Iridoids from Neopicrorhiza scrophulariiflora and Their Hepatoprotective Activities in Vitro

Traditional medicinal knowledge of Sherpa people: Assessment in Xizang, China

ETHNOPHARMACOLOGICAL RELEVANCE

The people of the Pan-Himalayan region are among the most isolated and economically disadvantaged populations worldwide. The Sherpa people, located along the China and Nepal border, rely largely on the natural environment to access essential healthcare services. The region's ongoing economic and social developments threaten indigenous medicinal practices and biodiversity. However, there has been limited comprehensive investigation and documentation of traditional medicine and its associated knowledge in this region.

AIM OF THE STUDY

The aims are to document the traditional medicinal knowledge of the Sherpa community, assess the conservation status of medicinal plants, and explore the historical factors that have influenced their traditional medicine practices.

MATERIAL AND METHODS

Semi-structured interviews with 78 Sherpa people were conducted in Chenthang Town, Xizang, China. Use reports (URs) was used to determine the most frequently mentioned medicinal plants or a specific ailment or disease category. The International Classification of Primary Care-2nd edition (ICPC-2) was used to transform the original records into an internationally unified classification.

RESULTS

A total of 51 plant species, one fungus (Ophiocordyceps sinensis (Berk.) G.H.Sung, J.M.Sung, Hywel-Jones & Spatafora), two lichens (Flavopunctelia soredica (Nyl.) Hale and Parmotrema cetratum (Ach.) Hale), and four minerals were documented, resulting in 824 URs. Ranunculaceae had the most species (5 spp.). The most commonly used method for preparing medicinal substances was decoction (23 species, 40%). Oral application was the preferred route of administration for 81% (41 medicinal substances). Forty-four ailments across 14 ICPC-2 disease categories were documented. Respiratory (320 URs) and digestive (122 URs) categories are among the most common diseases. The top-five ailments were influenza (18 substances; URs = 227), injury blood/lymph/spleen other (11 substances; URs = 66), cough (10 substances; URs = 62), headache (7 substances; URs = 63), and abdominal pain/cramps general (6 substances; URs = 37). The most frequently reported medicinal substances were Panax pseudoginseng Wall. (URs = 128) and Neopicrorhiza scrophulariiflora (Pennell) D. Y. Hong (URs = 79). Two special therapies (hot spring therapy and dietary therapy) were described. In-depth ethnographic information on the livelihood and exchange history of Sherpa people were documented. A total of 25 species were sold, of which four species were listed as VU in the IUCN Red List (2023-1), six species were listed as VU, four species were NT, and one species was EN in the China Biodiversity Red list 2021.

CONCLUSION

This study provides the first comprehensive documentation of the 58 traditional medicine substances and two special therapies (hot spring therapy and dietary therapy) used by the Sherpa people in Chenthang. Sherpa's medicinal knowledge has been shaped by historical interactions and contemporary trade practices. To better protect the biocultural diversity of the Himalayan region, priority should be given to the rapid assessment of medicinal plants, knowledge, and use status in this area.

Two new iridoid glycosides from Hedyotis diffusa

Two new iridoid glycosides, named productasperulosidic acid butyl ester (1) and E-6-O-3-hydroxy-p-methoxycinnamoyl scandoside methyl ester (2), along with nine known ones (3-11), were isolated from Hedyotis diffusa Willd. The structures of them were elucidated by extensive 1D, 2D NMR and HR-ESI-MS spectral data. Compounds 1-11 showed no significant cytotoxic activity against HeLa cells.

Iridoid glycosides from Picrorhiza genus endemic to the Himalayan region: phytochemistry, biosynthesis, pharmacological potential and biotechnological intercessions to boost production

Iridoid glycosides are monoterpenoids synthesized in several plant species known to exhibit a diverse range of pharmacological activities. They are used as important bioactive ingredients in many commercially available drug formulations and as lead compounds in pharmaceutical research. The genus Picrorhiza comprises two medicinally important herbs endemic to the Himalayan region viz. Picrorhiza kurrooa Royle and Picrorhiza scrophulariiflora Hong. The medicinal properties of these two species are mainly due to iridoid glycosides present in their root, rhizome, and leaves. Unregulated harvesting from the wild, habitat specificity, narrow distribution range, small population size and lack of organized cultivation led to the enrolling of these species in the endangered category by the International Union for Conservation of Nature and Natural Resources (IUCN). Therefore, there is a need for immediate biotechnological and molecular interventions. Such intercessions will open up new vistas for large-scale propagation, development of genomic/transcriptomic resources for understanding the biosynthetic pathway, the possibility of genetic/metabolic manipulations, and possible commercialization of iridoid glycosides. The current review article elucidates the phytochemistry and pharmacological importance of iridoid glycosides from the genus Picrorhiza. In addition, the role of biotechnological approaches and opportunities offered by next-generation sequencing technologies in overcoming challenges associated with the genetic engineering of these species are also discussed.

Neopicrorhiza scrophulariiflora (Pennell) Hong: A comprehensive review of its traditional uses, phytochemistry, pharmacology and safety

ETHNOPHARMACOLOGICAL RELEVANCE

Neopicrorhiza scrophulariiflora (Pennell) Hong is important medicinal plant that is native to the eastern Himalayas and Hengduan mountains in China. It is also distributed in Nepal, north east India, Bhutan and northern Myanmar. Plant parts are traditionally used against different kinds of diseases and various compounds present in different plant parts are also effective against many diseases. Thus, N. scrophulariiflora has a high potential to maintain human health.

