Determination of the Phytochemical, Nutritional and Microbial Flora of Mountain Thistle (Acanthus montanus) Leaves: A Medicinal Plant from Port Harourt Metropolis

Acanthus montanus is a medicinal plant traditionally used in the management of various ailments and is recognised for its phytochemical and nutritional constituents. However, information on its phytochemical composition, nutritional properties and associated microbial flora remains limited, particularly in locally collected samples. Evaluating these characteristics is important for understanding the plant's nutritional potential and identifying possible microbial contamination that may affect its quality and safety. This study characterised the phytochemical, proximate, mineral and vitamin composition, together with the culturable microbial flora, of Acanthus montanus leaves collected from Igwuruta Town, Rivers State. Studies on the phytochemical, nutritional and microbial flora of Acanthus montanus were conducted in the Department of Plant Science and Biotechnology and Food Science and Technology at Rivers State University, Port Harcourt. Fresh leaves of Acanthus montanus were harvested from Igwuruta Town in Ikwerre Local Government Area, Rivers State, washed and packaged in sterile polythene bags for phytochemical and nutrient analyses and microbial contamination assessment. Samples were analysed in triplicate using standard procedures, while microbial isolation and identification were performed using cultural methods and morphological characteristics. Data were analysed using SPSS for analysis of variance (ANOVA) and expressed as the mean ± standard error. The phytochemical analysis revealed the presence of phytate, oxalate, saponin, tannin, carotenoids, polyphenols, flavonoids and lignans. The highest value was recorded for lignan (15.15±0.00), and the lowest was recorded for phytate (0.12±0.00). The proximate composition results showed that moisture (65.45±0.07) had the highest value and ash (2.80±0.00) had the lowest. The mineral composition results showed that potassium (313.50±2.12) had the highest value and sodium (1.27±0.03) had the lowest. Vitamin C was recorded at 127.50±2.12, while thiamin was recorded at 1.72±0.00. Microbial assessments identified Fusarium sp., Mucor sp., and Aspergillus niger as the fungal isolates of concern, reflecting spoilage risk and possible health implications, while Bacillus sp. was the bacterial isolate identified. In conclusion, these findings confirm the phytochemical and nutritional value of Acanthus montanus but highlight the need for proper preservation to reduce microbial contamination and for further safety studies.