Drug-Yielding plants – Cinchona, Digitalis, Papaver and Cannabis

History of medicinal plants

The history of medicinal plants is a profound narrative that traces humanity’s relationship with nature, reflecting a continuous quest to alleviate suffering and cure ailments. This exploration begins with primitive practices rooted in superstition and speculation, evolving into a scientific understanding of pharmacology that we recognize today.

• Primitive Practices: Throughout history, mankind has utilized plants for medicinal purposes. Early humans relied on trial and error to identify plants that could alleviate physical suffering. Initially, their understanding of medicine was speculative and heavily influenced by superstition, with many believing that illness was caused by evil spirits. Remedies often included the use of harmful or unpleasant substances designed to drive these spirits away, a practice typically overseen by the tribe’s medicine men.
• Early Civilizations and Drug Use: As civilizations developed, so did the knowledge and application of medicinal plants. In ancient China, records indicate that medicinal drugs were in use as early as 5000 to 4000 B.C. Similarly, Sanskrit texts provide insights into the collection and preparation of medicinal herbs. The Assyrians, Babylonians, and ancient Hebrews also possessed significant knowledge regarding these plants. Notably, Egyptian papyri from around 1600 B.C. document a range of medicinal plants, including myrrh, cannabis, opium, aloes, hemlock, and cassia.
• Greek Contributions: The Greeks made significant contributions to the understanding of medicinal plants. Influential figures such as Aristotle, Hippocrates, Pythagoras, and Theophrastus wrote extensively on the subject, demonstrating familiarity with many drugs still recognized today. However, the Greek worldview still intertwined supernatural beliefs with medicine. The rhizotomoi, or root diggers, played a crucial role as a specialized group believed to possess the unique knowledge required to differentiate between beneficial and harmful plants.
• Roman Influence: The Romans showed less interest in medicinal plants compared to their Greek predecessors. Nonetheless, in 77 B.C., Dioscorides authored “De Materia Medica,” an extensive treatise that classified and described the properties of medicinal substances known at the time. This work remained highly regarded for over fifteen centuries and continues to hold value in various cultures today, including among the Moors and Turks. Other notable Roman scholars like Pliny and Galen also contributed to the discourse on medicinal plants.
• The Dark Ages and Herbalism: Following the fall of the Roman Empire, the Dark Ages saw a regression in medical knowledge. However, this period also marked the emergence of herbalists and encyclopedists in Northern European monasteries, where significant compilations of both accurate and inaccurate information about plants were produced. The Doctrine of Signatures emerged during this time, a belief that plants bore markings that indicated their medicinal uses. For example, plants with heart-shaped leaves were thought to be beneficial for heart conditions. This doctrine influenced the common names of various plants, such as heartsease, Solomon’s seal, dogtooth violet, and liverwort, which are still used today.
• Evolution into Modern Pharmacology: Over time, the study of medicinal plants transformed into a formal discipline. As a testament to the intertwining of botany and medicine, many of the early botanists in the United States were also trained medical professionals. Today, pharmacology stands as a vital branch of medicine, built upon the foundations laid by these historical practices and understandings.

Classification of drugs

The classification of drugs based on plant sources is a systematic approach that identifies and categorizes medications derived from various parts of plants. This classification not only aids in understanding the origins of these drugs but also highlights their specific medicinal applications. The following sections detail the classification of drugs obtained from different plant components, including barks, woods, leaves, flowers, fruits, seeds, and lower plants.

