Tropical Asia Research Articles

The influence of climate change on the sesame yield in North Gondar, North Ethiopia: Application Autoregressive Distributed Lag (ARDL) time series model

Sesame is a major annual oil crop that is grown practically everywhere in tropical and subtropical Asia, as well as Africa, for its very nutritious and tasty seeds. Rising temperatures, droughts, floods, desertification, and weather all have a significant impact on agricultural production, particularly in developing countries like Ethiopia. Therefore, the main objective of this study is to examine the influence of climate change on the sesame yield in North Gondar, North Ethiopia, by using the autoregressive distributed Lag (ARDL) time series model. This study employed climate data from the Bahirdar Agrometeorological Center and secondary data on sesame production from the Ethiopian Statistical Service, spanning 36 years, from 1987 to 2023. Autoregressive Distributed LAG (ARDL) includes diagnostic tests for both short- and long-term autoregressive models. The results for the long-run and short-run elastic coefficients show a significant positive association between temperatures and sesame yield. Sesame yield and rainfall have a significant negative long-run and short-run relationship in North Gondar, North Ethiopia. ARDL results confirm that temperature and rainfall have significant effects on sesame productivity. Temperature had a considerable favorable effect on sesamen production, but rainfall had a negative effect in North Gondar, Ethiopia. Based on the evidence acquired from our study, we made several policy recommendations and suggestions to government officials, policymakers, new technologies, researchers, policy development planners, and other stakeholders in order to develop or implement new technology to halt its production and direct adaptation measures in light of the certainty of global warming and the characteristics of climate-dependent agricultural production.

Water and development in the Asian tropics, 1900–1939

AbstractEnvironmental conditions significantly affected development in the Asian tropics. This paper investigates the relationship between weather risk and agriculture in four regions with distinct climatological features. Using new data, we estimate the scale of crop output sensitivity to rainfall shocks across ecological zones. Output was sensitive to shocks in regions with low levels, concentrated spells and high volatility of rainfall. Canal irrigation protected some districts while unirrigated regions remained vulnerable. Regions with high rainfall levels and long seasons remained protected. Regions with large interruptions deterred investment and were underdeveloped while regions with small interruptions invited investment‐led growth.

Biphyly of the genus Wendlandia and establishment of a new tribe Clavistigmateae and a new genus Clavistigma of Rubiaceae from Asia

AbstractWendlandia, as currently circumscribed, is a genus of Rubiaceae comprising about 90 species mainly in tropical and subtropical Asia. By sampling species from all four series (Clavigerae, Euexsertae, Montigenae, Subinclusae) and all tribes in the subfamily Dialypetalanthoideae, we examined the monophyly of Wendlandia based on phylogenetic reconstruction using the nuclear ribosomal internal transcribed spacer and four plastid DNA regions. Wendlandia was resolved as biphyletic, consisting of two distantly related lineages that correspond to the monotypic series Clavigerae (Wendlandia pendula), sister to the Chinese endemic genus Trailliaedoxa, and a clade containing the remainder sampled members of Wendlandia. Based on the isolated phylogenetic position of W. pendula and its unique morphological characteristics compared to the recognized tribes of the Vanguerieae alliance, we herein erect a new monotypic genus, Clavistigma, and a new tribe, Clavistigmateae to accommodate the unique species. The secondary pollen presentation and the unique seed morphology were firstly described for the species. The divergence time between Clavistigma and Trailliaedoxa was dated back to 13.8 mya, coinciding with the climate change in northwestern Yunnan driven by the uplift Tibet Plateau and the river incision in the Hengduan Mountains during the Miocene and Late Pliocene.

