HPLC-DAD Phenolic Composition, Antioxidant, Anticholinesterase, Antidiabetic and Anti-quorum Sensing Properties of Bitter Kola (Garcinia kola) and Kolanut (Cola acuminata)

Abstract

Background: Eating Cola acuminata and Garcinia cola nuts in African societies symbolizes in socio-cultural hospitality. They stimulate the nervous system, reduce fatigue and sleep. Objectives: To determine the phenolic composition and bioactivities of G. kola and C. acuminata. Materials and Methods: Hydro-ethanol extracts of the nuts were prepared and their phenolic profiles determined using HPLC-DAD. Antioxidant, anticholinesterase, antidiabetic, antimicrobial, antibiofilm and anti-quorum sensing properties were determined. Results: The most abundant phenolic compound was caffeic acid (105.4±0.75 mg/g) in C. acuminata and myricetin (277.2±0.90 mg/g) in G. kola. The extracts showed good antioxidant activity in five complementary assays and G. kola was more active than both α-tocopherol and BHA standards in the DPPH • , CUPRAC and ABTS •+ assays while C. acuminata was more active than only the α-tocopherol standard in the same assays. Activities were close to those of standards in the β-Carotene-linoleic acid and metal chelation assays. Both extracts had good inhibition of Butyrylcholinesterase (BChE) and Acetylcholinesterase (AChE) with IC 50 values 63.27±0.98 µg/mL and 94.15±1.05 µg/mL for C. acuminata and G. kola respectively compared to 5.50±0.25 µg/mL for galantamine in the AChE assay. In the BChE assay, the inhibitory activity was higher for G. kola (IC 50 = 38.66±0.80 µg/ mL) that the standard galantamine (IC 50 = 42.20±0.48 µg/mL) while that for C. acuminata (IC 50 = 87.31±0.77 µg/mL) was moderate. The extracts inhibited α-amylase and α-glucosidase with G. kola (IC 50 =18.43±0.74 µg/mL) being more active than standard acarbose (IC 50 =20.52±0.84 µg/mL in the α-glucosidase assay. The nuts could inhibit expression of virulence factors in Chomobacterium violaceum CV12472 by disrupting violacein production and flagellated Pseudomonas aeruginosa PA01 by disrupting swarming motility. Conclusion: The results indicate good nutraceutical potential of both nuts.

Inhibitory effect of extracts from edible parts of nuts on α-amylase activity: a systematic review

“…25 In a separate investigation, the observed IC 50 value for kola nut was nearly ten-fold higher, though it is important to note that a positive control was not utilised so the reliability of the enzyme assay system cannot be ascertained. 38 In this systematic review, among the 17 studies that utilised porcine pancreatic α-amylase as the only enzyme, 16,22,23,[25][26][27][34][35][36][37][38][39]41,43,48,50,52 four of them specifically investigated the inhibitory potential of polyphenolic extracts from the edible parts of nuts belonging to the Anacardiaceae family, including pistachio (Pistacia vera), 36,37,48 and Atlantic terebinth (Pistacia terebinthus). 23 The Pistacia genus predominantly inhabits the northern hemisphere, encompasses both evergreen and deciduous varieties, and has long been recognised for medicinal properties.…”

“…All three studies by Tsujita et al, used porcine pancreatic α-amylases in addition to human α-amylases. 42,44,45 Additionally, 17 papers explicitly mentioned or referenced the utilisation of porcine pancreatic α-amylases 16,22,23,[25][26][27][34][35][36][37][38][39]41,43,48,50,52 (Table 2). Four studies indicated or referenced the use of α-amylases derived from a bacterial 24,31,47 or fungal source.…”

“…25 Polyphenolic extracts from two varieties of kola nut, Cola acuminate and Garcinia kola, demonstrated inhibition of porcine pancreatic α-amylase with IC 50 values of 56.7 ± 0.7 µg mL −1 and 35.1 ± 0.6 µg mL −1 , respectively (acarbose IC 50 : 32.6 ± 0.8 µg mL −1 ). 25 In a separate investigation, the observed IC 50 value for kola nut was nearly ten-fold higher, though it is important to note that a positive control was not utilised so the reliability of the enzyme assay system cannot be ascertained. 38 In this systematic review, among the 17 studies that utilised porcine pancreatic α-amylase as the only enzyme, 16,22,23,[25][26][27][34][35][36][37][38][39]41,43,48,50,52 four of them specifically investigated the inhibitory potential of polyphenolic extracts from the edible parts of nuts belonging to the Anacardiaceae family, including pistachio (Pistacia vera), 36,37,48 and Atlantic terebinth (Pistacia terebinthus).…”

“…24,27,32,35,40,43,44,52,53 Notably, two studies did not mention the origin/supplier of the nuts used, 24,53 and 16 studies did not specify the supplier (s) for all chemicals used. 22,25,33,37,38,[40][41][42][43][44][45][47][48][49]52,53 Eight of them lacked important information on the specific characteristics of the extraction procedure, such as duration, temperature, and pH levels; 25,29,33,37,40,49,52,53 for example, two studies failed to specify the temperature conditions for the rotatory evaporator 25 or water bath. 40 Furthermore, two studies subjected nuts to prolonged immersion in a solvent for over a week; however, there is no explicit mention of whether the nuts were stored in a dark environment during this experimental process.…”

Inhibition of biofilm, quorum‐sensing, and swarming motility in pathogenic bacteria by magnetite, manganese ferrite, and nickel ferrite nanoparticles

“…QS network inhibition is a new effect strategy in antimicrobial chemotherapy as it prevents inter-bacterial cells communications and reduces severity and pathogenicity during infections. [79][80][81][82] An easily measurable QS effect involves the production of violacein pigment in C. violaceum CV12472 and the biosensor strain C. violaceum CV026. All the MNPs in this study inhibited violacein production in the two chromobacteria species.…”