1. Drugs Obtained from Barks:
   • Cascara: Derived from the western buckthorn (Rhamnus purshiana), it serves as a tonic and laxative. The European buckthorn bark (R. frangula) exhibits similar laxative properties.
   • Quinine: Extracted from the bark of several species of Cinchona, quinine is essential in treating malaria and functions as a tonic and antiseptic.
   • Slippery Elm: Sourced from the inner bark of the slippery elm (Ulmus fulva), this non-poisonous drug is valued for its soothing effects on inflamed tissues.
2. Drugs Obtained from Woods:
   • Ephedrine: An alkaloid from the entire woody plant of Ephedra sinica, E. equisetina, and other Asian species, ephedrine is utilized for treating colds and other medicinal purposes.
   • Guaiacum (gum guaiac): This hard resin is obtained from lignum vitae trees (Guaiacum officinale and G. sanctum) and is known for its stimulant, laxative, and chemical indicator properties.
   • Quassia: Derived from Jamaican quassia (Picraena excelsa) and Surinam quassia (Quassia amara), it is used as a tonic, insecticide, and for treating dyspepsia and malaria.
3. Drugs Obtained from Leaves:
   • Aloe: Sourced from various species, including Aloe vulgaris, A. perryi, and A. ferox, aloe is primarily used as a purgative.
   • Belladonna: Extracted from the dried leaves, tops, and roots of Atropa belladonna, this drug alleviates pain, reduces perspiration, suppresses coughs, and dilates pupils (atropine).
   • Cocaine: Obtained from the leaves of the coca shrub (Erythroxylon coca), it serves as a local anesthetic and tonic for digestive and nervous systems, although its use is restricted due to addictive properties.
   • Buchu: Derived from the dried leaves of Barosma betulina, B. serratifolia, and B. crenulata, buchu acts as a disinfectant, stimulates excretion, and aids in indigestion.
   • Cajeput: An essential oil from the leaves of Melaleuca leucadendron, cajeput is utilized as a counterirritant and antiseptic for skin diseases, rheumatism, and bronchitis.
   • Digitalis: Extracted from the dried leaves of the foxglove (Digitalis purpurea), this vital drug strengthens and regulates heartbeats, thereby improving blood circulation and nutrition.
   • Eucalyptus Oil: Obtained from the dried leaves of the blue gum (Eucalyptus globulus), it is effective for treating respiratory disorders, malaria, and other fevers.
   • Hamamelis: Also known as witch hazel, it is extracted from the dried leaves of Hamamelis virginiana and functions as an astringent to stop bleeding.
   • Henbane: The leaves and flowering tops of Hyoscyamus niger contain poisonous alkaloids and are used as sedatives.
   • Hoarhound: Derived from Marrubium vulgare leaves and flowering tops, it is traditionally used for colds, rheumatism, and dyspepsia.
   • Lobelia: Extracted from the leaves and tops of Indian tobacco (Lobelia inflata), it serves as an expectorant, antispasmodic, and emetic.
   • Pennyroyal: The essential oil from Hedeoma pulegioides is utilized in internal medicine, liniments, and as an insect repellent.
   • Senna: Sourced from the leaflets and pods of Cassia acutifolia and C. angustifolia, senna is known for its cathartic properties.
   • Stramonium: Extracted from the leaves and flowering tops of the poisonous Jimson weed (Datura stramonium), it acts as a substitute for belladonna in asthma treatment.
   • Wormwood: Artemisia absinthium is used to flavor absinthe; its essential oil treats fevers, although caution is advised due to potential toxicity in large amounts.
4. Drugs Obtained from Flowers:
   • Chamomile: Derived from Matricaria chamomilla, it is employed as a tonic and gastric stimulant. Russian chamomile (Anthemis nobilis) serves similar purposes and is used in poultices.
   • Hops: Humulus lupulus is recognized for its sedative, soporific, and tonic effects. It is also integral to brewing, preventing spoilage and enhancing flavor.
   • Santonin: Extracted from the dried flower heads of Levant wormseed (Artemisia cina), santonin is a potent remedy for intestinal worms.
5. Drugs Obtained from Fruits and Seeds:
   • Chaulmoogra Oil: Pressed from the seeds of the chaulmoogra tree (Hydnocarpus kurzii), it plays a role in leprosy treatment.
   • Colocynth: The dried pulp from the bitter apple (Citrullus colocynthis) functions as a strong purgative.
   • Cubebs: The dried unripe fruits of Piper cubeba are used for catarrh and as a kidney stimulant, historically used as a spice.
   • Croton Oil: Extracted from the seeds of Croton tiglium, it serves as a powerful purgative.
   • Nux Vomica: Obtained from the seeds of Strychnos nux-vomica, it contains toxic alkaloids (strychnine and brucine), with strychnine used as a tonic for treating nervous disorders and paralysis.
   • Opium: The dried latex from unripe opium poppy capsules (Papaver somniferum) contains morphine and codeine, used to alleviate pain and induce sleep, with strict regulations due to its addictive potential.
   • Psyllium: The seed of fleawort (Plantago psyllium) serves as a mild laxative, comparable to agar and mineral oil.
   • Strophanthus: Derived from the seeds of Strophanthus kombe and S. hispidus, it is a potent heart stimulant.
   • Wormseed: Sourced from American wormseed (Chenopodium ambrosioides var. anthelminticum), it is used for expelling worms.
6. Drugs Obtained from Lower Plants:
   • Agar: A mucilage from various seaweeds, agar is employed as a culture medium for bacteria and fungi and serves as a laxative.
   • Ergot: The fruiting body of the fungus Claviceps purpurea, which grows on rye, is used to elevate blood pressure and control hemorrhages and uterine issues.
   • Kelp: Specifically, giant kelps like Macrocystis pyrifera, kelp is a source of iodine, potash, and other vital minerals and vitamins, leading to its incorporation in various medicinal products.
   • Male Fern: The rhizomes and stalks of Dryopteris filix-mas contain oleoresin utilized for expelling worms.

