Abstract
Variation in cultivars can influence plant biological activities. This study aimed to identify superior cultivars while determining the variability in the phytochemical content, antioxidant, alpha-glucosidase inhibitory and antibacterial activities of cladode extracts from selected spineless Burbank cactus pear (Opuntia ficus-indica and Opuntia robusta) cultivars. Total phenolic and flavonoid contents were determined using the Folin-Ciocalteu and aluminum chloride spectrophotometric methods, respectively. Antioxidant activity was investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and β-carotene linoleic acid assays. Alpha-glucosidase inhibition was determined using a spectrophotometric method and antibacterial activity using a non-polar (petroleum ether) and polar (50% methanol) extracts against two Gram-positive and two Gram-negative bacteria. Significant variation in phytochemical content, antioxidant, antidiabetic and antibacterial activities was observed amongst the cultivars. Alpha-glucosidase inhibitory activity varied widely with IC50 values ranging from 0.06 to 1.85 mg/mL. Radical scavenging activity of Polypoly cultivar was about seven fold higher than that recorded in other cultivars with low activity. Turpin and Berg x Mexican cultivars had the highest total phenolic and flavonoid contents, whilst the non-polar extract of Turpin also exhibited higher antibacterial activity against Bacillus subtilis and Escherichia coli. Sicilian Indian Fig was amongst the cultivars with a higher antioxidant activity, whilst also showing a strong inhibition against B. subtilis and E. coli. Polypoly cultivar demonstrated strong antioxidant and antidiabetic activities while its polar extract showed the highest total antibacterial activity against B. subtilis. The cultivar Malta was superior in terms of its antibacterial potency and efficacy against B. subtilis, Staphylococcus aureus and E. coli. The potential of using spineless cactus pear cladodes as a functional food with antioxidant, antidiabetic and antibacterial properties against pathogenic food spoilage bacteria in place of synthetic compounds was established. The significance of cultivar selection to increase this potential was highlighted.
Highlights
Lifestyle changes, poor nutrition and exposure to hazardous conditions, amongst others, have a negative impact on public health, as reflected in an increase in chronic diseases such as diabetes, cancer, obesity and hypertension [1]
The higher yields recorded with 50% MeOH extracts may be due to the fact that polar solvents extract polar compounds, which are in a higher abundance than non-polar compounds that are extracted by a non-polar solvent [23]
The cultivars exhibited different levels of activity, some cultivars are superior in terms of their phytochemical content and/or biological properties
Summary
Poor nutrition and exposure to hazardous conditions, amongst others, have a negative impact on public health, as reflected in an increase in chronic diseases such as diabetes, cancer, obesity and hypertension [1]. Resistance to current drugs, insufficient/incompatible therapies and negative side effects associated with some currently used drugs, amongst others, have rendered some management practices of diabetes and some infectious diseases almost ineffective [5,6] All of these issues favor the growing interest in the use of herbal remedies for the treatment of diabetes and infectious diseases, as they are perceived to have a high economic value and fewer side effects when compared to synthetic agents [5,6]. Foodborne pathogenic bacteria such as Staphylococcus aureus, Bacillus subtilis and Escherichia coli have biofilm-forming abilities, causing food deterioration or spoilage, which is another global health dilemma [7,8]. There is an increase in research activities to find new alternative and strong antimicrobial agents, from plants [9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
