Nui Ba National Park Research Articles

A new species of Diderma from Bidoup Nui Ba National Park (southern Vietnam)

A new species of Diderma from Bidoup Nui Ba National Park (southern Vietnam)

Wound healing activity of Conyza canadensis (L.) Cronquist

Conyza canadensis (L.) Cronquist (CCL) has been used by K’Ho minority in Bidoup Nui Ba national park, Lam Dong province, Vietnam as one of wound healing remedies. However, the scientific proof of treatment is still unclear. This study aimed to evaluate this wound healing potential of CCL. CCL power was extracted by ethanol and then partitioned consecutively with petroleum ether, ethyl acetate and water. Wound healing potential was evaluated by antibacterial activity, stimulation of fibroblast and keratinocyte proliferation. Agar-well diffusion was used in the antibacterial tests and the results showed that CCL had antibacterial activity against 02 dermatitis bacteria (Pseudomonas aeruginosa, Staphylococcus aureus) and 02 opportunistic infection bacteria (Escherichia coli, Enterococcus faecalis). Moreover, our results illustrated that CCL stimulated the fibroblast and keratinocyte proliferation compared to the control. Particularly, the fibroblast division increased 1.6 times at 31.25 µg/mL when treated by ethanolic extract, while ethyl acetate fraction showed 1.7 times increase at 10 µg/mL in keratinocyte proliferation compared to the control. Taken together, our study contributed scientific base of CCL in the wound healing.

Optimization of an anti-inflammatory screening model on the RAW 264.7 macrophage cell

Inflammation is the response of living tissues to the injury. Prolonged or inappropriate inflammation has been involved with many diseases such as, cancer, diabetes, heart disease… These days, inflammation has been treated by nonsteroidal and steroidal anti-inflammatory drugs, which have a lot of side effects. It opens the need and interest of new drugs discovery. Particularly, scientific and pharmaceutical communities show great interest in finding new anti-inflammatory compounds in traditional medicinal plants. This study aimed to optimize an in vitro anti-inflammatory model. Cell heterogeneity, cell density, LPS concentration and LPS incubation time were chosen to optimize the production of nitric oxide (NO) in RAW 264.7 macrophage cells. Our results show that 104 cells/well, FBS 1 %, starvation for 6 h, LPS 0.5 µg/mL in 24 h were optimized parameters in the model. Then, extracts from Hedyotis capitellata, a traditional medicinal plant used by K’ho minority, Bidoup Nuiba national park, Lam Dong province, Vietnam, was chosen to evaluate the in vitro antiinflammatory model. The anti-inflammatory activity was tested by measuring the production of NO in lipopolysaccharide-activated RAW 264.7 macrophage cells. The experimental data indicate that the extracts of this plant decreased NO production in LPS-stimulated RAW 264.7, particularly, the petroleum ether fraction at the concentration of 23.8 µg/mL inhibited NO production by 128.20 %; whereas dexamethasone 50 µM inhibited NO accumulation to 112 %.

Antioxidant and cytotoxic activity of lichens collected from Bidoup Nui Ba National Park, Vietnam

Lichens were some of the earliest colonizers of terrestrial habitats on Earth. They represent a unique symbiont between fungi (mycobionts) and algae and/or cyanobacteria (photobionts). Lichens have been used as a cure for diabetes, coughs, pulmonary tuberculosis, wound healing, and dermatological diseases. The aim of this study is to investigate the in vitro antioxidant and cytotoxic activities of methanol lichen extracts. Fourteen lichen species from Bidoup Nui Ba National Park were identified according to their morphology and anatomical and chemical characteristics. The antioxidant activity of the methanol lichen extracts was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity assay. The results showed that, of the lichens tested, L5 had the highest free radical activity with 50% inhibitory concentration (IC50) of 59.9 ± 4.65 mg mL−1. The methanol extract of L5 also showed the highest total flavonoid and polyphenol contents. In a cytotoxic assay, it was observed that the methanol extract of U38.1 exhibited high cytotoxic effect against MCF-7 cells, with IC50 of 34.27 ± 1.25 mg mL−1. The tested lichen extracts were also found to have slight cytotoxic effect on fibroblasts at screening concentration of 100 µg mL−1. All of the extracts were found to possess different cytotoxic activities against MO-91 cells, with IC50 values ranging from 10.50 ± 1.56 to over 50 mg mL−1. All of the extracts except U38.1 induced normal peripheral blood mononuclear cell (PBMC) proliferation, especially after 48 h of treatment at 25 µg/mL.

