A new iridoid glycoside from the fruits of Vitex rotundifolia

Vitex rotundifolia L. f. and Vitex trifolia L.: A review on their traditional medicine, phytochemistry, pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Vitex rotundifolia L. f. and Vitex trifolia L. belong to the genus Vitex, and Vitex rotundifolia L. f. evolved from Vitex trifolia L. Both are essential ethnic medicinal plants with a long history, commonly used to treat headaches, fever, diarrhea, hair loss, wound recovery, and other diseases.

AIM OF THE REVIEW

The research status of Vitex trifolia L. and its relative species Vitex rotundifolia L. f. were reviewed from the aspects of traditional medicinal use, phytochemistry, and pharmacological activities, to provide a reference for the further development and utilization of Vitex rotundifolia L. f. and Vitex trifolia L.

MATERIALS AND METHODS

In this paper, a comprehensive search of published literature was conducted through various books and online databases to obtain relevant information on Vitex rotundifolia L. f. and Vitex trifolia L. The search terms "(Vitex rotundifolia) OR (Vitex trifolia) OR (Fructus viticis)" were entered in PubMed, Web of Science, China national knowledge infrastructure (CNKI), Wanfang Data, Baidu Scholar, respectively. In addition to setting the year threshold of "2018-2022" on Baidu Scholar, other databases searched all fields and found 889, 283, 1263, 1023, and 147 articles, respectively. Among them, review, repetition, overlapping data, and other reasons were excluded, and finally, a total of 164 articles were included in the review study.

RESULTS

A total of 369 compounds have been identified, including 159 terpenoids, 51 flavonoids, 83 phenylpropanoids, and 76 other compounds. Pharmacological studies have shown that Vitex rotundifolia L. f. and Vitex trifolia L. have a variety of pharmacological activities, such as anti-tumor, analgesic, antipyretic, anti-inflammatory, antioxidant, antibacterial, and estrogen-like activity. Modern clinical use for treating cold headaches, diarrhea dysentery, irregular menstruation, and other diseases.

CONCLUSIONS

As traditional medicinal plants, Vitex rotundifolia L. f. and Vitex trifolia L. have wealthy chemical constituents and extensive pharmacological activities and are widely used in clinical practice from traditional to modern times. However, the research on the pharmacological activities of Vitex rotundifolia L. f. and Vitex trifolia L. is not in-depth, and the potential active components still need to be explored.

Sequence Analysis of the Complete Mitochondrial Genome of a Medicinal Plant, Vitex rotundifolia Linnaeus f. (Lamiales: Lamiaceae)

In the present study, we depicted the complete mitochondrial genome of a valuable medicinal plant, Vitex rotundifolia. The mitochondrial genome of V. rotundifolia, mapped as a circular molecule, spanned 380,980 bp in length and had a GC content of 45.54%. The complete genome contained 38 protein-coding genes, 19 transfer RNAs (tRNAs), and 3 ribosomal RNAs (rRNAs). We found that there were only 38.73% (147.54 kb), 36.28% (138.23 kb), and 52.22% (198.96 kb) of the homologous sequences in the mitochondrial genome of V. rotundifolia, as compared with the mitochondrial genomes of Scutellaria tsinyunensis, Boea hygrometrica, and Erythranthe lutea, respectively. A multipartite structure mediated by the homologous recombinations of the three direct repeats was found in the V. rotundifolia mitochondrial genome. The phylogenetic tree was built based on 10 species of Lamiales, using the maximum likelihood method. Moreover, this phylogenetic analysis is the first to present the evolutionary relationship of V. rotundifolia with the other species in Lamiales, based on the complete mitochondrial genome.

Identification of the Active Ingredient and Beneficial Effects of Vitex rotundifolia Fruits on Menopausal Symptoms in Ovariectomized Rats

Estrogen replacement therapy is a treatment to relieve the symptoms of menopause. Many studies suggest that natural bioactive ingredients from plants resemble estrogen in structure and biological functions and can relieve symptoms of menopause. The fruit of V. rotundifolia, called "Man HyungJa" in Korean, is a traditional medicine used to treat headache, migraine, eye pain, neuralgia, and premenstrual syndrome in Korea and China. The aim of the present study was to confirm that V. rotundifolia fruit extract (VFE) exerts biological functions similar to those of estrogen in menopausal syndrome. We investigated its in vitro effects on MCF-7 cells and in vivo estrogen-like effects on weight gain and uterine contraction in ovariectomized rats. Using the polar extract, the active constituents of VFE (artemetin, vitexicarpin, hesperidin, luteolin, vitexin, and vanillic acid) with estrogen-like activity were identified in MCF-7 cells. In animal experiments, the efficacy of VFE in ameliorating body weight gain was similar to that of estrogen, as evidenced from improvements in uterine atrophy. Vitexin and vitexicarpin are suggested as the active constituents of V. rotundifolia fruits.

