Otostegia fruticosa (Forssk.) - A comprehensive insight of its ethnopharmacology, phytochemistry, and pharmacological activities

Otostegia fruticosa (Forssk.) is a shrub of the Lamiaceae family with a wide geographic distribution in Saudi Arabia, Western and Eastern Africa, Ethiopia, and the Middle East. The current study provides an overview of recent developments in the knowledge of O. fruticosa's ethnobotanical, pharmacological, and phytochemical properties. In folkloric medicine, it has been used since ancient times for gastrointestinal disorders, oral health, ocular irritation, antiparasitic, diarrhea, tonsillitis, arthritis, respiratory complications, and sunstroke treatment. Pharmacological investigations of its antibacterial, antioxidant, anti-inflammatory, cytotoxic, analgesic, larvicidal, nephroprotective, and other effects further validated its folklore practice. A range of diterpenoids, triterpenes, flavonoids, and essential oils have been found in O. fruticosa, according to phytochemical studies, which are thought to be responsible for the pharmacological effects of this plant species. This scientific review summarizes the most important secondary metabolites isolated from the O. fruticosa. It also summarizes the biological activities, providing insights into further scientific exploration.

Authentication of the therapeutic Lamiaceae taxa by using pollen traits observed under scanning electron microscopy

Herbal medicines are gaining popularity worldwide for human healthcare because of their therapeutic potential. However, adulteration and use of unauthentic raw herbals as substitutes have become a major issue for the local communities and industry for reasons of safety and efficacy. Therefore, the authentication of medicinal plants before their use in herbal medicines is a need of time. Hence, the present study was designed with an aim, to authenticate the therapeutic Lamiaceous taxa by using pollen traits observed under scanning electron microscopy. Pollen micro-morphological studies solve the problem through discrimination and correct identification of the Lamiaceae species from the adulterants. Based on pollen features, Lamiaceae were further divided into two sub-families Lamioideae (tricolpate) and Nepetoideae (hexa-colpate). The pollen grains of Lamioideae were found as small to medium-sized, tricolpate, radially/bilateral symmetrical, sub-spheroidal and oblate shape. Besides, exine patterns bireticulate, reticulate and micro-reticulate, colpus surface sculpturing as psilate, gemmate, scabrate, and verrucate have also been reported. A significant variation was found in the pattern of the reticulum, thickness, and the number of secondary lumina per primary lumen. Similarly, Nepetoideae has a hexa zono-colpate pollen but tri and tetra zono-colpate pollen have also been observed. Hence, this study contributes to the authentication and correct identification of medicinally important Lamiaceae taxa by using scanning electron microscopic techniques and can help to solve the adulteration problem. Highlights Authentication of medicinally important Lamiceous taxa was carried out through scanning electron microscopic techniques. Chemotaxonomic characterization was used for the accurate identification of the therapeutic taxa. The medicinal, palynological and phytochemical significance of Lamiaceae taxa were evaluated. A significant variation was seen in the palynological traits that help in the determination and authentication of the therapeutic Lamiaceous species. Based on the chemotaxonomic characterization, our study can help to solve the adulteration problem for the reason of safety and efficacy.

Ethnomedicinal and phytochemical review of Pakistani medicinal plants used as antibacterial agents against Escherichia coli

Medicinal plants have always been part of human culture and have the potential to cure different diseases caused by microorganisms. In Pakistan, biologists are mainly focusing on plants’ antimicrobial activities against Escherichia coli due to its increasing resistance to antibiotics. In total, extracts from 34 ethnomedicinally valuable Pakistani plants were reported for in-vitro anti-E. coli activities. Mostly methanolic extracts of medicinal plants were used in different studies, which have shown comparatively higher inhibitory activities against E. coli than n-hexane and aqueous extracts. It has been found that increasing concentration (mg/ml) of methanolic extract can significantly increase (p < 0.01) anti-E. coli activities. Not all medicinal plants are extracted in solvents others than above, which should also be tested against E. coli. Moreover, medicinal plant species must be fully explored phytochemically, which may lead to the development of new drugs.

Highly glycosylated flavonols with an O-linked branched pentasaccharide from Iberis saxatilis (Brassicaceae)

Four flavonol glycosides isolated from non-flowering leafy shoots of Iberis saxatilis (Brassicaceae) were characterised by spectroscopic and chemical methods as saxatilisins A-D, the 3-O-β-D-glucopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)[β-D-glucopyranosyl-(1→2)-α-L-rhamnopyranosyl-(1→6)]-β-D-glucopyranoside, 3-O-β-D-glucopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)[α-L-rhamnopyranosyl-(1→6)]-β-D-glucopyranoside, 3-O-(6-O-E-sinapoyl)-β-D-glucopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)[β-D-glucopyranosyl-(1→2)-α-L-rhamnopyranosyl-(1→6)]-β-D-glucopyranoside, and 3-O-(6-O-E-feruloyl)-β-D-glucopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)[β-D-glucopyranosyl-(1→2)-α-L-rhamnopyranosyl-(1→6)]-β-D-glucopyranoside of isorhamnetin (3,5,7,4'-tetrahydroxy-3'-methoxyflavone), respectively. Analysis of (2)J(HC) correlations detected with the H2BC (heteronuclear two-bond correlation) pulse sequence aided the unambiguous assignment of glycosidic resonances in the (1)H and (13)C NMR spectra of these compounds. Saxatilisins A, C, and D, are the first flavonol glycosides to be described with a pentasaccharide chain at a single glycosylation site. Several pentaglycosides of kaempferol and quercetin, tentatively assigned as saxatilisin analogues from LC-MS/MS analyses, were present as minor constituents of the extracts.

Investigation of antitussive and toxicological activity of Ballota limbata in mice

CONTEXT

Ballota limbata Benth. (Lamiaceae) (syn, Otostegia limbata Hook.f.) is a species grown in the North West Frontier Province and the lower hills of West Punjab, Pakistan. Ballota species are renowned for their antispasmodic, antiulcer, diuretic, vermifuge, and especially sedative effects. However, little is known about the biological activity of B. limbata.

OBJECTIVE

Evaluation of antitussive activity and safety profile of dried B. limbata extract.

MATERIALS AND METHODS

Whole air-dried plants were partitioned with various solvents and the butanol fraction was subjected to antitussive evaluation using a sulfur dioxide (SO(2))-induced cough model in mice. Codeine and dextromethorphan were used as positive control. Safety profile of the testing material was established using standard toxicity tests.

RESULTS

B. limbata extract inhibited cough provoked by SO(2) gas in mice in a dose-dependent manner. The extract exhibited maximum protection against SO(2)-induced cough after 60 min of administration. B. limbata offered maximum cough suppressive effects, that is, number of coughs during 60 min was 11.66 ± 1.2 (mean ± SEM), after s.c. administration of 800 mg/kg, as compared with codeine 10 mg/kg, s.c., dextromethorphan 10 mg/kg, s.c., and saline showing a frequency of cough of 11.75 ± 1.18, 12.25 ± 0.83, and 46.25 ± 1.52, respectively. LD(50) value of B. limbata was greater than 5000 mg/kg. No sign of neural impairment was observed at antitussive doses and the extract has been well-tolerated at higher doses.

DISCUSSION AND CONCLUSION

This study demonstrates that the extract of B. limbata has shown strong cough suppressive effect in mice without yielding any notable toxicity.