Macrosolen bidoupensis (Loranthaceae), a new species from Bidoup Nui Ba National Park, southern Vietnam.

Macrosolen bidoupensis Tagane & V.S.Dang, sp. nov. (Loranthaceae) is newly described from Bidoup Nui Ba National Park in Lam Dong Province, southern Vietnam. The new species is characterized by small broadly elliptic to circular leaves, sessile to short petioles, slightly cordate to rounded leaf bases, 4–5 pairs of lateral veins and a basally green corolla tube. An illustration, a summary of DNA barcoding of the plastid genes rbcL and matK, and a key to the species of Macrosolen in Vietnam are provided.

Biological activities and micropropagation of non-vascular plants from Bidoup-Nui Ba National Park, Lam Dong

At the present time, non-vascular plants (bryophytes) are less studied, especially in Vietnam. Therefore, this research focuses on studying biological activities of some bryophytes species collected in Bidoup–Nui Ba National Park, such as antioxidative, antibacterial activity, acetylcholinesterase inhibitory activity and quantitative analysis of the major secondary metabolites. Moreover, one of the most potential species was micropropagated in vitro in order to get the initiative pharmaceutical materials. Among the six bryophyte species collected in Bidoup–Nui Ba National Park, three of them are mosses (Pyrrhobryum spiniforme, Bryum argenteum and Campylopus umbellatus) and three of them are liverworts (Lepidozia fauriana, Plagiochila trabeculata and Schistochila blumei). Our results showed that L. fauriana had the highest antioxidative activity and acetylcholinesterase inhibitory activity (IC50 = 6.617 ± 0.080 mg/mL), S. blumei had the potent antibacterial activity. In vitro propagation results showed that silver moss could be micropropagated using spores in MS medium supplemented with 1 mg/L 2,4-D and 2 mg/L kinetin.

Evaluating the wound healing ability of Melicope pteleifolia (Champ. Ex Benth.) T.g. Hartley

Melicope pteleifolia (Champ. ex benth.) T.g. Hartley, a folk medicinal plant, is used by ethnic minorities in Bidoup–Nui Ba National Park, Lam Dong Province, Vietnam to treat effectively wound, inflammation and skin ulcer. To scientifically prove the claimed utilization and understand the mechanism of action of the plant, the in vitro and in vivo healing properties of the extract and fractions of the plant were investigated. The ethanol 70 % extract (50 – 400 mg/mL), aqueous (200 mg/mL), ethyl acetate (100 mg/mL) and petroleum ether (50 mg/mL) fractions were used to evaluate the antibacterial activities by using agar diffusion method. The healing properties were in vitro investigated through fibroblasts and keratinocytes proliferation and migration (7.8 g/mL to 250 g/mL in accordance with each extract and fraction). Besides, the macrophage-induced inhibition of the nitric oxide (NO) production was examined (15.6 – 62.5 g/mL). In addition, the excision wound model was used to test the wound healing activity on mice model. We found that the ethanol extract and the ethyl acetate fraction showed potent activity against Staphylococcus aureus, Enterococcus feacalis and Pseudomonas aeruginosa. The extract and fractions stimulated fibroblasts and keratinocytes proliferation in a concentration-dependent way. They also inhibited macrophage produce NO. In addition, mice treated by the extract formed scabs on wound excision of mice model faster than the control group. The wound healing efficiency seems to involve antibacterial, stimulating fibroblasts and keratinocytes proliferation, inhibition of macrophages produce NO.

Garcinia hopii (Clusiaceae), a new species from Bidoup Nui Ba National Park, southern Vietnam.