Important medicinal plants

1. Papaver somniferum

Papaver somniferum, commonly known as the opium poppy, is a significant plant in the family Papaveraceae, recognized for its medicinal and culinary applications. Originating from Eastern Europe and Western Asia, it has spread across various regions, including Nepal, India, Turkey, Russia, Laos, and Cambodia. In India, it is primarily cultivated in the states of Madhya Pradesh, Uttar Pradesh, and Rajasthan.

• Cultivation
  • The opium poppy is cultivated as a rabi (winter) crop in India.
  • Seeds are sown in October-November, with latex collection occurring in March-April.
  • The plant thrives in well-drained sandy loam but cannot endure extreme cold conditions.
  • Propagation occurs through seeds, with flowering commencing after 90 to 115 days.
  • Three to four days post-flowering, the petals drop, leading to the development of capsules.
  • When capsules transition from green to yellowish, incisions are made in the capsules to harvest the latex, which is collected the following morning.
• Morphology
  • Papaver somniferum is characterized as an erect, annual, glaucous herb, typically measuring between 30 to 100 cm in height.
  • The leaves are ovate-oblong, often shallowly pinnately lobed, and embrace the stem at the base.
  • The flowers are solitary, bisexual, and actinomorphic, exhibiting a variety of colors such as white, pale pink, and pale purple, sometimes with black blotches at the base.
  • The fruit is a globular capsule containing small seeds with oily endosperm. All plant parts contain latex.
• Chemical Composition
  • The latex, or opium, harvested from the capsules, consists of a complex mixture, including dextrose, pectin, wax, pigments, volatile oils, triterpenoids, and approximately 20-30% alkaloids by dry weight.
  • Crude opium comprises around 40 different alkaloids, of which the most commercially and medicinally relevant include:
    • Morphine (9-14%): A potent analgesic and narcotic that also stimulates the central nervous system.
    • Codeine (2-3%): An important analgesic and anticough agent that is less sedative and toxic than morphine.
    • Thebaine (5-7%): A convulsant and poison, primarily utilized as a precursor in the manufacture of codeine and other semisynthetic analgesics.
    • Narcotine (5-8%): Typically used in cough medicine formulations.
    • Papaverine (1%): Acts as a smooth muscle relaxant and cerebral vasodilator, applied in treating conditions such as asthma and angina pectoris.
• Uses
  • The various alkaloids derived from Papaver somniferum are integral to modern medicine. Morphine, for instance, is renowned for its efficacy in pain management.
  • Codeine serves a dual role as an analgesic and a cough suppressant.
  • Thebaine’s role is mainly as a precursor for synthesizing other narcotics, and narcotine finds its place in cough remedies.
  • Papaverine is utilized to relax smooth muscles and improve blood flow, especially in cerebral circulation.
  • The seeds of Papaver somniferum are nutritious, offering a pleasant nutty flavor, often used in baking and cooking, and yielding poppy oil utilized in various culinary preparations.
• Harvesting Techniques
  • The harvesting of latex is performed on unripe capsules, which contain the richest concentrations of morphine.
  • Harvesters make transverse or oblique incisions in the unripe capsules using specially designed knives, ensuring not to penetrate the inner wall to prevent juice loss and seed damage.
  • Following incision, the white latex oozes and solidifies into brownish masses that are scraped off the capsules the next day.
  • The collected latex is kneaded to achieve a uniform consistency and shaped into marketable forms, such as balls or sticks.
  • It is crucial to harvest at specific times, particularly 10-30 days post-flowering, to ensure a higher morphine content in the collected opium.

