Antimicrobial and antioxidant activity of methanol extracts of Arnebia benthamii (Wall ex. G. Don) Johnston—a critically endangered medicinal plant of North western Himalaya

Phytochemicals as Antimicrobials: Prospecting Himalayan Medicinal Plants as Source of Alternate Medicine to Combat Antimicrobial Resistance

Among all available antimicrobials, antibiotics hold a prime position in the treatment of infectious diseases. However, the emergence of antimicrobial resistance (AMR) has posed a serious threat to the effectiveness of antibiotics, resulting in increased morbidity, mortality, and escalation in healthcare costs causing a global health crisis. The overuse and misuse of antibiotics in global healthcare setups have accelerated the development and spread of AMR, leading to the emergence of multidrug-resistant (MDR) pathogens, which further limits treatment options. This creates a critical need to explore alternative approaches to combat bacterial infections. Phytochemicals have gained attention as a potential source of alternative medicine to address the challenge of AMR. Phytochemicals are structurally and functionally diverse and have multitarget antimicrobial effects, disrupting essential cellular activities. Given the promising results of plant-based antimicrobials, coupled with the slow discovery of novel antibiotics, it has become highly imperative to explore the vast repository of phytocompounds to overcome the looming catastrophe of AMR. This review summarizes the emergence of AMR towards existing antibiotics and potent phytochemicals having antimicrobial activities, along with a comprehensive overview of 123 Himalayan medicinal plants reported to possess antimicrobial phytocompounds, thus compiling the existing information that will help researchers in the exploration of phytochemicals to combat AMR.

A Review of Medicinal Plants of the Himalayas with Anti-Proliferative Activity for the Treatment of Various Cancers

Simple Summary

Drugs are used to treat cancer. Most drugs available in the market are chemosynthetic drugs and have side effects on the patient during and after the treatment, in addition to cancer itself. For instance, hair loss, loss of skin color and texture, loss of energy, nausea, infertility, etc. To overcome these side effects, naturally obtained drugs from medicinal plants are preferred. Our review paper aims to encourage the study of anticancer medicinal plants by giving detailed information on thirty-three medicinal plants and parts that constitute the phytochemicals responsible for the treatment of cancer. The development of plant-based drugs could be a game changer in treating cancer as well as boosting the immune system.

Abstract

Cancer is a serious and significantly progressive disease. Next to cardiovascular disease, cancer has become the most common cause of mortality in the entire world. Several factors, such as environmental factors, habitual activities, genetic factors, etc., are responsible for cancer. Many cancer patients seek alternative and/or complementary treatments because of the high death rate linked with cancer and the adverse side effects of chemotherapy and radiation therapy. Traditional medicine has a long history that begins with the hunt for botanicals to heal various diseases, including cancer. In the traditional medicinal system, several plants used to treat diseases have many bioactive compounds with curative capability, thereby also helping in disease prevention. Plants also significantly contributed to the modern pharmaceutical industry throughout the world. In the present review, we have listed 33 medicinal plants with active and significant anticancer activity, as well as their anticancer compounds. This article will provide a basic set of information for researchers interested in developing a safe and nontoxic active medicinal plant-based treatment for cancer. The research will give a scientific foundation for the traditional usage of these medicinal herbs to treat cancer.

Phytochemical constituents, distributions and traditional usages of Arnebia euchroma: A review

ETHNOPHARMACOLOGICAL RELEVANCE

The present study has indicated phytochemical composition, distribution and ethno-medicinal uses of Arnebia euchroma (Royle) I.M. Johnst, which is commonly known as "Ratanjot" in the Indian subcontinent. It has widely been used in the traditional systems of the Unani, Ayurvedic and Chinese medicines recipes due to its anti-fungal and anti-microbial properties. Instead, the gap of earlier studies is well defined that will be helpful for researchers to carry out more analysis and increase medicinal importance of this plant.

AIM OF STUDY

The main aim of this review study is to demonstrate the phytochemical composition and traditional ethno-medicinal uses of A. euchroma all over the world. Earlier studies related to this plant have been discussed in the present study and on that basis, future perspective of A. euchroma is also proposed.