Antibacterial Activity of lemongrass plant (Cymbopogan citratus) against pathogens

From the traditional health care system, we use plants as a good source of medicine/drugs. They have been an essential part of traditional health care system as cure or food supplements. Lemon grass (Cymbopogon Flexuosus and Cymbopogon Citratus) is a native aromatic tall sedge/grass belonging to family (Poaceae / Gramineae) with diverse medicinal value and grown in many parts of tropical and subtropical south east Asia and Africa. It was grown in India a century back and now commercially cultivated in different parts of India (Jharkhand, Bihar, UP). The oil has been found to possess bactericidal, anti-bacterial and anti-fungal properties comparable to Penicillin in its effectiveness. The purpose of study was to find the antibacterial activities of the lemongrass plant Cymbopogon citratus. The crushed leaves of selected plant were extracted with methanol and solvent extracts were evaporated for dryness with help of rotary Incubator. Remaining dry residue was dissolved in (E- Ethanol, Cl- Chloroform, A- Acetone, C- Control) and the leaf sample in four different solvents was applied for its antibacterial action. The antibacterial screening of the selected extracts was determined by the Kirby-Bauer’s Disc diffusion technique on the following bacteria- Pseudomonas aeruginosa and Bacillus subtilis. The maximum zone of inhibitions was noted with solvent ethanol (11mm) against plate 1(Pseudomonas aeruginosa) and 12mm against plate 2(Bacillus subtilis). The sample dissolved in ethanol showed the maximum zone of inhibition followed by chloroform and least with acetone against both the pathogens.

GEOGRAPHICAL DESCRIPTION AND PHARMACOLOGICAL PROPERTIES OF DICHANTHIUM ANNULATUM: A REVIEW

Dichanthium annulatum herb belongs to Poaceae family; also referred to as marvel grass. It grows to a height of about 25cm. Due to its straightforward and affordable development from seed, it is used as forage. The present review was based on the geographical description and pharmacological properties of dichanthium annulatum. It is indigenous to regions of Africa, the Middle East, and tropical Asia. It has been brought to many different regions of the world for cultivation, and in some, like Australia, it has established itself as a native species. This pasture grass is well-liked in various regions. It can be harvested for hay and silage and used in fields to graze livestock. It can grow in a wide range of soil types, including those with a lot of clay and sand, poor drainage, and a little saline and alkaline soil. It creates turf that can withstand pressure from grazing animals. It can bounce back from fire and drought, but it can't stand frost and shade as well. Although it doesn't need fertiliser, it does benefit from a little more nitrogen. It concluded that D. annulatum is versatile herb having diverse pharmacological activities including antioxidant, antioxidant activity index, DNA damage protection assay, antimicrobial assay, and cytotoxic activity. It also reported for protective effect against DNA damage. These biological properties are reported due to numerous phytochemicals present in the D. annulatum herb.

HPLC-DAD quantification of mangiferin, antioxidant potential and essential oil composition of the leaves of five varieties of Mangifera indica L. of North India

Mangifera indica L. (Mango), native of tropical Asia, has enormous genetic diversity. Comparative phytochemical analysis of leaves of five varieties of Mangifera indica viz. Dashahri, Chausa, Langra, Lucknow Safeda and Gola grown in North India was carried out. Mangiferin content (using HPLC) was found to vary from 0.96 g to 3.00 g per 100 g of dry leaves. Essential oil composition (through GC–MS) showed the major components of all the five varieties to be caryophyllene (4.14–46.26%), humulene (3.19–30.45%), caryophyllene oxide (2.98–17.23%) and humulene epoxide 2 (1.56–4.73%). Results indicated that there was a direct relationship between total phenolic and flavonoid contents and DPPH radical scavenging activities. Our studies indicate that M. indica leaves, which are a form of biomass waste, could be used as an economical and renewable source of antidiabetic compound mangiferin as well as other biologically active phytoconstituents having nutraceutical as well as pharmaceutical applications.

Plastid phylogenomics clarifies broad-level relationships in Bulbophyllum (Orchidaceae) and provides insights into range evolution of Australasian section Adelopetalum