2. Digitalis spp.

Digitalis spp., commonly known as “Witch’s Bells” or foxglove, belongs to the family Plantaginaceae (previously classified under Scrophulariaceae). This genus is significant in both horticulture and medicine, primarily recognized for its cardiac glycosides, which are used to treat heart conditions. The species Digitalis purpurea and Digitalis lanata are notable representatives with specific distributions and applications.

• Origin and Distribution
  • Digitalis purpurea is native to Europe and the United Kingdom.
  • Digitalis lanata is found in Austria, the United States, Central Europe, England, and Argentina.
  • In India, Digitalis purpurea is predominantly cultivated in Kashmir and the Nilgiri hills, while Digitalis lanata thrives in higher altitudes above 2100 meters in Kashmir and is also found in Uttar Pradesh (Chakrata).
• Cultivation
  • To ensure healthy plants, disease-free strains of seeds are selected for cultivation.
  • The soil should be enriched with manure and leaf mold to promote optimal growth.
  • Seedlings are carefully hand-transplanted to maintain their health and vigor.
• Morphology
  • Digitalis species are biennial herbs, occasionally perennial, growing to heights of 45-150 cm.
  • The leaves are simple, dorsiventral, and vary from lance-shaped to oval, either arranged alternately or oppositely. They are covered with gray-white pubescent hairs.
  • In the first year, a rosette of long-stalked leaves develops, leading to a raceme inflorescence in the second year.
  • The flowers are arranged in conspicuous terminal elongated clusters, exhibiting colors such as purple or yellowish. They are hermaphrodite and zygomorphic, featuring a protruding lower lip. The inner surface of the flower tube is characteristically spotted.
  • The fruit is a capsule containing seeds.
• Chemical Composition
  • The active constituents of Digitalis are primarily located within the epidermal and subepidermal collenchyma and the endodermal cells of the leaves.
  • Digitalis purpurea leaves contain approximately 0.2-0.45% of a mixture of cardenolides, a type of cardiac glycoside.
  • Physiologically active glycosides include digitoxin, gitoxin, and gitalin, derived from naturally occurring purpurea glycosides A, B, and C, respectively, through the loss of a glucose residue.
  • Digitoxin is recognized as the most potent of the Digitalis glycosides, possessing an activity level 1000 times greater than powdered digitalis.
  • Digitalin, another active cardiac glycoside, is sourced from the seeds of Digitalis purpurea.
  • Digitalis lanata possesses stronger medicinal properties with comparatively lower toxicity than Digitalis purpurea. The active glycosides in its leaves include digitoxin, gitoxin, and digoxin.
• Uses
  • Cardiac glycosides from Digitalis spp. exert a significant influence on cardiac muscle function.
  • Medicinal applications include:
    • Enhancing blood circulation.
    • Alleviating edema (dropsy), often associated with heart conditions.
    • Reducing swelling in the extremities, such as hands and ankles.
    • Supporting renal secretion.

