Sanjeeva Nayaka

Commercial and Ethnic Use of Lichens in India

The diversity of Indian lichen flora has undergone a considerable decline in the last five decades. Among the various anthropogenic activities, overexploitation and selective removal of economically important lichens have become major threats to the lichen flora of the country. Commercial samples of lichens collected from different states of India were studied for their source and commercial use. Among samples offered for sale, 38 different lichen species were identified. The western Himalayas proved to be the main area for lichen collection, while some lichen species also come from the central and Western Ghats. Local traders coordinate the lichen collection and then sell the material to traders in the foothills, and from there it is processed and distributed to other parts of the country and abroad. Because lichens belonging to the families Parmeliaceae and Physciaceae are the ones most exploited commercially, they are recommended for inclusion in the CITES list.

Biodiversity, bioaccumulation and physiological changes in lichens growing in the vicinity of coal-based thermal power plant of Raebareli district, north India.

The lichen diversity assessment carried out around a coal-based thermal power plant indicated the increase in lichen abundance with the increase in distance from power plant in general. The photosynthetic pigments, protein and heavy metals were estimated in Pyxine cocoes (Sw.) Nyl., a common lichen growing around thermal power plant for further inference. Distributions of heavy metals from power plant showed positive correlation with distance for all directions, however western direction has received better dispersion as indicated by the concentration coefficient-R(2). Least significant difference analysis showed that speed of wind and its direction plays a major role in dispersion of heavy metals. Accumulation of Al, Cr, Fe, Pb and Zn in the thallus suppressed the concentrations of pigments like chlorophyll a, chlorophyll b and total chlorophyll, however, enhanced the level of protein. Further, the concentrations of chlorophyll contents in P. cocoes increased with the decreasing the distance from the power plant, while protein, carotenoid and phaeophytisation exhibited significant decrease.

Development and characterization of a novel Swarna-based herbo-metallic colloidal nano-formulation – inhibitor of Streptococcus mutans quorum sensing

Herbo-metallic preparations such as bhasmas (ash) are used traditionally in Indian and Chinese medicinal systems. In Ayurveda, Swarna (gold) nanoparticles are used as Swarna bhasma to treat several clinical manifestations. While Usnea longissima, a medicinal lichen, ethnobotanical is known for the treatment of tooth cleaning and infectious diseases. The study aims to develop a herbo-metallic colloidal nano-formulation containing Swarna nanoparticles and polyphenols rich U. longissima extract (ULE) and evaluate its anti-quorum sensing (QS) property against Streptococcus mutans, an idea that has never been explored before, with a view towards combating the emergence of antibiotic resistance often linked with QS-regulated virulence factors and biofilms. The synthesized Uh-Au@Nano-CF was confirmed by a peak at 550 nm in the UV-visible spectrum. The obtained XRD data confirmed the crystalline nature of nanoparticles of 28 nm size. TEM image revealed that all the particles were spherical with a narrow size range of 5–23 nm. The FTIR result clearly showed that the ULE containing secondary OH as functional groups induces encapsulation of nanoparticles. HPTLC and HPLC fingerprinting of ULE confirmed the presence of polyphenols, including orcinol, arabitol, apigenin, and usnic acid. The data from the inhibition of violacein production in C. violaceum 12 472 revealed that the Uh-Au@Nano-CF at sub-lethal concentrations (5, 10 and 15%) show potent anti-QS activity. The treatment of Uh-Au@Nano-CF was found to inhibit the secretion of S. mutans virulence factors, including acid production, ATPase, enolase, lactate dehydrogenase, protease, total exopolysaccharide content, and glucosidase. The Uh-Au@Nano-CF in a concentration dependent manner showed anti-biofilm activity, inhibiting biofilm formation. Eventually, it was also documented that the Uh-Au@Nano-CF at 15% dilution enhanced the susceptibility of S. mutans to its conventional antibiotics. This study introduces not only a novel antimicrobial herbo-metallic colloidal nano-formulation, but also explores its new biomedical application, which targets QS-regulated virulence factors and biofilm of S. mutans rather than its viability.