Molecular Characterization of Terpenoid Biosynthetic Genes and Terpenoid Accumulation in Phlomis umbrosa Turczaninow

The root of Phlomis umbrosa has traditionally been used as a medicine in South Asian nations to treat colds and bone fractures, to staunch bleeding, and as an anti-inflammatory, and such use continues today. We identified 10 genes that are involved in terpenoid biosynthesis, while using the Illumina/Solexa HiSeq2000 platform. We investigated the transcript levels of the 10 genes using quantitative real-time PCR and quantified the level of terpenoid accumulation in different organs of P. umbrosa while using high-performance liquid chromatography. The transcript levels of PuHDR and PuHMGR1 were the highest among the studied genes. Sesamoside, an iridoid glycoside, appeared in higher quantity than shanzhiside methylester, umbroside (8-O-acetyl shanzhiside methyl ester), and acteoside. We speculate that PuHDR and PuHMGR1 may contribute to terpenoid biosynthesis in P. umbrosa. This study highlights the molecular mechanisms that underlie iridoid glycoside biosynthesis in P. umbrosa.

Antimalarial diterpenoids from Vitex rotundifolia: Isolation, structure elucidation, and in vitro antiplasmodial activity

Vitex rotundifolia is an important medicinal plant frequently employed in traditional medicines for the treatment of various ailments. Although this plant species has been under exploration for its constituents by various research groups including our own group, no reports were found regarding the antimalarial potential of this plant or of its purified phytochemicals. Phytochemical investigation of this plant yielded three new (1-3) and five known (4-8) diterpenoids. These compounds were purified by modern chromatographic techniques and their structures were determined by advanced spectroscopic techniques such as nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS). The in vitro antiplasmodial activities were encouraging, as compounds 2, 6, and 8 were found to have significant IC₅₀ values of 1.2, 1.3 and 11.0 µM, respectively against Plasmodium falciparum.

Anti-Atherosclerotic Effects of Fruits of Vitex rotundifolia and Their Isolated Compounds via Inhibition of Human LDL and HDL Oxidation

Low-density lipoprotein (LDL) and high-density lipoprotein (HDL) oxidation are well known to increase the risk for atherosclerosis. In our ongoing research on natural products with inhibitory activities against oxidation of lipoproteins, fruits of Vitex rotundifolia were found to be highly active. There is no report on the effects on LDL and HDL oxidation. Herein, we investigated the inhibitory effects of V. rotundifolia fruit extract and its six compounds, which are: (1) artemetin, (2) casticin, (3) hesperidin, (4) luteolin, (5) vitexin, and (6) vanillic acid, against LDL and HDL oxidation. The LDL and HDL oxidations were determined by measuring production of conjugated dienes and thiobarbituric acid reactive substances, amount of hyperchromicity and carbonyl content, change in electrical charge, and apoA-I aggregation. In addition, the contents of the compounds in the extracts were analyzed using HPLC-DAD. Consequently, extracts of Vitex rotundifolia fruits and compounds 2 and 4 suppressed oxidation of LDL and HDL, showing inhibition of lipid peroxidation, decrease of negative charges in lipoproteins, reduction of hyperchromicity, decrease in carbonyl contents, and prevention of apoA-I aggregation. In particular, compounds 2 and 4 exhibited more potent inhibitory effect on oxidation of LDL and HDL than the extracts, suggesting their protective role against atherosclerosis via inhibition of LDL and HDL oxidation. The contents of artemetin, casticin, and vanillic acid in the extracts were 1.838 ± 0.007, 8.629 ± 0.078, and 1.717 ± 0.006 mg/g, respectively.

Phytochemical composition and larvicidal activity of essential oils from herbal plants

The essential oils (EOs) of Plectranthus amboinicus showed the highest larvicidal activity among four herbal plants studied and β-caryophyllene might be the major component responsible for its differential toxicity to the larvae of Culex quinquefasciatus and Aedes Aegypti. Mosquitoes act as vectors for many life-threatening diseases, including malaria, dengue fever, and Zika virus infection. Management of mosquitoes mainly relies on synthetic insecticides, which usually result in the rapid development of resistance; therefore, alternative mosquito control strategies are urgently needed. This study characterized the major component of essential oils (EOs) derived from the vegetative parts of four herbal plants and their larvicidal activity toward important mosquito vectors. The EOs were extracted by hydro-distillation and subjected to gas chromatography-mass spectrometry (GC-MS) analysis and a larvicidal activity assay toward Aedes aegypti, Ae. albopictus and Culex quinquefasciatus. In total, 14, 11, 11 and 9 compounds were identified from the EOs of Plectranthus amboinicus, Mentha requienii, Vitex rotundifolia and Crossostephium chinense, respectively. The EOs derived from four herbal plants exhibited remarkable larvicidal activity against the three mosquito species. In particular, the EOs of P. amboinicus showed the highest larvicidal activity, and the larvae of Cx. quinquefasciatus were more sensitive to the P. amboinicus EOs than that of Ae. Aegypti. Although carvacrol (61.53%) was the predominant constituent of the P. amboinicus EOs, its precursors, γ-terpinene (8.51%) and p-cymene (9.42%), exhibited the most larvicidal activity toward Ae. aegypti and Cx. quinquefasciatus. However, β-caryophyllene (12.79%) might be the major component responsible for the differential toxicity of the P. amboinicus EOs, as indicated by the significant differences in its LC₅₀ values toward both mosquitoes. Information from these studies will benefit the incorporation of EOs into integrated vector management.