Introduction

Mushrooms have been used as medicine since Neolithic and Paleolithic eras20. The wild edible mushrooms comprise a vast and yet largely untapped source of powerful new pharmaceutical products4. Several active principals of mushrooms have been used in health care for treating simple and age old common diseases like skin disease to present day complex and pandemic disease like AIDS and cancer24871117321. Recent findings indicate that mushrooms are valuable source of biologically active compounds with potential of protecting cellular DNA from oxidative damage, such protective compounds have possible commercial value as dietary supplements for offsetting adverse biological effects associated with coronary heart diseases, cancer and age related neurodegenerative diseases5. They might also facilitate the development of treatments for the repair of indiscriminate cellular DNA damage that occurs during certain forms of chemotherapy and radiotherapy2. The mushrooms are known as rich source of antioxidants which protects our body from toxic effects of free radicals responsible for damaging all components of the body viz. Lipids, proteins, DNA, sugars and are responsible for many types of mutation and cancer18161. Shi et al.,23 reported that Agaricus bisporus has significant antioxidant activity, and the compound assigning this property to the species is tyrosinase. Mau et al.,14 analysed the antioxidant activity of ear mushrooms and recommended its use for inhibiting the activity of oxidases. Compounds, like Tocopherol, butylated hydroxytolune (BHT), catechol are commonly used antioxidants, but use of these synthetic antioxidants proved to be having adverse effects such as toxicity and carcinogenicity27. Due to certain limitations of synthetic antioxidants, usage of natural antioxidants has been recommended and mushrooms constitute the best choice2319. Last 2-3 decades have seen steady expansion in the use of mushroom derived preparations for reducing the effect of spontaneously produced oxidative compounds in our body. The Present study was carried out to evaluate the antioxidant activity of some wild mushrooms collected from different sites/areas in Kashmir valley.

Materials and Methods

The mushroom species were collected from different sites of Kashmir Himalaya and were cleared to remove any residual compost/soil and dried subsequently (sun dry followed by oven dry at 45oC for 3 hours). All the dried specimens were ground to fine powder (0.1mm in size) and stored in air-tight plastic bags in a desiccators at room temperature for further analysis. The antioxidant activity was determined by DPPH (1,1-diphenyl-2-picrylhydrazyl) method given by Hatano et al9. Catechol was taken as control.

Procedure: 10gms of catechol were dissolved in 10ml of 70% ethanol. 10gms of fresh wild dried mushroom powder were homogenised in 70% ethanol. The homogenate was placed on a magnetic stirrer for 2 hours at 4oC. The mixture was centrifuged in a cooling centrifuge at 10,000 rpm for 20 minutes. The supernatant was concentrated by using vacuum evaporator. Different series of concentrations of the extract were taken in test tubes and to each tube were added one ml of DPPH solution. After few minutes of incubation at room temperature readings were recorded at 517nm on a spectrophotometer22. The percent inhibition shown by different mushroom extracts at different concentrations was calculated by using the formule

Results and Discussion

After following the above mentioned procedure for estimating the antioxidant activity of the selected mushrooms, the results obtained are indicated in the Table 1.

Table 1- Antioxidant activity of some wild mushrooms of Kashmir Valley.

*mean of five replicates.

Fig. 1: Graphical representation of antioxidant activity of some wild mushrooms of Kashmir Valley.

It is quite evident from the the results (Table 1) that mushroom extract at all the concentrations showed antioxidant activity. The maximum antioxidant activity was found at highest concentration (600µg/ml and 500mg/ml) followed by lower concentrations 400µg/ml, 300µg/ml, 200µg/ml and 100µg/ml sequentially, when compared to control (catchol) which showed the similar trend in all its concentrations. However, Different concentrations of catechol showed either higher or lower anti oxidant activity as compared to different concentrations of mushroom extract. Amongst all the mushroom species tested for antioxidant activity, Lentinus tigrinus showed higher antioxidant activity followed by Ganoderma applanatum, Coprinus plicatilis, Flumulina velutipes and Helvella Crispa respectively. In case of Lentinus tigrinus, the antioxidant activity varies from 86.24% to 50.98% in different concentrations of mushroom extract, similarly in Ganoderma applanatum, Coprinus plicatilis, Flummulina velutipes and Helvella crispa the antioxidant activity varies from 86.14% to 36.11%, 78.91% to 45.35%, 83.24 to 19.19% and 55.55% to 9.0% in different concentration of mushroom extracts respectively.

Naturally occurring antioxidant components, including ascorbic acid and phenolics have been reported in most of the mushrooms28, Thus antioxidant activity of mushrooms might be due to antioxidants such as phenolics and ascorbic acid26156. Triterpenoides has been identified as the main chemical compounds in Ganoderma lucidium responsible for antioxidant activity1929 similar compounds may be present in the Ganoderma applauntum. Teows25; Shi et al.23 Lakshmi et al.1213 Jayakumar et al.10 also worked out the antioxidant activity of number of wild mushrooms and reported mushrooms as one of the best sources of antioxidants.

Conclusion

It is therefore clear from the results that all the species of mushrooms selected for screening of their antioxidant potential at at different concentrations of extract showed significant antioxidant activity, but higher concentration showed much more antioxidant activity followed by lower concentrations of mushroom extracts. Since some of the selected mushrooms like Lentinus tigrinus and Flummulina velutipes are commonly used edible mushrooms, Therefore, the present finding encourages their use in human diets, which in turn might serve as possible protective agents to help humans to reduce oxidative damage.