Chemical constituents from the roots of cultivated Ilex pubescens

A first insight into the genomic background of Ilex pubescens (Aquifoliaceae) by flow cytometry and genome survey sequencing

BACKGROUND

Ilex pubescens is an important traditional Chinese medicinal plant with many naturally occurring compounds and multiple pharmacological effects. However, the lack of reference genomic information has led to tardiness in molecular biology research and breeding programs of this plant.

RESULTS

To obtain knowledge on the genomic information of I. pubescens, a genome survey was performed for the first time by next generation sequencing (NGS) together with genome size estimation using flow cytometry. The whole genome survey of I. pubescens generated 46.472 Gb of sequence data with approximately 82.2 × coverage. K-mer analysis indicated that I. pubescens has a small genome of approximately 553 Mb with 1.93% heterozygosity rate and 39.1% repeat rate. Meanwhile, the genome size was estimated to be 722 Mb using flow cytometry, which was possibly more precise for assessment of genome size than k-mer analysis. A total of 45.842 Gb clean reads were assembled into 808,938 scaffolds with a relatively short N50 of 760 bp. The average guanine and cytosine (GC) content was 37.52%. In total, 197,429 microsatellite motifs were detected with a frequency of 2.8 kb, among which mononucleotide motifs were the most abundant (up to 62.47% of the total microsatellite motifs), followed by dinucleotide and trinucleotide motifs.

CONCLUSION

In summary, the genome of I. pubescens is small but complex with a high level of heterozygosity. Even though not successfully applied for estimation of genome size due to its complex genome, the survey sequences will help to design whole genome sequencing strategies and provide genetic information support for resource protection, genetic diversity analysis, genetic improvement and artificial breeding of I. pubescens.

Anatomical Characterization, HPLC Analysis, and Biological Activities of Ilex dipyrena

Ilex dipyrena Wall (Aquifoliaceae), is a traditional medicinal plant abundantly found in India and Pakistan. In the current research work, initially, the anatomical characteristics were recorded through microscopic examination of selected plant parts, such as leaf, petiole, and midrib. Then, the quantitative phytochemical screening was performed using standard tests reported in literature. The whole-plant powdered sample was then soaked in methanol to obtain crude extract, which was then fractionated into solvents of different polarities to obtain ethyl acetate, chloroform, butanol, hexane, and aqueous extracts. The phytochemical composition of the crude ethyl acetate and chloroform extracts (being the most active fractions) was then confirmed through HPLC analyses, where the possible phytochemical present were predicted through comparison of retention time of a given compound peak with the available standards. The extracts were also evaluated for their in vitro antioxidant and ani-lipoxygenase potentials using standard methods. The microscopic examination revealed the presence of anomocytic type stomata on the abaxial side of the leaf as well as unicellular trichrome and calcium oxalate druses crystals in the midrib and petiole, with a single, centered U-shaped collateral arterial bundle, which was directed toward the adaxial and the phloem toward the abaxial sides of the selected plant parts, respectively. Almost all tested representative groups of phytochemicals and essential minerals were detected in the selected plant, whereas five possible phytochemicals were confirmed in crude and chloroform extract and seven in ethyl acetate fraction. As antioxidant, chloroform fraction was more potent, which exhibited an IC₅₀ value of 64.99, 69.15, and 268.52 µg/mL, determined through DPPH, ABTS, and FRAP assays. Ethyl acetate extract was also equally potent against the tested free radicals. Chloroform and ethyl acetate extracts were also potent against lipoxygenase, with IC₅₀ value of 75.99 and 106.11 µg/mL, respectively. Based on the results of biological studies, Ilex dipyrena was found to good inhibitor of free radicals and lipoxygenase that could be further investigated to isolate compounds of medicinal importance.

Phytochemical and Biological Screening of Leaf, Bark and Fruit Extracts from Ilex dipyrena Wall

The Aquifoliaceae is an important family and has been used traditionally for some time. One of the members of this family is the Ilex dipyrena wall, which itself possesses a potential medicinal importance. This plant is traditionally used for the treatment of various ailments including pain, swelling, burns, and fever. The current study was designed to screen out the antioxidant and analgesic potential of this plant and to verify its traditional uses, along with its phytochemical profile. Extracts were subjected to antioxidant, analgesic, and phytochemical analysis using DPPH, chemical-induced (acetic acid and formalin) nociception models and GC-MS analysis, respectively. The leaf, bark, and fruit extracts showed significant antioxidant activity compared to that of standard. Likewise, all the extracts demonstrated significant (p < 0.01) analgesic activity in a mice model. In acetic acid induced analgesia, the leaf, bark, and fruit extracts caused 51.64, 56.13 and 59.52% inhibition, respectively at a dose of 100 mg/kg while at 200 mg/kg it showed 83.01, 71.69 and 75.47% inhibition, respectively. In Formalin-induced paw-licking assay, fruit extract showed 59.42 and 64.19% inhibition at 200 mg/kg dose in the first and second phase, respectively. The GC-MS analysis revealed the presence of cathinone, phenylpropanolamine, dl-phenylephrine, amphetamine, myristic acid, and palmitic acid. Results of the study suggest that crude extracts from different parts of this plant may be a useful source for the development of novel analgesics. However, further investigation in terms of isolation of bioactive compounds and their toxicological evaluations are needed to validate the observed results.

Evaluation of antinociceptive activity of Ilex dipyrena Wall. in mice

BACKGROUND

In order to find a new natural resource for pain-relief, the analgesic effects of Ilex dipyrena crude extract, fractions, and subfractions were evaluated in in-vivo mouse models with possible mechanism of action.

METHODS

Analgesic effects of crude extract (100 and 200 mg/kg body weight), fractions and subfractions (75 mg/kg body weight) were screened using heat-induced (tail-immersion and hot plate test) and chemical-induced (formalin and acetic acid) nociception models in mice. The samples were also tested for the elucidation of a possible mechanism through opioidergic and GABAergic systems.

RESULTS

The administration of crude extract, fractions and subfractions produced analgesic responses in acetic acid, formalin, tail immersion, and hot plate model for pain similar to those obtained with the standard. Naloxone antagonized the antinociceptive effects of the tested samples, whereas bicuculline showed partial inhibition. Considering the analgesic response, crude extract, fractions, and subfractions demonstrated promising inhibitory activity against all test models for pain, which was further supported by the possible involvement of opioidergic and GABAergic systems.

CONCLUSION

The results suggest that this plant may be useful in the development of new analgesic drugs. Further research with regard to the isolation of bioactive compounds is required to verify these findings.