Size controlled biosynthesis of silver nanoparticles using Ophiorrhiza mungos, Ophiorrhiza harrisiana and Ophiorrhiza rugosa aqueous leaf extract and their antimicrobial activity.

In this work, the aqueous leaf extracts of three Ophiorrhiza genus species, namely Ophiorrhiza mungos (Om), Ophiorrhiza harrisiana (Oh) and Ophiorrhiza rugosa (Or), have been used as the reducing and capping agents to control the size of AgNPs, Om-AgNPs, Oh-AgNPs and Or-AgNPs, respectively and found to be an effective antimicrobial agent against a wide range of bacteria and fungi. The biosynthesized AgNPs were studied by UV-Visible spectrophotometer, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray, transmission electron microscopy (TEM) and Fourier transform infrared spectrometer (FTIR). The average particle sizes of Om-AgNPs, Oh-AgNPs and Or-AgNPs were measured as 17 nm, 22 nm and 26 nm, respectively, and observed to be spherical and face-centered cubic crystals. The antibacterial test of synthesized AgNPs was performed against Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Vibrio cholerae where the maximum antibacterial activity was observed by reducing the nano-size and increasing the silver content of AgNPs. The antifungal effect of these three types of AgNPs on Penicillium notatum and Aspergillus niger was also evaluated and their growth with AgNPs concentrations of 450 µg/mL was inhibited up to 80-90% and 55-70%, respectively. The size-control synthesis of AgNPs using the Ophiorrhiza genus species is presented here for the first time where the synthesized AgNPs showed higher stability and antimicrobial activities. Therefore, this study might lead to synthesize AgNPs with different morphologies using plant extracts of the same genus but from different species and provide strong encouragement for future applications in treating infectious diseases.

Medicinal plants and formulations used by the Soren clan of the Santal tribe in Rajshahi district, Bangladesh for treatment of various ailments.

The Santals form the largest tribal community in northern Bangladesh reside primarily in Rajshahi and Rangpur Divisions, where they live in the districts of Rajshahi, Rangpur, Thakurgaon, Dinajpur, and Panchagarh. Although they are fast losing their traditional medicinal practices, they still have their own medicinal practitioners who rely mostly on medicinal plants for treatment of a variety of ailments. The traditional medicinal practices vary quite extensively between the twelve clans of the Santals. The objective of the present study was to conduct an ethnomedicinal survey amongst the Soren clan of the Santal community residing in two villages of Tanor Santal Para in Rajshahi district to collect information on their use of medicinal plants. Interviews were conducted of the two existing Santal traditional medicinal practitioners of the Soren clan with the help of a semi-structured questionnaire and using the guided field-walk method. Plant specimens as pointed out by the practitioners were collected and pressed on the field and identification completed at the Bangladesh National Herbarium. Information on 53 medicinal plants distributed into 32 families was obtained in this survey. Ailments treated by these plants included skin disorders, respiratory tract disorders, gastro-intestinal disorders, sexual dysfunctions, sexually transmitted diseases, diabetes, helminthiasis, pain, urinary problems, filariasis, leprosy, tuberculosis, epilepsy, snake bite, enlarged heart, and paralysis. The medicinal plants used by the Santals merit further scientific studies for some of their formulations are used to treat diseases like diabetes, paralysis, enlarged heart, tuberculosis, and filariasis for which modern medicine has no known cure or medicines have developed resistant vectors.

Survey and scientific evaluation of medicinal plants used by the Pahan and Teli tribal communities of Natore district, Bangladesh.

The Pahans and the Telis are two of the smallest indigenous communities in Bangladesh. The Pahans, numbering about 14,000 people are widely scattered in several northern districts of the country, while the Telis are such a small community that nothing has been reported on their numbers and lifestyle. Both tribes are on the verge of disappearance. One each of the Pahan and the Teli community was located after much search in two adjoining villages of Natore district, Bangladesh. Since the tribes were found to still depend on their traditional medicinal practitioners for treatment of ailments, it was the objective of the present study to document their traditional usage of medicinal plants and to evaluate such plants against modern research-based pharmacological activity studies on these plants. Interviews were conducted of the practitioners of the Pahan and Teli community of Natore district with the help of a semi-structured questionnaire and using the guided field-walk method. Plant specimens as pointed out by the practitioners were collected and pressed on the field and identification completed at the Bangladesh National Herbarium. The Pahan tribal practitioners used 13 plants distributed into 9 families for treatment of 14 different ailments. The Teli tribal practitioner used 15 plants divided into 14 families for treatment of 17 different ailments. Eight out of the thirteen plants used by the Pahan tribal practitioner (61.5%) had reported relevant pharmacological activities in the scientific literature, while six out of the fifteen plants used by the Teli tribal practitioners (40%) had such relevant pharmacological activities in accordance with their usage. The medicinal plants used by the Pahans and Telis warrant further scientific studies toward discovery of lead compounds and efficacious drugs and the documentation and protection of the traditional medical knowledge held by these tribes.