ovariectomized rats. Thus, the use of this plant for anticancer treatment needs to be reassessed or used with caution.