The hyperdiverse orchid genus Bulbophyllum is the second largest genus of flowering plants and exhibits a pantropical distribution with a center of diversity in tropical Asia. The only Bulbophyllum section with a center of diversity in Australasia is sect. Adelopetalum. However, the phylogenetic placement, interspecific relationships, and spatio-temporal evolution of this section remain largely unclear. To infer broad-level relationships within Bulbophyllum, and interspecific relationships within sect. Adelopetalum, a genome skimming dataset was generated for 89 samples, which yielded 70 plastid coding regions and a nuclear ribosomal DNA cistron. For 18 additional samples, Sanger data from two plastid loci (matK and ycf1) and nuclear ITS were added using a supermatrix approach. The study provided new insights into broad-level relationships in Bulbophyllum, including phylogenetic evidence for the non-monophyly of sections Beccariana, Brachyantha, Brachypus, Cirrhopetaloides, Cirrhopetalum, Desmosanthes, Minutissima, Oxysepala, Polymeres, and Sestochilos. Section Adelopetalum and sect. Minutissima s.s. formed a highly supported clade that was resolved as a sister group to the remainder of the genus. Divergence time estimations based on a relaxed molecular clock model placed the origin of Bulbophyllum in the Early Oligocene (ca. 33.2 Ma) and sect. Adelopetalum in the Late Oligocene (ca. 23.6 Ma). Ancestral range estimations based on a BAYAREALIKE model identified the Australian continent as the ancestral area of the sect. Adelopetalum. The section underwent crown diversification from the mid-Miocene to the late Pleistocene, predominantly in continental Australia. At least two independent long-distance dispersal events were inferred eastward from the Australian continent to New Zealand and to New Caledonia from the early Pliocene onwards, likely mediated by predominantly westerly winds of the Southern hemisphere. Retraction and fragmentation of the eastern Australian rainforests from the early Miocene onwards are likely drivers of lineage divergence within sect. Adelopetalum facilitating allopatric speciation.

Global potential distributions and conservation status of rice wild relatives

Societal Impact StatementRice wild relatives (RWR) provide valuable genetic resources for modern rice breeding, yet knowledge gaps constrain their conservation and further utilization. To address these gaps, the potential distributions of 22 RWR taxa were modeled, and their conservation statuses were assessed. Most taxa were identified as medium priority for further conservation. Further ex‐situ collecting hotspots are in Southeast and South Asia, Northern Australia, West Africa, and tropical Americas, while habitat protection lies in Southeast and South Asia, Northern Australia, and West Africa. Climate change may shift equatorial habitats to higher latitudes and mountain habitats to higher altitudes.Summary Rice wild relatives (RWR) provide valuable genetic resources for modern rice breeding. However, knowledge gaps on their geographic distributions and conservation status constrain their conservation and further utilization. To fill these critical gaps, we modeled the potential distributions of 22 RWR taxa under current climate scenarios, assessed their conservation status, both ex situ (in genebanks or botanical gardens) and in situ (in protected areas), and examined changes in taxa richness of RWR in predicted areas under future climate scenarios. The RWR were primarily distributed in tropical Asia to tropical Australia, tropical Africa, and South and Central America. We identified 4 out of 22 taxa as high priority (HP) for further conservation action and 18 taxa as medium priority (MP). Hotspots requiring further collecting for ex situ conservation are concentrated in Southeast and South Asia, Northern Australia, West Africa, and tropical Americas. Meanwhile, habitat protection should be enhanced in Southeast and South Asia, Northern Australia, and West Africa. Under future climate change, suitable habitats near the equator are expected to shift toward higher latitudes and some in lower‐latitude basins may become unsuitable due to excessive heat, resulting in decreased taxa richness in these areas. Additionally, suitable habitats in high mountain areas may shift to higher altitudes, potentially augmenting taxa richness in the highlands. Our findings provide vital insights to guide future rescue conservation efforts for RWR.

Review of the high bed–low ditch system as an alternative to lowland paddy in tropical and subtropical Asia