3. Rauwolfia serpentina

Rauwolfia serpentina, commonly known by its vernacular names such as Snake root, Serpent wood, Chandrabhaga, and Sarpgandha, belongs to the family Apocynaceae. The genus Rauwolfia was named in honor of the 16th-century German physician and explorer Dr. Leonhard Rauwolf. This species is recognized for its significant alkaloids, especially reserpine, which have various medicinal applications.

• Cultivation
  • R. serpentina thrives in tropical and subtropical regions, flourishing particularly in hot and humid conditions.
  • The plant is best propagated from root cuttings; however, seeds and stem cuttings can also be used.
  • Despite attempts by pharmaceutical companies to mass-cultivate Rauwolfia, success has been limited, resulting in a continued reliance on wild-sourced plants for commercial supplies.
  • Historically, Indonesia was a major supplier of Rauwolfia, but current leading producers are India and Thailand, following the exhaustion of Indonesian resources.
• Morphology
  • Rauwolfia serpentina is characterized as an erect, evergreen, perennating glabrous undershrub.
  • The roots are greyish-brown and tuberous, displaying a distinctive slightly wrinkled and coarse surface. The cylindrical, tapering, and twisted taproot is commercially valuable.
  • The bark of the root is considered more valuable than the wood itself, and roots are harvested from plants that are 2-3 years old, specifically after they have shed their leaves, as this timing increases their alkaloid content.
  • The leaves are simple, glabrous, and vary in shape from lanceolate to obovate. They are arranged in whorls of 3 or 4, densely crowding the upper portion of the stem. Both leaves and stems contain small amounts of alkaloids.
  • The inflorescence is typically terminal but can occasionally be axillary, taking the form of a cyme. The flowers are tubular and can be pinkish-white or greenish-white in color.
  • The fruit produced is small (approximately 0.5 cm), oval, fleshy drupes that turn shiny black when ripe.
  • Rauwolfia species are known to contain about 80 or more alkaloids, with reserpine, rescinnamine, ajmaline, ajmalicine, and serpentine being of particular commercial importance. Reserpine is the most significant among these due to its therapeutic applications. Chemically, it is similar to serotonin, a neurotransmitter in the brain, and is structurally related to LSD (Lysergic acid diethylamide).
• Uses
  • For centuries, the powdered taproots of Rauwolfia serpentina have been employed in traditional Indian medicine to treat “moon disease” or lunacy, as well as for addressing snakebites and insect stings, which is reflected in its common names like Chandrabhaga and Sarpgandha.
  • Reserpine has been used in the U.S. for the treatment of schizophrenia; however, its most significant application arose from its hypotensive properties, which allow it to effectively lower blood pressure. This action is often utilized in conjunction with other medications.
  • The mechanism by which reserpine functions involves the dilation of blood vessels, resulting in reduced blood pressure.
  • Extracts from the leaves have been utilized to treat corneal opacity, providing a natural remedy for this condition.
  • Furthermore, root extracts are beneficial for intestinal disorders and are sometimes combined with other plant extracts to treat cholera, colic, and fever.
  • Additionally, Rauwolfia root extract can stimulate uterine contractions, making it a valuable resource during childbirth.

4. Artemisia annua

Artemisia annua, belonging to the family Asteraceae, is commonly referred to as Mugwort, Wormwood, or Sagebrush. This plant, which is native to temperate regions across Europe, Asia, Northern Africa, and Alaska, is recognized for its invasive nature in North America. The name “Artemisia” is derived from Artemis, the Greek goddess associated with hunting, forests, and childbirth.

