A report on pharmacognostical evaluation of four Adiantum species, Pteridophyta, for their authentication and quality control

Genus Adiantum L., Pteridaceae, is an important fern used in traditional systems of medicine. Different species of Adiantum are known as avenca in Brazil; hansraj/hanmspadi in India; maiden hair fern in English. The present study aims to develop the quality control parameters of four similar looking Adiantum species viz. A. capillus-veneris L., A. lunulatum Burm. f., A. peruvianum Klotzsch, and A. venustum D. Don. Standard methods for macro-microscopic evaluation, physico-chemical parameters and HPTLC were used for authentication and identification. The salient distinctive characters under the microscope are the presence of slightly wavy elongated epidermal cells in A. capillus-veneris; epidermal cells strongly wavy in A. lunulatum; star shaped epidermal cells and mixed spores of regular and irregular shaped in A. peruvianum; stomata on both the surfaces of pinnule, absence of spinulus spores only in A. venustum. In addition, rachis anatomy showed different cellular and stellar characteristics as identifying characters of aforesaid four Adiantum species. Physico-chemical parameters and HPTLC finger print profiles along with stigmasterol and lupeol play significant role for the quality evaluation of raw drugs. The above finding will serve the purpose of quality control and assurance for the future studies.

Comparison of two ferns (Adiantum capillus-veneris Linn. and Microsorium punctatum (Linn.) Copel) for their Cr accumulation potential and antioxidant responses.

Study was undertaken to compare Cr accumulation in two ferns (Adiantum capillus-veneris Linn. and Microsorium punctatum (Linn.) Copel) and the role of antioxidants were also investigated towards metal tolerance in order to assess the use of ferns in phytomediation/ phytostabilization. Different concentrations (0, 50, 100, 150 microg g(-1) dw) of Cr were added to fern planted in pot containing 1 kg soil. In both the ferns, Cr accumulation increased with increase in metal concentration and maximum accumulation of 800.5 microg g(-1) (fronds) and 1457.4 microg g(-1) (roots) in M. punctatum and 660.8 microg g(-1) (fronds) and 1259.6 microg g(-1) (roots) in A. capillus-veneris was recorded. The increase in the levels of malondialdehyde, antioxidants and antioxidant enzymes (superoxide dismutase, glutathione peroxidase) in A. capillus-veneris was less pronounced than M. punctatum under Cr exposure as compared to their respective controls. In view of less decrease in chlorophyll content and antioxidants along with higher accumulation of Cr in the fronds M. punctatum, is indicative of its higher tolerance towards Cr. However, bioaccumulation factor (concentration of Cr in fronds/concentration of Cr in the soil) of both the ferns was recorded > 1 which qualifies the plants as potential Cr hyperaccumulator and suitable for phytoremediaton.

In-vitro shoot regeneration via caulogenesis in fern, Pteris vittata L.

An attempt was made to standardize the protocol for the shoot regeneration via caulogenesis in Pteris vittata L. employing leaf primordium explants. Calli were induced on Murashige and Skoog's (MS) and Parkers and Thompson's (P and T) media supplemented with different combinations of 2, 4-dichlorophenoxyaceticacid (2, 4-D), 6-benzylaminopurine (BAP), alpha-naphthalene acetic acid (NAA) and Indole-3-acetic acid (IAA). A combination of full strength MS medium with 2, 4-D (2.26 microM) and BAP (2.22 microM) was found to be ideal for profuse callusing (80%) against other combinations. More shoot differentiation (2.8 +/- 0.06) was achieved from the calli on one-fourth strength of P and T media fortified with BAP (4.44 microM) and NAA (2.68 microM) when compared to other combinations but statistically not significant.

Metabolic adaptation of Pteris vittata L. gametophyte to arsenic induced oxidative stress.

