Arup Kumar Das

An ethnobotanical study of traditional anti-inflammatory plants used by the Lohit community of Arunachal Pradesh, India.

AIM OF THE STUDY Most people especially in rural areas depend on herbal medicines to treat many diseases including inflammation-related ailments such as rheumatism, muscle swelling, cut wound, accidental bone fracture, insect bites, pains and burn by fire and hot water. The objectives of this study were: to catalog ethno-medicinal plants of Lohit community, ecological status, indigenous folk medicinal uses, morphological parts used and to determine their reported pharmacological studies. MATERIALS AND METHODS The ethnobotanical information on traditional medicinal plants exclusively used for management of inflammation-related ailments by the Khampti community of Arunachal Pradesh, India was based on first-hand field survey work through semi-structured interviews. RESULTS AND CONCLUSION A total of 34 species in 32 genera and 22 families were encountered during the field survey. Botanical families such as Asteraceae, Euphorbiaceae, Zingiberaceae and Lamiaceae were represented by the highest numbers of species reported in this study. Thirteen plant species, namely: Bombax ceiba, Canarium strictum, Chloranthus erectus, Xanthium indicum, Lycopodium clavatum, Coleus blumei, Batrachospermum atrum, Chlorella vulgaris, Marchantia palmata, Marchantia polymorpha, Eria pannea, Sterculia villosa and Alpinia galanga are reported for the first time for the treatment of inflammation-related diseases.

Evaluation of anti-inflammatory potential of Chloranthus erectus (Buch.-Ham.) Verd. leaf extract in rats

AIM OF THE STUDY Chloranthus erectus (Buch.-Ham.) Verdcourt (Chloranthaceae) is a shrub native to tropical and temperate zone of Eastern Himalaya of India and South-East Asia and have traditionally been used as a folklore medicine to treat localised swelling, joint pain, skin inflammation, fever and bodyache. In this study, an attempt has been made to demonstrate the anti-inflammatory activity of methanol extract obtained from Chloranthus erectus leaves (MECEL) in acute, sub-acute and chronic mouse models. MATERIALS AND METHODS Inflammation in the hind paw of Wistar albino rat was induced by carrageenan, histamine and serotonin, and tissue granuloma pouch was induced by cotton pellet method. Anti-inflammatory drug-phenylbutazone was used as standard drug for comparison. RESULTS In acute carrageenan-induced rat hind paw edema, oral administration of MECEL at 200 mg/kg produced significant inhibition of edema by 38.34% (p < 0.01) while the histamine- and serotonin-induced sub-acute model, the inhibition of paw edema reached 52.54% (p < 0.001) and 25.5% (p < 0.01), respectively. In a 7-day study, MECEL at 20 and 50 mg/kg produced significant suppression of cotton pellet-induced tissue granuloma formation in rats. CONCLUSIONS This preliminary study revealed that the methanol extract of Chloranthus erectus exhibited significant anti-inflammatory activity in the tested models, and may provide the scientific rationale for its popular folk medicine as anti-inflammatory agent.

Phytochemical assisted synthesis of size and shape tunable gold nanoparticles and assessment of their catalytic activities

A faster and environmentally viable phytochemical assisted reduction method of synthesizing gold nanoparticles (GNPs) is reported. Leaf extract of Amentotaxus assamica plant is used for the first time both as reducing and capping agent for GNPs. The size and shape of GNPs can be systematically tuned by varying the concentrations of metal ion and extract. The GNPs are characterized by microscopic, spectroscopic and diffractometric techniques. The microscopic results confirmed that when the concentration of HAuCl4 is increased, keeping the concentration of the plant extract fixed, the size increase is accompanied by formation of polygonal GNPs. However, when the concentration of plant extract is decreased, keeping the concentration of HAuCl4 the same, the population as well as the size of polygonal GNPs are increased. The results are further confirmed from UV-vis spectroscopic analysis in which all the samples show a major absorption peak at 537 nm, which is accompanied by another weak peak in the higher wavelength region as the polygonal GNPs are formed at higher HAuCl4 concentration. This longitudinal band red-shifted as the size of polygonal GNPs increased. X-ray diffraction studies suggest the formation of pure crystalline GNPs. These GNPs show excellent catalytic activity towards borohydride reduction of different isomeric nitrophenols.

