KG, commonly known as Sand Ginger, is native to Asian countries such as India, China, Indonesia, Malaysia and Thailand. It has traditionally been used as a food seasoning and as a folk medicine for the relief of skin ailments.
Recent studies have shown that various extracts of KG exhibit antiangiogenic, anti-inflammatory, and antiviral activities.
For example, the major components in the rhizome extract of KG include cinnamic acid derivatives such as ethyl p-methoxycinnamate (EPMC) and ethyl cinnamate, and flavonoids such as kaempferol. EPMC in particular has a wide range of biological activities, including anti-inflammatory activity.
In an effort to find new sources of anti-aging agents, Thai researchers conducted a study to extract KG rhizome using four solvents of different polarity to investigate its antioxidant, anti-collagenase, and anti-elastase effects on human fibroblast cells.
KG rhizomes were collected in northern Thailand and extracted by maceration method using the following solvents: deionized water, absolute ethanol, ethyl acetate, and hexane.
The highest extraction yield was observed with deionized water (6.43%), followed by absolute ethanol (5.3%), ethyl acetate (4.62%), and hexane (3.68%).
These results indicate that more polar solvents (water, absolute ethanol) give higher extraction yields than less polar solvents (ethyl acetate, hexane).
Furthermore, absolute ethanol and ethyl acetate were found to be the best solvents for extracting flavonoids and phenolic compounds from KG rhizomes.
In particular, the total flavonoid and phenolic contents were highest when extracted with absolute ethanol and ethyl acetate, and lowest when extracted with deionized water and hexane, respectively (p < 0.05).
The antioxidant (free radical scavenging) activities of the four KG extracts were evaluated by DPPH and ABTS+ assays, and their ability to reduce iron (III) ions (Fe3+) was assessed by ferric reducing antioxidant power (FRAP) assay.
The results showed that the extract obtained with absolute ethanol exhibited the strongest antioxidant activity in both DPPH and FRAP assays compared to the other extracts (p < 0.05).
Meanwhile, the aqueous extract showed the highest activity in the ABTS+ assay (p < 0.05).
“The high antioxidant activity of KG extracts could be attributed to their high content of flavonoids and phenolic compounds. However, the different polarity of compounds in different extraction solvents indicates different antioxidant mechanisms.
“The ethanol extract of KG showed the most effective antioxidant activity, collagenase and elastase inhibitory effects, and showed low or no cytotoxicity. Therefore, the ethanol extract of KG is suitable for the development of cosmetics for anti-aging applications.” The authors write:
Prevents the breakdown of collagen and elastin
Skin ageing is influenced by intrinsic and extrinsic factors, both of which induce the production of reactive oxygen species (ROS) in skin cells, negatively affecting cellular functions such as collagen and elastin synthesis.
Since collagenase and elastase are involved in the degradation of collagen and elastin, the ability to inhibit these enzymes based on spectrophotometry is used to evaluate the anti-aging effect.
The greatest collagenase inhibitory effect was observed when absolute ethanol was used as the solvent (71.83 ± 4.65%), followed by hexane (67.43 ± 1.4%), ethyl acetate (56.08 ± 5.48%), and deionized water (37.61 ± 2.97%).
The KG extract obtained with absolute ethanol showed higher anti-elastase activity (66.35 ± 7.21%) than the KG extracts obtained with ethyl acetate (43.39 ± 6.75%), hexane (45.07 ± 6.51%), and deionized water (22.7 ± 1.63%).
“The highest collagenase and elastase inhibitory activity was observed in the KG extract obtained with absolute ethanol, which may be due to its higher total phenolic and total flavonoid content compared to the other solvents.
“The results showed a positive correlation between the anti-aging and antioxidant activities of KG extracts. It should be noted that the effects of different extraction solvents on collagenase and elastase inhibitory activities may depend on the part of the plant, the stage of harvesting, the content of phytochemicals, the concentration of active biological compounds, and their antioxidant activities.”
Source: Cosmetics
https://doi.org/10.3390/cosmetics11030097
“Exploring the in vitro antioxidant, anti-aging and cytotoxic properties of Kaempferia galangal Linn rhizome extract and its application in cosmetic formulations”
Author: Panikchar Wichayapreechar et al.
