Psychotria Species Research Articles

A Comprehensive Description of the Anatomy and Histochemistry of Psychotria capillacea (Müll. Arg.) Standl. and an Investigation into Its Anti-Inflammatory Effects in Mice and Role in Scopolamine-Induced Memory Impairment.

Species of the genus Psychotria are used in popular medicine for pain, inflammatory symptoms, and mental disorders. Psychotria capillacea (Müll. Arg.) Standl. (Rubiaceae) is commonly known as coffee and some scientific studies have demonstrated its therapeutic potential. The goal of this study was to investigate the anti-inflammatory and neuroprotective effects, and acetylcholinesterase (AChE) inhibitory activity of a methanolic extract obtained from leaves of P. capillacea (MEPC), as well as the micromorphology and histochemistry of the leaves and stems of this plant. In addition, the MEPC was analyzed by UHPLC-MS/MS and the alkaloidal fraction (AF) obtained from the MEPC was tested in a mouse model of inflammation. MEPC contained three indole alkaloids, one sesquiterpene (megastigmane-type) and two terpene lactones. MEPC (3, 30 and 100 mg/kg) and AF (3 and 30 mg/kg) were evaluated in inflammation models and significantly inhibited edema at 2 h and 4 h, mechanical hyperalgesia after 4 h and the response to cold 3 h and 4 h after carrageenan injection. Scopolamine significantly increased the escape latency, and reduced the swimming time and number of crossings in the target quadrant and distance, while MEPC (3, 30 and 100 mg/kg), due to its neuroprotective actions, reversed these effects. AChE activity was significantly decreased in the cerebral cortex (52 ± 3%) and hippocampus (60 ± 3%), after MEPC administration. Moreover, micromorphological and histochemical information was presented, to aid in species identification and quality control of P. capillacea. The results of this study demonstrated that P. capillacea is an anti-inflammatory and antihyperalgesic agent that can treat acute disease and enhance memory functions in mouse models.

A new species of Psychotria (Rubiaceae) from Bidoup - Nui Ba National Park, Vietnam

A new species of Psychotria (Rubiaceae) from Bidoup - Nui Ba National Park, Vietnam

Correlation of total phenolic and flavonoid contents on the antioxidant activity of Psychotria gitingensis and Psychotria pilosella

The genus Psychotria (Rubiaceae) possesses various biological properties, ranging from phytochemical and pharmacological properties of their chemical constituents to traditional medical applications. Most Psychotria species remain unstudied despite high diversity and endemism in the Philippines. Hence, this study investigates the total phenolic and flavonoid contents of Psychotria gitingensis and Psychotria pilosella methanolic crude extracts, evaluates their antioxidant properties, and assesses their antibacterial properties. Results revealed that P. gitingensis fruit extract exhibited the highest phenolic content (254.45 ± 6.63 mg GAE/g extract) and flavonoid content (9.85 ± 0.49 mg QE/g). In addition, it also displayed the highest antioxidant activity (0.993 ± 0.041 mg/mg) in the ABTS assay. P. pilosella leaf extract exhibited the highest antioxidant activity in DPPH (70.53% ± 1.50), and P. gitingensis leaf extract showed the highest iron-reducing antioxidant power (86.06% ± 0.73) in FRAP. Paper disk diffusion tests, however, did not exhibit activity against selected nosocomial pathogens. The results of this study contribute to expanding the field of knowledge on alternative treatments and paving the way for the development of new medicinal products.

Compartmentalization of specialized metabolites across vegetative and reproductive tissues in two sympatric Psychotria species.

