Enhanced Antioxidant, Anti-Aging, Anti-Tyrosinase, and Anti-Inflammatory Properties of Vanda coerulea Griff. Ex Lindl. Protocorm through Elicitations with Chitosan

Abstract

This study aimed to investigate the effects of elicitors on Vanda coerulea Griff. Ex Lindl. protocorms to enhance bioactive compound production and evaluate their biological activities relevant to cosmeceutical applications. The protocorms were developed from the callus treated with different elicitors, including 6-benzylaminopurine (BA), methyl jasmonate (MeJA), and chitosan. Both the adult plant and protocorms were extracted by maceration in 80% methanol and investigated for their chemical compositions using high-performance liquid chromatography. The extracts were evaluated for antioxidant, anti-collagenase, anti-elastase, and anti-tyrosinase activities. In addition, anti-inflammatory properties were assessed using a real-time polymerase chain reaction. The irritation potency was evaluated using the hen's egg test-chorioallantoic membrane test. The findings revealed that protocorms treated with BA and chitosan developed a greener color, while those treated with MeJA exhibited a distinct darker coloration. Elicitation with BA and chitosan resulted in protocorms with comparable or higher levels of syringic acid, rutin, and quercin compared with the adult plant, with rutin being the most prominent identified compound. Furthermore, rutin was reported as the compound responsible for all biological activities. The chitosan-treated protocorm extract exhibited potent inhibition against oxidation, collagenase, elastase, tyrosinase, and inflammatory cytokines, along with a nonirritating effect, making it a promising candidate for cosmeceutical applications.

Keywords: Vanda coerulea; anti-skin wrinkle; antioxidant; blue vanda; callus; chitosan; cosmeceutical; elicitor; protocorm; whitening.

Figure 1

The external appearance of the eight-month-old V. coerulea (a) along with the four-week-old protocorm without elicitor (b), with 3 µM 6-benzylaminopurine (BA) (c), 10 µM methyl jasmonate (MeJA) (d), and 2 µM chitosan (e).

Figure 2

HPLC chromatograms of standard compounds, including catechin (1), syringic acid (2), rutin (3), ellagic acid (4), rosmarinic acid (5), quercetin (6), and the methanolic extracts of eight-month-old V. coerulea (PLANT), four-week-old V. coerulea protocorm without elicitor (PTC) or with 3 µM 6-benzylaminopurine (BA), 10 µM methyl jasmonate (MeJA), and 2 µM chitosan (CHI).

Figure 3

Dose–response curves against DPPH inhibition (a) and ferric reducing antioxidant power (b) of ascorbic acid (AS), rutin (RT), and the methanolic extracts of eight-month-old V. coerulea (PLANT), four-week-old V. coerulea protocorm without elicitor (PTC) or with 3 µM 6-benzylaminopurine (BA), 10 µM methyl jasmonate (MeJA), and 2 µM chitosan (CHI).

Figure 4

Dose–response curves against collagenase inhibition (a) and elastase inhibition (b) of epigallocatechin gallate (EGCG), rutin (RT), and the methanolic extracts of eight-month-old V. coerulea (PLANT), four-week-old V. coerulea protocorm without elicitor (PTC) or with 3 µM 6-benzylaminopurine (BA), 10 µM methyl jasmonate (MeJA), and 2 µM chitosan (CHI).

Figure 5

Dose–response curves against tyrosinase inhibition of kojic acid (KA), rutin (RT), and the methanolic extracts of eight-month-old V. coerulea (PLANT), four-week-old V. coerulea protocorm without elicitor (PTC) or with 3 µM 6-benzylaminopurine (BA), 10 µM methyl jasmonate (MeJA), and 2 µM chitosan (CHI).

Figure 6

Inhibitory activities against interleukin-6 (IL-6) (a) and tumor necrosis factor-α (TNF-α) (b) of MC3T3-E1 cells treated with lipopolysaccharide (LPS) and along with dexamethasone (DEX), and the methanolic extracts of eight-month-old V. coerulea (PLANT), four-week-old V. coerulea protocorm without elicitor (PTC), with 3 µM 6-benzylaminopurine (BA), 10 µM methyl jasmonate (MeJA), and 2 µM chitosan (CHI). Different letters denote significant differences among the extracts (p < 0.05).

Figure 7

The photographs illustrating the impacts of various substances, including negative control (0.9% w/v NaCl), positive control (1% w/v SLS), vehicle control (80% v/v MeOH), and the extract of four-week-old V. coerulea protocorm treated with 2 µM chitosan (CHI) at concentrations of 0.001, 0.01, and 0.01% w/v, that were applied to the chorioallantoic membrane before treatment (0 min), after a 5 min interval, and at the 60 min endpoint.