A new species, Garcinia hopii H.Toyama & V.S.Dang is described from Bidoup Nui Ba National Park, southern Vietnam. This species is similar to Garcinia hendersoniana Whitmore but differs from that species in having larger leaves, clustered pistillate flowers, a greater number of sterile anthers and a larger stigma of young fruits. A description, preliminary conservation assessment, illustration, photographs and DNA barcodes of the new species are provided, as well as an updated key to Garcinia sect. Hebradendron in Indochina.

A preliminary survey of the taxonomic composition of contents of Nepenthes smilesii Hemsl. pitchers in Bi Doup ' Nui Ba National Park (South Vietnam)

We present a taxonomic analysis of contents of Nepenthes smilesii Hemsley, 1895 (Nepenthaceae) pitchers collected in Bi Doup – Nui Ba National Park (South Vietnam). 230 specimens of insects, belonging to 7 orders and 17 families, as well as 7 specimens of arachnids (2 orders), 2 specimens of chilopods, 2 specimens of isopods and 1 specimen of oligochaetes were identified. Animal composition from N. smilesii pitchers is dominated by flightless and poorly flying invertebrate forms. Small ant species Technomyrmex yamanei Bolton, 2007 is a predominant prey. Besides ants, Heteroptera and Blattodea are groups dominating in ration, that distinguishes N. smilesii from other Nepenthes species, studied before in this context.

A survey on avifauna of Bidoup - Nui Ba national park, Lam Dong province

Located in Lac Duong và Dam Rong districts, Lam Dong province, Bidoup - Nui Ba national park (NP) covers 64.800 ha of the Da Lat Endemic Bird Area. Bidoup - Nui Ba NP supports three Important Bird Areas with 256 species including several globally threatened and near-threatened birds, such as the Crested Argus, Grey-crowned Crocias and Vietnamese Greenfinch. Changes in systematics of the avifauna in the recent years and lack of information on current status of birds in remote areas of the park generated the need to conduct supplementary studies of the avifauna of the national park. During four surveys conducted from November 2009 and March 2012 we recorded and photographed 106 bird species; of those, 12 species are newly recorded for Bidoup - Nui Ba NP, that increased the total of bird species to 268. At least five bird species are listed in Vietnam Red Book 2007 and IUCN 2009 List of Threatened Species, and five endemic species are recorded in these surveys.

Two new cryptic species of the Cyrtodactylus irregularis complex (Squamata: Gekkonidae) from southern Vietnam

We describe two new species of the Cyrtodactylus irregularis complex both based on phylogenetic analysis of 654 bp of COImtDNA gene and morphological analyses of voucher specimens from Binh Phuoc and Lam Dong provinces, southern Vietnam.Cyrtodactylus bugiamapensis sp. nov. is described from the monsoon tropical forests of Bu Gia Map National Park, BinhPhuoc Province, and is distinguished from the remaining representatives of the C. irregularis complex by a combination of thefollowing characters: (1) size medium, with a maximum SVL of 76.8 mm; (2) original tail relatively thin, longer than body; (3)presence of enlarged femoral scales without femoral pores; (4) preclocal groove lacking; (5) 36–46 longitudinal rows of ventralscales at midbody; (6) males with 7–11 precloacal pores in an angular continuous series; (7) absence of enlarged subcaudals;(8) dorsal pattern consisting of a dark neck band which can be medially divided, and irregular dark brown spots with brightwhite edges. Cyrtodactylus bidoupimontis sp. nov. is described from mountainous evergreen tropical forests of Bidoup – NuiBa National Park, Lam Dong Province, and is most similar to C. irregularis sensu stricto from which it is distinguished by acombination of the following characters: (1) absence of enlarged, strongly keeled conical tubercles on the dorsal tail-base; (2)presence of flat rounded smooth to weakly keeled dorsal tubercles; (3) pallid dorsal head surface pattern lacking distinct darkbrown irregular spots with light edges; and (4) elongated limbs. Phylogenetic analyses revealed the presence of a number ofcryptic allopatric species within the C. irregularis complex. Long geological history and complicated relief of the Lang Bianplateau and surrounding areas might have shaped the present diversity within the C. irregularis complex. COI DNA-barcoding appears to be a useful tool to reveal cryptic diversity within the genus Cyrtodactylus.