The sporophyte and gametophyte of Pteris vittata are arsenic hyperaccumulators, however, little is known about the mechanism by which the gametophyte deals with this toxic element. An in vitro system (spores grown in arsenic amended nutrient media) was used to investigate the impact of arsenic on growth of the gametophyte and the role of antioxidative systems in combating As-stress. When mature spores of P. vittata were grown in medium amended with 0-50 mg kg(-1) of arsenic (as arsenate), the arsenic concentration in the gametophyte increased, with increasing arsenate in the media, but did not inhibit the spore germination and biomass development. Increases in the level of antioxidant enzymes, superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase, and glutathione-Stransferase) and of ascorbic acid and glutathione probably enabled the gametophyte to withstand the oxidative stress caused by arsenate.

Arsenic accumulation pattern in 12 Indian ferns and assessing the potential of Adiantum capillus-veneris, in comparison to Pteris vittata, as arsenic hyperaccumulator.

The present study was undertaken to evaluate the ability of some Indian ferns to accumulate and tolerate arsenic. Twelve species of Indian ferns were exposed to 10 mg L(-1) arsenic as sodium arsenate for 15 days in hydroponic system. Depending on the arsenic uptake in the plant parts--Pteris vittata, Pteris cretica, Adiantum capillus-veneris and Nephrolepis exaltata may be categorised as arsenic accumulator. Further, A. capillus-veneris plants were grown in arsenic contaminated soil (200-600 mg kg(-1)) under green-house condition, to assess its arsenic accumulation and tolerance mechanism, in comparison to known As-hyperaccumulator--P. vittata Linn., growing in the same conditions. The experiment identified A. capillus-veneris having a potential to tolerate arsenic up to 500 mg kg(-1). The plants were analysed for the extent of oxidative stress, as a result of arsenic accumulation. A. capillus-veneris was able to detoxify the arsenic stress through induction of anti-oxidant defence system.

In Vitro Antibacterial and Antifungal Properties of Aqueous and Non-Aqueous Frond Extracts of Psilotum nudum, Nephrolepis biserrata and Nephrolepis cordifolia.

Plants are an important source of neutraceuticals that have proved to be effective against important microbial infections of humans. Lower plants are gaining importance in this regard. The present study is aimed at investigating the antimicrobial properties of three selected ferns, Psilotum nudum, Nephrolepis biserrata and Nephrolepis cordifolia. The aerial parts of the selected ferns, P. nudum, N. biserrata and N. cordifolia, were fractionated in different solvents. These fractions were concentrated to obtain a powder and were tested against nine bacterial and three fungal strains according to disc diffusion method. The water and ethanol fractions were active against most of the tested bacterial and fungal strains, some of these were more effective than the controls tested. Present study suggests that the pteridophytes, P. nudum, N. biserrata and N. cordifolia could be good source of antimicrobials. These natural compounds might be more effective as the microbes may have lesser chance of developing resistant mutants.

Antimicrobial activity of some important Adiantum species used traditionally in indigenous systems of medicine.

Adiantum Linn. of Adiantaceae family is one of the most common and widely distributed species. Ethnomedicinally, the genus is important and popularly known as "Hansraj" in Ayurvedic System of Medicine. It has been used in cold, tumors of spleen, liver and other viscera, skin diseases, bronchitis and inflammatory diseases. It is also considered as tonic and diuretic. In the present study its four important species, i.e. Adiantum capillus-veneris, Adiantum peruvianum, Adiantum venustum and Adiantum caudatum were collected and extracted with methanol. These extracts were tested for their antimicrobial agents against five gram positive, six gram negative (including multiresistant bacteria Staphylococcus aureus) and eight fungal strains using standard microdilution assay. The maximum activity was exhibited by the methanolic extract of Adiantum venustum followed by Adiantum capillus-veneris, Adiantum peruvianum and Adiantum caudatum. The methanolic extract of Adiantum capillus-veneris had very low MIC value (0.48 microg/ml) against Escherichia coli whereas, Adiantum venustum extract against Aspergillus terreus with MIC of 0.97 microg/ml. Total phenolic constituents of Adiantum species viz. Adiantum venustum, Adiantum capillus-veneris, Adiantum peruvianum and Adiantum caudatum were 0.81% (w/w), 0.83% (w/w), 0.71% (w/w) and 0.52% (w/w), respectively (as gallic acid equivalent); implying that the observed activity could be related to the amount of phenolics.