The specialized metabolites of plants are recognized as key chemical traits in mediating the ecology and evolution of sundry plant-biotic interactions, from pollination to seed predation. Intra- and interspecific patterns of specialized metabolite diversity have been studied extensively in leaves, but the diverse biotic interactions that contribute to specialized metabolite diversity encompass all plant organs. Focusing on two species of Psychotria shrubs, we investigated and compared patterns of specialized metabolite diversity in leaves and fruit with respect to each organ's diversity of biotic interactions. To evaluate associations between biotic interaction diversity and specialized metabolite diversity, we combined UPLC-MS metabolomic analysis of foliar and fruit specialized metabolites with existing surveys of leaf- and fruit-centered biotic interactions. We compared patterns of specialized metabolite richness and variance among vegetative and reproductive tissues, among plants, and between species. In our study system, leaves interact with a far larger number of consumer species than do fruit, while fruit-centric interactions are more ecologically diverse in that they involve antagonistic and mutualistic consumers. This aspect of fruit-centric interactions was reflected in specialized metabolite richness-leaves contained more than fruit, while each organ contained over 200 organ-specific specialized metabolites. Within each species, leaf- and fruit-specialized metabolite composition varied independently of one another across individual plants. Contrasts in specialized metabolite composition were stronger between organs than between species. As ecologically disparate plant organs with organ-specific specialized metabolite traits, leaves and fruit can each contribute to the tremendous overall diversity of plant specialized metabolites.

Solved at last: The Philippine endemic Psychotriaphilippensis is a synonym of Scyphiphorahydrophylacea (Rubiaceae, Scyphiphoreae).

Psychotriaphilippensis (Rubiaceae) was described by Chamisso and Schlechtendal in 1829, was the first Psychotria name published for the Philippines and is currently considered a Philippine endemic. The name remained in a taxonomic limbo for almost two centuries as it was variously accepted, synonymized or considered obscure, probably because the type specimen in the Berlin herbarium was destroyed and no original material has survived or is currently known. A combined analysis of the information on morphology, type locality and ecology contained in the protologue and a review of relevant literature on the study of the name by various authors over the last two centuries finally clarified the identity of P.philippensis. The name is confirmed here as a synonym of the rubiaceous mangrove Scyphiphorahydrophylacea, as first proposed by Schumann, one of the authorities of the family in the late 19th century, and the application of P.philippensis is fixed by neotypification. This reduces the number of Philippine species of Psychotria by one, but fortunately, this is not happening through extinction, as has been the case with too many species of the highly endangered Philippine flora. In addition, the history of the discovery and study of S.hydrophylacea and its synonyms are described in detail, and one lectotype and one neotype are designated.

Evolution of distyly breakdown in Palicoureeae Robbr. & Manen and Psychotrieae Cham. & Schltdl. (Rubiaceae)

Distyly is a floral polymorphism with reciprocal placement of male and female structures, heteromorphic self-incompatibility, and other ancillary traits. However, breeding system breakdowns and loss of polymorphism are common. Here we traced the diversification of breeding strategies in the type genera of tribes Palicoureeae and Psychotrieae and discussed the evolution of distyly in a phylogenetic framework. We used literature and field information for breeding systems transitions in 46 species of Palicourea and Psychotria. Beyond distyly, we found four additional breeding systems, including monomorphism with herkogamy, homostyly (without herkogamy), monoecy and dioecy. Breeding transitions arose independently and were mostly derived from distyly. Only two species presented monomorphism as an intermediate state into gender specialization. It was not possible to evaluate the origin and evolutionary pathways for distyly in Psychotria and Palicourea as a whole, since distyly seems to be ancestral to their diversification. Breeding transitions in Psychotria and Palicourea appeared to be phylogenetically and biogeographically independent and occurred mostly in islands or isolated forest fragments, with distinct divergence times. Breeding transitions were not related to changes in ploidy. We propose that evolution of breeding transitions in Psychotria and Palicourea represent phylogenetically independent strategies to reproductive assurance in isolated or disturbed habitats.

Evaluation of pharmacognostic profile, phytochemical, and antimicrobial properties of Psychotria vogeliana Benth. (Rubiaceae), Leaf