• Origin and Distribution
  • The genus Artemisia consists of over 200 species, with A. annua being one of the most notable.
  • This species is primarily found in sunny, warm conditions, preferring an optimal growth temperature between 20 and 25 °C.
  • A. annua requires approximately 600 mm of rainfall for optimal growth and typically thrives in dry or semi-arid habitats.
  • The plant is often found in nitrogen-rich soils, particularly in wastelands and along roadsides.
• Morphology
  • Artemisia annua is a hardy, tall, perennial herb or shrub, growing to heights ranging from 30 to 100 cm.
  • The stems are erect and exhibit a brownish to violet-brown coloration. The leaves, measuring 3-10 cm in length, are deeply divided into two or three small leaflets, presenting a dark green color and a pinnate arrangement.
  • The underside of the leaves is covered with dense white tomentose hairs, which contribute to the plant’s characteristic texture.
  • The inflorescence of A. annua is in the form of a capitulum, comprising small florets that are radially symmetrical and feature yellow or dark red petals. These florets are organized into racemose panicles and typically bloom from midsummer to early autumn.
  • Artemisia species are noted for their potent essential oils, which are utilized in both traditional and modern medicinal applications, as well as in the cosmetics and pharmaceutical industries. The presence of terpenoids and sesquiterpene lactones in these species gives them a strong aroma and bitter taste, deterring herbivory. Additionally, larvae of various Lepidoptera species use Artemisia plants as food sources.
• Chemical Composition
  • A prominent sesquiterpene lactone found in A. annua is artemisinin, which is synthesized in the glandular trichomes located on the leaves and floral buds.
  • Artemisinin serves as the primary therapeutic agent for treating malaria. Historically, A. annua was utilized in Chinese medicine as a tea to combat fever, and recent studies have demonstrated that both tea infusions and dried leaf consumption possess both prophylactic and therapeutic efficacy.
  • The essential oils derived from this aromatic medicinal plant contain various volatile compounds, including thujone, isothujone, alpha-pinene, beta-pinene, myrcene, camphor, camphene, caryophyllene, cineole, and artemisia ketone, along with terpenes, terpenoids, and phenolic compounds.
• Uses
  • The oils and compounds derived from different Artemisia species have been recognized for their antimicrobial, insecticidal, and antioxidant properties. They are effective in treating parasitic infections, including those caused by roundworms, pinworms, tapeworms, hookworms, and flukes.
  • Chinese mugwort, known as Artemisia argyi, is commonly employed in traditional Chinese medicine for various therapeutic purposes.
  • The roots of mugwort are known to act as a general tonic, enhancing both physical and mental strength. Additionally, they stimulate gastric juice secretion, thereby improving digestion, and may help alleviate rheumatic pain. However, excessive dosages may lead to side effects such as acidity and heartburn.
  • The leaves and flower tops of A. annua are utilized therapeutically, providing pain relief, reducing fever, and acting as a diuretic agent. Furthermore, they stimulate bile secretion, aiding in fat metabolism and improving intestinal movements to relieve constipation.
  • The plant contains sedatives, antidepressants, and compounds that exert calming effects on the mind, relieving stress, depression, and anxiety.
  • It is crucial to note that the use of mugwort during pregnancy is not recommended, as it may stimulate uterine contractions, increasing the risk of spotting, bleeding, or miscarriage.
  • Some species, like Artemisia arborescens, are used for flavoring, particularly in teas combined with mint.
  • Artemisinin, derived from A. annua, is an essential treatment for malaria, particularly against the Plasmodium falciparum strain globally.
  • Other Old World species of Artemisia, such as Artemisia cina, provide the source for the antihelminthic drug, santonin.

5. Catharanthus roseus

Catharanthus roseus, commonly known as Madagascar Periwinkle or Sadabahar, belongs to the family Apocynaceae. This perennial plant, renowned for its ornamental value, possesses significant medicinal properties that have garnered the attention of researchers and herbalists alike.

