This study evaluated anti-oxidant, whitening, wrinkles effects, and anti-allergic effects of the noni (Morinda citrifolia L.) adventitious roots, selected an indicator material showing a great anti-allergic effects, and then established qualitative an...
This study evaluated anti-oxidant, whitening, wrinkles effects, and anti-allergic effects of the noni (Morinda citrifolia L.) adventitious roots, selected an indicator material showing a great anti-allergic effects, and then established qualitative and quantitative methods for purification and structural analyses of the active ingredient. Also, several different extraction and drying methods were compared to see change in rubiadin, anthraquinone, phenolic, flavonoid, and extraction yield, and to identify effective processing.
1. Evaluation of biological activity
The toxicity on the extracts of tissue cultured noni adventitious roots, were evaluated, and their effects on DPPH scavenging, SOD-like, and protection against H2O2 induced cell damage were identified and proved to be slight. As a result of tyrosinase inhibition, inhibition of melanin in B16F1 melanoma, and western blotting of tyrosinase, TRP-1, and TRP-2 expression, the effect of whitening activity was minor. The activity of elastase inhibition, stimulation of collagen, and procollagen type-Ⅰ synthesis was little which means that the effect on wrinkles was negligible.
However, when the noni adventitious roots were evaluated on anti-allergic, crude extracts showed excellent effectiveness on histamine releasing inhibition of 85% at 100 μg·mL-1. Thus, liquid-liquid extractions were conducted using several organic solvents and each fraction was evaluated on histamine releasing and TNF-α synthesis inhibition. Among them, hexane and methylene chloride extracts were more effective than others, in which the hexane fraction showed about 54% efficacy at 25 μg·mL-1. In the results of the effect of lethality inhibition through systemic anaphylactic reaction on tissue cultured. lethality by systemic anaphylactic reaction decreased by almost 36% in the groups that noni adventitious roots and stem cell medicated were orally administered. Also, as a result of evaluated effect of histamine releasing inhibition using a rat visceral mast cell, it was controlled effectively when treated with 1 mg·mL-1.
2. Selection of target compound
To select target compounds with anti-allergic activity in noni adventitious, the extracts were partitioned with solvents. Active ingredients obtained from hexane and methylene chloride layers were a fraction with preparative LC. Target compound from HPLC was identified by GC/MS/MS, LC/MS-IT-TOF, and UV/VIS spectrophotometer. From these results, rubiadin was selected as a target compound.
In addition, the structural analysis was conducted through extraction and purification of rubiadin in noni adventitious roots to establish qualitative analysis. Noni adventitious roots were extracted with chloroform : ethyl acetate mixture (100%, 100:1, v/v). The extract was developed by preparative TLC with chloroform : ethyl acetate (3:1, v/v), a band Rf 0.68 were collected, and. further purification was conducted to get rubiadin by preparative LC. Purified rubiadin was identified by LC/MS/MS, LC/MS-IT-TOF, UV/VIS spectrophotometer, FT-IR, and NMR analysis.
3. Efficiency of extraction and dry methods
To evaluated optimum extraction condition on rubiadin, extraction of noni adventitious roots was performed with different solvent types, ratio of water to methanol (20%, 40%, 60%, 80%, and 100% water), extraction time, and extraction method. In contrast, a reverse-phase HPLC assay method was developed to determine rubiadin content in noni adventitious roots in which HPLC equipped with a C-18 column using a gradient solvent system of methanol and water and UV detector at 280 nm was used.
As a result, roots contained 0.02% of rubiadin but no rubiadin was detected in other plant part. Rubiadin, anthraquinones, phenolic, flavonoid content and extraction yields in the adventitious roots were higher than theose in the ex vitro roots.
The extraction efficiency using different types of solvents were increased in order of methanol (0.08%) > ethanol (0.05%) > acetonitrile (0.03%) > acetone (0.02%) and methylene chloride (0.02%). Rubiadin extraction using different solvents showed that 1 hour of ultrasonic extraction was effective in order of 60 % methanol (0.21%) > 80% methanol (0.13%) > 100% methanol (0.07%), 40% methanol (0.07%) and 2 hours of reflux extraction was effective in order of 60% methanol (0.21%) > 40% methanol (0.17%) > 80% methanol (0.14%).
To compare the extraction efficiency of active ingredient by the extraction methods and extraction time for noni adventitious roots were extracted by ultrasonic extraction, shaking extraction, reflux extraction, homogenizer extraction, high pressure extraction, and soaking extraction. The order of extraction efficiency of rubiadin content was homogenizer extraction (2 h) > ultrasonic extraction (8 h) > shaking extraction (24 h) > high pressure extraction (24 h) > soaking extraction (6 h) > reflux extraction (2 h). The highest phenolic content was found in the extraction from ultrasonic extraction and anthraquinone content was highest in the reflux extraction. But extraction yield was found to be insignificant differences according to the extraction methods
Two-time extraction and 1:100 were promising for cost-effective method. To find out the best drying methods, noni adventitious roots were dried using freeze dry, oven dry, and shade dry method. Rubiadin, anthraquinone, and extraction yield were highest in the freeze dry method.
4. Conclusion
Noni adventitious roots from bioreactor culture conditions were excellent in anti-allergic activity. Rubiadin, a target compound was isolated from noni adventitious roots and its structure was identified by spectral data. To evaluate the effective extraction condition of the active ingredient, extraction process of noni adventitious roots was performed with various solvents, apparatus, and drying methods. The results suggested that the noni adventitious roots can be used for valuable resource.