The use of plants for the treatment of human diseases is as old as mankind on earth.. While there are reports on some Psychotria species there is virtually none on the plant Psychotria vogeliana Benth, (Rubiaceae). This research aims to evaluate the pharmacognostic, phytochemical and antimicrobial activities of the leaves of the plant. Macroscopic and microscopic characters of the plant material were evaluated and recorded. The plant material was sequentially extracted with n-hexane, ethyl acetate and methanol using a soxhlet extractor. The methanol extract was evaluated for acute toxicity using Lorke’s method. Phytochemical analysis was carried out using standard methods while antimicrobial screening was done to test for antibacterial and antifungal activities following methods Clinical and Laboratory Standards Institute (CLSI) document M07-A9 2012). The phytochemical analysis was carried out using standard methods. Extraction yield; Methanol Extract = 9.73 %, ethyl acetate extract= 6.35 %, n-hexane extract = 7.22 %. The bitterness value (expressed as Mean ± SEM) was 0.65±0.04 IU/g, swelling index was insignificant. Results for Foaming Index indicated an insignificant foaming index. Ethanol soluble extractive (%) was 5.2±0.00, Water soluble extractive (%) was 5±0.012 Total ash (%) was 6.67±0.003, Moisture content (Loss-on-drying) (%) was 7.50±0.00. The leaf is hypostomatic with the paracytic type of stomata, with stomatal number 30.6 ±0.27, stomatal size 293.56 ±9.95 stomatal index 27.7 ±0.17%, vein islet number 3.82. The methanol extract was found to be non-toxic at doses below 400 mg kg-1. The qualitative phytochemical analysis revealed the presence of alkaloids, reducing sugars, tannins, glycosides, saponins, terpenoids, steroids, flavonoids, phenols, cyanogenic compounds. The methanol extract has activity against all the tested organisms, but the n-hexane extract has no activity against Pseudomonas aeruginosa, while the ethyl acetate extract had no activity against Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. The methanol and n-hexane fractions showed activity against C.albicans. The qualitative phytochemical analysis revealed the presence of alkaloids, reducing sugars, tannins, glycosides, saponins, terpenoids, steroids, flavonoids, phenols, cyanogenic compounds. The plant Psychotria vogeliana Benth (Rubiaceae), leaf contains many major phytochemicals and methanol extract possesses antimicrobial activity. Further work should be carried out to investigate other activities of the plant.

A methanol extract and N,N-dimethyltryptamine from Psychotria viridis Ruiz & Pav. inhibit Zika virus infection in vitro.

Zika virus (ZIKV) is a public health problem due to its association with serious fetal and neurological complications and the lack of antiviral agents and licensed vaccines against this virus. Surveillance studies have alerted about the potential occurrence of a new South American epidemic episode due to the recent circulation of an African ZIKV strain detected in Brazil. Therefore, it is essential to discover antiviral agents, including natural substances, that are capable of neutralizing the action of ZIKV. Several Psychotria species have antimicrobial and anti-inflammatory properties. Thus, a methanol extract and dimethyltryptamine from Psychotria viridis were evaluated for their ability to inhibit ZIKV infection in vitro by measuring the effective concentration that protects 50% of cells and investigating their possible mechanisms of action. The tested samples showed antiviral activity against ZIKV. The extract showed virucidal activity, affecting viral and non-cellular elements, inactivating the virus before infection or when it becomes extracellular after the second cycle of infection. It was also observed that both extract and dimethyltryptamine could inhibit the virus at intracellular stages of the viral cycle. In addition to dimethyltryptamine, it is believed that other compounds also contribute to the promising virucidal effect observed for the methanol extract. To our knowledge, this is the first report of the activity of a methanolic extract and dimethyltryptamine from Psychotria viridis against cellular ZIKV infection. These two samples, extracted from natural sources, are potential candidates for use as antiviral drugs to inhibit ZIKV infections.

In vitro antiplasmodial activity, targeted LC-MS metabolite profiling, and identification of major natural products in the bioactive extracts of Palicourea and Psychotria species from the Amazonia and Atlantic Forest biomes, Brazil.

