**4. Conclusion**

132 Fungicides for Plant and Animal Diseases

Among the species tested, *Mentha* was less active. No enhancing effect was observed for *Mentha* extract against *Aspergillus fumigatus* at higher concentrations (20 mg/mL and 25 mg/mL) while the lowest concentrations i.e. 5 mg/mL, 10 mg/mL showed some inhibition activity against the mold strain. The percent of inhibition were statistically significant with

None of the above concentrations completely inhibited the test fungus. The percent of

Multi-drug resistance is a medical problem in world-wide and has therefore led researchers in the search for new antimicrobial drugs or resistance, particularly from natural resources (Sharma et al., 2005; Moghaddam et al., 2010). Recently, various natural products or synthetic compounds have been reported to increase the antifungal activity (Duraipandiyan

Antifungal activity was exhibited by different concentrations extracts. The chronological age of the plant, percentage humidity of the harvested material, the method of extraction were

The results presented indicate different spectrum of antifungal activity of the two extracts. The antifungal activity of *Thymus mastichina* extract against the mentioned fungi was dosedependent and increased with the increase in the plant extract concentrations. It also supports the earlier investigations of other authors (Bobbarala et al., 2009; Moghaddam et al., 2010). Previous studies have shown that *Thymus* possess antimicrobial activity (Pinto et

In the other way, it was revealed in this study, that the antifungal activity of *Mentha* was

Therefore, this study suggests that plant extracts of screened plants could be helpful in

However, there is little information about *Thymus* and *Mentha* and their derivatives in the fungal cell in order to promote fungistatic or fungicide effect (Pina-Vaz et al., 2004; Figueiredo et al., 2008). They have been empirically used as antimicrobial agents, but the mechanisms of action are still unknown (Pinto et al., 2006). Generally, inhibitory action of natural products on fungi involves cytoplasm granulation, cytoplasmic membrane lesion, and inactivation and/or inhibition of intercellular and extracellular enzymes (Cowan, 1999; Pinto et al., 2006) and might be due to various compounds, including terpenoids, phenolics and alkaloids. These compounds jointly or independently, exert different levels of antifungal effect culminating with mycelium germination inhibition (Cowan, 1999). Also, it is reported that plant lytic enzymes act in the fungal cell wall causing breakage of β-1,3 glycan, β-1,6 glycan and chitin polymers (Brull & Coote, 1999). The antimicrobial action of the aqueous extracts could be attributed to the anionic components such as thiocyanate, nitrate, chlorides and sulphates besides other water soluble components which are naturally

Use of aromatic plants as microbial growth inhibitor in foods is often limited because of flavor considerations as effective antimicrobial dose may exceed the organoleptically

possible sources of variation for the bioactivity of the extracts (Panghal et al., 2011).

et al., 2006; Bobbarala et al., 2009; Moghaddam et al., 2010; Pai et al., 2010).

different concentrations in *Mentha*.

inhibition ranged from 0.9 to 19.1%.

al., 2006; Figueiredo et al., 2008).

enhanced in low concentrations of the extracts.

treating diseases in plants caused by *Aspergillus fumigatus*.

occurring in the plant material (Darout et al., 2000).

**3.5 Discussion** 

It was possible the establishment of a micropropagation protocol in order to multiplicate and maintain *in vitro* the aromatic and medicinal plants, to have enough material to use in future studies of antifungal activity and of genetic variability.

Considering the fact that *in vitro* cannot be directly extrapolated to *ex vitro* effects the results suggests that, the use of plant extracts such as *Thymus* and *Mentha* against *Aspergillus sp.* has potential as a topical antifungal agent as they offer a cheap and effective module for therapeutic and/or preventive purposes.

Our results showed that extracts from *Thymus and Mentha* may be particularly useful against *Aspergillus fumigatus*. These results may justify the popular use of these aromatic plants.

Compound-activity relationship for oils components against fungus organisms must be elucidated to explain its antifungal activity (Tomczykowa et al., 2008).

However, in order to evaluate possible clinical application in food microbiology and therapy of aspergillosis, further studies needed to be made.

Further phytochemical studies are required to determine the types of compounds responsible for the antifungal effects of these species.