Many forms of traditional raised bed systems could be found around the world. Several of them have been identified as Globally Important Agricultural Heritage Systems (GIAHS) sites by Food and Agriculture Organization of the United Nations. Unlike traditional raised bed systems with similar structures in the Americas, the high bed–low ditch (HBLD) system in tropical and subtropical Asia, which is originated and developed from rice production, has been playing an important role in enhancing food security and maintaining farmer livelihood for centuries. Moreover, products provided by HBLD system are not only important for the livelihood of the local farmers, but also important for people living in the nearby towns and cities especially for vegetable and fruit supply. In this system, the ditches or sunken beds can be used to lower the groundwater table, retain nutrients and soil particles washed from the bed, grow rice or aquatic vegetables, and raise fish or shrimp. The HBLD system can also help to reduce salinity in coastal lowlands due to the presence of ditches. The raised beds can be used to grow various upland crops. Compared with rice monocropping, the adoption of HBLD system significantly improves the cropping intensity, productivity, employment, and income of farmers. Famers’ long-term practices fully demonstrate that this system is a type of sustainable agriculture with strong adaptability to the changes of natural environment. However, it should also be noted that the large-scale development of HBLD systems is not simply dependent on natural conditions, but is also determined by specific socioeconomic factors, such as good transportation facilities, a well market system, and a sufficient supply of labor. As a model of equilibrium between food production and high levels of biodiversity maintenance, the HBLD system is an important agricultural heritage system with global significance, and it should be well preserved and utilized in new ways to realize its important multiple functions under conditions of rapid urbanization in lowland and coastal regions.

Changes in endangered hornbill populations over space and time and potential ecological impacts in peninsular Thailand

Hornbills are particularly important seed dispersers in tropical Asian forests, but most of the species in the region are declining. In addition, long-term data on the extent of the declines and how forest degradation impacts hornbills remain mostly unquantified. Here, we used multi-covariate distance sampling to estimate the densities of hornbills in 2021–2022 in Hala-Bala Wildlife Sanctuary and Budo Su-Ngai Padi National Park protected areas in southern Thailand. These two sites are particularly useful for comparison due to differences in protection levels, with Bala being relatively less disturbed than Budo Mountain and because Bala was surveyed 20 years prior (2001–2002). Fig tree watches were also conducted in 2021–2022 to assess the potential impact of forest disturbance on hornbill visitation rates. Results indicated significant differences in hornbill densities between the two sites. The mean density of the Rhinoceros (Buceros rhinoceros) and Wreathed Hornbill (Rhyticeros undulatus) was 3.2 and 5.1 times higher in Bala than in Budo, while the mean density of the Great Hornbill (Buceros bicornis) was 2.2 times higher in Budo than in Bala. The density of the Helmeted Hornbill (Rhinoplax vigil) was notably lower than other hornbill species. There were also significant changes over the past 20 years in large hornbill densities, with Great Hornbill and Wreathed Hornbill significantly increasing, while the Helmeted Hornbill declined more than 90 %. Also, the probability of hornbills visiting fruiting Ficus trees was higher in the less-disturbed Bala than the Budo Mountain, making hornbills more reliable visitors in the less-disturbed site. We demonstrate the applicability of the multi-covariate distance sampling approach to estimate densities of rare hornbills, the negative impacts of habitat degradation on hornbills and the ecological role they play as seed dispersers. Additional surveys are needed throughout tropical Asia to establish further sites for long-term monitoring, especially in the Sunda region, where the Helmeted Hornbill is under extreme threat.

A Taxonomic Revision of Indo-Burmese Trichodesma R. Br. (Boraginaceae)

The genus Trichodesma, occurring in tropical and sub-tropical Asia, Africa and Australia has about 45 species. The area taken up for revision is India, Bhutan and Burma. C. B. Clarke in Hook. f. FI. Brit. India described 5 species and 1 variety from this area. In this paper 7 species and 2 varieties have been described.

Safety and efficacy evaluation of Simo decoction and Arecae semen in herbal medicine practice

