Antibacterial and COX-1 Inhibitory Effect of Medicinal Plants from the Pamir Mountains, Afghanistan

Comparative Effect of Antioxidant and Antibacterial Potential of Zinc Oxide Nanoparticles from Aqueous Extract of Nepeta nepetella through Different Precursor Concentrations

Antibiotic resistance is a global health crisis caused by the overuse and misuse of antibiotics. Accordingly, bacteria have developed mechanisms to resist antibiotics. This crisis endangers public health systems and medical procedures, underscoring the urgent need for novel antimicrobial agents. This study focuses on the green synthesis of ZnO nanoparticles (NPs) using aqueous extracts from Nepeta nepetella subps. amethystine leaves and stems, employing different zinc sulfate concentrations (0.5, 1, and 2 M). NP characterization included transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD), along with Fourier transform infrared spectroscopy (FTIR) analysis. This study aimed to assess the efficacy of ZnO NPs, prepared at varying concentrations of zinc sulfate, for their capacity to inhibit both Gram-positive and Gram-negative bacteria, as well as their antioxidant potential using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. SEM and TEM results showed predominantly spherical NPs. The smallest size (18.5 ± 1.3 nm for leaves and 18.1 ± 1.3 nm for stems) occurred with the 0.5 M precursor concentration. These NPs also exhibited remarkable antibacterial activity against both Gram-positive and Gram-negative bacteria at 10 µg/mL, as well as the highest antioxidant activity, with an IC50 (the concentration of NPs that scavenge 50% of the initial DPPH radicals) of 62 ± 0.8 (µg/mL) for the leaves and 35 ± 0.6 (µg/mL) for the stems. NPs and precursor concentrations were modeled to assess their impact on bacteria using a 2D polynomial equation. Response surface plots identified optimal concentration conditions for antibacterial effectiveness against each species, promising in combating antibiotic resistance.

The genus Nepeta: Traditional uses, phytochemicals and pharmacological properties

ETHNOPHARMACOLOGICAL RELEVANCE

Nepeta is a multiregional genus of the "Lamiaceae" (Labiatae or Mint) family. Species of Nepeta are a valuable part of traditional medicine and used extensively, particularly in the Himalayan region of India (Uttarakhand, Himachal Pradesh, Jammu and Kashmir, Leh-Ladakh), Pakistan (Khyber Pakhtunkhwaand Pakistani Kashmir), Nepal (Baglund district), also in China and hilly regions of Turkey and Iran. Nepeta species are extensively used as a remedy against a variety of ailments and conditions like chicken pox, tuberculosis, malaria, pneumonia, influenza, measles, stomach disorders, eye complaints, respiratory disorders, asthma, colds, coughs etc. AIM OF THE REVIEW: The main aim of this review is to present a comprehensive and detailed study on traditional uses, pharmacology, phytochemistry, toxicology of Nepeta species and suggest future direction on the design and conduct of various preparations, either alone or in blends with prevailing conventional remedies. The review also emphasizes encouraging researchers towards the wide range of pharmaceutical applications of the various species of Nepeta for their better use and exploration in the future.

MATERIAL AND METHODS

All the relevant data and information on different species of Nepeta were assembled using different databases, such as Science Direct, Springer, PubMed, Taylor and Francis imprints, Chemspider, Google scholar, review and research articles from peer-reviewed journals and unpublished data. Some select 'grey literature' sources viz. ethnobotanical books, chapters, Wikipedia and webpages were also studied.

RESULTS

A variety of bioactive secondary metabolites and nutraceuticals has been isolated from various species of Nepeta. These bioactive compounds belong to different classes of secondary metabolites, such as phenolic acids and their glycosides (rosmarinic acid, gallic acid, caffeic acid), flavonoids and their glycosides (cirsimaritin, salvigenin, luteolin, apigenin), iridoids (nepetalactones and their derivatives), terpenoids (1,8-cineole, linalool, β-caryophyllene, germacrene D, parnapimaro, β-amyrin, oleanolic acid, ursolic acid), steroids (β-sitosterol, stigmasterol), lignans, amino acids, carbohydrates, volatile oils, etc. The species of the genus Nepeta possess a variety of pharmacological activities namely anti-inflammatory, anti-nociceptive, anti-alzheimer, anticancer and cytotoxic, antioxidant, immunomodulatory, antimicrobial, antifungal, insecticidal and along with other biological activities.

CONCLUSION

The species of the genus Nepeta contains a rich source of various bioactive compounds, which are well tolerated as traditional medicines. In fact, different species of Nepeta are widely used in a variety of traditional medicinal systems all around the world. Owing to the variety of pharmacological properties of Nepeta species, more comprehensive and inclusive clinical trials are necessary for the utilization of different Nepeta species against the treatment of a wide range of ailments. There are also various other uses such as food, cosmetic and agriculture that can be investigated or explored in future. Some of the major domains that can be explored within this genus are the investigation of different species for their unexplored biological potential, isolation and characterization of new bioactive constituents and finally, investigation of new applications and possible commercialization of these bioactive leads. No doubt, there are various viable research domains outside those discussed above, but presently for the purposes of this review we will only emphasize the activities herein.