The genus Usnea: a potent phytomedicine with multifarious ethnobotany, phytochemistry and pharmacology

The genus Usnea Adans. (Parmeliaceae; lichenized Ascomycetes) is a typical group of mostly pale grayish-green fruticoselichens that grow as leafless mini-shrubs. More than 360 species of Usnea are known in the world. Usnea has long been thought to have treat various illnesses in addition to its historical use as dyes, cosmetics, preservatives, and deodorants, particularly in eastern countries such as China, Japan, Taiwan, India and Europe. The current review focuses on the traditional uses and phytochemistry aspects of different Usnea species, and discusses the pharmacological findings and toxicology of their extracts and isolated compounds. The available compilation of data will provide a new base for future perspectives and highlight the need for further studies of this potent herbal source to harvest more beneficial therapeutic drugs. Nineteen species of the genus Usnea are found to be important folk medicines all over the world. It is evident from the comparative analysis of the searched literature that the genus Usnea has been used for various purposes for centuries and its long and traditional medicinal history was well documented in the past. As per ancient records and recent scientific literature, the species of genus Usnea have been used as promising traditional medicines, exerting an array of therapeutic properties to relieve sore throats, bronchitis, cold, flu, infection, and indigestion. Phytochemical analysis confirms the general presence of a wide range of metabolites, polysaccharides, fatty acids, phenolic acids, flavonoids, terpenes, sterols, depsides, depsidones, and benzofurans. As specific constituents, usnic acid, polyphenols, and depsides have been considered as main efficacy component for antibacterial and antifungal activities. In addition, pharmacological analysis also revealed that other pure compounds and crude extracts of Usnea species prove to be significant anti-cancer, anti-proliferative, anti-oxidant, anti-viral, anti-inflammatory, anti-ulcer, hepatoprotective, and anti-genotoxic agents. However, there is a need for more precise investigations to examine the clinical value of both isolated pure compounds and crude extracts and to elucidate their mechanisms of action. Apart from clinical validation and elucidation of their mechanism of action, biosafety studies of the compounds are also important to legitimately use the potential bioactive compounds for the further development of future lead drugs.

Effect of metal content on chlorophyll fluorescence and chlorophyll degradation in lichen Pyxine cocoes (Sw.) Nyl.: a case study from Uttar Pradesh, India

The major aim of the present study is to identify the relationship of physiological parameters of the photosynthetic system with the elemental content of the naturally growing lichen Pyxine cocoes. The epiphytic foliose lichen P. cocoes was used as biomonitoring indicator and effect of atmospheric pollutants on physiological integrity was examined. Potential quantum yield of Photosystem II (fluorescence ratio Fv/Fm), chlorophyll degradation ratio and quantitative estimation of Al, As, Cd, Cr, Cu, Pb, Fe and Zn contained in the lichen thallus were ascertained. Statistical analysis revealed significantly positive correlations between Fv/Fm and element contents (Al and Cr). The chlorophyll degradation as well as alteration in the pigment content was found to be the most sensitive parameters to assess the vitality of lichen thallus against polluted environment. The species accumulated higher amounts of elements (Al, As, Cu, Fe and Zn) in the polluted sites as compared to the non polluted sites. It was also evident from this study that vehicular emission played a significant role in the release of elements as pollutants in the surrounding environment. The effectiveness of this lichen could be further investigated by comparing this species with other biomonitors.