Antipyretic and antibacterial activity of Chloranthus erectus (Buch.-Ham.) Verdcourt leaf extract: A popular folk medicine of Arunachal Pradesh

Objective: The main objective of this work was to study the antipyretic and antibacterial activity of C. erectus (Buch.-Ham.) Verdcourt leaf extract in an experimental albino rat model. Materials and Methods: The methanol extract of C. erectus leaf (MECEL) was evaluated for its antipyretic potential on normal body temperature and Brewer’s yeast-induced pyrexia in albino rat’s model. While the antibacterial activity of MECEL against five Gram (−) and three Gram (+) bacterial strains and antimycotic activity was investigated against four fungi using agar disk diffusion and microdilution methods. Result Yeast suspension (10 mL/kg b.w.) elevated rectal temperature after 19 h of subcutaneous injection. Oral administration of MECEL at 100 and 200 mg/kg b.w. showed significant reduction of normal rectal body temperature and yeast-provoked elevated temperature (38.8 ± 0.2 and 37.6 ± 0.4, respectively, at 2–3 h) in a dose-dependent manner, and the effect was comparable to that of the standard antipyretic drug–paracetamol (150 mg/kg b.w.). MECEL at 2 mg/disk showed broad spectrum of growth inhibition activity against both groups of bacteria. However, MECEL was not effective against the yeast strains tested in this study. Conclusion This study revealed that the methanol extract of C. erectus exhibited significant antipyretic activity in the tested models and antibacterial activity as well, and may provide the scientific rationale for its popular use as antipyretic agent in Khamptis’s folk medicines.

Sunlight induced biosynthesis of silver nanoparticle from the bark extract of Amentotaxus assamica D.K.Ferguson and its antibacterial activity against Escherichia coli and Staphylococcus auerus

Green synthesis of nanoparticles has gained importance due to its eco-friendly, low toxicity and cost effective nature. This study deals with the biosynthesis of silver nanoparticles (AgNPs) from the bark extract of Amentotaxus assamica. The AgNPs have been synthesised by reducing the silver ions into stable AgNPs using the bark extract of Amentotaxus assamica under the influence of sunlight irradiation. The characterisation of the biosynthesised AgNPs was carried out by UV-vis spectroscopy, X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray analysis. The UV-vis spectrum showed a broad peak at 472 nm. Also, the XRD confirmed the crystalline structure of the AgNPs. Moreover, the SEM analysis revealed that the biosynthesised AgNPs were spherical in shape. Also, dynamic light scattering techniques were used to evaluate the size distribution profile of the biosynthesised AgNPs. Furthermore, the biosynthesised AgNPs showed a prominent inhibitory effect against both Escherichia coli (MTCC 111) and Staphylococcus aureus (MTCC 97). Thus the biosynthesis of AgNPs from the bark extract of Amentotaxus assamica is found to eco-friendly way of producing AgNPs compared to chemical method.

Bio-Resources of Northeast India: Sustainable Utilization and Challenges

The lofty mountainous state of India, popularly called a land of the rising sun, Arunachal Pradesh, Northeast India, has exceedingly a diverse geology, topography and climate referred to as “Paradise of the Botanist” which exhibits a plethora of trees, shrubs, herbs, epiphytes, ferns and cryptogams and houses numerous rare, endangered and endemic species. Because 80 % of the people are farmers relying heavily on agriculture especially “jhum” cultivation of the hilly states, therefore the local communities have to depend on wild food and animals as supplement. Bio-resources in Northeast India have been exposed to many challenges in recent years. Many important species of plants having potential medicinal properties, e.g. aromatic plants, cereals and pulses, ornamental plants, timber-yielding plants, etc., are being overexploited in recent years which have resulted in depletion of such species in their natural habitat. Due to enormous prospect of indigenous knowledge on utilization of medicinal plant species and other crop plants, proper conservation measures should be initiated through sustainable utilization of bio-resources so as to prevent exploitation which is a serious concern as regard these species.

Rhodiola sedoides (Crassulaceae), a New Species from Arunachal Pradesh, India

Rhodiola sedoides Lidén & P. Bharali (Crassulaceae), an alpine hermaphroditic species from NW Arunachal Pradesh, India, is described as new to science and compared with other low-growing, hermaphroditic and narrow-leaved alpine Rhodiola species.