A great variety of bioactive natural products has been reported for different Palicourea and Psychotria species (Rubiaceae). However, few of them as well as few of species of these botanical genera have been evaluated for antiplasmodial activity. To assess the antiplasmodial activity of 24 extracts from Palicourea and Psychotria genera, along with the targeted LC-MS metabolite profiling, as well as identification of the main metabolites in the bioactive extracts. Twenty four ethanol and acid-base extracts from Palicourea and Psychotria genera collected in the Amazonia and Atlantic Forest, Brazil, were evaluated against chloroquine-resistant Plasmodium falciparum W2 strain by PfLDH. The metabolite profiling and putative identification of metabolites from bioactive extracts were determined by LC-DAD-ESI-MS and LC-HRMS, respectively. The ethanol extracts disclosed low antiplasmodial activity (% GI < 50%). High antiplasmodial effect was observed for the acid-base extracts from Psychotria apoda and Psychotria colorata with 100% inhibition of parasite growth inhibition. Fragment ions related to pyrrolidinoindoline alkaloids were observed by LC-DAD-ESI-MS mainly in the most bioactive extracts. The results of the in vitro screening associated with the LC-DAD-ESI-MS and LC-HRMSn data allowed to predict, for the first time, the pyrrolidinoindoline alkaloids as possible antiplasmodial representing, then, new potential natural antimalarial hits. In addition, other metabolite classes such as flavanones, lignans and chalcones were also putatively identified in the bioactive extracts of Psychotria apoda, Psychotria capitata, and Psychotria poeppigiana. The present results point to Palicourea and Psychotria species as sources of new antimalarial hits.

Rediscovery and amended description of Psychotria palimlimensis (Rubiaceae): a rare species found only in Ilocos Norte, Philippines

Recent exploration on the northern Cordillera Mountain Range of Ilocos Norte, Philippines, resulted in the rediscovery of Psychotria palimlimensis Sohmer &amp; A.P. Davis. This is an endemic Psychotria species first collected by Ramos in 1918 and identified as P. subalpina. However, the diagnosis of Sohmer and A.P. Davis in 2007 proposed it as a new species based on herbarium materials, and no further recollection was made to date since its last collection in 1953. Therefore, an amended taxonomic description of P. palimlimensis is proposed with color photographs, additional records on the distribution and morphological comparison with its allied species. The current conservation status is also provided.

Do reciprocal herkogamy and pollinators affect legitimate pollen flow in distylous species of Rubiaceae?

AbstractThe function of the reciprocal position of anthers and stigmas of the floral morphs in distylous flowers is to promote cross-pollination between morphs (legitimate pollination). Deviations from reciprocity can negatively affect the rates of legitimate pollen deposition, but other floral traits or the pollination environment might contribute to the function of distyly. In populations of four species of Palicourea and Psychotria, we quantified reciprocity using adaptive inaccuracy and measured the stigmatic lobe length to estimate how these traits influenced legitimate pollen deposition. We described the functional groups of pollinators and compared legitimate pollen flow between morphs in populations visited by different groups. Variations in reciprocity and stigmatic lobe length correlated with the rates of legitimate pollen depositions, with more reciprocal stigmas and longer stigmatic lobes presenting proportionally more legitimate pollen. Populations most frequently visited by bees or with generalized pollination displayed asymmetries in pollen flow between morphs, but with higher legitimate pollination in the S-morph. In contrast, L- and S-flowers showed similar legitimate pollen deposition in the population predominantly visited by hummingbirds. Our results suggest that reciprocity affects the function of distyly; however, floral traits such as stigmatic lobe length and the pollination environment can also influence the rates of legitimate pollen.

Chemical composition, antimycobacterial and anti-inflammatory activities of iridoids and triterpene from Psychotria suterella (Rubiaceae)

Background: Psychotria species are known for their medicinal properties and psychoactive activities. Extracts of Psychotria suterella showed anti-tuberculosis (TB) activity; however, the substances related to this activity are unknown. Objectives: The objective was to study on the chemical constituents of the leaves of plant and evaluate the anti-TB and anti-inflammatory activity. Materials and Methods: Solvent extraction, partition, and column chromatography were used to separate the compounds. The structures of these compounds were determined by extensive one dimensional-and two dimensional-Nuclear Magnetic Resonance, infrared and mass spectrometry spectroscopic analyses. Some compounds were evaluated for their in vitro activity against Mycobacterium tuberculosis and their ability to inhibit nitric oxide (NO) production by lipopolysaccharide-stimulated macrophages. Results: This study led to the isolation and characterization of a new iridoid, named epi-geniposidic acid (1), together with nine known compounds: geniposidic acid (2), 3-O-acethyloleanolic acid (3), pomolic acid (4), spinolic acid (5), maslinic acid (6), tormentic acid (7), methyl oleanolate (8), lyalosidic acid (9), and strictosidinic acid (10). Triterpene 3-O-acethyloleanolic acid (3) was found to display antimycobacterial activity against M. tuberculosis H37Rv strain and hypervirulent strain (minimum inhibitory concentration 6.7 ± 0.1 and 89.1 ± 1.3 μg/mL, respectively). Epi-geniposidic acid (1), geniposidic acid (2), and 3-O-acethyloleanolic acid (3) showed promising inhibitory activities against NO production (IC50 range 4.12–5.12 μg/mL). The iridoid mixture showed no cytotoxicity against RAW 264.7 macrophages up to a concentration of 100 μg/mL. Conclusion: P. suterella presents relevant biological properties and should be considered for further in vivo studies using a pulmonary TB model.