Two new species of saxicolous Pyxine with yellow medulla from southern India

Abstract: Two new species of Pyxine with yellow medulla from saxicolous habitats are described asnew to science. The new species P. punensis has an isidiate, UV+ yellow thallus with 0 3–0 6mmwide lobes. Pyxine yercaudensis has smaller ascospores (13–16 6–7mm), lacks vegetative propagulesand lacks lichexanthone.Key words: Dirinaria, Eastern Ghats, lichens, Physciaceae, taxonomyAccepted for publication 23 August 2012 IntroductionThe lichen genus Pyxine was established byElias Fries in 1825 and it is a prominentmember of the family Physciaceae. The genusis characterized by closely appressed, radiat-ing, whitish to bluish grey, foliose thalli withnarrow lobes often covered with pruina,maculae and pseudocyphellae. The apothe-cia have a lecanorine to lecidine margin, K+purple epihymenium, hyaline hymenium andbrown hypothecium. Ascospores are mostly2-celled, brown, thick-walled, ellipsoidaland mischblastiomorphic-type. Pyxine is veryclose to Dirinaria, which can be differentiatedby the absence of rhizines (placodioid condi-tion),K-- epihymenium,andmedullarychem-istry. Molecular phylogenetic studies haveshown that there is a close relationship be-tween these two genera but they are clearlyseparated as distinct lineages (Helms et al.2003). In Pyxine, the colour of the medullacan range from white to stramineous orsometimes distinctly yellow or orange ochra-ceous and it plays an important role in thetaxonomyofthegenus.Thespecies ofPyxinemostly contain atranorin and several un-identified terpenes as secondary metabolites.Some species contain lichexanthone ratherthan atranorin and such thalli emit a cream-ish, yellow fluorescence when viewed underlong wavelength ultraviolet light (350 nm).The genus Pyxine is mainly pantropicalto subtropical with several species extendinginto temperate or oceanic regions, and com-prises c. 65 species (Elix 2009). Index Fun-gorum (www.indexfungorum.org) holds atotal of 162 records for Pyxine,which include96 species and several infra-specific taxa.However, many taxa in that list need valida-tion (e.g. P. consocians Vain. is mentioned assynonym of P. subcinerea Stirt.). A number ofstudies on Pyxine throughout the world areavailable. Swinscow & Krog (1975) reported23 species from East Africa. Initially Rogers(1986) studied Pyxine from Australia butthis treatment was later updated by Kalb(1994) and Elix (2009), where 26 specieswere reported. Amtoft (2002) studied Pyxinefrom the eastern United States, Imshaug(1957) from North and Middle America,Kalb(2001)fromtheGreaterSonoranDesertRegion, Hu & Chen (2003) from China,Moberg (1983) from Europe and Kashiwa-dani (1977a, b, c) from Japan. Obermayer &

New taxa and new reports of Phyllopsora (lichenized Ascomycotina) from India

An account of 14 species of Phyllopsora from India is provided. P. catervisorediata and P. himalayensis are described as new species, while P. corallina var. subglaucella as a new variety. P. albicans, P. breviuscula, P. chlorophaea, P. confusa, P. isidiotyla, P. kalbii, P. mauritiana, P. nemoralis, P. subcrustacea, and P. swinscowii are new records for the Indian lichen biota.

A new isidiate species of Hemithecium Trevis. (Ascomycota, Graphidaceae ) from India

Hemithecium isidiatum from the Eastern Himalayas is described as new to science. It is the first isidiate species in the genus Hemithecium and is otherwise characterized by hyaline muriform ascospores and the presence of salazinic acid.

Two new species in the lichen genus Phlyctis (Phlyctidaceae) from India

An account is given of the lichen genus Phlyctis in India. Phlyctis monosperma, with single spored asci and psoromic acid, and P. subhimalayensis, lacking secondary metabolites, are described here as new to science. A worldwide key to the genus is provided.

Lichen synusiae in East Antarctica (Schirmacher Oasis and Larsemann Hills): substratum and morphological preferences

Antarctic terrestrial ecosystems experience some of the most extreme growth conditions, where plant distribution is determined by favourable environmental gradients of temperature and moisture along with micro-topography of habitats. Lichens are among the most tolerant symbiotic organisms which constitute dominant component in the terrestrial biota of Antarctica. There are various studies dealing with patterns of lichen diversity of various regions of Antarctica are done but in east Antarctica such studies are scanty. Lichen synusiae of Schirmacher Oasis and McLeod Island, Larsemann Hills, East Antarctica were studied in order to determine their morphological and substratum affinities. The Lichen synusiae of the study sites was represented by 71 species, 24 genera and 13 families in Schirmacher Oasis and 27 species, 18 genera and 10 families in McLeod Island, Larsemann Hills. Hierarchical cluster analysis of lichen communities on the basis of growth form diversity and substratum occurrence showed that crustose growth form and saxicolous (on rock, stones and moraines) habitat were the most preferred, in both study sites. The study presents a representative account of morphological and substratum preference patterns in lichen synusiae of east Antarctica, which can be of fundamental importance for future lichenological investigation in the region.