The study aims to report the ethnobotanical significance of medicinal plants for the treatment of various diseases, phytochemical constituents of those plants, their allelopathic effect, and impact of those plants on the socioeconomic aspect in Gulmi and Okhaldhunga district of Nepal. Altogether 41 species of medicinal plants from two areas were documented, using a semi-structured questionnaire. They have been using those species for the treatment of different ailment ranging from gastrointestinal problems, respiratory tract related problems, cuts and wounds, and dermatological problems. 18 of the potentially valuable medicinal plants were brought for performing secondary metabolites tests in methanol extract. The extracts have shown the presence of alkaloid, carbohydrate, glycosides, flavonoids, tannins, terpenoids, saponins, oil and protein, out of which alkaloid was found to be present in every sample. In contrast, only 5 possessed protein. Out of 18 plant extracts, 11 most valued ones were isolated to carry out allelopathy tests on mungbean seed. Only the control treatment bored germination of the mungbean with full radicle and plumule development. This study also reports the impact of the use of medicinal plants in people’s daily life.

In the present study, the seaweeds belong to Phaeophyaceae (Cystoseira elegans Sauvageau 1912, Cystoseira amentacea (C.Agardh) Bory 1832, Padina crassa Yamada 1931) and Florideophyceae (Corallina elongata J.Ellis & Solander 1786) collected from nearby Iskenderun-Turkey of Mediterranean Sea were detected for their antimicrobial activities against seven bacterial strains (Escherichia coli ATCC 35218, Bacillus cereus NRRL B-371, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 13883, Salmonella typhimurium ATCC 14028, Proteus vulgaris RSKK 96029). The antimicrobial activities were expressed as minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs). According to the results obtained from MICs and MBCs values of the extracts on pathogenic microorganisms were between 0.78 to 50 mg/mL. The lowest MICs and MBCs values were recorded for C. elegans extract against B. cereus with a MIC value of 0.78 mg/mL. These results suggest that secondary metabolites of brown and red algae are important sources that could be used as broad spectrum of biological and pharmaceutical activities.

Ageratum conyzoides is a widely spread weed, especially in the tropical and subtropical regions. It has been reported to be used as folk medicine in different countries for treating burns, wounds, skin disorders, headaches, fever, pneumonia, gynecological diseases, leprosy, snakebites, rheumatism, inflammations, stomach ailments like parasites, colic, diarrhea, dysentery, used as a painkiller during childbirth, and many more. It has been reported to contain active secondary metabolites such as alkaloids, tannins, phenols, saponins, coumarins, essential oils, and flavonoids, which support its medicinal uses in disease treatment and prevention. It can be a potential source of drugs for various diseases. In fact, pharmaceutical companies are being run in Brazil using A. conyzoides as raw material with recommendations from the Brazilian Drug Centre. It is also used for agricultural purposes as manure, insecticide, pesticide, herbicide, nematicide, fodder, etc. In China, it is widely intercropped in the citrus orchard to control pests and weeds. The review attempts to bring together medicinal and agricultural usage of Ageratum conyzoides with scientific evidence to demonstrate its efficacy. This weed has a negative influence in agriculture and the ecosystem but after studying about its potential medical and agricultural uses, we now have a different viewpoint on this weed, and we believe that further harnessing it for such positive uses might be a management strategy for this weed.

Ultraviolet-B (UV-B: 280 to 320 nm) radiations have appeared to be detrimental to plants, due to their damaging effects on proteins, lipids, membranes and DNA. UV-B radiations are a significant regulator of plants’ secondary metabolites. High intensity of ultraviolet radiations may interfere with growth and productivity of crops. But low levels of UV-B radiations give rise to changes in the plants’ secondary metabolites such as phenolic compounds, carotenoids and glucoseinolates. Therefore, low intensity of UV-B radiations may be used to generate plants, enriched with secondary metabolites, having improved reproductive ability, early ripening and tolerance against fungi, bacteria and herbivores.

Public health around the globe is still under the major threats and of some serious infectious diseases though a marvelous progress carried out in the field of human medicines. Therefore, use of products from natural sources as medicinal agent probably antecede in human history. The advancement and knowledge of various useful plants and their properties, functions and its use over synthetic drugs has increased in recent years. Bauhinia variegata L. (Kachnar) is an ornamental flowering plant within the Leguminosae family. Hairy branches of the plant are widely used in various traditional remedies to cure vast range of disease infections. Several plant portions, like roots, stem and stem bark, leaves, buds and flowers, are not only popular in different disease treatment but also useful in the manufacture of fibers, gum and to conserve the nature. The phytochemical screening exposed that B. variegata consist of various important secondary metabolites like flavonoids, terpenoids, cardiac glycosides and steroids, saponins and tannins compounds that are appropriate to be used in the treatment of various biological activities, such as antibacterial, antidiabetic, antitumor, antimicrobial, anticancer, antiulcer, anticarcinogenic effects, anti-inflammatory, nephro and hepatoprotective effects and wound healing effect. The current review is to demonstrate the medicinal, nutritional and biological importance of B. variegata as multidimensional effects on various diseases.