The Genus Lagochilus (Lamiaceae): A Review of Its Diversity, Ethnobotany, Phytochemistry, and Pharmacology

The genus Lagochilus (Lamiaceae) is native to Central, South-Central, and Eastern Asia. It comprises 44 species, which have been commonly used as herbal medicines for the treatments of various ailments for thousands of years, especially in Asian countries. This review aims to summarize the chemical constituents and pharmacological activities of species from the genus Lagochilus to unveil opportunities for future research. In addition, we provide some information about their traditional uses, botany, and diversity. More than 150 secondary metabolites have been reported from Lagochilus, including diterpenes, flavonoids, phenolic compounds, triterpenoids, iridoid glycosides, lignans, steroids, alkaloids, polysaccharides, volatile, non-volatile and aromatic compounds, lipids, carbohydrates, minerals, vitamins, and other secondary metabolites. In vitro and in vivo pharmacological studies on the crude extracts, fractions, and isolated compounds from Lagochilus species showed hemostatic, antibacterial, anti-inflammatory, anti-allergic, cytotoxic, enzyme inhibitory, antispasmodic, hypotensive, sedative, psychoactive, and other activities.

Glechoma curviflora Volatile Oil from Palestine: Chemical Composition and Neuroprotective, Antimicrobial, and Cyclooxygenase Inhibitory Activities

The rise of the emergence of microbial resistance of antibiotics, the dangerous side effects of nonsteroidal anti-inflammatory drugs, and noncompetent medications of Alzheimer's, Parkinson's, and other neurodegenerative diseases prompt scientists to search for phytochemicals that could be utilized in the remedy of lethal diseases. Glechoma curviflora (Boiss.) Kuntze (Nepeta curviflora) is a medicinal herb growing in the eastern parts of the Mediterranean Sea Basin and is widely consumed as a tea. The leaves of this plant have been traditionally used for the treatment of various infectious diseases. The current research was designed to identify the chemical composition of Glechoma curviflora (Boiss.) essential oil (EO) and to assess its antibacterial, antifungal, and cyclooxygenase inhibitory activities and the biophysical gating effect on AMPA receptors. Twenty phytochemicals were identified from G. curviflora leaves and flowers EO amounting to almost 100% of the total constituents using GC-MS technique, of which 1,6-dimethylspiro[4.5]decane (27.51%) 1, caryophyllene oxide (20.08%) 2, and β-caryophyllene (18.28%) 3 were the main constituents. The biophysical properties' effect from the plant extract on various AMPA-type receptors expressed in Human Embryonic Kidney (HEK293) cells was assessed by exploiting the whole-cell patch-clamp technique. Microdilution assay was adopted for assessing the antimicrobial property against eight virulent microbial strains whilst the cyclooxygenase inhibition effect was accomplished utilizing COX inhibitory screening colorimetric assay G. curviflora EO displayed potent activity against P. aeruginosa (MIC = 1.25 μg/mL), S. sonnei (MIC = 3.12 μg/mL), and E. coli (MIC = 1.25 μg/mL), compared with ciprofloxacin (positive control) and potent antibacterial activity against S. aureus, MRSA, S. sonnei, E. coli, and P. aeruginosa compared to Ampicillin (2nd positive control). It also showed anti-Candida (MIC = 6.25 μg/mL) and antimold (MIC = 3.125 μg/mL) activities compared with fluconazole (antifungal positive control). Likewise, our results showed an inhibition and biophysical impact of G. curviflora on all AMPARs subunits.

Medicinal plants with anti-inflammatory activities from selected countries and regions of Africa

Various nonsteroidal anti-inflammatory drugs have been shown to reduce pain and inflammation by blocking the metabolism of arachidonic acid by isoform of cyclooxygenase enzyme, thereby reducing the production of prostaglandin. Sadly, there are many side effects associated with the administration of nonsteroidal anti-inflammatory drugs. However, there are medicinal plants with anti-inflammatory therapeutic effects with low or no side effects. The Afri-can continent is richly endowed with diverse medicinal plants with anti-inflammatory activities that have been shown to be effective in the treatment of inflammatory conditions in traditional medicine. Interestingly, scientists have examined some of these African medicinal plants and documented their biological and therapeutic activities. Unfortunately, medicinal plants from different countries in Africa with anti-inflammatory properties have not been documented in a single review paper. It is important to document the ethnobotanical knowledge and applications of anti-inflammatory medicinal plants from selected countries representing different regions of the African continent. This paper therefore documents anti-inflammatory activities of various medicinal plants from different geographical regions of Africa with the aim of presenting the diversity of medicinal plants that are of traditional or therapeutic use in Africa.

