Recently, the public demand for herbal medicine and the rise of antibiotic-resistant bacteria have motivated scientists to look for new natural sources with potential pharmaceutical capabilities. Besides, the indiscriminate use of antimicrobial drugs has created immense clinical problems in the treatment of infectious diseases (Davis et al., 1995). This has necessitated the development of alternative antimicrobial drugs from the medicinal herbs which are rich sources of novel antibacterial and antifungal chemotherapeutics (Jones and Firn, 1977). It has been reported that 80% of the world’s population depend on plants to meet their primary health care needs (WHO, 2002). In order to solve issues related to antimicrobial resistance, drivers of resistance and possible solutions have been listed for future approaches. One of these could be the discovery and development of new antimicrobial agents that have clinical significant importance from natural sources. Obadoni and Ochuko (2001) reported that presently in industrialized nations, some 50% of all prescribed drugs are derived or synthesized from natural products and that their only available sources are animals, marine species, plants and microorganism. Among the estimated 250, 000 plant species existing worldwide, only a few percentages have been investigated phytochemically and the fraction submitted to biological and pharmacological screening is even smaller (Bindu et al., 2012). Though angiosperms are immense sources of therapeutics, lower plants are attracting more attention in recent times for the search for new and effective molecules. The medicinal values of pteridophytes have been known for several years. Hansel and Lagare (2005) reported that the antimicrobial properties of ferns are remarkable compared to the higher plants probably because of a large number of defensive biochemical compounds. Traditionally, people use pteridophytes as medicine and antibacterial agents. Generally, many species of pteridophytes are yet to be explored for their potential applications for future use and to isolate new active principles from them (Suvarnalatha et al., 2015).

N. biserrata and N. cordifolia belong to the family Nephrolepidaceae. Both have been reported to be of immense ethnobotanical importance. The ethnobotanical importance of N. biserrata in boils, abscesses and blisters have been documented (Baltrushes, 2006). Incidentally, boils and abscesses are due to bacterial infections (Lindenmayer et al., 1998; Smith et al, 2003) while blisters are caused by fungal infections (MERK, 2010). Hence, N. biserrata can be a potential plant to fight pathogenic microbes. N. cordifolia is being used in general disorders of renal and liver systems, skin diseases and as a contraceptive (Baltrushes, 2009). Considering the diversity of medicinal plants, including pteridophytes, the screening of plant extracts for