AIM OF THE REVIEW

Although N. scrophulariiflora is very important and widely studied plant species but there is no comprehensive up-to-date review of published and unpublished literature. So, in the present article we have compiled and critically commented on the botanical characteristics, traditional uses, plant growth and cultivation, micropropagation, conservation status, secondary metabolites, pharmacology and toxicity of the plant.

MATERIALS AND METHODS

Extensive literature searches both electronic online databases (Google Scholar, Scopus, Springer Link, Web of Science, ScienceDirect, ResearchGate, PubMed, ChemSpider, USPTO, Google patents and Espacenet) and library visits in Nepal were carried out to collect the literature on information published prior to April 2019.

RESULTS

N. scrophulariiflora was traditionally used for 82 ailments/diseases. There are 124 major phytochemicals extracted from the plant. Several compounds are effective in bioactivity. Pharmacologically, the plant is proved to be anti-atherosclerotic, antidiabetic and anti-inflammatory in-vivo studies, and antimicrobial, antimalarial, antioxidative, hepatoprotective, immunomodulatory and nerve growth factor potentiating from in-vitro studies. Renal improvement activities were confirmed from both in-vivo and in-vitro studies. Toxicological tests and a single clinical trial in human beings have supported the notion that the plant is not poisonous but beneficial for curing wide ranges of diseases.

CONCLUSION

N. scrophulariiflora is valuable medicinal plant that can serve as promising source of non-harmful and potential medicinal herbal remedies for human beings.

Nine new compounds from the whole plants of Rehmannia henryi

Eight new iridoids (1-8) and an ionone glucoside (9), together with 31 known compounds (10-40), were isolated from the whole plants of Rehmannia henryi. The structures of these compounds were elucidated on the basis of their spectroscopic data and chemical evidence.

Chemical components from the seeds of Catalpa bungei and their inhibitions of soluble epoxide hydrolase, cholinesterase and nuclear factor kappa B activities

22 compounds, including two rare cage chlorinated iridoids, bungosides A (1) and B (2), were isolated fromCatalpa bungei. of soluble epoxide hydrolase (sEH), acetylcholinesterase (AChE) and BChE, and NF-κB activity.

Piscroside C, a novel iridoid glycoside isolated from Pseudolysimachion rotundum var. subinegrum suppresses airway inflammation induced by cigarette smoke

ETHNOPHARMACOLOGICAL RELEVANCE

Pseudolysimachion rotundum var. subintegrum (Speedwell, Plantaginaceae) is used as a traditional herbal medicine for treating bronchitis, cough and asthma in Korea, China, Russia, and Europe.

AIM OF THE STUDY

In this study, we investigated the protective effects of the novel iridoid glycoside, piscroside C (compound 1) isolated from the methanolic extract of P. rotundum var. subintegrum against inflammatory responses using a cigarette smoke induced chronic obstructive pulmonary disease (COPD) and TNF-α-stimulated human airway epithelial NCI-H292 cells.

MATERIALS AND METHODS

The novel iridoid glycoside piscroside C was isolated from the methanolic extract of P. rotundum var. subintegrum. The chemical structure was established by NMR, HRESIMS, and optical rotation. In in vivo experiment, the mice received 1h of cigarette smoke for 3 days. Piscroside C was administered to mice by oral gavage 1h before cigarette smoke exposure for 3 days. In in vitro experiment, we evaluated the effect of piscroside C on proinflammatory mediators in H292 cells stimulated with TNF-α.

RESULTS

Piscroside C significantly reduced the neutrophil influx, reactive oxygen species production, IL-6, TNF-α, and elastase activity in bronchoalveolar lavage fluid in COPD animals. In addition, piscroside C attenuated NF-κB and IκB phosphorylation, leading to reduced recruitment of inflammatory cells into the lung tissue. Consistent with the results of in vivo experiment, piscroside C significantly inhibited the expression of inflammatory cytokines (IL-6, IL-8 and IL-1β) by inhibiting NF-κB activation, as resulting decrease in the phosphorylation of IKKβ, IκBα and TAK1 in TNF-α-stimulated H292 cells.

CONCLUSION

These findings indicate that piscroside C effectively inhibits inflammatory responses, which is an important process in the development of COPD through suppression of IKK/NF-κB activation. Our study suggest that piscroside C might represent a useful therapeutic for the treatment of inflammatory airway disease.

Naturally occurring iridoids, secoiridoids and their bioactivity. An updated review, part 3

Naturally occurring new iridoids and secoiridoids published during 2005-2008 are reviewed with available physical and spectral data: mp, [alpha](D), UV, IR, (1)H- and (13)C-NMR and plant source. The works on biological and pharmacological activity of naturally occurring iridoids and secoiridoids reported during 2005-2008 are also reviewed. Bioactivities like antibacterial, anticancer, anticoagulant, antifungal, anti-inflammatory, antioxidative, antiprotozoal, hepatoprotective and neuroprotective activities are highlighted.