Soxhlet extractor coupled with Liquid-liquid extraction: Setting up a pilot library of refined crude extracts from indigenous medicinal plants of Lesotho

Abstract

Infections associated with multidrug resistant organisms result in increased morbidity and mortality in Lesotho and globally, thus, there is immediate need to discover new antibiotics against resistant bacteria through systematic examination of inexpensive local herbs. Here, we report for the first time, the welldefined and publicly available prototype library that consists of 20 different crude extracts derived from crude drug samples of medicinal plants of Lesotho used for treatment of infectious diseases. We also described the coupling of soxhlet extraction with liquid-liquid fractionation to give partially refined organic and aqueous extracts, and disclose that the extracts from the leaves and whole plant contained about twice as much organic soluble phytochemicals as aqueous soluble phytoconstituents. While the roots and bark contained about 2 and 5 times more of aqueous soluble than organic soluble phytochemicals respectively, especially when extracting with 90% ethanol. The library represents the potential phytochemicals in herbal prescriptions dispensed by traditional healers in Lesotho. The extracts are publicly available upon request through the corresponding author and efforts to expand the library are still continuing. This methodology could be followed to develop other libraries.

Untitled

“…[16] The root powder of T. asperata has been used in Lesotho traditional medicine to alleviate shoulder pain and for internal and external wounds. [3] In our previous study, [1] we reported the establishment of a prototype library of crude extracts derived from samples of medicinal plants of Lesotho used for the treatment of infectious diseases as our effort to advance search for novel secondary metabolites with potential pharmaceutical applications. In spite of their wide usage in folk remedies, K. capensis and T. asperata are still underexplored.…”

“…The extracts were prepared using Soxhlet extractor followed by liquid-liquid fractionation according to the procedure reported by us. [1] Each of the 44.29 g of K. capensis and 50.22 g of T. asperata samples was refluxed at 78°C using 500 mL of solvent systems; ethanol/water (9:1 v/v), in Soxhlet extraction apparatus Ace Glass Incorporated, Vineland, NJ.…”

“…[22] In our previous study that established a prototype library of crude extracts, the preliminary antimicrobial assay of five medicinal plants against S. aureus using the well diffusion method showed high antibacterial activities, confirming previously known data. [1] In the current study, the biological properties of ethanolic root extracts of K. capensis and T. asperata were evaluated for the 1 st time.…”

“…Plants are often described as the massive storage of pharmacologically active chemical compounds. [1] The flora of Lesotho, which is known to encompass about 200 plant families, provides up to 303 species that are used in folk remedies. [2] Even though Basotho relied on traditional medicinal herbs for the treatment of…”