Some distinctive new species of Psychotria (Rubiaceae, Psychotrieae) from Madagascar

Taylor, C.M., R.E. Gereau & H.H. Schmidt (2020). Some distinctive new species of Psychotria (Rubiaceae, Psychotrieae) from Madagascar. Candollea 75: 159–182. In English, English and French abstracts.Psychotria L. (Rubiaceae, Psychotrieae) is an unusually species-rich genus in Madagascar. Recent botanical explorations here have found a number of undescribed species, and some unusual morphological structures for this genus. Here ten new Psychotria species from Madagascar are formally described: Psychotria ambatovensis C.M. Taylor, Psychotria antilahimenae C.M. Taylor, Psychotria birkinshawiana C.M. Taylor, Psychotria davisiana C.M. Taylor, Psychotria eumachioides C.M. Taylor, Psychotria hamifera C.M. Taylor, Psychotria mutabilis C.M. Taylor, Psychotria notopleuroides C.M. Taylor, Psychotria palifera C.M. Taylor, and Psychotria razafimandimbisonii C.M. Taylor. Unusual morphological features of some of these species include a prostrate habit, deeply retuse leaves, and enlarged, persistent, funnelform stipules. Assessment of the conservation status of these using IUCN Red List categories finds four of them “Vulnerable” and six “Endangered”.

Short Communication: Rediscovery of Psychotria species, subspecies, and varieties collected in the 1990s and new records of Antirhea benguetensis (Elmer) Valeton and Ixora longifolia Smith (Rubiaceae) in Northern Sierra Madre Natural Park, Luzon, Philipp

Abstract. Biag RD, Alejandro GJD. 2020. Short Communication: Rediscovery of Psychotria species, subspecies and varieties collected in the 1990s and new records of Antirhea benguetensis (Elmer) Valeton and Ixora longifolia Smith (Rubiaceae) in Northern Sierra Madre Natural Park, Luzon, Philippines. Biodiversitas 21: 4524-4535. Tagged as the “last great forest” for it possesses the widest remaining tropical rainforest in the island of Luzon, the Northern Sierra Madre Natural Park (NSMNP) in the province of Isabela is worth-conserving. Owing to the species richness and high levels of endemism in the said area, it was identified as a key biodiversity area for conservation and protection. After a botanical exploration in the park conducted from April to August 2019, 89 Rubiaceae species were found dominated by the genus Psychotria. These Psychotria species were then separated from other genera and were morphologically examined and eventually identified. This study, therefore, primarily aims to provide the list of Psychotria species that were collected long before, particularly in the 1990s and still exist in NSMNP continuously battling against the catastrophic activities within the forest. Eight Philippine endemic Psychotria species and varieties were recollected. As to their current conservation status following IUCN criteria, we herein propose these species, except for Psychotria pubilimba, to be treated as Data Deficient (DD) since there is lack of distributional data for these species. Additional surveys are to be conducted on the areas where these species were previously collected. In this way, information on population size and threats to the species can also be obtained. P. pubilimba is restricted to Cagayan and Isabela. Only one mature individual has been found; hence, a Narrow Endemic Species (NES). Being an NES, it was then assessed as Critically Endangered (CR) based on IUCN rules. It is also worth noting that new records of Antirhea benguetensis and Ixora longifolia species were found in the park, particularly in Divilacan, Isabela. The former has been regarded as Luzon endemic, known to be distributed only in Benguet, Ilocos Sur, Rizal, and Bataan. The latter, on the other hand, is mostly distributed in the provinces of Visayas and Mindanao, and only Masbate and Palawan for Luzon. Moreover, this flora has been recorded in other parts of the world like China, India, Myanmar, Indonesia, Malaysia, and Vietnam.

