Rajesh Bajpai

Accumulation and toxic effect of arsenic and other heavy metals in a contaminated area of West Bengal, India, in the lichen Pyxine cocoes (Sw.) Nyl.

Ecological indicators can be used to assess the condition of the environment, to provide an early warning signal of changes in the surrounding environment or to diagnose the causes of an environmental problem. The study aims to evaluate the applicability of a common foliose lichen Pyxine cocoes (Sw.) Nyl., as an indicator to evaluate the arsenic and heavy metal rich sites. The naturally growing lichen and its substratum (bark) were utilized to biomonitor the accumulation of arsenic (As) and other heavy metals (Al, Cd, Cr, Cu, Fe, Pb and Zn) in Chinsurah, a highly As contaminated area of West Bengal. Significantly higher levels of Al, Cr, Fe, Pb and Zn (p<0.01), Cd and Cu (p<0.05) were found in the lichens especially in samples collected from road sites. Higher As concentration (48.1±2.1 μg g(-1)) in samples were found near the paddy field, indicating pesticide-herbicides as its source used in agriculture. The substrate exhibits lower concentration of most of the metals while Cr, Cd and Pb were below detection limit. As evident from the bioaccumulation factor most of the metals accumulated in lichen thallus are air borne. Chl a and Chl b concentrations decreased significantly with increasing distance from roadside whereas the carotenoid and protein showed an enhanced level. The chlorophyll stability index, chlorophyll degradation and carotenoid contents were found to be the most sensitive parameters to assess the vitality of lichen thallus against changing environment.

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.

Performance of a naturally growing Parmelioid lichen Remototrachyna awasthii against organic and inorganic pollutants

The present study aims to assess the level and possible sources of organic and inorganic pollutants in Mahableshwar city in Western part of India and their effect on naturally growing foliose lichen Remototrachyana awasthii (Hale & Patw.) Divakar & A. Crespo. This lichen species growing abundantly in the area was collected from eight different sites on the basis of anthropogenic activities detected in the area. The concentration of inorganic heavy metals (Al, As, Cd, Cr, Fe, Pb, Mn, and Zn) and polycyclic aromatic hydrocarbons (PAHs) were analyzed and correlated with photosynthetic pigments (Chl a, Chl b, total chlorophyll, and carotenoid) together with chlorophyll degradation and protein contents. The concentration of most of the metals at different sites was significantly greater than at the control site (P < 0.001). The highest metal content was found at Bus Stand and Panchgani, a tourist place that experiences heavy traffic activities. The concentration of PAHs, particularly of two-and three-ringed PAHs, was also found to be the highest in samples collected at Bus Stand area. The chlorophyll degradation and protein content were found to be the most sensitive parameters to assess the vitality of lichen thallus against wide range of air pollutants. The effectiveness of R. awasthii as a biomonitor will be investigated in the near future by comparing this species with other biomonitors.

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.

Recent Advances in Lichenology

This chapter focuses on the application of spaceborne remote sensing and GIS for biodiversity conservation in the context of the state-of-the-art technology which has enhanced the classical approach. It reviews currently available instruments, i.e. space-borne or satellite sensors providing data which can be used without analysis or interpretation for studying individual organisms, species assemblages or ecological communities on ground. Subsequently, the image processing and GIS techniques developed to derive information from the captured satellite data are reviewed, and finally, this chapter concludes by reviewing the use of remote sensing and GIS techniques for mapping, monitoring and modelling lichens and their habitats.

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.

Preliminary Lichenometric Studies in Eastern and North-Western Himalaya

Lichenometry is an extremely useful technique in dating moraine ridge and recent glacier retreat in polar and alpine regions. The study relates the size of the lichen thallus to the minimum age of the exposure of the surface on which it grows which consequently helps in assessment of the age of the boulders. The Lichenometric studies are carried out in Kupup and Thangu area of eastern Himalaya in Sikkim and Thajiwas glacier in Ganderbal district of north western Himalaya of Jammu and Kashmir with the help of diameters of a common crustose lichen Rhizocarpon geographicum growing luxuriantly on exposed boulder. The Thajiwas glacier showed retreat of 200 m in 279 years while in Thangu and Kupup area of eastern Himalaya the retreat was estimated as 200 m in 100 and 91 years respectively. The rate of retreat was slightly more faster in eastern Himalayan (20 mm/century) than the north-western Himalaya region (18.5mm/century).

Ecological implication of variation in the secondary metabolites in Parmelioid lichens with respect to altitude.

Lichens are known to synthesize a variety of secondary metabolites having multifunctional activity in response to external environmental condition. Two common lichen extrolites, atranorin and salazinic acid, are known to afford antioxidant as well as photoprotectant nature depending on the abiotic/biotic stress. The present investigation aims to study the influence of altitudinal gradient on the quantitative profile of atranorin and salazinic acid in three lichen species, Bulbothrix setschwanensis (Zahlbr.) Hale, Everniastrum cirrhatum (Fr.) Hale and Parmotrema reticulatum (Taylor) Choisy, Parmeliaceae using liquid chromatography-mass spectrometry (LC-MS/MS) technique. Samples were collected from high-altitude area, usually considered as non-polluted sites of Garhwal Himalaya. Characterization and quantification of the lichen substances in samples were carried out comparing with the standards of atranorin and salazinic acid. Results indicated significant variation in the chemical content with the rising altitude. All the three lichen species showed higher quantities of chemical substances with the altitudinal rise, while among the three lichen species, E. cirrhatum showed the highest quantity of total lichen compounds. The higher abundance and frequency of E. cirrhatum with increasing altitude as compared to B. setschwanensis and P. reticulatum may be attributed due to the presence of higher quantity of photoprotecting/antioxidant chemicals especially salazinic acid. Thus, the present study shows the prominent role of secondary metabolite in wider ecological distribution of Parmelioid lichens at higher altitudes.

Change in atmospheric deposition during last half century and its impact on lichen community structure in Eastern Himalaya.

Climatic fluctuations largely affects species turnover and cause major shifts of terrestrial ecosystem. In the present study the five decade old herbarium specimens of lichens were compared with recent collection from Darjeeling district with respect to elements, PAHs accumulation and carbon isotope composition (δ13C) to explore the changes in climatic conditions and its impact on lichen flora. The δ13C has increased in recent specimens which is in contrast to the assumption that anthropogenic emission leads to δ13C depletion in air and increased carbon discrimination in flora. Study clearly demonstrated an increase in anthropogenic pollution and drastic decrease in precipitation while temperature showed abrupt changes during the past five decades resulting in significant change in lichen community structure. The Usneoid and Pertusorioid communities increased, while Physcioid and Cyanophycean decreased, drastically. Lobarian abolished from the study area, however, Calcicoid has been introduced in the recent past. Probably, post-industrial revolution, the abrupt changes in the environment has influenced CO2 diffusion and/C fixation of (lower) plants either as an adaptation strategy or due to toxicity of pollutants. Thus, the short term studies (≤5 decades) might reflect recent micro-environmental condition and lichen community structure can be used as model to study the global climate change.