Antioxidant, Cytotoxicity and Cytoprotective Potential of Extracts ofGrewia FlavaandGrewia BicolorBerries

Abstract

Objectives: Accumulation of cellular reactive oxygen species (ROS) leads to oxidative stress. Increased production of ROS, such as superoxide anion, or a deficiency in their clearance by antioxidant defences, mediates cellular pathology. Grewia Spp fruits are a source of bioactive compounds and have notable antioxidant activity. Although the antioxidant capacity of Grewia Spp has been studied, there is very limited evidence that links the antioxidant activities of Grewia bicolor and Grewia flava to the inhibition of free radical formation associated with damage in biological systems. Methods: This study evaluated the protective effects of Grewia bicolor and Grewia flava extracts against free radical-induced oxidative stress and the resulting cytotoxicity effect using HeLa cells. Antioxidant properties determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and total phenolic content (TPC) assays showed significantly higher (p < 0.05) antioxidant activity in Grewia flava (ethanol extract) than Grewia flava (water extract) and Grewia bicolor (ethanol and water extracts). Results: Using 3-(4,5-dimethylthiazol-2-yl)-2,5diphenyltetrazolium bromide or MTT assay, cytotoxicity results showed that extracts of Grewia bicolor and Grewia flava were less toxic to HeLa cells at tested concentrations compared to the untreated control. This confirmed the low toxicity of these edible fruits at the tested concentrations in HeLa cells. Furthermore, hydrogen peroxide (H 2 O 2 )-induced cell loss was effectively reduced by pre-incubating HeLa cells with Grewia bicolor and Grewia flava extracts, with Grewia flava (ethanol extract) revealing better protection. Conclusion:The effect was speculated to be associated with the higher antioxidant activity of Grewia flava (ethanol extract). Additional studies will warrant confirmation of the mechanism of action of such effects.

Coal-Derived Humic Substances: Insight into Chemical Structure Parameters and Biomedical Properties

“…Numerous studies have shown that natural antioxidants have the ability to scavenge free radicals, thereby contributing significantly to the management of oxidative pathologies [55]. Dietary antioxidants, derived from natural sources, are of particular interest because of their potential health benefits, as they can provide protection against diseases that result from oxidative stress [55][56][57].…”

The Chemical Composition and Health-Promoting Effects of the Grewia Species—A Systematic Review and Meta-Analysis

“…Eleven studies investigated the antioxidant potential of the Grewia species; eight of them studied G. asiatica [1,24,[46][47][48][49][50][51], one article focused on G. optiva [27], one evaluated G. lasiocarpa [15], and one appraised both G. flava and G. biocolor [52]. The scavenging and reducing potential of various parts of the Grewia species was reported to be dose dependent.…”

Pentacyclic triterpenoids from the stem of Grewia bracteata Roth demonstrate promising inhibition on tumour cells

“…In recent studies, leaves and fruits of G. asiatica were evaluated for their memory enhancer, and antitumor effects like epidermal cervical, kidney, lung, breast, and laryngeal (Paul et al 2019;Joy et al 2019). There are other species like G. flava and G.bicolor that have also been studied for cytotoxicity (Masisi et al 2021). Focus on stem or bark, the antimicrobial and cytotoxicity activities have been reported for G. lasiocarpa (Akwu et al 2020) whereas, G. asiatica stem has been studied for anti-hyperlipidemic potentials (Khatune et al 2016).…”