• Origin and Distribution
  • Native to the West Indies and the Indian Ocean island of Madagascar, C. roseus is cultivated globally as an ornamental plant.
  • In particular, it is commercially grown in India, Israel, and the USA, with large-scale cultivation occurring in the Ramnathpuram, Tirunelveli, and Madurai districts of Tamil Nadu, India.
• Cultivation
  • Fresh seeds are utilized for propagation, and the plant adapts well to various soil types and tropical climates.
  • An ideal annual rainfall of approximately 100 cm or more supports its growth.
• Morphology
  • C. roseus is characterized as a perennial, erect subshrub, typically reaching a height of 1 meter.
  • The plant branches near its base, spreading across an area of about 60 to 70 cm in diameter.
  • The leaves are smooth, glossy, and dark green, measuring up to 5 cm in length.
  • In its natural state, the plant features two flower varieties: alba (white) and roseus (pink), alongside several hybrids.
  • The flowers, which bloom at the ends of branching stems, are fragile and have distinctive purplish-red or yellowish circular nectar guides at the corolla tube’s mouth.
  • The fruit of C. roseus is a cylindrical follicle containing numerous black seeds.
• Chemical Composition
  • Interest in C. roseus surged in the 1950s when reports emerged about “periwinkle tea” consumed in Jamaica for its antidiabetic properties.
  • All parts of the plant contain alkaloids; however, the leaves serve as the primary commercial source for two critical anticancer alkaloids: vincristine and vinblastine.
  • These alkaloids are known for their ability to inhibit tumor growth, contributing to the plant’s medicinal reputation.
  • In total, C. roseus contains over 90 known alkaloid compounds, underscoring its diverse therapeutic potential.
• Uses
  • Vinblastine Sulfate: Primarily employed in treating Hodgkin’s disease, a cancer affecting the lymphatic system.
  • Vincristine Sulfate: Utilized for the treatment of leukemia, particularly lymphocytic leukemia.
  • Traditional Remedies: Long before scientific validation, folk healers used Madagascar Periwinkle for various medicinal applications:
    • In India, the juice from the leaves has been applied to treat wasp stings.
    • In Hawaii, an extract from the boiled plant is used to halt bleeding.
    • In Central America, it is utilized as a gargle for sore throats and chest ailments.
    • In Cuba, Puerto Rico, Jamaica, and other Caribbean islands, an extract of the flowers serves as an eyewash.

6. Adhatoda vasica L. (syn. Justicia adhatoda)

Adhatoda vasica, commonly known as Malabar nut, Adulsa, or Vasakat, belongs to the family Acanthaceae. This perennial shrub is recognized for its extensive medicinal applications, particularly in traditional systems of medicine such as Siddha, Ayurvedic, homeopathy, and Unani.

• Origin and Distribution
  • Native to Asia, Adhatoda vasica is widely distributed across India, Bangladesh, Nepal, Sri Lanka, and Myanmar.
  • The plant flourishes in crowded areas, often found along wastelands and roadsides throughout India.
  • Its introduction in various regions has facilitated its use in diverse medicinal practices.
• Morphology
  • A. vasica is characterized as a large, evergreen shrub, typically reaching an average height of 3 meters.
  • The leaves are simple, ovate or lance-shaped, measuring about 10 to 15 cm in length and 4 cm in width.
  • Leaves are oppositely arranged, smooth-edged, and borne on short petioles, contributing to the plant’s distinctive appearance.
  • The bark of the shrub is yellowish in color.
  • Flowers are predominantly white, arranged in large, dense, axillary spike inflorescences, featuring large, attractive white petals with a purple line on the lower lip.
  • The fruit consists of small, ovate, or club-shaped capsules.
• Cultivation
  • A. vasica thrives best in loamy soil found in hilly and plain regions.
  • The optimal temperature range for the growth of this plant lies between 20 to 27 °C.
• Chemical Composition
  • The leaves of Adhatoda vasica are rich in phytochemicals, including alkaloids, tannins, saponins, phenolics, and flavonoids.
  • The most significant alkaloids present in the plant are vasicine, vasicol, and adhatodinine, with vasicine yield measured at approximately 0.541 to 1.1% by dry weight.
• Uses
  • A. vasica is renowned for its traditional medicinal applications across various systems of medicine:
    • In Ayurveda, it is primarily utilized for treating respiratory diseases, serving as a key ingredient in remedies for cough, cold, and asthma. The plant effectively reduces inflammation of the lung airways.
    • Vasicine, an alkaloid found in A. vasica, acts as a bronchodilator, easing breathing and alleviating wheezing associated with asthma.
    • The plant also exhibits antibacterial and antimicrobial properties, enhancing its therapeutic profile.
    • According to Ayurvedic texts, A. vasica is beneficial for managing bleeding disorders and ulcerations. It has demonstrated efficacy in treating peptic and duodenal ulcers.
    • Additionally, the shrub aids in reducing hyperacidity in the stomach and has shown favorable results in addressing dyspepsia and gastritis. It functions as an appetite stimulant, improving overall appetite.
    • A. vasica acts as a mild antihypertensive agent, effectively reducing blood pressure.
    • The plant helps alleviate joint inflammation and, when combined with other herbs, assists in reducing elevated uric acid levels and the pain associated with gout. For gouty arthritis, it is commonly used alongside giloy (Tinospora cordifolia) and amaltas (Cassia fistula).
    • Decoctions of A. vasica roots are beneficial in lowering blood urea levels and other nitrogenous waste products.