MATERIALS AND METHODS

The information of A. euchroma has been gathered from various electronic database, reference books and available literature.

RESULTS

The study has indicated that Arnebia euchroma owing to anti-microbial and anti-inflammatory properties is used in the traditional medicines and pharmaceutical industries for the treatment of hair problems, remitting, chronic diseases, burnt limbs, cough and cold, etc., and besides as a vegetable colorant and dyeing of cloths. The important phytochemical constituents viz., shikonin, acetyl-shikonin, iso-butyryl-shikonin, β,β-di-methylacryl-shikonin, isovaleryl-shikonin, β-hydroxy-isovaleryl-shikonin, deoxy-shikonin, isobutyl-shikonin, arnebinone, arnebin-7, stigmasterol, etc., isolated from the roots of Arnebia euchroma are used for curing various harmful diseases.

CONCLUSIONS

The earlier studies have confirmed that Arnebia euchroma is having wound healing, anti-microbial and anti-bacterial properties and thus used for the treatment of several diseases. Although, a little works is done on the experimental study regarding anti-HIV, anti-cancer diseases, etc., so there is a requirement of more exploration via analytical studies on phytochemical compounds to treat such diseases. Moreover, the information of its clinical and pharmacokinetics uses is also limited. Therefore, further research is needed to understand bioavailability and pharmacokinetics of this species. In-situ and ex-situ conservations for the management of this endangered species are also lacking in the Himalayan perspective. Such studies will emphasize to explore the possibilities for its conservation and development of agro-technological protocol.

Arabian Primrose leaf extract mediated synthesis of silver nanoparticles: their industrial and biomedical applications

The present study encompasses green synthesis of silver nanoparticles (AgNPs) using aqueous leaf extract of Arabian Primrose within 6 min of reaction at 60 °C, pH 7 and their characterisation using physico-chemical analytical techniques. UV-Visible spectroscopy elucidated the surface plasmon resonance around 420 nm. FESEM and TEM images revealed that AgNPs were spherical with average diameter 10-60 nm. XRD pattern confirmed their crystalline nature. The leaf extract rich in phenolics and flavonoids was subjected to GC-MS analysis that identified bioactive compounds helping in reduction and stabilisation of AgNPs. The synthesised AgNPs possessed high anti-oxidant potential against DPPH and H₂O₂ radicals. Incidentally, the AgNPs acted as excellent nanocatalyst towards borohydride reduction and degradation of structurally different organic dyes. The AgNPs also exhibited selective colorimetric sensing of hazardous mercuric, ferric ions and ammonia. Such AgNPs were cytotoxic against HeLa cells (IC₅₀ 7.18 µg/mL) and compatible towards normal L₂₀B cells. These AgNPs showed effective anti-microbial activity against different human pathogens tested (bacterial and fungal). This is probably the first report of AgNPs synthesis using Arabian Primrose leaf extract showing strong anti-oxidant, catalytic, biosensing, anti-cancer and anti-microbial activities and find remarkable applications in medical, industrial and ecological sectors.

Manipulation of Plant Growth Regulators on Phytochemical Constituents and DNA Protection Potential of the Medicinal Plant Arnebia benthamii

Arnebia benthamii of the family Boraginaceae is a critically endangered nonendemic plant of the Kashmir Himalayas and is used to treat a number of human diseases. The current study was based on developing an in vitro micropropagation protocol vis-à-vis induction of various secondary metabolites under in vitro conditions for the possible biological activity. A tissue culture protocol was developed for A. benthamii for the first time in the Himalayan region using varied combinations and proper media formulations, including various adjuvants: Murashige and Skoog (MS) media, growth hormones, sugars, agar, and so forth. The influence of different media combinations was estimated, and the MS + thidiazuron (TDZ) + indole 3-acetic acid (IAA) combination favors a higher regeneration potential. The higher amounts of chemical constituents were also recorded on the same treatment. The in vitro plant samples also showed a noteworthy effect of scavenging of hydroxyl radicals vis-à-vis protection from oxidative DNA damage. The in vitro raised plants are good candidates for the development of antioxidant molecules.