Chapter I
INTRODUCTION
RodcnT S hav e aivVSy'S u66 n with us, mostly as pes lS, SVoT SiHOG Li iS
primitive man became an agriculturist and started having granaries. They
have become a global problem as they damage standing crops, stored food
grains and other commodities. Rodents being the most destructive vertebrate
pests, pose a great threat to our country's economy. Percentage damage by
rodents to various agricultural crops varies under different agroclimatic
conditions (Malhi and Parshad 1990; Islam et al 1993; Jain et al 1993). They
serve as vectors of several diseases (Neelanarayanan and Kanakasabai
2000). They may also gnaw at insulating material causing electrical
installations out of order and creating fire hazards. Rodent problem is very
serious due to their high rate of reproduction, complex behaviour and ability to
adapt under diverse ecological conditions.
Several traditional and modern approaches of rodent
control/management are being used (Parshad 1999). These include non-
lethal approaches like environmental and cultural methods (harbourage
reduction, food source reduction and immigration reduction), cultural practices
(crop rotation, tillage, varietal resistance and crop scheduling) and biological
methods (the use of predators, parasites and pathogens). Lethal or reductional approach includes mechanical methods such as hunting, killing,
trapping of rodents and use of chemicals. However, at present there is no
single effective method that can be applied for all pest species under different
ecological conditions as the response of different species to different
management strategies is very specific. So, there is need to adopt an
integrated approach using all types of control/management methods. One of
the management methods in Integrated Pest Management (iPM) being in
practice is through regulation of their breeding activity (reproduction) by
chemicals (antifertility, antispermatogenic, spermicidal, antiimplantation and
resorptive) (Sinha et al 1984a,b; Upadhyay et al 1993b; Kaur and Parshad
1997). A number of synthetic compounds have been reported to arrest
spermatogenesis or induce 'functional sterility' in rodents (Kaur et al 1997;
Singla and Parshad 2000; Cheng et a/2001; Grima et a/2001). Indiscriminate
use of synthetic chemicals/pesticides have created so many problems like
pesticide resistance, contamination of food, resurgence of pest species and
acute effects on non-target species. The high cost of these chemicals have
generated the need for intensified research on environment friendly chemicals
of plant origin i.e. phytochemicals (Kasturi et al 1995; Sharma and Dixit 1998;
Verma et al 1998; Mazaro et al 2000).
India's rich biodiversity has a vast source of natural products and there
is considerable scope for developing new and improved fertility regulating
agents of plant origin. Extracts of many plants are known to possess antifertility activity (Pakrashi and Pakrasi 1977; Murugavel and A..»jarsha
1991; Raji and Bolarinwa 1997; Aladakatti and Ahamed 1999; Sarkar et al
2000).
Neem (Azadirachta indica) is an outstanding example of tree species,
a versatile gift of nature (Rawat 1995; Kapoor 2000) having antifertility
properties (Tripathi 1998). Tandan et al (1995) and Gupta (1997) reported
that Azadirachta indica possesses various pharmacological activities. Every
part of neem tree namely leaf, flower, fruit, seed kernels, bark, wood, twig and
root, etc. has been used in Ayurvedic and Unani systems of medicine
(Pandey 1993; Rahman and Jairajpuri 1993).
Neem extracts/products have been found to possess antifertility effects
in females (Sharma and Saksena 1959a,b; Sinha et al 1984a; Khare et al
1984; Lai et al 1986; Tewari et al 1986; Riar et al 1988; Upadhyay et al 1990;
Bardham et al 1991; Chattopadhyay 1993; Juneja and William 1993; Dhaliwal
et al 1998; Mukherjee et al 1999).
A few studies were carried out to demonstrate antifertility effects of oral
administration of neem leaf extracts in male rats (Choudhary et al 1990;
Shaikh et al 1993; Kasturi et al 1995; Joshi et al 1996; Parshad et al 1997;
Aladakatti and Ahamed 1999). No detailed study has been made till now to
establish the antifertility effect of oral administration of bark extract and neem
oil in a single rodent species.
Therefore, the present study entitled "Effect of neem (Azadhirachla
indica A. Juss) extracts on growth and reproduction of albino mice" has been
made* on male albino mice Mus musculus to know the effects of oral
administration of neem extracts (leaves, bark and seed oil) on:
i) Histomorphology of the testes
ii) Spermatogenic activity at different cellular levels
iii) Histomorphological changes in accessory reproductive organs
iv) Sperm parameters
v) Fertility index
vi) Testicular biochemistry
vii) Changes in testicular trace elements
viii) Growth