The alkaloid brachycerine contributes to protection against acute UV-B damage in Psychotria

Plants developed several strategies to cope with ultraviolet radiation (UV) exposure, including accumulation of specialized metabolites, with a recognized major role played by flavonoids. The unique alkaloid brachycerine of Psychotria brachyceras (Rubiaceae) is induced by leaf exposure to high UV intensity and is a potent antioxidant, so it is likely to participate as a protecting factor against this radiation. The capacity of brachycerine as a putative agent in acute UV protection was tested by comparison of P. brachyceras with P. carthagenensis, a closely related and co-ocurring species devoid of alkaloids, in UV-B exposure experiments. Leaves of P. brachyceras were very tolerant to high UV doses when compared with P. carthagenensis, lacking chlorophyll loss and membrane lipid peroxidation. Overall, well known leaf defenses against UV-B, such as flavonoids and cuticular waxes, were not markedly different between Psychotria species. The alkaloid was found both in the epidermis and mesophyll in leaves of P. brachyceras. Brachycerine is an effective in vitro superoxide scavenger and, when applied to the surface of P. carthagenensis leaves, significantly increased UV-B tolerance, improving chlorophyll concentration and several photosynthetic parameters under this treatment. Profiles of brachycerine extracted from alkaloid-treated P. carthagenensis leaves showed partial degradation after UV exposure, suggesting alkaloid involvement in chemical quenching of reactive oxygen species. In addition to flavonoids, the alkaloid brachycerine may improve tolerance to acute UV-B, representing a chemical tool to protect plants against this harmful condition.

Host affinity of endophytic fungi and the potential for reciprocal interactions involving host secondary chemistry

Interactions between fungal endophytes and their host plants present useful systems for identifying important factors affecting assembly of host-associated microbiomes. Here we investigated the role of secondary chemistry in mediating host affinity of asymptomatic foliar endophytic fungi using Psychotria spp. and Theobroma cacao (cacao) as hosts. First, we surveyed endophytic communities in Psychotria species in a natural common garden using culture-based methods. Then we compared differences in endophytic community composition with differences in foliar secondary chemistry in the same host species, determined by liquid chromatography-tandem mass spectrometry. Finally, we tested how inoculation with live and heat-killed endophytes affected the cacao chemical profile. Despite sharing a common environment and source pool for endophyte spores, different Psychotria host species harbored strikingly different endophytic communities that reflected intrinsic differences in their leaf chemical profiles. In T. cacao, inoculation with live and heat-killed endophytes produced distinct cacao chemical profiles not found in uninoculated plants or pure fungal cultures, suggesting that endophytes, like pathogens, induce changes in secondary chemical profiles of their host plant. Collectively our results suggest at least two potential processes: (1) Plant secondary chemistry influences assembly and composition of fungal endophytic communities, and (2) host colonization by endophytes subsequently induces changes in the host chemical landscape. We propose a series of testable predictions based on the possibility that reciprocal chemical interactions are a general property of plant-endophyte interactions.

New records of the genus Psychotria (Rubiaceae) from Thailand

Four species of Psychotria are newly recorded from Thailand: P. bonii, P. griffithii, P. langbianensis and P. pachyphylla. Descriptions and list of synonyms are provided and a lectotype for P. bonii is designated.

