Comparative pharmacognostical and antimicrobial studies of acacia species (Mimosaceae)

Various Acacia species have been reported to be effective against a variety of disease including malaria, leprosy and most concerning cancer. The fresh plant parts of different Acacia species are considered as astringent, spasmolytic, demulcent, anthelmintic and abortifacient in Indian traditional medicine system. Currently, numerous herbal products derived from Acacia species are available in market. In present exploration, a total of five species of genus Acacia including: Acacia nilotica ssp. indica (Benth.) A. F. Hill, Acacia tortilis (Forsk.) Hayne, Acacia senegal (L.) Willd., Acacia catechu (L.)Willd, Acacia jacquemontii Benth were undertaken for preliminary ethnomedicinal and antimicrobial screening. Subsequently, the two most active species: A. catechu and A. nilotica were further considered for detail pharmacognostical studies. During antimicrobial screening experiments, A. catechu and A. nilotica exhibited highest activity against three bacterial (Escherichia coli, Staphylococcus aureus and Salmonella typhi) and two fungal strain (Candida albicans and Aspergillus niger). The pharmacognostical study revealed that both species (A. catechu and A. nilotica) can be distinguished on the basis of their macroscopic, microscopic and phytochemical characters. Different plant parts (bark and pods) of both species were found to contain various secondary metabolites such as alkaloids, flavanoids, tannins and sponins.