Chemical composition and bioactivity of methanolic extract obtained from Lepista sordida

The present study aimed at the evaluation of chemical composition and bioactive potential of methanolic extract obtained from Lepista sordida in terms of antioxidative and antimicrobial efficacy. The macrofungus is recognized for its high nutritional value and medicinal properties. However, to the best of our knowledge bioactivity of its methanolic extract is yet to be explored. In this investigation, quantitative analysis of mycochemicals revealed the extract contained significant amount of phenolic compounds such as phenols and flavonoids. Ascorbic acid was found in higher amount than β carotene and lycopene which were present in vestigial amounts. A phenolic profile was also determined using high performance liquid chromatography that further confirmed the presence of 10 phenolic constituents in the extract. Furthermore, the extract was subjected for determining antioxidant potential in different in-vitro assays. The findings showed remarkable 2, 2-Diphenyl-1-picrylhydrazyl and ABTS radical scavenging ability which was evident by low EC50 values, 330 µg/mL and 30 µg/mL respectively. The extract also demonstrated good chelating and reducing ability, an important marker of antioxidant compounds. Antimicrobial screening displayed positive results against Staphylococcus aureus and Escherichia coli. Altogether, the observations recommend therapeutic application of this mycotaxon on a commercial basis.

Phytochemical Study and Antioxidative Property of Ethanolic Extract from Termitomyces clypeatus.

The present study documents the phytochemical screening and antioxidant properties of ethanolic extract of Termitomyces clypeatus. Phytochemical constituents like phenols, flavonoids and ascorbic acid were much higher than β carotene and lycopene. The analysis of the phenolic compounds performed by HPLC, revealed the presence of pyrogallol (0.223 μg/mg) and cinnamic acid (0.095 μg/mg). Antioxidant activity was evaluated through superoxide radical scavenging assay, DPPH radical scavenging assay, chelating ability, reducing power and total antioxidant capacity determining assays. Their EC50 values ranged from 0.21 μg/ml to 3.22 mg/ml. Result implies that T. clypeatus can not only serve as a food supplement but also be used as treatment for various oxidative stress related diseases.

In vitro free radical scavenging activity of wild edible mushroom, Pleurotus squarrosulus (Mont.) Singer.

Cellular damage caused by reactive oxygen species has been implicated in several diseases and hence antioxidants have significant importance in human health. Cold water, hot water and methanolic extract of Pleurotus squarrosulus were evaluated for antioxidant activity against hydroxyl radical, DPPH (1,1-Diphenyl-2-picrylhydrazyl) radical, superoxide radical, nitric oxide (NO) scavenging, reducing power, ferrous ion chelating ability and -carotene/linoleic acid assay. Total phenol, flavonoid, -carotene and lycopene content were also determined. Hot water extract showed significant antioxidant activity in all the test systems. Hydroxyl radical scavenging activity of all the extracts has been significant compared to positive control. Hot water extract has been found to have higher phenolic, total flavonoid, -carotene and lycopene content than cold water and methanolic extract of the mushroom. Results of this study showed that, hot water extract has maximum antioxidant property and may be utilized as a promising source of therapeutics.

Antioxidant and nitric oxide synthase activation properties of Ganoderma applanatum.

In vitro evaluation of antioxidant activities of Ganoderma applanatum showed significant inhibition of lipid peroxidation, and potent hydroxyl radical scavenging activity when compared with standard drug catechin. IC50 values of crude, boiled and ethanolic extracts of G. applanatum were 604.8, 624 and 267 microg/ml, respectively in case of hydroxyl radical scavenging activity, and 441, 520.5 and 166.16 microg/ml, respectively in case of lipid peroxidation. Furthermore, crude, boiled and ethanolic extracts also increased significantly nitric oxide production (156.67, 121.88 and 742 pmole/mg dry wt/hr, respectively) over the control. The results of present investigation revealed that G. applanatum have potential therapeutic use.

Nitric oxide: a common antipathogenic factor of plants.

In the present study, nitric oxide synthase/nitric oxide (NOS/NO) status was tested in the host plants infected with fungi, bacteria and virus. In each case cytosolic nitric oxide synthase (Cyt-NOS) of diseased plants was inhibited and inhibition was competitive in nature in respect to l-arginine, the substrate for the enzymic activity. Elevation of host nitric oxide (NO) level before infection using nitric oxide (NO) donor protected disease initiation significantly. The nature of enzyme kinetics and the manner of disease protection by nitric oxide donor (NO-donor) was similar in all the three cases of infection. It was concluded that nitric oxide was a common antipathogenic factor of plants.

Antioxidant and nitric oxide synthase activation properties of Auricularia auricula.

In vitro evaluation of antioxidant activities of Auricularia auricula showed significant inhibition of lipid peroxidation, and potent hydroxyl radical scavenging activity when compared with standard drug catechin. IC5o value of crude, boiled and ethanolic extracts of A. auricula represented 403, 510, and 373 microg/ml respectively in case of hydroxyl radical scavenging activity and 310, 572 and 398 microg/ml respectively in case of lipid peroxidation. Furthermore, crude, boiled and ethanolic extracts also increase significantly nitric oxide production (664, 191 and 850 pmole/mg dry wt/hr respectively) over the control. The present results revealed that A. auricula had potential therapeutic use.