ObjectiveThe traditional Chinese patent medicine (TCPM), Simo decoction (Simo decoction oral solution), with its primary ingredient Arecae semen (Binglang, Areca catechu L.), known for its potential carcinogenic effects, is the subject of this study. The research aims to analyze the effectiveness and potential risks of Simo decoction, particularly as a carcinogen, and to suggest a framework for evaluating the risks and benefits of other herbal medicines. MethodsThe study is based on post-marketing research of Simo decoction and Arecae semen. It utilized a wide range of sources, including ancient and modern literature, focusing on the efficacy and safety of Simo decoction. The research includes retrospective data on the sources, varieties, and toxicological studies of Arecae semen from databases such as Pubmed, Clinical Trials, Chinese Clinical Trial Registry, China National Knowledge Infrastructure, WHO-UMC Vigibase, and China National Center for ADR Monitoring. ResultsCommon adverse drug reactions (ADRs) associated with Simo decoction include skin rash, nausea, vomiting, abdominal pain, and diarrhea. However, no studies exist reporting the severe ADRs, such as carcinogenic effects. Arecae semen is distributed across approximately 60 varieties in tropical Asia and Australia. According to the WHO-UMC Vigibase and the National Adverse Drug Reaction Monitoring System databases, there are currently no reports of toxicity related to Arecae semen in the International System for Classification of ADRs (ISCR) or clinical studies. ConclusionRisk-benefit analysis in TCPM presents more challenges compared to conventional drugs. The development of a practical pharmacovigilance system and risk-benefit analysis framework is crucial for marketing authorization holders, researchers, and regulatory bodies. This approach is vital for scientific supervision and ensuring the safety and efficacy of drug applications, thus protecting public health.

Description of Protosticta khasia sp. nov. and Yunnanosticta siangi sp. nov., with new records of P. samtsensis Gurung & Phan, 2023 from Northeast India (Odonata: Zygoptera: Platystictidae)

Protosticta Selys is a genus of damselflies of the family Platystictidae Kennedy found in forests of tropical Southeast Asia. The genus Protosticta has rarely been reported from Northeast India. In this paper, we describe Protosticta khasia sp. nov. (subfamily Protostictinae Dijkstra et al.) based on holotype male and paratype female collected from Maraikaphon, East Khasi Hills district, Meghalaya, India. Protosticta khasia can be identified by the markings of the prothorax and the shape of the male paraproct with two arms. We also describe Yunnanosticta siangi sp. nov. (subfamily Sinostictinae Wilson) from Arunachal Pradesh, India, based on two males and two females. This species is differentiated from its congeners by the thoracic and abdominal markings as well as the shape of male caudal appendages. The key for males of Yunnanosticta is provided. Additionally, we provide new records of Protosticta samtsensis Gurung & Phan, along with an updated key to the Protosticta species of Northeast India.

A Review on Ethnobotany, Phytochemistry and Pharmacological Activities of Euphorbia antiquorum L.

Euphorbia antiquorum L. is a small plant in the Euphorbiaceae family that is found primarily in tropical and subtropical Asia. It has a long tradition of being utilized in Chinese, Ayurvedic, and other traditional systems for a variety of ailments. To date, More than 116 bioactive constituents were isolated from Euphorbia antiquorum, with diterpenoids being the most abundant. Extracts and isolated chemicals from various portions of the plant have demonstrated significant pharmacological activities such as anti-inflammatory, analgesic, antidiabetic, anticancer etc. It is necessary to conduct an in-depth investigation of the phytochemicals along with the pharmacological properties of E. antiquorum. This review summarised the knowledge of ethnobotany, phytochemistry and pharmacological activities of the plant which will provide a better understanding to clarify the traditional uses of the species and its relation to modern pharmacology which will ultimately pave the way for its clinical application.

The complete chloroplast genome assembly of Amorphophallus tonkinensis Engler and Gehrmann 1911 from southwestern China

Species in the Amorphophallus genus are important cash crops in many tropical and subtropical Asian countries. Although several molecular markers have been employed to determine relationships and assess genetic variation in the Amorphophallus genus, some conflicts remain in infrageneric classification and evolution. To aid in the phylogenetic research of the Amorphophallus genus, we collected one sample of Amorphophallus tonkinensis Engler and Gehrmann 1911 from southwestern China. We assembled the first chloroplast genome of this species using high-throughput sequencing. The assembled genome was 169,341 bp long with a typical quadripartite structure (GenBank accession number: PP234804). The lengths of the large single-copy region, small single-copy region, and two inverted repeats were 90,705 bp, 15,640 bp, 31,498 bp, and 31,498 bp, respectively. We annotated 129 genes across the chloroplast genome of A. tonkinensis. The phylogenetic trees suggested that the Amorphophallus species distributed in continental Asia split into two main clades. The chloroplast genome reported in our study provided valuable genomic resources for the future phylogenetic research of the Amorphophallus genus.

