Antifungal activity of some Himalayan medicinal plants using direct ...

96 Sanjay Guleria and Ashok Kumar
Table 1. Plant species used in the study.
Scientific name Family Weight of lipophilic extracts (g)/100 g dry leaf
Murraya koenigii Rutaceae 1.10
Vitex negundo Verbanaceae 1.89
Adhatoda vasica Acanthaceae 1.18
Zantoxylum alatum Rutaceae 2.35
Agave americana Amaryllidaceae 0.52
Azadirachta indica Meliaceae 1.05
Eucalyptus globuluse Myrtaceae 3.05
Datura innoxia Solanaceae 1.17
Ipomea carnea Convolvulaceae 0.59
Thuja orientalis Cupressaceae 1.45
Cinnamomum camphora Lauraceae 1.40
Solanum xanthocarpum Solanaceae 1.73
Table 2. Antifungal activity of dichloromethane leaf extracts of the plants under study by direct bioautography.
Scientific name Diameter of inhibition zone (mm) R F Value
A. alternata C. lunata
V. negundo 28 14 0.85
Z. alatum 18 15 0.86
I. carnea 10 7 0.86
T. orientalis 30 22 0.80
C. camphora 9 12 0.79
Plants have supplied over 25% of prescription
drugs used in human medicine and such
pharmacologically active plants have also provided
leads to natural pesticides (Sener et al., 1998).
Himalayas has an extraordinarily rich flora and wide
knowledge of indigenous medicinal plants is well
documented. Accordingly, we are investigating the
potential of Himalayan medicinal plants as a resource
for new biofungicides. To investigate the biological
activity of Himalayan medicinal plants we have used
direct bioautography procedure (Lago et al., 2004) and
Alternaria alternata and Curvularia lunata as target
organisms.
Materials and methods
Extraction of plant material
Fresh leaves of test plants (Table 1) were air dried, and
the ground powder (100 g) was soaked in 500 ml of
dichloromethane for forty-eight hours. The solvent
was then removed under reduced pressure in a rotary
evaporator. Dark green mass obtained was dissolved
in dichloromethane to have 50 mg crude mass/ml.
P reparation of pathogen inoculum
Alternaria alternata was isolated from single spot
from infected leaves of sesame on potato dextrose
agar (potato 200 g, dextrose 20 g, agar 20 g and water
to make total volume of 1 L) and pure culture was
maintained on PDA at 26±2 o C. Similarly,
Curvularia lunata was isolated from the seed
mycoflora of mustard. Conidia were isolated from the
10 days old culture of the pathogens by flooding
culture plates with 5 mL of sterile distilled water and
conidia were dislodged by using a L-shaped glass rod.
Conidial suspension was filtered through sterile
double layered muslin cloth to remove bits of
mycelia. Spore suspension was then prepared in liquid
potato dextrose (potato 200 g, dextrose 20 g and water
to make total volume of 1 L) to obtain a
concentration of 3 x 10 5 conidia/mL.
Bioautography
20 µL of solutions corresponding to 1000 µg of crude