7. Ephedra sinica L

Ephedra sinica, commonly referred to as Joint Pine or Mahuang, belongs to the family Ephedraceae. This evergreen shrub is notable for its diverse applications in traditional medicine, particularly in treating respiratory ailments.

• Origin and Distribution
  • Ephedra sinica is a gymnosperm and is the sole representative of the family Ephedraceae and order Ephedrales.
  • It is of Chinese origin, with various species distributed widely in arid and semi-arid regions, including southwestern America, southern Europe, northern Africa, southwest and central Asia, northern China, and Mongolia.
  • The plant thrives in dry climates and is found globally, with the exception of Australia.
  • In India, Ephedra sinica is located in the dry regions of Punjab, Haryana, Rajasthan, Sikkim, and Jammu and Kashmir.
• Cultivation
  • Ephedra is well-suited for arid and semi-arid environments, demonstrating resilience in these conditions.
  • Most species grow in sandy soils or along shores, requiring direct sunlight for optimal growth.
  • Propagation is generally accomplished through its rhizomes, allowing for effective cultivation.
• Morphology
  • Ephedra sinica manifests as an evergreen shrub, though some species may develop as climbers or even trees.
  • The plant features a prominent underground taproot system, supplemented by numerous adventitious roots.
  • The stems are green, ribbed, extensively branched, and serve a photosynthetic role, essential for the plant’s energy needs.
  • Leaves are scale-like or needle-shaped, reaching lengths of up to 3 cm, and are arranged oppositely or in whorls. These leaves fuse at their bases to create a protective sheath.
  • The majority of Ephedra species exhibit dioecy, with male strobili arranged in whorls containing up to 10 cones. Each cone consists of a series of decussate bracts.
  • Female cones are also arranged in whorls and feature bracts that fuse around a single ovule. Each strobilus contains one or two seeds, which can vary in color from yellow to dark brown.
• Chemical Composition
  • The dried stems and leaves of Ephedra sinica are utilized for medicinal purposes.
  • The plant contains several alkaloids, including ephedrine, pseudoephedrine, norpseudoephedrine, and methyl ephedrine, along with tannins, amino acids, and phenolic compounds.
• Uses
  • Ephedra sinica has been employed for centuries in traditional Chinese medicine, primarily to treat hay fever, asthma, and bronchitis.
  • The plant is effective for alleviating flu symptoms, colds, nasal congestion, and headaches. The dried stems and leaves are commonly processed into tablets, capsules, extracts, and teas.
  • Additionally, Ephedra is often utilized for weight loss and obesity management, sometimes in conjunction with aspirin and caffeine to enhance efficacy.
  • The plant is recognized for its ability to boost energy levels, leading to its use among athletes seeking performance enhancement.
  • However, recent research by the U.S. Food and Drug Administration (FDA) has indicated limited evidence supporting Ephedra’s effectiveness, particularly concerning short-term weight loss. Concerns have been raised about its association with increased risks of heart problems and strokes, leading to a ban on its use in the United States.
  • Adverse effects associated with Ephedra consumption may include severe skin reactions, irritability, nervousness, dizziness, trembling, headaches, insomnia, profuse sweating, dehydration, and itchy skin or scalp. More severe potential side effects encompass irregular heartbeat, seizures, heart attacks, strokes, and even fatalities.