Landscape and Socioeconomic Factors Determine Malaria Incidence in Tropical Forest Countries.

Deforestation, landscape dynamics, and socioeconomic factors within the tropical Americas, Africa, and Asia may have different impacts on malaria incidence. To evaluate how these drivers affect malaria incidence at the global and regional scale, we collected malaria incidence rates from 2000 to 2019 from 67 tropical countries, along with forest loss, land use change types, and socioeconomic elements. LASSO regression, linear mixed effect modeling, and k-fold cross validation were used to create and evaluate the models. Regionality plays a role in the significance of varying risk factors. The Tropical Americas model had the highest coefficient of determination (marginal R2 = 0.369), while the Africa model showed the highest predictive accuracy with only a 17.4% error rate. Strong associations between tree cover loss (β = -4037.73, p < 0.001) and percentage forest area (β = 5373.18, p = 0.012) in Africa, and percent of key biodiversity areas under protection (β = 496.71, p < 0.001; β = 1679.20, p < 0.001) in the tropical Americas and Asia with malaria incidence indicates that malaria risk should be considered during conservation policy development, and recommends that individual approaches to policy and investment be considered when implementing malaria interventions on different spatial scales.

Medical Applications and Distribution of Borneol during the Joseon Period.

Borneol(yongnoe) was a fragrance and medicinal ingredient with unique efficacy. However, it could be produced only in tropical Southeast Asia and obtained only through international trade. In addition, camphor(jangnoe) with similar material properties was developed and distributed as an inexpensive replacement for borneol, although the processing method is different from that of borneol. Even in Joseon Korea, borneol and camphor were recognized as separate medicines, and efforts were made to obtain a high-quality borneol. Borneol and camphor have a unique effect of relieving inflammation, pain and heavy feeling, so it could be widely applied to symptoms in various diseases. During the Joseon period, borneol was a rare item that could only be obtained through foreign trade, and it was also used for perfumes and insect repellents, but most widely used as medicine. There are many records of actually prescribing borneol to the royal family, and many medicines containing borneol and its effective symptoms were also recorded in the medical books. Borneol was able to spread widely in Joseon society thanks to the practice of distributing 'nabyak' to court officials every year in the twelfth month of the lunar calendar. Since nabyak was used as a household medicine that was stored and used when necessary, pills containing borneol that could be applied to various symptoms were suitable for this purpose. Despite considerable medical demand, borneol was one of the important 'dangyakjae', the Chinese medicines imported to Joseon. During the Joseon period, borneol was imported through China and Japan, but genuine borneol was difficult to obtain, so it was often presented to Joseon as gifts of envoy trade. It is thought that camphor was also imported, but it is not well mentioned in official records or medical books reflecting national demand. Perhaps this is thought to be because the government prioritized securing better quality borneol rather than campher. In the early 17th century, due to the instability of the envoy's route to the Ming Dynasty, Joseon had to import borneol only through the sea. As a result, there were problems with the supply and quality of borneol, and national interest in Japanese borneol temporarily increased. However, as the relationship with the Qing Dynasty stabilized, a system was established to import national borneol demand through the annual envoy trade. Naeuiwon, the medical center for the royal family is in charge of securing and prescribing Chinese medicines, but the cost was covered by the silver paid by Hojo, the ministry of finance of Joseon Dynasty. Since the amount of Chinese medicines used in the preparation of nabyak was not small, the financial burden of importing enough medicines including borneol increased. The purveyors for government played a role in supplying Chinese medicines to the government. Their appearance shows that private merchants were actively involved in the trade of Chinese medicines including borneol. The formation of the medicinal market by private merchants' activities greatly contributed to the widespread expansion of the applications and distribution of borneol.

