Anti-collagenase, Anti-elastase and Antioxidant Activities of Pueraria candollei var. mirifica root Extract and Coccinia grandis Fruit Juice Extract: An In vitro study

Aims: To determine the in vitro anti-elastase, anti-collagenase and antioxidant properties of two Asian herbs: Pueraria candollei Graham ex Benth. var. mirifica and Coccinia grandis (L.) Voigt that were selected for their anti-aging properties according to their ethnobotanical and chemotaxonomic information.

Place and Duration of Study: School of Agriculture, Food and Rural Development, Newcastle University, United Kingdom, between June and August 2014.

Methodology: The methanolic extract of the roots of P. candolleivar. mirifica (PMM) and the fruit juice extract of C. grandis (CGJ) were investigated by in vitro enzymatic assays to mimic the breakdown of elastin and collagen fibres. Total phenolic content was determined using the Folin-Ciocalteu method (gallic acid equivalent, GAE), while antioxidant capacity was determined as Trolox equivalents (TE) by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging assays.

Results: PMM significantly inhibited elastase activity with IC50 of 143.0±4.78 µg/mL, and its anti-collagenase activity was comparable with that of the positive control, epigallocatechin gallate (EGCG). Based on the same concentration, the elastase inhibitory activity of PMM was significantly higher compared with that of CGJ (P< .001), while the collagenase inhibitory activities of both extracts were comparable. Total phenolic content, DPPH and ABTS radical scavenging activities of 1.0 g equivalent of the dried roots of PMM were 0.6±0.04 mg of GAE, 16.4±6.20 and 9.3±1.38 µmole TE respectively. The antioxidant values of PMM were significantly higher compared with those of 1000 µg/mL of CGJ (GAE, P< .0001; DPPH radical scavenging activity, P< .05; ABTS radical scavenging activity, P< .001). The free radical scavenging activities of both plant extracts were positively correlated with their total GAE (P < .0001).

Conclusion: PMM may play a role in decelerating the skin ageing process and could be formulated for anti-wrinkle skincare products. Further research is required to examine anti-elastase, anti-collagenase and antioxidant activities of individual compounds contained in the roots of PMM and expand the investigation into such anti-ageing effects of the whole fruits of C. grandis, which might contain higher amounts of phytochemicals than the fruit juice.