Phylogenetic and geographic distribution of nickel hyperaccumulation in neotropical Psychotria

Hyperaccumulation of heavy metals in plants has never been documented from Central America or Mexico. Psychotria grandis, P. costivenia, and P. glomerata (Rubiaceae) have been reported to hyperaccumulate nickel in the Greater Antilles, but they also occur widely across the neotropics. The goals of this research were to investigate the geographic distribution of hyperaccumulation in these species and explore the phylogenetic distribution of hyperaccumulation in this clade by testing related species. Portable x-ray fluorescence (XRF) spectroscopy was used to analyze 565 specimens representing eight species of Psychotria from the Missouri Botanical Garden herbarium. Nickelhyperaccumulation was found in specimens of Psychotria costivenia ranging from Mexico to Costa Rica and in specimens of P. grandis from Guatemala to Ecuador and Venezuela. Among related species, nickel hyperaccumulation is reported for the first time in P. lorenciana and P. papantlensis, but no evidence of hyperaccumulation was found in P. clivorum, P. flava, or P. pleuropoda. Previous reports of hyperaccumulation in P. glomerata appear to be erroneous, resulting from taxonomic synonymy and specimen misidentification. Hyperaccumulation of nickel by Psychotria is now known to occur widely from southern Mexico through Central America to northwestern South America, including some areas not known to have ultramafic soils. Novel aspects of this research include the successful prediction of new hyperaccumulator species based on molecular phylogeny, use of XRF technology to nondestructively obtain elemental data from herbarium specimens, and documentation of previously unknown areas of ultramafic or nickel-rich soil based on such data.

Identification of genes encoding ALMT and MATE transporters as candidate aluminum tolerance genes from a typical acid soil plant, Psychotria rubra (Rubiaceae).

To understand how tropical plants have adapted to acid soils, we analyzed the transcriptome of seedlings of Psychotria rubra, a typical species found on acid soils. Using RNA-seq, we identified 22,798 genes, including several encoding proteins of the Al3+-activated malate transporter (ALMT) and multidrug and toxic compound extrusion (MATE) families. Molecular phylogenetic analysis of ALMTs and MATEs revealed the grouping of those from P. rubra, which may be useful to select targets for elucidating the molecular basis of P. rubra adaptation to acid soils in the future. The transcriptome datasets obtained in this study would help us to further understand the physiological and ecological aspects of soil adaptation of Psychotria species.

In vivo antidiabetic and antioxidant potential of Psychotria dalzellii in streptozotocin-induced diabetic rats

Psychotria species have been known for wide array of health benefits as per traditional knowledge and only a few scientific evidences are available. In the current study in vivo antidiabetic property of methanol extract of Psychotria dalzellii (MEPD) was elucidated in alloxan-induced type 1 diabetes in Wistar rats. MEPD, acetone and ethylacetate extracts were examined for potential anti-diabetic properties (α-amylase and α-glucosidase inhibition) in in vitro and the significantly potent extract – MEPD was analyzed for in vivo antioxidant activity. Blood glucose levels, TBARS, antioxidant, creatinine, alkaline phosphatase etc., were measured. Results of the study revealed that, oral intubation of 400 mg kg−1b.w. of MEPD for a period of 20 days prior inducing diabetes resulted in the normalization of blood glucose level (259.83 ± 10.11 mg/dL as opposed to induced 389.5 ± 8.97; healthy animals had 129.16 ± 4.12 mg/dL glucose) suggesting the antidiabetic potency of MEPD. Biochemical analysis substantiated the antidiabetic property of MEPD as revealed by normalization of altered TBARS/oxidant and antioxidant levels. Results were further substantiated by in vitro studies, where MEPD exhibited good antioxidant activity – reducing power activity (IC50–8.81 U/mg vs Ascorbic acid – 6.21 U/mg; MEPD); hydrogen peroxide activity (IC50−26.57 μg/mL vs Ascorbic acid 19.12 μg/mL); MEPD inhibited α-amylase and α-glucosidase activity with (IC50 47.11 ± 2.8 μg/mL vs Acarbose – IC50 40.86 ± 1.7 μg/mL); (IC50 40.34 ± 1.2 μg/mL vs Acarbose – IC50 40.99 ± 2.3 μg/mL); providing evidence for the first time for the antidiabetic property of P. dalzellii. The potent anti-type I diabetic property could be due to antioxidant and inhibition of α-glucosidase/amylase which results in control of release of glucose levels into the circulation. Phytochemical analysis of revealed that MEPD is enriched in phenolics and flavonoids compound. In order to understand its probable mechanism of action, antioxidant status during healthy, diabetic and sample treated groups of animals were also investigated.