Bioprospecting is basically the search for commercially valuable biochemical and genetic resources in plants, animals and microorganisms. These resources may be used in food production, pest control, and the development of new drug and for other related biotechnological applications. Keeping in view the importance of the Bioprospecting, in India, being a megadiversity country, the current national priorities are a) Bioresources mapping, inventorisation and monitoring of biological diversity, and b) Bioprospecting of molecules and genes for product development especially from higher plants, microbes, fungi and lichens from different agro climatic regions including Hot Spots, Temperate, coastal and Desert (both Arid and Cold) region.
At MSSRF studies in the last few years focused on developing a site specific ecological methodology (Mangrove, rainforest ecosystems) to quantify the lichen diversity and the key environmental gradients determining their distribution, as well as extensive studies on the secondary compounds of selected plant species such as Excoecaria agallocha, Dodonea viscosa etc. based on traditional knowledge that provided leads for developing effective bioprospecting of secondary compounds.
The focus of the bioprospecting program at the MSSRF lies in
- a thorough understanding on the target species (Medicinal plants, Lichens),
- extraction and characterization, bioassays, preliminary and secondary screening for drug prospecting and screening against target pest through field trials
- a conservation strategy to reduce pressure on naturally occurring lichen/plant material for compound extraction is undertaken by establishment of tissue culture protocols. These culture protocols have provided additional compounds for preliminary exploration of the molecular aspects of selected plant/lichen species.
In vitro protocols has been developed for medicinal plants like Aegle marmelos, Bacopa monniera, Curculigo orchioides, Eupatorium triplinerve, Gymnema sylvestris, Hemidesmus indicus, Jatropha curcas, Sauropus androgynous, Tinospora cordifolia, Tylophora indica. MSSRF also carried out a comprehensive genetic fidelity analysis of the micro-propagated plants to confirm their genetic uniformity with the parent material and also assess their stability in the field. MSSRF has so far developed protocols for the propagation of rare or endangered or threatened plants like Casearia rubescens, Ceropegia bullbosa var lishii, Ceropegia jaini, Crotolaria logipes, Freria indica, Kaempferia glanga, Myxopyrum serratulum, Piper barberi, Rauwolfia micrantha, Rauwolfia tetraphylla, Syzygium travancoricum and Uraria picta.
Bioprospecting for secondary compounds from mangroves and terrestrial plants
Mangroves and estuarine plant species are critically challenged for survival owing to the biotic and abiotic stress that has eventually strengthened their secondary metabolic machinery to synthesize a plethora of small molecules of therapeutic and agricultural importance. Due to the informidability of their habitat only limited research is being done around the world. Hence, the Bioprospecting project at MSSRF has been focused on elucidation of bioactive natural molecules from mangroves. Some of the naturally available secondary metabolites possess pesticidal, anti-microbial and anti-cancer properties. Owing to the insect stress and the microbial load, many of the mangrove plants have adapted themselves to combat and survive by producing an array of molecules that are pesticidal and microbicidal. Our strategies were focused on purification and characterization of these phytochemicals that could be formulated for mass-utility applications.
The Bioprospecting research has focussed on utilising species such as Excoecaria agallocha, Syzygium travancoricum, Lobelia nicotianafolia, Rhizhophora apiculata, Salicornia brachiata, Jatropha gossypifolia and Catharanthus roseus for various medicinal and agricultural applications.
The significant outcome of these initiatives are:
- Anti-fungal property of essential oil from S. travancoricum revealed the presence of Trans Ocimin, Trans Caryophyllin and Copaene.
- Pesticidal bioassays with the hexane extract of E. agallocha against Helicoverpa armigera suggested the presence of Taraxerol, Taraxerone, labdane diterpenoids, linear hydrocarbons and a mixture of uncharacterized ditrpenoids. 1% and 3% biopesticide formulations show promising results against H. armigera, Earias vitella and Spilosoma obliqua, under the field conditions in various crops like Lady’s finger, Chickpea, Pigeon pea, Tomato and Cotton.
- Pesticidal activity of crude extracts of L. nicotianafolia is promising and needs to be further worked on.
- 2% crude water extract of E. agallocha leaf inhibited 100% of Mycobacterium tuberculosis H37Rv strain.
- Crude methanol extract of E. agallocha leaf effectively controlled the malignancy in Breast Cancer (MDA-MB) and Thoracic cancer (HEp-2) Cell Lines.
- Crude hexane extract and fractions of E. agallocha roots effectively inhibited the larva of Culex quinquefasciatus mosquitos.
- Essential oil analysis of S. brachiata suggested the superiority of the constituents when compared to other edible oils available in the market.
- Root extracts taken from C. roseus suggested the presence of anti-microbial compounds against Bacillus cereus, B. subtilis and a few gram negative human bacterial pathogens.
- Lipophilic extract of the whole seed oil of C. roseus was detrimental to 2nd instars larva of H. armigera under in-vitro conditions. GC-MS analysis of the purified fraction suggested the presence of a mixture of fatty acids.
- Jatrophone, purified from the crude hexane extract of J. gossypifolia roots exhibited remarkable anti-bacterial activity against the tested human pathogens. Further testing of the compound against other human pathogens would help us to understand the metabolite better.
- In vitro herbivore-induction studies in J. curcas showed the presence an unknown compound being synthesized after the wounding
- Phytochemical profiling of Navara and other 10 medicinal rice landraces i.e. Chennellu, Veliyan, Gandhakashala, Cheerakashala, Arupatham cheera and other Navara varieties, were done. 2 of the purified oils from the lipophilic extract of Navara (black variety) are analyzed by GC-MS for fatty acids and volatile plant oils. Another amorphous metabolite from the same extract that is unique to Navara and Veliyan varieties is under spectral analysis for characterization. Anti-fungal properties of essential oils from S. travancoricum and pesticidal property of L. nicotianafolia are being further worked on. E. agallocha formulation is available for controlling pests in nursery gardens and farmers’ fields. Crude water extract of E. agallocha leaf could be fractionated and assayed against M. tuberculosis. Formulation of the hexane extract of E. agallocha roots, as oil (similar to the linear hydrocarbon larvicides in the market) or mosquito mat against other vector species.