Regional effects and local climate jointly shape the global distribution of sexual systems in woody flowering plants

Abstract. Understanding the evolution and maintenance of plant sexual diversity needs to incorporate both regional processes and local climate factors across large geographic scales. Using data of woody flowering plants from a global set of large-scale forest plots and multinomial logistic regression, we quantified regional effects on the proportions of dioecious, monoecious, and hermaphroditic species and their abundance while incorporating evolutionary history and local climate factors. Our results showed that plants were more likely to be dioecious than hermaphroditic in Oceania and tropical Asia but were more likely to be monoecious than dioecious in Europe and North America compared with tropical Africa. We further found that plants were more likely to be monoecious than dioecious in island communities. Plants were more likely to be monoecious than dioecious in areas with high precipitation but were more likely to be dioecious than monoecious in areas with high precipitation of coldest quarter. Our results suggest that both regional processes and local climate factors play important roles in shaping the geographic distribution of plant sexual systems, providing a baseline for predicting future changes in forest communities in the context of global change.

CamTrapAsia: A dataset of tropical forest vertebrate communities from 239 camera trapping studies.

Information on tropical Asian vertebrates has traditionally been sparse, particularly when it comes to cryptic species inhabiting the dense forests of the region. Vertebrate populations are declining globally due to land-use change and hunting, the latter frequently referred as "defaunation." This is especially true in tropical Asia where there is extensive land-use change and high human densities. Robust monitoring requires that large volumes of vertebrate population data be made available for use by the scientific and applied communities. Camera traps have emerged as an effective, non-invasive, widespread, and common approach to surveying vertebrates in their natural habitats. However, camera-derived datasets remain scattered across a wide array of sources, including published scientific literature, gray literature, and unpublished works, making it challenging for researchers to harness the full potential of cameras for ecology, conservation, and management. In response, we collated and standardized observations from 239 camera trap studies conducted in tropical Asia. There were 278,260 independent records of 371 distinct species, comprising 232 mammals, 132 birds, and seven reptiles. The total trapping effort accumulated in this data paper consisted of 876,606 trap nights, distributed among Indonesia, Singapore, Malaysia, Bhutan, Thailand, Myanmar, Cambodia, Laos, Vietnam, Nepal, and far eastern India. The relatively standardized deployment methods in the region provide a consistent, reliable, and rich count data set relative to other large-scale pressence-only data sets, such as the Global Biodiversity Information Facility (GBIF) or citizen science repositories (e.g., iNaturalist), and is thus most similar to eBird. To facilitate the use of these data, we also provide mammalian species trait information and 13 environmental covariates calculated at three spatial scales around the camera survey centroids (within 10-, 20-, and 30-km buffers). We will update the dataset to include broader coverage of temperate Asia and add newer surveys and covariates as they become available. This dataset unlocks immense opportunities for single-species ecological or conservation studies as well as applied ecology, community ecology, and macroecology investigations. The data are fully available to the public for utilization and research. Please cite this data paper when utilizing the data.

Bioactive compounds of Citrus hystrix peel ethanolic extract and their antioxidant potential under hydrogen peroxide-induced oxidative stress in Caco-2 cells

Citrus hystrix is a fruit native to tropical Southeast Asia and Southern China. The fruits and leaves are well-known spice ingredients in Asian dishes, but the peels are usually discarded, producing a large amount of waste despite the presence of phenolic compounds. Phenolic compounds are essential for scavenging reactive oxygen species (ROS) generated naturally during metabolism. This study aimed to investigate the profile of phenolic compounds (total phenolic content, total flavonoid content, and individual phenolic compounds) and antioxidant activities (2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, ferric reducing antioxidant power, and oxygen radical absorbance capacity) of Citrus hystrix peel ethanolic extract (CHPPE). Their functional properties in a biological model (cell viability and intracellular ROS) were also evaluated using Caco-2 cells under H2O2-induced oxidative stress. We identified 37 compounds, including flavonoids (26), phenolic acids (3), stilbenes (2), lignans (1), and other phenolic compounds (5). CHPPE contained (mg/g CHPPE) hesperidin (16.10±0.05), diosmin (1.95±0.08), neohesperidin (23.83±0.06), and naringin (2.39±0.03). CHPPE exhibited remarkable antioxidant activity, which significantly improving cell viability and reducing the presence of intracellular ROS. The cytoprotective effect of CHPPE was higher than that of ascorbic acid, indicating a strong natural antioxidative capacity. Our research reveals the potential of CHPPE as a functional ingredient in the food and pharmaceutical industries.