Antibacterial screening of Rumex species native to the Carpathian Basin and bioactivity-guided isolation of compounds from Rumex aquaticus

Plants belonging to the genus Rumex (family Polygonaceae) are used worldwide in traditional medicine for the treatment of various diseases caused by different microorganisms (e.g. bacteria-related dermatologic conditions, dysentery and enteritis). The present study focused on the antibacterial screening of Rumex species native to the Carpathian Basin, and isolation of compounds from one of the most efficient species, Rumex aquaticus. The antibacterial effects of n-hexane, chloroform and aqueous fractions of methanol extracts prepared from different parts of 14 Rumex species (R. acetosella, R. acetosa, R. alpinus, R. aquaticus, R. conglomeratus, R. crispus, R. hydrolapathum, R. obtusifolius subsp. obtusifolius, R. obtusifolius subsp. subalpinus, R. patientia, R. pulcher, R. scutatus, R. stenophyllus and R. thyrsiflorus) were investigated against Staphylococcus epidermidis, S. aureus, MRSA, Bacillus subtilis, Moraxella catarrhalis, Streptococcus pyogenes, S. pneumoniae, S. agalactiae, Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae using the disc diffusion method. Mainly the n-hexane and chloroform extracts prepared from the roots of the plants displayed high antibacterial activity (inhibition zones>15mm) against one or more bacterial strains. The highly active extracts of the aerial part and root of R. aquaticus were subjected to a multistep separation procedure. 19 Compounds, among them naphthalenes (musizin, and its glucoside, torachrysone-glucoside, 2-methoxystypandrone), anthraquinones (emodin, chrysophanol, physcion, citreorosein, chrysophanol-8-O-glucoside), flavonoids (quercetin, quercetin-3,3'-dimethylether, isokaempferide, quercetin 3-O-arabinoside, quercetin 3-O-galactoside, catechin), stilbenes (resveratrol, piceid), and 1-stearoylglycerol were isolated from the plant. The antibacterial activities of isolated compounds were determined, and it was observed that especially naphthalenes exerted remarkable antibacterial effects against several bacterial strains.

Kazakh Ziziphora Species as Sources of Bioactive Substances

Ziziphora species represent the prototypical example of the Lamiaceae family. The phytochemicals present in Ziziphora include monoterpenic essential oils, triterpenes and phenolic substances belonging to the flavonoids. In Kazakh traditional medicine, Ziziphora species possess several medicinal uses. In particular, Z. bungeana Lam. and Z. clinopodioides Lam. are used for the treatment of illnesses related to the cardiovascular system or to combat different infections. Unfortunately, the majority of the information about the complex Ziziphora species is only available in Russian and Chinese language, therefore, we decided gather all available information on Kazakhstan Ziziphora, namely its content compounds, medicinal uses and published patents, to draw the attention of scientists to this very interesting plant with high medicinal potential.

Comparative ethnobotany of the Wakhi agropastoralist and the Kyrgyz nomads of Afghanistan

BACKGROUND

The mountainous Wakhan and Pamir in northeastern Afghanistan is one of the most isolated yet inhabited places in Asia. It is home to the agropastoralist Wakhi and the last Afghan semi-nomadic Kyrgyz. We present a study of plant names and uses, along with comparisons of plant name etymology, origins of plant resources, intra- and intercultural exchanges and relations, and the relative availability of the known and used plants.

METHODS

The fieldwork was conducted as an expedition in the summer of 2010, and visited settlements and pastures in Upper Wakhan and Big and Little Pamir. Semi-structured group interviews, talks and observations gave initial data on names, uses and the relative availability of used plants, and provided foundation for individual interviews using an interview-herbarium containing vouchers of the 72 most frequently used plants or plant groups.

RESULTS

Wakhi and Kyrgyz plant names are recorded in western transcription, the new Wakhi alphabet, phonetically and in Cyrillic. The present study documents a large body of endemic, indigenous plant knowledge; on crops, fuel, fodder, cosmetics, dyes, vegetables, veterinary medicine, traditional medicines and other plant uses which sustain life in Wakhan and Pamir. Overall, the Wakhi use considerably more plants than the Kyrgyz, and their materia medica and use thereof is more complex. Although the Wakhi and Kyrgyz are close neighbours, there are few indications of direct knowledge transfer between them. Most shared plant uses are strictly necessary for survival in the mountains. While there are few differences between genders and cultural subgroups within the two cultures, the Wakhi and Kyrgyz exhibit great differences both in their total number of use-plants and the distance from which they obtain them. The agropastoralist Wakhi appear to have their basic needs for wild natural resources covered within half a days travel, while the relatively plant-derived environment of the high Pamir appears to have necessitated the nomadic Kyrgyz to adapt by developing uses and obtaining plants that are comparatively remote.

CONCLUSION

The comparative differences in plant uses between the agropastoralist Wakhi and nomadic Kyrgyz appear to be accentuated by an environment at the extreme of what is humanly possible.